Question

In your first job, you are working for a large aerospace firm that is constructing a new regional jetliner. You are assigned the task of performing a process audit on a small heat treat company in Pennsylvania that has had several precipitation hardened spars and wing struts rejected for low hardness. During your audit, you observe that they are not properly monitoring the time that they are holding the parts at temperature. What is the condition of the aluminum alloy called?

A. Austenizing

B. Solutionizing

C. Normalizing

D. Embrittlement

E. Overaging

Answer 1

Precipitiation Hardness involves the strengthning of a material by generating finne sized impurities that obstruct the movement of dislocations.

This is acheived by keeping the alloys at elevated temperature for hours to allow precipitation to take place. If the duration for which it is kept at elevated temperature is not monitored properly it may lead to either too little diffusion or very big particles which decrease the Hardness.

So the condition of the Aluminium alloy is called OVERAGING