Materials Engineering

Materials Engineering

  • Taha Ibrahim added an answer:
    How can we model fatigue in ABAQUS? How can I create amplitude?
    I have read many things about this, but could not find any tutorial on fatigue simulation for example fatigue simulation of round specimen (dog bone) under constant amplitude loading, and need to get stress-life curve.
    Taha Ibrahim · Benha University

    You may check: http://www.egr.msu.edu/software/abaqus/Documentation/docs/v6.7/books/usb/default.htm?startat=pt03ch06s02at05.html

  • Thomas Korimort added an answer:
    Hello. I am doing single screw extrusion simulation in polyflow and I am getting the following error message. Can anyone help me in resolving it.?

    *summary of simulation*
    ************************
    the computation failed.


    ****************************
    *expert tool diagnostics*
    ****************************
    stack error

    *****************************
    *expert tool suggestions*
    ********************************

    a serious internal error has occurred (in DPGETB) please, contact Polyflow s.a. and send us , if possible, the mesh and data files.
    we apologize for the inconvenience.

    Thomas Korimort · Not affiliated

    Stack usually can mean execution stack or it can be used as a data structure by the program itself. Maybe execution stack ran out of memory because of (unexpected) memory requirements?

  • Amirhosein Ghavimi added an answer:
    What are the industrial applications of Aluminum/Brass bimetals?

    Nowadays there is a high interest to use bimetals like Aluminum/Magnesium, Aluminum/Cast iron, and etc. that provide several propeties in one component.

    Amirhosein Ghavimi · Iran University of Science and Technology

    Aluminum brass tubes are highly accepted and one of the extensively used material for various industrial applications. This alloy develops a protective film that has self-healing properties. This film is dependent on oxygen, which is dissolved in the water and does not renew itself in polluted or stagnant water. High resistance to corrosion in clean seawater or in land conditions is difficult.

    Aluminum Brass tubes resists the action of high velocity salt and brackish water. The outstanding characteristic of this alloy is its superior resistance to impingement attack.

    High strength combined with good general corrosion resistance and low susceptibility to stress corrosion cracking of aluminum brass tubes make it a highly preferred material for load bearing masonry fixings.

    In case, the brass tubes are used in hard drawn conditions, or if they have been severely cold worked through bending or swaging in assembly, they should generally be heat treated to ensure freedom from stress corrosion cracking.

  • Emerson Escobar Nunez added an answer:
    What is the suitable pressure supply for polyphenylene sulfide in pin on disc test?

    In pin on disc test , I have polyphenylene sulfide as a pin , what is the suitable pressure supply for polyphenylene sulfide? d=6mm

    Emerson Escobar Nunez · Autonomous University of the West
    • Look into the hertzian solution for a sphere in contact with a flat surface. The normal load necessary to cause yielding can be found as W=[0.78*(phi)3*R2*Sy3]/E*2

    Where R is the radius of the sphere, Sy is the yield strength of the material of interest and E* is the combined Young´s modulus

  • Zol Bahri Razali added an answer:
    Are there other Mössbauer spectra at RT and 5K ?

    Good evening,

    I am glad to see our spectrum collected at 6K (not published) looks quite like yours. However, we simply couldn't measure any splitting for the other positions (we measured them all at 6K later on).

    The limited capacity we observed seemed to fit with the limited capacity observed by other folks in Tours who worked on a Na/Fe-Sb system you may have heard of.

    By curiosity, did your spectra collected at RT look like ours at all?

    Moreover, did you have the chance to measure other spectra at 5 K ?

    Anyways, congrats on your nice work !

    Zol Bahri Razali · Universiti Malaysia Perlis

    You can get the similar or apropriate answer by searching the keyword in the GOOGLE SCHOLAR page. Usually you will get the first paper similar to your keyword.

    From my experience, this way will help you a lot. If you still have a problem, do not hasitate to let me know.

    Kind regards, Dr ZOL BAHRI - Universiti Malaysia Perlis, MALAYSIA

  • Salah Gariani added an answer:
    Is there any way of increasing the tool life of lathe machine without changing machining parameters?

