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Metallurgical Engineering - Science topic

Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use. Metallurgy is distinguished from the craft of metalworking.
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I have attached the Phase diagram of Mn and Mo. I need some explanation about these graphs. thanks
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Hello!
What do you want to know about it?
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Ansys Granta is not a free programme. Is there any other materials selection software that you would recommend, and what is the name of it? ( https://www.ansys.com/en-in/products/materials/granta-selector )
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Hi, If you mind take a look at tables of the following paper (all links and licenses are mentioned):
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Generally observed at low strain rate for fine grained material.
For industrial scale
which are viable materials?
which parameters need to alter?
Kindly express your views.
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Agree with Mohammad Abboud sir
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Hello there, I want to ask, how to determine the rpm and times to blend and mixing powder in powder metallurgy? As for my case, I want to blend iron and silicon powder but I don't know the right blending parameter like rpm and times. Can someone solve it for me and give the link of journal needed?
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In maraging steels Fe and 18 to 22% Ni is using, this steel is quenched fully martensite is forming depending upon Ni content. Ni is a austenite stabilizer, why retained austenite not forming in these steels.
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In maraging steels, due to their higher Ni content, elevates the martensite start (Ms) temperature which promotes the easy transformation of austenite to martensite. The martensite formed in maraging steel is different from the one we observe in plain carbon steels. The martensite formed in plain carbon steel is formed by quenching. This martensite so formed is hard and brittle with a BCT structure. However, in the case of maraging steel, martensite formation occurs even with air cooling. This is due to the lower carbon content and higher Ni concentration. The martensite so formed is soft with a BCC structure.
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The total slurry contained 50 wt% Alumina (D50 = 0.5 um, 11 m2/g surface area), 50 wt% DI water. Powder was dispersed using NH4PMA aqueous solution. PVA aqueous solution was used as binder (20 wt% active matter w.r.t Al2O3), PEG-300 was used as plasticizer (20 wt% w.r.t Al2O3, 1:1 binder to plasticizer ratio). After mixing and debubbling, the slurry seemed good, and a good tape (~450 um thickness) without cracks was obtained after tape casting.
Debinding of single tape (40 mm x 40 mm x 450 um) at 1 C/min, 600 C, 2 h holding gave debinded tape without cracks, which could be sintered too without cracks.
Problem:
I did lamination of 9 tapes via thermocompression using uniaxial warm-press. The temp. used was 80 C, and 15 MPa was the maximum pressure that could be applied.
I also tried with increasing number of tapes up to 15, and for those i used temp of 100 C so that a higher pressure could be applied, and the max. pressure that could be applied was 40 MPa, with change in dimesnions of the pressed tapes. I even tried only two layers pressed at 100 C, 40 MPa.
But: Every time debinding of laminated samples resulted in cracks. I tried with 1 C/min, 0.5 C/min, and 0.3 C/min heating rates up to 600 C. I also tried with giving steps, for example using 0.3 C/min heating rate and holding at 100 C for 2 h, at 300 C for 6 h, at 500 C for 4 h. But the samples always cracked. Please find attached the TG/DTA data of a single tape.
Please guide me how to achieve debinding without cracks. I'll appreciate your kind help.
Thank you.
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Dear Muhammad,
the reason for your problem is quite clear: lamination creates obstacles to the removal of the evaporated binder. When PVA evaporates, pressure builds up that ruptures the material.
To begin with, you can try replacing the aqueous solution of PVA with an aqueous solution of methylcellulose, the evaporation of which occurs in a wider temperature range and does not create such a high vapor pressure.
If replacing PVA with methylcellulose does not help, then I see no other solution to the problem other than replacing the water-soluble binder with a water-insoluble binder. The new binder must not evaporate, but must be removed by another mechanism, such as melting or oxidation with atmospheric oxygen.
In ceramics, wax-based binders are often used, the removal of which does not cause an increase in pressure in the material. There is also an old technology in which a solution of rubber in gasoline is used as a binder. Rubber does not evaporate as intensely as PVA and does not generate such high vapor pressure. Of course, the use of paraffins or rubber as binders completely changes and complicates the technology of forming a ceramic tape, but there may simply not be another solution.
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Can anyone suggest me some binder for Fe-Mn powders ?
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There are many boride in nickel base superalloy.
Such as M5B3, M3B2.
How to analyze the boride?
Is there any  test method ?
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Hi
You can use EPMA for elemental distribution map in specific area for example in ISZ and DAZ area in transient liquid phase diffusion bonding after that use EBSD for more information such as crystal structure and ..... You can use:
Effect of bonding temperature on the microstructure and mechanical properties of Hastelloy X superalloy joints bonded with a Ni–Cr–B–Si–Fe interlayer
Holding time influence on creep behavior of transient liquid phase bonded joints of Hastelloy X
Influence of bonding time on the transient liquid phase bonding behavior of Hastelloy X using Ni-Cr-B-Si-Fe filler alloy
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I want to make slurry for aqueous tape casting of alumina (500 nm avg. particle size) using PVA binder and PEG plasticizer, but I am not being able to optimize the contents.
1. In what quantity range (wt% or vol%) should I use alumina to get high relative density?
2. In what range (wt% or vol% w.r.t total composition or w.r.t alumina) should I use PVA binder? Should the PVA added be in solid granules form or aqueous solution, and hence will that quantity represent binder active matter or binder solution?
3. Should PEG added be in aqueous solution form?
4. Is optically high grade PET film ok as substrate for tape casting? Can the tape be detached from this substrate easily? (I could not be able to detach yet).
Thank you so much~
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Hello Khalid,
I have some experience working with aqueous alumina tapes, but instead of PVA and PEG, used an acrylic emulsion that performs both functions (binder and plasticizer).
For this particle size, I sintered tapes with 25 vol% (~52 wt%) at 1550 ºC for 2 h and obtained a relative density higher than 98%.
The solid content will depend on how you performed your slurry optimization (dispersant, binders, etc.). By the correct optimization, you will find the higher solid content and formulation suitable to produce defect-free tapes.
PET film works good as carrier film and should be OK for you to detach the tape. You can use also a silicon-coated PET film that would help you to easily detach the tape. However, in this case, you may need to play with some tricks of the surface stresses between silicon and the ceramic slurry.
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I had prepared 50ml of 0.5M Sulphuric acid and to that I added 20ml of 0.5M sulphuric acid containing 9 drops of 2M sodium hydroxide. I then leached the mixture for 15 minutes using a magnetic stirrer. In the same standard procedure I continued to increase the pH by adding more drops of sodium hydroxide that is from 9 to 34 and 50 drops. 
thank you
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follow
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The structure is asked of As-Cast Condition, and after annealing and (then) after normalizing. No elements other than those mentioned are assumed to be existant, the rest of the unmentioned composition is contributed by Fe (Iron).The caveat is, there is no access to simulation.
