Questions related to Sintering
Can anyone explain how the carbon dioxide gas is protecting the weldments in MAG welding. Since this gas is active/reactive in nature with the hot metal how does this affect the weldment. Further, can this be utilized to avoid oxidation in the sintering process?
A discussion that I would like to explore, is whether a low loss (<0.0005) and low sintering temperature (<700 °C) microwave dielectric ceramic is a good candidate for Microwave sintering? What are the fundamental aspects that have to be considered for the comparison with the conventional sintering process?
I thank you and looking forward to having your valuable resposne.
what happened if we tried to re-sintering of produced powder (by means of grinding)that obtained from previously sintered ceramic compact based on zirconia ? is it accepted in ceramic community? i understood that in the previous sintering, there was necking and grain growth. so if we re-sintered the powder produced from it, i think that it will undergo to further grain growth and may affect the properties of zirconia through changing the existed tetragonal phase. is this true?
I need a detailed breakdown of how I can get the CTE of a sintered sample from the obtainable data after the use of SPS machine to sinter. I am finding it difficult to manipulate the relative piston displacement and temperature data to obtain the correct value of CTE. I need guidance on the complete and useful set of data required to get CTE (based on SPS).
To make a good mixture of all the constituents of our sintering powder (Alumina and other additives), it is necessary to disperse these constituents well. This requires the use of a dispersing agent (such as DARVAN C), which one?
Nbc-Ni Cermets samples are sintered in a vacuum sintering furnace at @1450 degrees. The Samples were placed in the Alumina Piece as shown in the attached pictures. after sintering the color of the alumina piece changes to blue as shown in the picture. what can be the reason behind it? Thanks
Each time I am sintering YBCO pallet, the levitation is being reduced.
More the sintering temperature, the levitation is reduced more.
Does it mean, that Levitation is lost implies that the superconductivity is lost?
Thanks and Regards
Currently sintering NASICON at 1180, 1200 and 1230 degrees C in a tube furnace under argon. The NASICON is melting and sticking to the alumina crucible at all 3 temperatures. Has anyone else experienced this and know a solution?
I prepared YBCO ( 123) heated at 920°C and formed pellet and observed very good levitation.
But, after that, I sintered the pallet at 950°C and then the Levitation reduces to a great extent.
Does this mean that the Superconducting YBCO is damaged and transition experiment is not possible?
Thanks and Regards
I am making cermets with nickel binder, post sintering excess nickel sticks to the crucible. What is a reasonable solution for Ni removal without damaging or reaction with alumina. I was thinking of immersing the crucible in 30% diluted hcl @40celcius for 4 to 5 hours. I can be wrong. Please share a convenient method. I tried sanding but its not working.
I have some sintered Alumina and 8YSZ samples. For my research I need to do the SEM so that we can observe the grain boundary and sizes and their distribution. I looked at online and found out that i need to mirror polish the sample and then put them in etchant solution. But I could not find a good resource that will tell me to use which etchant for 8YSZ and which to use for alumina? I need some advise regarding that.
Can I use miedema model to calculate the thermodynamic analysis of a sintered metal. I carried out sintering of Mg-Al-Zn powder at a temperature between 380-500. i want to estimate the enthalpy and Gibbs free enegy of all the phases at those temperature. Can i plugin some parameters into the miedema model to estimate these variable. I can not get publication that applied it to direct thermal analysis except for powder mixing and transition metals. pls i need help.
Another question is, can I get amorphous phase in low-temperature sintered sintered Mg alloy? Pls all your helps are very useful. Thanks
May I know why commercial sintering die attach paste is always based on silver? Why not other metals, such as copper and aluminum? Thanks.
In my 3D printing of zirconia research, I have found a common trend to be an increase of transmittance (%) with increasing wavelength for my sintered samples. I have attached one example plot of this. The zirconia is tetragonal phase and has around 3mol% of yttria.
The samples are thin, maybe 0.5mm or less. The test performed is UV-Vis. There is a sharp increase around 360-420 nm and then has a small slope slightly increasing until 850 nm.
Why might I see this trend in my samples?
