posted by ChemGeek .
In chem lab we did an experiment with two rods, one that was martensite (one that made a thud sound) and the other austenite (one that made a ping sound). We put both of the rods in N2 and another time we put it in boiling water. Each time the rod would make an opposite sound of what it is at room temperature (the martensite sounds like PING after heated and cooled & austenite sounds like THUD when heated....but when their temperatures go back to room temp, martensite goes back to sounding like thud, and austenite goes back to sounding like ping)...why is that?
...hope this makes sense