    I want to increase tool life (cutting tool) of lathe machine without changing machining parameters like speed, feed etc. The change should be in terms of material (material should not be very costly) or design of tool.

    Salah Gariani · Northumbria University

    Increasing tool life depending upon the following factors:

    1. Cutting tools

    2. Cutting conditions ( speed, feedrate , DOC)

    3. Cutting fluids

    4. Chatter ( Machine vibration) 

    However the senstivity of these factors are different for each materils. In your condition you have Cutting condition constant , But you need to state the material after that you conduct  an experiments using Taguchi and ANOVA to assess the senstivity of each for improving tool life.

  • Ravi Bollina added an answer:
    Is anyone aware of any references with pictures on Defects in Refractories?

    Hi

    I am looking into defects in refractories that are used in furnaces. I would like to analyze the defects that generally arise during manufacturing of these refractories.  Specifically looking for books in this field. Any suggestions?

    Ravi Bollina · Mahindra Ecole Centrale

    Mostly arise from Thermal cracking. Best is the above books mentioned by Mr. Sahu

  • Hao Kun Yang added an answer:
    Is there an effective method to observe dynamic strain aging effect in TWIP steel?

    Recently I find that the dynamic strain aging effect has an effect on the mechanical properties of TWIP steel. Is there any effective method to observe the DSA phenomenon?

    Hao Kun Yang · Chinese Academy of Sciences

    Thanks so much for your blessing, Professor Phaniraj!

  • A. Abdi added an answer:
    What will happen if I make a multiple-metal galvanic cell?

    From learning the galvanic corrosion theory, I know that when two dissimilar metals are in electric contact and are surrounded by electrolyte, the metal with lower electrode potential will corrode. My question is what will happen if there are more than two dissimilar metals which are in direct electric contact and are surrounded with electrolytes?

    A. Abdi · Ecole Militarie Polytechnique

    It is interesting to make a predictive study of galvanic coupling by plotting the current-potential curve of each material and then superimpose all curves. We can detect the behavior of each material (polarity), by drawing a line parallel to the axis of the current intensity and intersecting the axis of the potential at the value obtained experimentally from the galvanic coupling. It is imperative to consider the report of the different surfaces of materials. For this it is only necessary to multiply the values of current densities obtained independently for each material by the actual surfaces upon superposition.

  • Nicole Ashley Estrich added an answer:
    Can anyone help with the structural alignment of Nanorods?

    I want to do structure alignment of nanorods (see in attachment) for strain and displacement vector calculation. I would really apperciate your comment/suggestion.

    Thanks!

    Nicole Ashley Estrich · North Carolina State University

    You could functionalize your particles by attaching thiolated DNA to them, in a manner such that a second batch of particles with the complementary DNA would cause them to attach and align with one another. Here is an example: http://pubs.acs.org/doi/pdf/10.1021/nn401413b

  • Martin Siemer added an answer:
    What are the possible materials that are used in Philae?

    I want people to discuss under that question about the possible materials which are used in Philae. What are their manufacturing process and I am also interested in electrochemical manufacturing processes. If anyone send me a beneficial link or source about it I will appreciate. 

    Thanks in advance. 

    Martin Siemer · German Aerospace Center (DLR)

    http://en.wikipedia.org/wiki/Honeycomb_structure

    http://en.wikipedia.org/wiki/Carbon-fiber-reinforced_polymer

    http://en.wikipedia.org/wiki/Chromate_conversion_coating

    and many more....

  • Abhijit Banik added an answer:
    How to simulate temperature distribution in friction stir weld plate during welding using comsol multi physics?

    I am using stationary heat source for friction stir welding simulation making the heat source stationary(tool) as it is given in the solved example.I want to do it for moving tool(heat source) time dependent one.I have made little modification in the given example of stationary heat source like,I have dis able the stationary mode and use transient one,but it seems it is not enough .can any one help me in this direction the primary stages.and what is moving mesh technique.how to do it and is it help full in this context.