I am trying to analyze SPS sintering data for ceramics. We sintered this sample at two different temperatures and two different pressure, each apart by 20ish. For example, we started with 1000C and 30mpa withholding of an hour, then increased to 1200C and 50mpa withholding of 25 minutes.
When we try graphing the displacement vs. temperature graph, we expected a positive stair-looking graph as we are calculating the displacement by subtracting the ram position from the starting ram position.
We do get a similar graph. However, we see a decrease in the displacement right when the temperature starts to increase after the hold at 1000. We looked at other values like the ram force and current, where we realized that all values that were increasing dropped sharply as soon as the temperature starts increasing after the hold. Does anyone know why this happens?
I want to develop 45s5 bioactive glass-ceramic but I don't want to go through melting approach first followed by heat treatment. So I felt if I should just compact the powder and sinter without melting to develop crystalline phases, can the product be referred to as glass-ceramic.
Hi¡ We are working with Lithium Cobalt Oxide ceramics, and I would like to know the sintering temperatures of these kind of materials. We are starting with 900 ºC, but any ideas about lowering or increasing this temperature are welcome¡ Thanks¡
I want to find out a material's coefficent of linear thermal expansion. Also I need the know the sintering behaviour of our material. Which experimental method will be better, dilatometer or TMA? Finally, the material will be placed in a engine where it will act as a catalyst, in the engine temperature's will rise very quickly.
I am getting mixed reviews about the comparison. In terms of feasibility, TMA is much more widely available. I am mainly getting confused about the force applied in each technique.
Any help will be appreciated also, if anyone could point to a good literature sources that would be really helpful
I am looking for a reason for my research, which strange looking bumps appeared onto zirconia grain structure.
The material i am using is 5.5 mol % yttria-stabilized zirconia (ZPEX smile, tosoh), and the image is thermally etched surface of a specimen after sintering -> polishing.
I have etched at 1350C for 20 mins, at heating rate of 5C/min. (the sintering condition is 1500C, 2h)
These strange bumps keep appearing in my grain structure, and i am guessing something is done at thermal etching process (such as contamination of other material), since i cannot find these shape before etching.
Does anyone know what could be the reason for this bumpy shapes? if so, it would be helpful to know what material (e.g. alumina) could be the source of this feature based on given image.
thanks in advance!
In literature, i found sintering temperatue should be more than melting temperature. can anyone let me know why it should be high
I'm trying to sinter inorganic oxide powder and achieve density close to theoretical. I first agglomerate powder and then sinter it via SSS process. Because I can't compact the powder properly I can't achieve more than 80% of theoretical density. I’m thinking about trying LPS with sintering aids but my concern is that agglomerated particles will start sintering to each other.
Does anybody has successful experience sintering free flowing powder via LPS?
When im doing reactive DC-sputtering with an aluminum target, the texture after a while tends to be like fine like small 1mm grains on the surface. I guess this is due to the crystal structure in the sintered aluminum target. som times however very lerge structures appear on the alumium target surface. each "grain is about 3-6mm in diameter. They are unevenly distributed.
Could this surface defect aoccure due to to hig temperature on the sputter surface?
See attach picture. A is the normal target surface B is when the problematic structure.
The deposition seems to be affectad also by this texture.
I need ideas on how to reduce the sintering temperature (presently 1050°C) of a newly synthesized solid electrolyte (a lithium based oxide) in order to form a catholyte (without initiating an irreversible reaction between the electrode and cathode) and I was wondering if anyone has any insight that could be of help. I have thought about sintering aids such as lithium metavanadate, lithim carbonate, etc., but they reduced the conductivity of the electrolyte. Apart from using a cold sintering approach, I would appreciate any/every insight on innovative ways to reduce the sintering temperature. Thanks in anticipation.
As the title say i am looking for information on intense pulsed light machines for particle sintering. If you know a manufacturer or if you have details on the conception of the electronic circuit of such machine please share your experience.
A year ago, I had prepared (Bi,As)-2212 superconducting cuprate samples, sintered at 840 degrees and the XRD showed a good phase formation but the resistivity displayed a Tc 10 K lower than expected. For curiosity I had chosen a pellet of the pure sample and one at x=0.1 of As. Those pellets were placed in a tube furnace for 2 hours under Argon flow at T=845. This was done in the hopes of somewhat reducing Oxygen content (as EDX results were going to be late for logistical reasons). When I removed them I found that they had completely melted and I'm still baffled till this day.