Specific points to be asked are-
  1. What would be phases present in equilibrium at room temperature? Would there be both stable FCC and BCC phases co-existant? What would be stable structure before solidification from liquid starts?
  2. Is there any mathematical approximating formula that would provide approximate widening/narrowing down of FCC or BCC field with alloying?
  3. What would likely be composition range of Mixed Carbo-nitro-sulfides (CNS) that are going to be precipitated at equilibrium, from melting point down to room temperature? How to likely estimate the dissolution temperature of mixed CNS's other than looking at individual pseudo-binary phase diagram of Fe with carbide/nitride/sulfide of Mn, Cr, Ni and W ? What are going to be possible intermetallic compounds (other than mixed CNS) in this composition range? How to predict?
  4. What would be approximate distribution of the alloying element in the inclusions, intermetallic, and metallic phases, at least as a first order approximation?
  5. How the alloying elements, and hence the inclusions and intermetallics (other than their dissolution) affect the annealing and normalizing time as well as grain morphology of the initially as-cast structure, and then heat-treated structure? Is there any approximate mathematical formula to find out change of heat-treatment parameters with complex alloying?
  6. How would I estimate strength of the alloy other than classic weighing of ferrite-pearlite strength (+ hall-petch relations for precipitates and grain sizes), and how would I find formula for solid-solution strengthening of metallic and nonmetallic phases? What would be temperature dependence of the strength?
If not possible to answer all at once, then please provide at least partial reference to research articles. Note the Research work is going to be a rapid one. Please refer to (https://www.researchgate.net/project/Prediction-of-Structure-and-Properties-of-Ferrous-alloys-and-subsequent-heat-treatment) for details.
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There are so many questions that it is difficult to answer at once.
First of all, I'll give you some helpful keywords.
1. In the case of carbon steel other than stainless steel, it is difficult for the FCC phase to exist at room temperature without enough nickel or manganese.
2. Each phases stabilizing elements are studied well for FCC Austenite and BCC Ferrite. Please open the follow.
3. Nitro-carbide often coexists, but in general carbon steel, nitride and carbide exist separately. In this carbon steel, W is a strong carbide-forming element, so it is possible to first form tungsten carbide at high temperatures during solidification. And if Al is present, it is expected that AlN will form, then followed by the formation of chromium carbide. At a lower temperature, iron carbide Fe3C will form with remaining carbon after forming (W, Cr)23C6.
Sulfides may exist as WS2 or FeS, which are formed independently at lower temperatures than tungsten carbide and iron carbide.
4. In the Fe-C Diagram, the volume of the matrix phase and intermetallic compound can be approximately predicted by the lever rule. However, the actual ratio is depended on cooling rate. Because it is not an equilibrium solidification.
5. The cooling rate affects the segregation of elements and phase transformation. Therefore, depending on the cooling conditions after casting, and in severe cases, depending on the shape of the casting, different structures may be obtained. If the casting is high alloyed, has the higher differences.
6. I would like to recommend reviewing two papers. Lei Wang Et al., Prediction of mechanical behavior of ferrite-pearlite steel, J. Iron and Steel Research, 2017 and W.C. Leslie, The Physical Metallurgy of Steels, McGraw-Hill, New York, 1981. See the graph at p.217.
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I am trying to do EBSD analysis of deformed beta titanium alloys but I have problem in indexing the deformation products. As the EBSD data base does not know the orthorhombic α″ phase, we had to create it. Therefore, I need to know the lattice parameters and Wyckoff Positions. I found some information in literature but I still have problem in indexing deformation products (martensite, twins and slip lines).
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Dear Saed Sadeghpour,
I am facing the same issue. I have the same lattice parameters but not the wyckoff positions of atoms in Ti-1023 and Ti-5553.
Kindly share your findings regarding the unindexed regions and also the wyckoff positions.
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what is best way to producing of wire rod 10 mm or less of superalloys such as Alloy 718 (Inconel 718) to reach optimum mechanical properties? casting in VIM (Vacuum induction melting) is probably first step, is it essential remelting (ESR or VAR) for wire production? what is aspect necessary for mold dimension (diameter) in casting and remelting to produce wire rod of 10 mm?
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Hot rolling is preferable process with heat treatment by annealing and normalizing.
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The effect of B2O3 additions on CaO-MgO-SiO2-Al2O3 based slag/flux was studied by many researchers. B2O3 addition helps in lowering the viscosity of slag which helps in eliminating the sticking of slag to ladle cover during refining of steel. It was found that B2O3 can be used as a replacement to conventional CaF2. But what will be the effect of B2O3 addition on slag line erosion and inclusions in steel.
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Hello,
You may check the article below;
The study is not directly related with the ladle refractory but they have found that compared to CaF2, the erosion on snorkel refractory of CAS-OB increased with the addition of B2O3 within the same amount.
But the process parameters like the addition sequence in process route, chemical composition of slag, processing temperatures, the physical and chemical stability of refractories on slag line will effect erosion level and also B pick-up ratio. Thus, I think it is better to compare these specific conditions with using computational thermodynamic software; FactSage, ThermoCalc, etc.
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Hi, I am trying to solve the motion of bubbles. The argen gas are injected from an inlet into liquid steel. Therefore the air generates the bubble. For the bubble motion I used DPM model and for the liquid steel, molten slag and top gas, I used VOF model.Now for the last step of my project I have to delete the bubble as soon as they impact the top gas. I wanna deleting bubbles with UDF.The idea for this UDF is that I want to delete the bubbles when they arrived at the position that the volume fraction of top gas is larger than 0.5. This is the UDF I am using:
#include "udf.h"
#include "dpm.h"
#include "sg_mphase.h"
DEFINE_DPM_SCALAR_UPDATE(stream_index,c,t,initialize,p)
{
cell_t c;
thread *t;
Thread *gas;
gas = THREAD_SUB_THREAD(t,2);
if(C_VOF(c,gas)>=0.5)
p->stream_index = -1;
}
Thanks.
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I also want to delete particles in DPM model . Load this UDF , I want fluent16.1 to show the particle trajectories. the following error occurs : Error: received a fatal signal (Segmentation fault). Error Object: #f.
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Usually I measure grain size of my dense ceramic samples from SEM microstructures using ImageJ by line-intercept method. But now I have a range of samples with 90 to 94% density. The SEM images have porosity levels different to one another in case of comparing all samples. How to measure grain size in this case from ImageJ as i don't think the method described is good now due to a lot of porosity? Should i measure grain size individually of many grains?