    Abhijit Banik · National Institute of Technology, Agartala

    Tarik Ömer Oğurtani sir I have solved the programme for moving tool using the deformed geometry in comsol. but the thermal contours are not showing properly.And there is a blank creates at the initial position of the tool in the work piece when i run the progarmme.i have attuched the programme file .sir please advise me what is wrong in rthe programme.

  • What method is used for measuring ZrO2 thermal sprayed coating?

    What method is used for measuring ZrO2 thermal sprayed coating?

    HASSAN ABDELWAHAB ABDELKARIM · Universiti Teknologi Malaysia

    If you intend to measure the coating thickness using non destructive technique XRF will be the proper measuring method

  • Mohammad Rejaul Kaiser added an answer:
    Can anyone please suggest, how can I conduct raman analysis for lithium sulphide powder (Li2S)?

    As we know, Li2S is very sensitive to moisture which makes it difficult to characterize. I have managed to do XRD by pasting Kapton tape on the powder but this process does not work for Raman (because the wavelength of the laser is too large to penetrate the kapton tape). Thanks in advance for your suggestions.

    Mohammad Rejaul Kaiser · University of Wollongong

    Thanks John.

  • Karar Abdali added an answer:
    Any suggestions on the minimum thermal conductivity?

    Usually the minimum thermal conductivity (kmin)indicates the high temperature thermal conductivity of an insulator when the mean phonon free path is close to the interatomic distance. The minimum thermal conductivity of Clark and then modified by Liu have been widely used to predict the kmin of a number of oxides. (1.D. R. Clarke, “Materials Selection Guidelines for Low Thermal Conductivity Thermal Barrier Coatings,” Surf. Coat. Technol., 163–164, 67–74 (2003). 2.B. Liu et al “Theoretical Elastic Stiffness, Structure Stability and Thermal Conductivity of La2Zr2O7 Pyrochlore,” Acta. Mater., 55, 2949–57 (2007).) 

    However, I just read a paper published in Chin. Phys. B, see the attached, that calculates the kmin of electrical conducting materials of M4AlC3. Since there is electronic contribution to the thermal conductivity, my question is :are these authors calculated are real minimum thermal conductivity?

    Karar Abdali · University of Babylon

    Dear, select the type of material.

  • Tarik Ömer Oğurtani added an answer:
    Why does high carbon steel behave in a brittle manner?

    It may have a very high yield stress, but fracture occurs at an elongation of few percent.

    Tarik Ömer Oğurtani · Middle East Technical University

    I have nothing to add  my above comments. But I would rather to recommend to every Physical Metallurgist in the field,   the following novel book entitled as ' Structure and Properties of Alloys' by  Late Professors  R. M. Brick (University of Pennsylvania) and Arthur Phillips ( Yale University) McGraw-Hill  1949 (Second Edition).  I hope you can  reach it in your library. This book contains enormous amount of experimental data and their well organized scientific interpretations by two leading authorities of  their times, in USA.  GOOD LUCK

  • Hamed Mirzadeh added an answer:
    Why is there an increase in hardness/strength when copper is made to brass?

    Although zinc acts only as a substitutional defect as the size is relatively the same.

  • Hamed Mirzadeh added an answer:
    What is the reason for surface cracking while open die forging of 17-4 PH steel?

    What is the reason for surface cracking while forging 

  • Hamed Mirzadeh added an answer:
    Which method is used to curve fit recrystallized fraction (Xa) against log of holding time?
    I conducted a series of double-hit compression tests. I have plotted the (Xa) against log(t).
    How (which software excel or matlab) do I curve fit my results to fit the AVRAMI softening equation? I need that nice sigmoidal shaped curve. Thanks alot.
  • Yuriy Ososkov added an answer:
    What is XRD+Rietveld phase fraction detection limit?

