Effect of Acceleration between extreme temperatures on metals

[scerab]

I know that heat increases the velocity in which the atoms move with in a solid substance that leads to farther expansion, and cooling does the opposite. My question how ever is this: will an alloy or metallic substance (say Iron) crack or break via accelerated heating then rapid cooling?
Thank you in advance

 

[Astronuc]

It's usually differential thermal expansion in case of heating or differential thermal contraction in which internal stresses occur that leads to cracking, or perhaps more accurately propagation of an internal flaw or defect. Rapid quenching doesn't necessarily produce cracking.

 

[nicky nichols]

A long time ago I was given a sample of a very strange alloy (ultra-low hysteresis electromagnetic torque sensor). It had to be machined at very high speed and it could not take any form of heat treatment. I can't remember what it was, but in any case, it is best forgotten!