Some info that might be helpful:
Before the press, the precursor powder was ball milled at a ratio of 10:1 for 30 minutes and then pressed at around 1 GPa, then sintered at T=840 for 50 hours.
Calculations using the Scherrer equation from XRD showed that the average crystalline size was around 32 nm.
I must've discarded the notes regarding the flow rate due to the method being unhelpful, so I don't have the flow rate for the Argon to share with you.
I am working on the development of magnesium alloy AZ91 composites by powder metallurgy route. During the sintering of pure alloy samples, there is a decrease in density. Generally, density increases after sintering. What can be the possible reason for this anomalous behaviour? I have read in some papers that this can be due to foaming. Also, please tell me how I can avoid this?
I am planning to buy LNO powder but not sure on how can I make the LNO target with 3 inch diameter and 0.125 inch thickness by using this LNO powder.
The external diameter of our pieces from our Sintering process (Powder Metallurgy with iron powder) have different dimensions even though we applied the same temperature parameters to all of them. I'm new to the process, do you have any explanation or source to research about phenomenon like these?
I am working on 430 SS substrate and doing the sintering in 96%Ar 4%H2 atmosphere at 1150C. After the sintering there is a formation of chromium oxide layer even in the reducing atmosphere. My working pressure is higher than 1 atm so possibility of air coming from outside can be ruled out. Is there any suggestions to solve this issue?
After sintering hard copper pipes at about 1000 degrees, we have a softening problem.
Is there any hardening process after sintering? If so, how should this be done? Or should we do the sintering with a copper tube with a different content?
The type of copper pipe we use for sintering is oxygen-free copper pipe.
Now we could characterize the disperion of Al2O3 in AMCs (pure Al reinforced by Al2O3 ) after sintering. But the process of powder metallurgy has a lot of steps, which take long time. The cycle of characterization is so long. So we wonder whether exist a method to characterize the the dispersion of aluminum oxide in Al matrix composite before sintering but after briquetting.
I am working on the development of metal matrix composites by powder metallurgy technique. Currently, I am using conventional sintering. Microwave sintering and plasma sintering are advanced sintering techniques. What are the differences between traditional sintering, microwave sintering, and plasma sintering? What are their advantages and disadvantages? Which one is better for the sintering of AZ91 magnesium alloy?
I am working on a masters project which involves sintering PTFE below Melting point using spark plasma sintering. My problem is how do I know if my sample is fully sintered using XRD and SEM. Your inputs will be highly appreciated
how can I Choice that (according to what conditions)? my powder's size is about 60nm .
I want to know the difference in kinetics of reaction would happen if MgO added in the form of carbonate and hydroxide during Iron ore sintering.
I am doing lignocellulosic extraction from biomass. After treatment with acid solution, I filtered the mixture with the help of G3 sintered frits bucchner funnel. I can see that later filtration is slow and stain over frits. Please help
i started work in simulation on iron ore pot sintering process. in this how to give sinter mix( mixture of iron ore fines + coke breeze+ dolamite fines+ limestone fines) data in ansys fluent.
Is there a method that can be done in the sintering process of alumina zirconia ceramic material by lowering the sintering temperature but can produce high density values. Because I have difficulty in getting a furnace that has a high sintering temperature.
I am examining laboratory cases about the effect of furnace dimensions and volume. but I have no experience or data about that.
We are looking for a supplier of a silver sintering paste to form electrodes on piezoceramic samples, unfortunately information about silver sintering paste is often not disclosed in papers. We need relatively small quantity for our experiments. Do you have any good recommendations (preferentially European supplier)?
We are trying to find out the sintering stress of two different compound by calculating grain boundary and surface energies. The main aim is to examine the effect of the different sintering stress on sintering efficiency and we already had post sintering SEM micrographs and EBSD analysis.
Could you plase suggest a route if it is possible to extract especially grain boundary energy from the grain size and morphology of grains ?
Thickness and diameter shrinkage percentage of the Al2O3 sample (after sintering):
I want to use a crucible that is thermal shock resistant when doing rapid cooling by high-speed air blowers.