    Hello my fellow scientists

    I have a question regarding a Rietveld analysis that I have done on an XRD pattern. I have done XRD on a microalloyed steel and when I do the refinement with GSAS it tells me that the volume fraction of a (Nb,Ti) (C,N) is 0.056% which is a pretty low volume fraction. In your opinion is this number reliable given the 1% error that we consider for XRD.

    I should mention that the 0.056% is actually expected and correlates well with thermodynamic calculation. But strictly from XRD stand point, does it have any significance. How can I mention this in a paper without raising eyebrows? 

    Thanks in advance,

    Nassed

    Yuriy Ososkov · Exova Canada Inc.

    Thanks now I see it 

  • Damia Ismail added an answer:
    Have anyone dissolved PLA with 1,4 dioxane and DMSO?

    hi. I'm currently making PLA solution for my  of the component of my composite using 1,4 dioxane and DMSO as solvent.My question are 

    1.do you involve temperature when you stir it, or just leave it at room temperature?few paper stated to leave it for 6hrs for 1,4 dioxane but I had to take longer time than that.

    2.is there any effect in using the unstabillized 1,4 dioxane?I've order stabilized extra dry 1,4 dioxane from fisher scientific but when it arrive, it stated unstabilize at the bottle.However,the product code is the same with what i order so I just use it.Will that make any difference?

    3.is there any suggestion in dissolving PLA in DMSO to be use as polymer solution in composite? Most paper I have read related to my study suggested 1% PLA in DMSO,however I wanted to use higher % of PLA in my study.

    Damia Ismail · The University of Edinburgh

    Tq Nabyl.This is useful for me.

  • Mani Senthilkumar added an answer:
    How to prove that water circulates in hollow part in wicking test of yarns?

    anyone has any idea to prove, in wicking test of yarns, that water circulates in hollow part besides to circulate in the inter filaments space in hollow multifilament yarns?

    Mani Senthilkumar · PSG POLYTECHNIC COLLEGE, COIMBATORE, INDIA

    We have published significant amount of articles in this area. Pore size and its distribution of yarn plays a  vital role in yarn wicking. In order to study the wicking characterisitcs of yarn, Yarn wicking with respect to time, has to be studied. Secondly, yarn has to kept under electtronic microscope to study the water transport mechanism at hollow part. thirdly, comparison is to be made with different hollow ness and the results are to be intrepreted accordingly.. i hope i have given in detail

  • Francesco Perrone added an answer:
    How can I avoid frequency estimation errors with the Teager-Kaiser Energy Operator?

    Since a couple of months I am working on the estimation of frequency and amplitude components of a given accelerometer signal. I initially intended to tackle the problem by employing the Hilbert transform, but in the end I also started using the Teager-Kaiser energy operator.

    After some preliminary checks on standard synthetic signals, such as cosine and sine, and chirps, the Teager-Kaiser operator seemed to perform better than Hilbert transform. However, when I process the accelerometer signal, Hilbert transform produces more reliable results in terms of frequency estimation.

    Attached you will find a copy of the Simulink block for both Teager operator and Hilbert transform, accompanied by an analysis example of the acceleration signal.

    I'd appreciate understanding how I could prevent the appearence of unexpected high-frequency estimation when using the Teager-Kaiser operator.

    I thank you all in advance.

    Francesco Perrone · Nordex SE

    Perfect, I will try approaching the problem from this new perspective. I thank you both for the support.

  • Ehab A. Ahmed added an answer:
    What type of Glass Fiber Reinforced Polymer (GFRP) bars provide higher bond stress with surrounding concrete?

    Does anyone know which type of GFRP bars provide higher bond stress with concrete? Is it sand-coated or ribbed-surface type?

    Ehab A. Ahmed · Université de Sherbrooke

    Of course we can share the findings. Good luck Hamdy!

  • Azzura Ismail added an answer:
    How can I do tafel fit to estimate the current density if the cathodic slope is flat?

    In cyclic potential polarization test, the logarithm current density increases rapidly after potential pass OCP, causing the flat cathodic curve. In this case, how can I do tafel fit to estimate the current density?