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dear Muhammad Waqas Khalid
One of the simplest techniques to estimate an average grain size is the intercept technique. A random straight line is drawn though the micrograph. The number of grain boundaries intersecting the line are counted. The average grain size is found by dividing the number of intersections by the actual line length.
Average grain size =1/(number of intersections/actual length of the line).
where actual line length = measured length divided by magnification
and also there is an easy way is to use a free software called SPIP. Just download the instruction manual and see the grain detection.... But the best way I suggest is to use Matlab... you can program Matlab according to the kind of image u 've ... there are several ways to program, but for that u shd provide the details of your image (I am not an expert, but I am suggesting this with my limited knowledge n experience... also, I guess u already 've the SEM image)
PS: You have a distribution of grains on the surface right?
yours
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During our experiments, we conducted multiple rotary degassing treatments with Ar and N2 purging gases on a 356 alloy with 200 ppm Sr. We found that the fading process of the added modifier is accelerated when nitrogen was used (The Sr concentration decreased and the thermal analysis results showed lower eutectic undercooling). Is it possible that nitrogen forms a compound with the strontium present in the melt? We found no thermodynamic data available for strontium nitrides with various stochiometry, so we could not calculate Gibbs energy of formation values at different temperatures.
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The FactSage databases contain at least information about Sr3N2, but in liquid aluminum, the program predicted, that the formation of AlN is more likely compared to the formation of Sr3N2.
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I want to coat monolayer of silica particles on W surface, but it is difficult to get mono-layer because of hydrophobic nature of surface. Tried Oxygen plasma treatment to get hydrophilic, but could not get ! Any suggestions/comments are welcome.
Thanks !
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I guess oxygen plasma would work. I am also looking for making tungsten hydrophilic. If it has not worked for you, i shall try along with oxygen plasma little bit of argon and let you know the result. I wish to coat Ba and Sr Carbonates on tungsten. I have prepared the solution by mixing the powders with water. Solution seems to be consistent. I am unable to coat this solution on tungsten wire. I heated the wire to more than 2000 degrees by passing current into that, then tried to coat the paste, did not work.
Did you try etching it by HF acid ? I am going to try this. If I get results I shall post it here.
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Theoretically, EBSD is a technique that able to determine the local crystal structure and crystal orientation at the surface of a specimen. So, what is the main important reason to do this analysis? is there any strong correlation with mechanical behaviour?
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Dear Nurly
Yes. there is. Actually, we can get much information about the microstructure of materials by EBSD data.
the grain orientation, grain boundaries (LAGB and HAGB), local misorientation, grain size, and etc, which have been post-processed by EBSD data, can affect on mechanical properties.
if you have more questions, please feel free to contact me.
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After melting the copper-aluminium in furnace, the black layer(copper oxide ) has formed on the surface.
which chemicals are useful to clean the oxidized layer?
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If you don't want to use chemicals, you can also put some salt on a sliced Lemon and use it as a "brush" or you could use a mixture of water, vinegar essence (5 parts water, one part vinegar) and salt.
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Ti Gr.7 (Ti-0.2Pd) is most corrosion res. grade of Ti alloys. for manufacturing of round bar we want compressing of sponge Ti by Pd, but weight of Pd is modest (about 60 gr in 30 Kg of round bar). What is best way for alloying and blending Ti with Pd for next briquetting and VAR (Vacuum Arc Remelting) step?
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I think you can consider also ball milling to mix Pd and Ti as powders, then remelting you can control the alloy ad you prefer,
best regards, Simone
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Hello everyone,
I have been trying to etch my microalloyed steel with a solution including 4 gr of picric acid and 100 mlit of ethanol (4% Picral) but I could not get any success in it and the sample does not etch even after 10 mins of etching. Do you have any suggestion to help me out solving the issue I encountered?
Many Thanks in advance!
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Dear Mohsen,
Prior-austenite grain boundaries are those of the steel when it was austenitized prior to quenching and tempering. If the steel's microstructure is fully martensitic after hardening, or contains some retained austenite or lower bainite, the prior-austenite grain boundaries may be revealed.
Prior austenite grain size(PAGB) is important for understanding the microstructure–property characterization relationships in steels. The PAGB plays an important role in defining the microstructural scale of low-temperature phases and the mechanical properties (e.g., strength, ductility, fracture toughness, etc.) of steels in the final product form. It is recommended that swab etching with a solution of 100 ml saturated aqueous picric acid and 0.5 g sodium dodecyl benzene sulfonate(% can you easily determine equivalent to 0.5%) can worked remarkably well for delineating the PAGBs in this steel.
Refer the site:
Hope content is useful for you.
Ashish
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I have recently started working on slip casting. I couldn't find the plaster of paris molds in the market where I could search for laboratory scale slip casting. Plus I have read in papers they cannot be used again once a slurry is poured and dried in them. Should I make the molds myself every time I need to use one? Is it ok to use some other molds made of anything instead of plaster of paris if I don't need to make a hollow object?
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Muhammad Waqas Khalid, It is difficult to find plaster of Paris (PoP) molds in the market for lab-scale experimentation. However, you can make PoP very easily using the dry PoP powders (~0.5-1 USD/kg) upon mixing with water properly & giving shape. Once it is dry, you can use it for casting your slurry. The pores in the PoP mold will draw out the water (or other liquid used for slurry making). So, after casting, you need to dry out the PoP completely before pouring slurry for another casting. You can use it many times (I used each mold at least 100 times, never counted though) until the integrity of the PoP remains ok. Hope this is helpful.
With best regards
MN
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Assume a solution with acidic pH, which consists of 2 and 3 valent iron ions. With increasing the pH, iron content will precipitate.
Do ferric and ferrous precipitate in an equal pH? If no, at what pH will precipitation happen for these ions?
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I read that after leaching of oxidized zinc concentrates with sulfuric acid, the resulting solution is purified from harmful impurities like iron, copper, cobalt, nickel. And with a weakly acidic medium, pH = 5.2–5.3 iron ions are practically precipitated by the formation of hydroxides.
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i am working on continuous annealing line for Low carbon steel , there is a problem of shiny spots from the furnace in ultra low carbon steel specially in IF grade material, furnace dents may be the possibility but spots are visible along the width and length in full coil in groups, their severity is increased if we run thicker gauge coils before IF grade i.e.above 1.2 mm, if we run thinner gauge coils or increase the furnace speed their severity considerably reduced , what can be the reason for it? Furnace roll coating or furnace tension? Experts comments are most welcome? Here i attach the strip picture.
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Dear Kumar,
I am also the chief engineer of CAL line. You should look at the cleaning section. Especially the hot water tank. You have a quality problem because of the alkali-NaOH. Alkali solution goes to the furnace section and NaOH decreases the melting temperature of the alloying elements.
