Question

Assume you have a metal alloy - an aluminum alloy for example - that has been welded and then heat treated in a way that leaves you uncertain as to the microstructure. Since the component is to be used for a critical application, you want to be sure of both the structure and mechanical properties. You want to create a single phase structure so that you can "start over" with a new heat treat cycle to more exactly and carefully create the desired properties. What type of heat treatment would you use to create the single phase structure?

Answer 1

As per the given condition the proper heat treatment process would be Precipitation Hardening. In Precipitation Hardening the alloy is subjected to three main processes

a. Solution Treatment :- In Solution treatment the alloy is heated upto a temperature at which all the alloying elements are dissolved in the solid solutioin and cant come out of phase. In the given problem since exact composition is not given though the temperature range at which alluminium alloy will be heated upto will be between 825 to 980

b. Quenching :- It rapidly cools the solutions in such a manner that Solid Solution cools in one single phase and alloying elements cannot precipitate out of the solution.

c. Aging :- Aging is done to relieve the overly caused stresses by alloying elements . by this process they precipitate out of the solution and distort and strengthen the alloy.