    Azzura Ismail · Universiti Tun Hussein Onn Malaysia

    CorrView Program might help perhaps

  • Which has high Heat diffusivity among coarse silica sand and fine Silica sand?

    I am using 45 GFN, 60GFN and 75 GFN Silica sand for my casting experiments to determine flowlength. I want to know which has higher heat diffusivity? I have two paper and both are giving contradictory result.

    Adachani Viswanathan Sethuraman · Hindustan University

    Dear Mr. Khandelwal,

    Coarse sand has less diffusivity due to its very sharp edges than rounded particles.

    Spherical p-articles give more surface area for heat diffusivity. But you have to be careful with any gas lockup. fine particles have more chances of gas lock up due to its low permeability. Sieve distribution 3or 4 sieves can give you a clear idea than the AFS  nos. Pl revert with your views

  • M. S. Leitner added an answer:
    How can I calculate the fluence and dpa (displacement per atom) in metal?

    I have done calculation with srim and I have vacancies data. I want to calculate fluence and dpa. also i have done an experiment of irradiation at different fluences.and i want to calculate vacancies at different fluence using SRIM.

    M. S. Leitner · Stanford University

    You could consider using FLUKA particle physics Monte Carlo package (www.fluka.org), which can compute fluence and DPA.

  • Emon Barua added an answer:
    How can I transfer a geometry from one coordinate system to the other considering node positions in ANSYS MAPDL?

    Hello, I have attached a picture of a geometry with nodes created in ANSYS MAPDL. As shown in the figure, I need to transfer the entire geometry  to the coordinate axes shown below with Node no.21 at the origin. Any kind of suggestions will be highly appreciated. Thanks in advance.

    Emon Barua · Tezpur University

    Yes sir, I am interested in stress analysis of the 3Dstructure after it is being wrapped up. Any idea about "wrapping of sheet" operations in ANSYS?

  • Elias Randjbaran added an answer:
    Does anybody know what substance is suitable for the freeze-casting process?

    Does anybody know what organic substanse is suitable for freeze-casting process? I know that a lot of researchers use camphene, but I can't find another organic substance for this process. In other words, substance creating crystals. Thanks in advance.

    Elias Randjbaran · Universidad Politécnica de Madrid

    Freeze-gelation, is a form of sol-gel processing of ceramics that enables a ceramic object to be fabricated in complex shapes, without the need for high-temperature sintering.
    The process is simple, but the science is, as of 2005, not well understood. The most common process involves the mixing of a silica solution with a filler powder. For example, if we were making a component out of alumina, aluminium oxide, then we would still use a silica sol, but alumina filler powder. The relative amounts used differ, normally between 3 and 4 times more filler than sol is added by weight.
    A wetting agent is added, such that the filler powder disperses properly in the sol, which is mostly water. This makes the mixture doughy and stiff. The mixture is, however, highly thixotropic, so that when vibrated it turns liquid. The stiff dough is placed in a mold and the mold vibrated to liquefy the mixture, filling the mold and releasing any trapped air.
    The filled mold is then frozen. On freezing, silica precipitates from the sol, forming a gel. This gel holds the filler powder together in something approximating a sintering greenform. The component is then dried in a furnace, leaving the component.
    The advantages of freeze-casting over sintering are essentially cost-based. It doesn't require high pressure equipment or powerful furnaces (drying temperatures are only just above water's boiling point), yet it creates a useful product which takes the shape of the mold very accurately.

  • Emmanuel Akpan added an answer:
    Does the protective layer Al2O3 form on the surface of aluminium alloys (such as Al-Zr) like pure aluminium?

    Does the protective layer Al2O3 form on the surface of aluminium alloys (such as Al-Zr) like pure aluminium

    Emmanuel Akpan · Ambrose Alli University

    First we need to know if the Zr remains as Zr in equilibrium conditions. If an intermetallic is formed we cannot expect the Zr contained intermetallic to partake in any reaction at room temperature to form oxides rather we will have the alpha aluminium phase to react with oxygen to form the coating. The Al-Zr phase diagram is an important point to start looking at.

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