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We know, there are many method, process, equipments and reagents to control acid mist in copper electrowinning plant.
demisting ball, acid mist supperessant, cells hood and scrubber
Which reagent and equipment commomly are used in industrial plant? 
Which method is the best way to control acid mist?
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Dear Kavin,
Acid mist control has been a severe problem in copper electrowinning operations around the world. The problem is becoming more relevant under the actual and future scenarios in which the production of copper using this route has increased dramatically in the last years. This in combination with environmental regulations are demanding the industry to explore for a definitive solution. The control of acid mist in Copper Electrowinning tankhouses produces a series of benefits such as: reduced corrosion of the buildings, savings in electrolyte heating needs, improves worker’s confort, etc. An important extension of the benefits introduced by the proper capturing and collection/cleaning of acid mist is the associated mechanization of the operations.
Capturing the mist in existing plants allows marginal expansions using same cells and electrodes, provides the electrometallurgical parameters are maintained under control. Additional cells are not needed.
Hope it is helpful to you.
Ashish
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What fields (topics) do you suggest to work as a metallurgy and Technical Inspection master degree Student in Cathodic Protection?
Thank you kindly
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Dear Naved,
Couple of interesting topics can be chosen for the cathodic potential research areas.
1. Cost of Impressed Current Cathodic Protection for coastal bridges
2. Selection of Thermal-Sprayed Metal Anodes for Cathodic Protection of Reinforced Concrete Structures
3. experimental and theoretical model validation to estimate the cost to install cathodic protections
4. Development of Cost-Effective Cathodic Protection tool for marine structures environments
Hope it is helpful for you.
Ashish
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Please give me an insight into the differences.I am only an undergrad in Metallurgical Engineering.
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Hi. In continuous casting, usually no material being wasted and could completely optimize production's cost effectiveness. The bars and slabs created are always solid with no cracks. But in ignot casting as traditional method, longer periods of time need due to the individual step and many cracks were created in products.
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1.Right handed screw dislocation
2.Left handed screw dislocation
3.Positive edge dislocation
4.negative edge dislocation
Please provide an insight focus into the statures of Burgers vector in all these cases.
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I recommend the answer from Ebenezer
for more information I suggest to read the book “Solid State Physics” by S O Pillai
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After cutting the plane I do not understand which plane of atoms corresponds to which one.If both the upper part and the bottom part are contained in the same straight line and we cut the partial of it where would the upper part go? (Please refer to the picture attached herewith)
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Dear rajoshri,
P=l.bXB= 2.1/2*4.5=4.5 (shortest dislocation parity)
simply tou can calculate half plane. Just simple.
The Burgers vector associated with a dislocation is a measure of the lattice distortion caused by the presence of the line defect. The Burgers vector defined in this way is a unit vector of the lattice if the dislocation is a unit dislocation, and a shorter stable translation vector of the lattice if the dislocation is a partial dislocation.
The displacement distance of the atoms around the dislocation is called Burgers Vector. Generally it is denoted by b. It is perpendicular to the edge-dislocation line and parallel to screw dislocation line. Burgers, is a vector, often denoted as b, that represents the magnitude and direction of the lattice distortion resulting from a dislocation in a crystal lattice. For the determination of the Burgers vector you need to insert the type of an expected dislocation. Then go around the dislocation core (line) adding the same amount of steps (vector). The missing vector component is the shift caused by the dislocation. That's the Burgers vector.
The edge defect can be easily visualized as an extra half-plane of atoms in a lattice. The dislocation is called a line defect because the locus of defective points produced in the lattice by the dislocation lie along a line. This line runs along the top of the extra half-plane. In crystal defect. Line defects, or dislocations, are lines along which whole rows of atoms in a solid are arranged anomalously. The resulting irregularity in spacing is most severe along a line called the line of dislocation. Line defects can weaken or strengthen solids.
High voltage electron microscopy (HVEM) as well as the computer simulation of the electron micrographs can be applied to study the contrast behaviour of mixed dislocations with a large screw component of the Burgers vector under different diffraction conditions in order to check the validity of the method proposed. The analysis of the contrast oscillations along inclined dislocations or the image shift relative to the projection of the dislocation line enables us to determine the ‘dislocation parity’ P = sgn (l × b · B) while the halo contrast can be used to define the orientation of the ‘additional half plane’, which is characterized by the normal e = l × b/|l × b| to the glide plane. The parity and sgn (g · e) analysis enables the unambiguous b vector determination whenever solely one invisibility criterion is applicable. The dislocation parameters in heterostructures are investigated by the above method.
Hope it is helpful to you.
Ashish
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I've been curious about how exactly HEA's are manufactured. Are they predominately cast? Printed with additive manufacturing?
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Dear Graham,
It is generally a novel class of material. In my opinion, it is not made by an additive manufacturing 3 D printing process. It can be produced by liquid phase and solid state processing methods. The alloy is of specific interest in medical industry.
Most HEAs have been produced using liquid-phase methods include arc melting, induction melting, and Bridgman solidification. Solid-state processing is generally done by mechanical alloying using a high-energy ball mill.
These alloys are currently the focus of significant attention in materials science and engineering because they have potentially desirable properties. HEAs have considerably better strength-to-weight ratios, with a higher degree of fracture resistance, tensile strength, as well as corrosion and oxidation resistance than conventional alloys. Yeh was also the first to coin the term "high-entropy alloy" when he attributed the high configurationally entropy as the mechanism stabilizing the solid solution phase.
High-entropy alloys (HEAs) are alloys that are formed by mixing equal or relatively large proportions of (usually) five or more elements. Prior to the synthesis of these substances, typical metal alloys comprised one or two major components with smaller amounts of other elements. For example, additional elements can be added to iron to improve its properties, thereby creating an iron based alloy, but typically in fairly low proportions, such as the proportions of carbon, manganese, and the like in various steels. Hence, high entropy alloys are a novel class of materials.
Ashish
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Lead is present in ppm level (1000ppm) in saturated Zinc Chloride solution. I want to remove lead from the solution. How can I do this.
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By adding drops of potassium iodide on cold , Lead will precipitate as the yellow precipitate PbI2, which can be completely separated than other by dissolving in hot water
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Good mourning, in metallic materials it is commun when people talk about the fracture toughness that they use the so called plane strain compact tension Ct test, and the standards (ASTM for example) are under relatively special conditions dictated by the standard to determine the Fracture Toughness (Kic), and amoung the most important conditions is the existance of a sharp crack in the vicinity of the notch, this is made in a fatigue testing machine and this requered sharpness is important to avoid any plastic instability (according to ASTM standards) during the monotonic-load testing of the CT specimen to determin a precise Kic.
My queries are:
1. Let's take the case of a high stength steels and with a sharp crack in the notch of the specimen, so how much is the maximum load for a specimen with a width of about 25 mm. could you pleas give a referance.