Sintering is a heat treatment applied to a powder compact in order to impart strength and integrity. The temperature used for sintering is below the melting point of the major constituent of the Powder Metallurgy material but how does sintering work in powder metallurgy?
Would any one know a Tungsten Carbide Sintering Expert? We are looking for a consultant to help assist with come mechanical property improvements based on sintering parameters. If anyone happens to know someone who could assist, please have them contact me
After I completed the sintering reaction to reduce fly ash at 1500oC, the XRD pattern shows the SiO2 (quartz) phase in the raw material remains unchanged and did not transform into cristobalite, rather the SiO2 component of the mullite. However, according to the SiO2 phase diagram, quartz is supposed to change at a temperature ~> 573oC at least to another polymorph.
Could someone offer reasons/explanations for this?
For different samples, i got decrease of particle size with annealing. Can anyone explain me about this?
In the case of fuel fired or electrically heated furnaces, a metallic muffle may be used to ensure a constant temperature zone within the heated chamber. The metal evens out temperature gradients. How can a constant temperature zone be obtained in a microwave oven for the sintering of ceramic bodies?
Dear all, I performed xrd diffraction on a sintered sample of alumina-mullite and after that I crashed the sample and performed the xrd on the powder.
The patterns that I obtained are different regard the mullite peaks: in sample pattern the relative height of mullite peaks are in agree with the theorical peak list; in powder pattern instead the mullite peaks highlights a wrong distribution of the heights. Do you have any idea of the reason? thanks a lot
I have powders of cupric oxide, magnetite, and nickel ferrite, which I would like to transform into dense particles approximately 500 microns across. With what methods can I go about this?
Spark plug insulators are usually made of a sintered alumina ceramic. The powder is pressed and then machined into shape after which it is sintered. During the machining and pressing a mandrel is present in the centre which gives a hollow centre to the insulator.
Think of it as a hollow revolve.
Now this insulator has a lot of bend defects which lead to wastage (scrapping). Basically, after sintering the hole/hollow core of the insulator is not straight anymore and a mandrel or the electrode body can't pass through it.
I wanted to know if anyone knew of the possible reasons behind it and also point me towards related research/reference.
I am trying to estimate the thermal stresses that develop during the sintering of yittria stabilized zirconia (YSZ) cylindrical pellet containing Gd2O3 sphere, from room temperature to 1500oC with a heating rate of 10oC/min and holding time of 20 min, using the heat transfer in solids interface, solid mechanics interface, and coefficient form PDE interface.
Problem description and simulation files are attached for your reference
As much as I know, there is a proportional relationship between initial permeability and density for a particular composition. It means, if density increases with increasing sintering temperature, the initial permeability of that sample will increase. But, in some cases I have experienced that, density falls but the initial permeability of that sample increases instead of decreasing. Why this kind of phenomenon does happen?
I am trying to develop a relationship between the permeability of sintered powdered metal to its given porosity and pore size. I am developing an experimental set-up to measure the permeability of a given product. The thing is I do not know for this material, whether the capillary tube model or sphere model is right.
Material: Ni Zn Ferrite
Sintering temperature: 1142 degree Celcius
Sintering atmosphere: Normal air
Will it occurs during the moulding or compacting process, profile grinding section, handling of pressed parts before sintering process and during sintering process. Also any method or process to eliminate it ?
I am working with Li substituted Ni-Zn ferrite. In my composition, I have partially replaced Ni by Li using auto-combustion method. I have noticed, the optimum sintering temperature to which the bulk density is high or maximum reduced with the doping of Li content against the Ni. What causes can have behind this fact?
Suppose, a ferrite sample is sintered at 1150℃ for 5-hour holding temperature. Now if the same sample is allowed for sintering at the same temperature for the second time as it mentioned above, is there any significant change of permeability, magnetization and dielectric can be observed?
I have sintered Mg3Zn1Ca15Nb composite at 630-degree temperature and measured the phases present in the composite through XRD. But, no phases are detected in XRD analysis. So what can be the reason behind this?
How to remove the sintered material which has been fully stuck at the base of alumina crucible? It is synthesized as stone like material after sintering at 1400 deg C. Should any other kind of non sticky crucible is re