Can we model alloys? That is, can we say that if you take so much iron and so much molybdenum, etc., the tensile strength of the resulting alloy will be X, or do we actually have to make the alloy and test it? If we can predict the properties, are these predictions a guess based on empirical data or is there a mathematical model that will describe it? Can we accurately predict the properties of other materials without synthesizing them?
Thanks for your help,
Rob
I do not know the answer to your questions. However, much of the non-emperical metalurgy work would be done on the chemical level (although I guess that’s kind of by definition). Bond types, intersticial or substitution, and the crystal latice shapes formed are inherent to the strength of the resulting alloy. So, although strength properties in general can be modeled, emperical evidence is most certaintly needed before the metal is used for a part.
I’m sure somebody more knowledgeable (and a better speller) will come along shortly.
I’ve spent years studying metallurgy, and it’s not easy to give an informative short answer to this, but I’ll try.
First of all, the properties of a metal alloy (including yield strength, ultimate tensile strength, elongation, hardness, resistance to creep, resistance to corrosion, resistance to fatigue, etc.) are dependent not only on the alloying elements, but also on the processing and heat treatment and (to a usually lesser extent) the machining.
Secondly, it would not be a good idea to ‘model’ a new alloy and then forge it or cast it, make it into a part, and then put it into service without any testing.
Most of the useful and affordable alloys have been well studied and understood so there is no need to predict their properties since they are already known and documented in ASM Handbooks and other texts. However, metallugists would be able to make reasonable model of a new alloy’s properties in many cases but unusual things somtimes happen in specific alloys under specific service conditions. For example, look up or Google: sigma phase embrittlement in 304 stainless steel.
As it is, samples of most metal parts manufactured especially those meant for critical applications undergo some form of testing as a means of quality control.
disclaimer: I am a licensed EIT and forensic metallurgist, but I answer your questions only informally. As part of my job, I perform and supervise mechanical testing of metals on a daily basis.
Thanks for your replies. Do you know anything about non-metals? It sounds like we have practically exhausted the field when it comes to developing metal alloys, but I am guessing that materials science continues to advance by studying things like oxides, organic molecules, etc. Do materials scientists develop their ideas with a model before they try and synthesize new materials? Also, with respect to metals, can you model things like heat treatment for a previously unsynthesized alloy?
Thanks,
Rob