2. Let's now suppose that there doesn't existe a sharp crack in the vicinity of the notch (round notch with verry smal radius of about 0.1 mm), could you give us an estimation of how high would be the Load at the onset of the notch during the test.
thank you very much
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For a valid fracture test, crack should be sharp. If this is not the case, the fracture toughness values will be very high. The is a critical tip radius below which there is no effect of tip radius on the fracture toughness. Please refer Fundamentals of Fracture Mechanics - J.F. Knott.
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we want reducing Carbon content of initial electrode of VAR furnace, electrode composition prepared for VAR is (FSX-414: 52Co 29Cr 10Ni 7W) but Carbon is higher than limited composition (about 0.2% exceeded). which technical parameter most modify to obtain correct composition?
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Practically no carbon is lost during vacuum arc remelting.If lower carbon is desired in your cobalt base super alloy , use virgin metals and controlled amount of low carbon Ferro-chromium to meet the the final requirement.
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Hi everyone;
I'm trying to simulate Friction Stir Welding (FSW) plunge state using Abaqus/Explicit, Coupled Eulerian Lagrangian technique (CEL).
As you can see in the picture, NT11, PEV and EVF are calculated. But the problem is that the elements in base metal are not deformed (Base metal type is Eulerian and Tool is Deformable). In other words, the base metal elements which are in contact with PIN remained intact and are not deformed.
Anyone could help me with this?
___________________
P.S: Based on my search through the Internet and Abaqus documentation, something must be wrong with "Volume Fraction Tool" under "Discrete Field". 
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Interesting... Please share me the final answer...
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How can I get rid of scratches for Pure Aluminium, the specimen is being extruded, we are able to view the grain orientation but with lot of scratches
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Dear srikar,
Try with electrochemical and ion etch(chlorine), plasma polishing.
General way it may be helpful for you.Use microfiber cloth, fluoride free toothpaste(take on soft cloth , rub it and wipe on the surface, remove surface layer and dry it,), remove scratches in baking soda, dry gently.
Just try it.
Ashish
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Especially elements that is predicted to be in 1% range.
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In the light of above discussion I can say that Laser Induced breakdown spectroscopy is better technique of elemental spectroscopy for the field application. Lot of new techniques are available and are still being investigated to enhance the sensitivity of LIBS technique. Particularly NELIBS Nanoparticle enhanced laser induced breakdown spectroscopy enhances the sensitivity of LIBS by order of magnitude.
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In the dynamic material model, area between the stress-strain rate curve and the strain rate axis is called 'G', and it is said to correspond to thermal power. Similarly, 'J' is the area between the curve and the stress axis and this area is said to correspond to power used for metallurgical changes (as shown in fig).
What is the basis for such an assignment? Why is G heat content and not metallurgical content? Is there any existing theory that proves that area under the stress - strain rate curve corresponds to heat energy?
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You are right, it is not explicitly explained. This is one of those ideas which is "understood". Let me answer as per my understanding. We can do a thought experiment. Suppose all the power we are putting in is wasted as heat. You can take it as zero efficiency heat engine. The rectangular area then is the total power and it is being converted into heat. Now suppose I am able to get some work out of it then area will decrease and complimentary area will be work done. This work in our case is irreversible microstructural change which you can also understand as increase in the entropy of the system.
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I am looking for ways to produce powder from an aluminum bar. I can't find an available grinder/mill, so I am looking for an alternative. I saw a method wherein a steel plate and a steel bar were used to produce the powder. However, I am worried that this method will introduce contaminants in the final product. More so, the method is quite tedious.
Here is a link of the said method.
Thank you!
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Aluminium bars could be converted as machined chips through machining process and then chips can be converted as powder through ball milling process
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I want to know the threshold carbide detection limit of X-Ray Diffraction Machine in Steels. Is there any explanation for it. I am working on high chromium Nuclear Materials. If possible, please give the reference.
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Sorry I cannot give detection limits, but classical narration states 5% (volume/mass fraction?). But I think this statement makes little sense, exept for that it makse aware of the fact that there is always a detection limit. The real detection limit always depends on the scattering power of your phase, on the level of the background intensity determining usually the scatter of the measured intensity. I remember cases where less than 1 mass % of some precipitation phase was clearly visible with a lab instrument. Let's list some important factors:
1. Scattering power (structure factor per volume) of the phase. A W containing carbide will be easier detectable than a 3d metal carbide.
2. Low symmetry will distribute your intensity on many different reflections. Cementite is much more difficult to detect than a NaCl type carbide.
3. The width of the Carbide reflections. Note that the invariant parameter is the integrated intensity, then, broad reflections are more difficult to detect.
4. And, as already indicated: You have to detect the peaks of the phase under consideration above the level of the background. If the latter is high, it is difficult (think about counting statistics). But this indicates that the detection limit can be improved by improving the peak/background ratio, and that is easiest done by suppressing background.
All this indicates that THERE IS NO GENERAL DETECTION LIMIT. If you want to get a feeling, e.g. in the course of a Rietveld refinement, you can introduce a corresponding phase as additional phase with a phase fraction. Then you can check what is the lowest phase fraction you would be able to see above your experimental background. As indicated in point (3) the width of the carbide's peaks (size, microstrain, faulting) will strongly affect the limit.
As you see, like nearly always, it is not so easy.
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Question: Calculate the equilibrium value of vacancies concentration for copper per atom of the order of 10^4 at 1000K the energy for vacancy formation is 0.9eV/atom.
Answer:N=N_0+exp(−Q/RT)is something that I know.However all that I could arrive is to calculate −Q/RT which calculates to give me 82.1.I have taken R to be equal to 0.0821 units and have taken T=1000K. Now I cannot proceed any further.I am not even sure what I am to calculate.
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Sorry, in my answer I vorgot the C0 . The correct formula is:
C=C0 exp-(Q/kT).
C0 is not temperature dependent and is defined by the local change of entropy if 1 vacancy is formed. C0 should be taken from experimental literature, since it is not easy to calculate theoretically.
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Hello all,:
I open this disscusion because it's not clear for me when to use each of these terms.
Can anyone tell the difference (at a definition level) between a Crystal, a Grain and a Domain in a polycrystalline material ?
Or does the three terms mean the same ?
Kind Regards !
:)
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Dear Franklin , firstly I will explain about crystal
A crystal consists of matter that is formed from an ordered arrangement of atoms, molecules, or ions. The lattice that forms extends out in three-dimensions. Because there are repeated units, crystals have recognizable structures. Large crystals display flat regions (faces) and well-defined angles. Crystals with obvious flat faces are called euhedral crystals, while those lacking defined faces are called anhedral crystals. Crystals consisting of ordered arrays of atoms that aren't always periodic are called quasicrystals.
The word "crystal" comes from the Ancient Greek word krustallos, which means both "rock crystal" and "ice." The scientific study of crystals is called crystallography.
now grains and domain Usually domains are parts of a grain so that domains are ideally always smaller than grains, but...of course in case of special grainboundaries it might happen that domains appear bigger than a grain. However, I wonder what really happens then along the grainsboundary. The "connected" domain should show there lattice defects, i.e. a small grain boundary. 
I hope you you will get better idea . best wishes , also follow this article link its very effective to your discussion
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The property of whether a substance is paramagnetic or antiferromagnetic is something that is bothering me.I know that for sure what the things are in terms of magnetic domains and stuff.However how do I solve these problems?Should I mug up?
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Best thing is search for its electronic configuration (and bonding in them)
next thing keep in mind for "ferro, ferri, anti...." requires at least two different lattices of atoms, rest is clear.
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There are two equations that are primarily used in context of the facture stress one with sqrt(2 *gamma*E/a0) and the other with sqrt(2*gamma*E/pi*C).I do not understand which one to use while finding the critical crack length.
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Dear Rajorshi
In fracture mechanics, there are many distinct formulas for calculating different parameters such as theoretical cohesive strength, fracture strength, critical crack length, and fracture toughness. In the following, two different formulas will be explained:
a) 𝝈𝒕𝒉=((𝑬.𝜸𝒔)/𝒂𝟎) (𝟏/𝟐)
where 𝝈𝒕𝒉 is the theoretical cohesive strength,𝜸𝒔 is the surface energy, and 𝒂𝟎 is the interatomic spacing.
However, the observed fracture strength is always lower than the theoretical cohesive strength. Therefore, eq.(b), “known as Griffith’s theory”, was developed:
b) 𝝈f=((2𝑬.𝜸𝒔)/πc)(𝟏/𝟐)
where 𝝈f is the fracture strength, and c is half of the crack length. Therefore, if the material contains a crack with length of 2c, then the fracture stress will be equal to 𝝈f . However, this equation is used for brittle materials. You can use Irwin’s modification if your material is ductile-brittle.
You can use eq.(b) considering that 𝝈f is the fracture strength of your material and 2c is the critical crack length. However, in linear elastic fracture mechanics, stress intensity factor, known as “fracture toughness” of the material (K1c) is calculated, and the critical crack length is determined regarding the amount of applied stress.
I hope this answer could be useful.\
Best regards
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I calculated activation energies for intermediate stage of sintering for alumina+tetragonal zirconia composite and alumina+cubic zirconia composite via non-isothermal CHR method in microwave hybrid sintering, and compared them. The particle sizes of both as-received zirconia were same. A+tZ shows slightly higher activation energy as compared to A+cZ, but the densification of A+tZ is also higher. Can someone please guide? Because if densification is higher, then the activation energy for sintering should be lower, but that's not the case here. Is some unusual factor of sintering kinetics involved here?
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Activation energy for a sintering is a system property, namely: the energy barrier which system must overcome to start sintering process. In the discussed case, obviously, the estimated activation energy is a combination of surface/grain boundaries/volume diffusion activation energies of the mentioned materials system.
On the other hand, densification is a sintering result. So, is sintering parameters permitted to overcome the energetic barrier, a sintering process was initiated and then resulted in a certain final density.
Taken into account the mentioned above, I do not see any contradiction between high activation energy and high sintered density, if sintering process was adjusted and optimized specially to the mentioned materials system.
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Let's say I have a material with a stable phase A that transitions to another stable phase B at temperature T. If the material also has a metastable phase A', I know that if I cool B fast enough I would get:
B -> A'
and if I cool very slowly I'd get
B-> A.
If I were to look at the interface between B and the new phase and somehow extract all possible information (energy/mass transfer, etc), what signal would indicate to me that I would expect A' (metastable) to form over A?
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When you refer to thermal gradients you propably refer to solidification processes. For these the temperature gradients are very important as the interface velocity is usually determined crucialy by the transport of the latent heat. Here, of course, special literature exist, but beyond what is taught in general lectures I cannot help much. Your reference to "metallurgy books" seems that there you looked at the soldification sections.
If you are more interested in solid-solid transformations, usually the thermal gradient is less important, simply becausee the latent heat associated with the transformations is much lower than for solidification (the invariant parameter is actually the transformation entropy, connected with the transformation enthalpy via the equilibrium transformation temperature). In that case there is a huge amount of concepts to describe phase transformation kinetics. Porter Easterling is a good starter (having also solidification sections). Models are of course on very different levels. If you want to find much more, you may refer to Christian.
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It seems that we have a perennial notion of relation Austentite and Ferrite in Fe-C phase diagram however we refer to them as gamma or alpha iron.Is having a minimal carbon content necessary for this polymorph to exist can we have other alloying elements instead of Carbon?
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Existence of ferrite (alpha or gamma) and austenite is independent of carbon content. However, the amount of carbon can control the temperature range of phase stability.
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In the given question is it not that the terms containing partial differential of pressure and temperature have switched the associations? Like dp should be in place of dT and dt should be in place of dp?
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They should be typos.
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I know that P2O5 production is favoured by increasing O content but why are we using high activity of FeO to favour dephosphorization?Please explain in detail keeping in mind that I am reading this for the very first time.
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In an oxygen rich top blowing steelmaking process, dephosphorisation occurs at the interface between slag and metal. The direct removal of P by oxygen into slag doesnt happen as P2O5 is unstable at steelmaking temperature and it will reduce immediately after its formation.
2 [P] +5 [O] = (P2O5) ∆ G° = −740375 + 535.365T J/mol
For example, at temperature > 1382 K, the delG becomes positive and P2O5 decomposes to P and O. How can we make the delG negative at high temperature?
Del G = del G0 + RT ln (aP2O5/aP^2*aO^5)
Decreasing the activity of P2O5 or increasing activity of P and O will help to move the reaction in forward direction. Therefore common practice is to add basic oxide such as CaO (strong basic oxide) to reduce the activity of P2O5 and makes the P2O5 phase stable in the slag phase. As mentioned in previous comment, the dephosphorisation reaction in steelmaking process proceeds via the following reaction:
[P] + 5[O] + 3(O2-) = (PO43-)
As you can see from the above reaction, P in the melt requires a oxidising environment([O]), which is generally provided by FeO in slag ( FeO = Fe+ [O]) and also it requires a basic slag (O2-) supplied by the addition of basic oxide ( CaO= Ca + O2-) to reduce the P2O5 activity in slag.
So to answer your question, a high FeO slag supplies [O] and favours the oxidation of P to P2O5. However, a basic slag is absolutely necessary to make P2O5 stable in the slag phase. Therefore beyond certain percentage, generation of more FeO does not help the dephosphorisation process . Also you have to keep in mind that oxidation of P is an exothermic reaction and a reduced T always assists the P removal process.
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The given below figure is the Gibbs free energy versus pressure plot for three phases, solid (S ), liquid (L ), and gas (G ), near the triple point for the one component system. It is known that the molar volume of the solid is greater than that of the liquid.(Followed by G vs P curve of a liquid,vapour and solid).
Which of the following options is CORRECT?
  • A) P – Gas, Q- Liquid, R- Solid
  • B) P – Gas, Q- Solid, R- Liquid
  • C) P – Solid, Q- Liquid, R- Gas
  • D) P – Solid, Q- Gas, R- Solid
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That is correct.
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Dear,
I'm trying to see if there is a rough (even very rough) statistical link with stainless steels chemical composition + microstructure + ... and the pitting potential.
It would be interesting to get a better indicator than the PREN to evaluate the corrosion resistance of stainless steels.
The main drawback of the PREN is that it does not take in account the Carbon amount (and if we want to get further, neither the Sulfure or Phosphore, that are very important inpurities). So that is only usable to roughly compare Stainless Steels with the same amount of Carbon.
I had a look at some results from saline fog tests I made. As a first approach I tried to divide it by log(%C² + 1), it gives a better idea but not at the point that there would be some rough proportionality with the saline fog results I know. It is clearly lacking a consideration for microstructure for example.
One other problem is that salin fogs results are not so stable. Using one of the normalized pitting potential tests would be better.
Is there some currently established relations or attempts that could prove to be usefull at the first steps of material selection ? The corrosion is too complex to have more than a very rough law, however that could still have some uses.
If not, I would still be interested in a datasheet with the measurement of different stainless steels pitting potential in some standardized conditions to see how it is distributed.
Regards
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I think, most of the research on pitting of stainless steels aim at developing a correlation between composition, microstructure, and pitting resistance. However, as mentioned, the corrosion process is very complex because the pitting is a stochastic process and influenced by pitting inducing anions (mostly Cl-, but also SO42-), pH, temperature, dissolved oxygen, concentration of other oxidizers and time. Pitting depends on the stability of the surface passive layer. The passive film stability is affected by small perturbations in the service conditions including stress level. With these many parameters affecting the process it is really difficult to propose a meaningful mathematical function to describe a pitting potential.
For materials selection, PREN is a good indicator. There are studies to correlate the pitting resistance using artificial intelligence, for example: Journal of Applied Logic 10 (2012) 291–297.
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Proove that the dislocation reaction is vectorially correct a/2[10-1]-->a/6[21-1]+a/6[11-2]...Please solve this and tell me the approach.
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The argument behind the dissociation of perfect dislocation with Burgers vectors a/2<110> in two partials with Burgers a/6<112> is related to the dislocation energy which is roughly proportional to the square of the norm of the Burgers vector. Then, for a perfect dislocation, it is a2/2, while for a partial it is a2/6.
Since a2/2 > a2/6 + a2/6, the dissociation is energetically favored.
Best
L.
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I have to mix two ceramic powders in volume percent (50 vol% each). I measured their tap density. I multiplied this tap density with 0.5. It gave me the mass that i can weigh to mix the powders. I can adjust these masses according to their ratio to get sufficient quantity of the mixed powder. Now I will weigh the powders according to these values of masses, and mix them.
Is this procedure right?
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What you mentioned is the correct except that tapping density. We should always take experimental/true density of the powders/compound.
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Assuming that the alloy is completely dissolved using acid digestion.
If possible, can someone please suggest the type of ICP to use?
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You can use radial view in ICP-OES
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How do we make Tungsten carbide cutting tool inserts? By powder injection molding or by mechanical pressing and sintering?
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I want to know about the Iron Oxide and gas conversions for the different DRI Processes. Can I get the reference data for it?
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DRI or sponge iron refers to porous iron produced by the DR process. The DR process is a solid-state reaction process (i.e., solid–solid or solid–gas reaction) in which removable oxygen is removed from the iron oxide, using coal or reformed natural gas as reductants, below the melting and fusion point of the lump ore or agglomerates of fine ore. The external shape of the ore remains unchanged.
DRI has been fast gaining ground throughout the world since the 1980s mainly because of the shortage of coking coal for BF and steel scrap in steelmaking. DRI is produced by the DR of iron ore by using noncoking coal/ natural gas. The major part of DRI production is used as a substitute for scrap in steelmaking. DRI is consumed in three primary product forms, namely, lump, pellets, and hot briquettes (as shown in Fig. 10). The other secondary product form is cold briquettes made from DRI fines. The hot briquette form is popularly known as HBI. HBI is a combined solid form of DRI lump and pellets, hot pressed at 700–800C (973–1073 K), immediately after its production. The most important characteristics of HBI are its high density and lower specific area, which improves the resistance to reoxidation and makes it easier to handle. Due to high density, the charging of HBI in furnace is much easier and melting is faster. Tables 6 and 7 compare the chemical composition and physical properties of different forms of DRI.
Based on the types of reductant used, the DR processes can be broadly classified into two groups:
1. Using solid reductant, that is, coal-based DR process
2. Using gaseous reductant, that is, gas-based DR process
Coal-based processes
In coal-based DR processes, noncoking coal is used as reducing agent. In solid reduction processes, iron oxides together with solid reductant (noncoking coal) are charged into the reactor. The generation of reducing gas (mainly CO) takes place in the reduction reactor, and the product has to be separated from excess reductant, ash, and/or sulfur absorbing materials (lime, dolomite) by magnetic separation after discharge at low temperature, which makes product handling more complicated.[3] Because of the presence of these substances in DRI, hot briquetting and hot feeding are not possible for coal-based process. Magnetic separator also does not work at high temperatures to separate the DRI.
Gas-based processes
Reformed natural gas is used as a reducing agent. Iron ore lumps or pellets are reduced in the solid state and oxygen from iron oxide is removed by a gaseous reducing agent. Natural gas is reformed at 950C (1223 K), in the presence
of catalysts (Ni or Al2O3), to produce reducing gases CO and H2. The reducing gases H2, CO, or mixture of H2 and CO, are introduced into the reactor at elevated temperatures [up to 1000C (1273 K)] and pressure (up to 5 bars)[3]. If CH4 is present in the reducing gas, it results in carburization of the reduced product.
The processes based on gaseous reduction are confined to the areas where natural gas is available in abundance at a reasonable price.
The following are gas-based processes:
1. Retort processes HyL I, Hoganas
2. Shaft furnace processes Midrex, HyL III, Plasmared, Armco, Purofer, NSC, HyL IV
3. Fluidized bed processes FIOR, Finmet, Circored
DR processes are very sensitive to chemical and physical characteristics of raw materials used in the process. Iron ore or pellets, reductant (i.e., noncoking coal or natural gas), and limestone/dolomite are the main raw materials for DR technology. For successful operations the process of DR technology has specified the characteristics of raw materials to be used in the process.
Characteristics of iron ore: Lumps or pellets have high iron content, low gangue content, and good mechanical strength and are readily reducible and of nondecrepitating variety. Iron ore feed to the reactors has the following characteristics:
1. Chemical composition
2. Reduction properties
3. Physical characteristics
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How to calculate CO/(CO+CO2) from reaction rate constant in the case of Baur-Glaessner diagrams?
I have the Log K values for the reaction at the different temperatures.
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You wrote: " I have the reaction constant values, " what reaction rate constants doyou have values for andwhat are the units?
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If I want to prepare alloy using vacuum arc melting. Do the metals have to be powder or scrap form?
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Hi all,
In my opinion, raw materials for arc-melting can be in form of powder or bulk (ingot, slugs, rod, scrap..)
- If they are in form of powder, i do agree with Jinghao that we should mix the powders as desired composition and then do green compact to form to pellet before arc melting so that powder blowing during arc-melting is minimized.
- If they are bulk form, it will be much easier for arc melting.
Noted: it is hardly controlled the temperature during arc-melting, so that some metals will be evaporated which make changing your alloy composition. some metals like Mg, Mn...could evaporate very quickly during arc-melting.
Hope it is usefull!
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I believe the most fundamental discoveries of all times - nanomaterial.
Is my perception matches your opinion? What alternative you can suggest?why?
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Dear Baskhar,
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What is the influence of Si, Cr and Mo on the tempering process of tool steels?
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Interesting..
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While, heat treating a steel (cooling or heating) at a rate different from equilibrium heating or cooling rate, transformations take place at temperatures higher than or lower than the temperature predicted by "equilibrium phase diagram". 
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I observed Hysteresis like shape while heating and cooling polymer, can any one explain to me what is the cause of this hysteresis?
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Like FIB-TEM.
I am looking for a technique by which polymer composite properties remain constant.
Plz insight us
Thanks in advance.
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Dear Bhaskar;
You have three choices:
1. You can prepare a very thin composite to see sharp nanofibers in the FE-SEM images (This method is specially useful for hydrogels reinforced with nanofibers).
2. You can provide a cross section and see the dispersion of fillers in the coating matrix ( ).
3. You can used AFM analysis (topographic and phase contrast images) to investigate the nanofillers.
Good luck
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High indexed conference in the world related to material science dedicated to composite?
Your productive views are highly appreciated.
Regards
Bhaskar
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Dear Bhaskar Bhatt,
I have attached herewith the list of High indexed conference in the world related to material science dedicated to composite.
I hope I have answered your question.
With Best Wishes,
Samir G. Pandya
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1-Way of dispersion of nanofiller is also increasing and decreasing Tg of PNCs.
2-crosslinking agent
3-processing cooling rate
4-tacticity
I am curious to know more insight regards this.
Which one is good for Tg measurement
DSC or DMTA.why
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The Tg measured with DSC and DMTA are not comparable quantities.
In DSC experiments the measurement of Tg should be done by cooling from the melt to the glassy state at given cooling rate (and this must be specified in any report). In DMTA the tests are influenced by both the cooling/heating rates and the test frequency. Changing the test frequency by a decade my give rise to Tg change of order of 4-5°C. The heating/cooling rates have similar effects. That is to say that if one uses very low testing frequency, f, and very low heating rate, H (namely , F=0.001Hz and H=0.1°C/min) the measured Tg may vary also 40-50°C in respect to faster heating and higher testing frequencies (namely, F=100Hz, H=10°C/min).
In all, the glass transition is a kinetics driven phenomenon . Thus is depends on the rates of testing (cooling/heating rates , test frequency and so on..)
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How is it possible to make shape memory alloys to forget its memory ? Is there any treatment method for it such as treating with high temperatures ?
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Normally, during thermal cycling shape memory effect will diapered.
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Aggflow & Metsim Softwares, using fields and benefits of these softwares.
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Aggflow is good for the simulation of aggregates or solids material flow for processes such as material handling, screening, crushing, etc. It is not recommended for complex processes containing slurries and thermodynamics. METSIM is good for both material handling and process plant (mill, flotation, hydromet, pyromet). It does good heat and mass balance. But METSIM is not used in coal processing. LIMN is popular in coal processing and is now getting popularity in milling, hydromet, and pyromet.
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Dear researchers,
What is the your percent gross zinc usage (e.g. (zinc consumed/production) times 100%) in the production of Steel Pipes by Hot-dip Galvanizing? with credits for dross or ash.
I am conducting a benchmark survey of technical information on hot dip galvanizing processes because of the lack of comparative data.
Here in a brazilian industry the percentage of zinc consumption for the production of steel tubes are between 1/2 "inch and 2" inches is 8.5% and between 3 "and 6" tubes is 7.8%. Considering dross and ashes.
Best Regards,
Leonardo Lopes
University Unisuam - Brazil
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It is a very interested question Leonardo
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Constant voltage power source is said to have better control over the parameters in a mechanised process. But still why do we prefer CC power source for SAW?
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It is very difficult to maintain stable arc length during SAW welding. If arc length unstable then we get various bead geometry and penetration . That is not suitable for a good welding... I thinks this is the reason
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I recently bought a one-way SMA wire, but after experimenting with it I come to the conclusion that the wire was already trained to be a two-way SMA wire.
Now I would like to reset the shape memory configuration to end up with a one-way SMA wire.
Is there a way to do this without irreversibly reducing the wires shape memory performance?
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My I ask you please, from where did you get the two way SMA?
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Hi all,
Does anybody have cif file of 1T structure of MoS2. As this structure is meta stable I am not getting the CIF file of the same  in any standard database. 2H or 3R MoS2 are quite common and hence existing. In case anybody has any cif file of 1T- MoS2 could you share with me.   
Thanks
Ankur
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Dear Zhao I am sending you the 1T bulk structure that I am using in my work.
It was published in Chem. Matr. 1998 10 2152
with best regards
Prof. Yosslen Aray
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It seems I am not so familiar with definite integral being changed to differentials.Can anyone justify me how the T1,P1 values and the limits are being changed to simply T and P as given in the attachment.
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Maybe the attachement helps.
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Hello Everyone,
I have just completed Masters in Metallurgical Engineering and I am looking for PhD position specially in area of Metal Additive Manufacturing. Please suggest Labs and professors that are working this area.
Thanks
Qamar
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