how to figure out HAZ in aluminium alloys

I venture to guess, grain growth, reduced hardness, and growth of precipitates, depending on the alloy and original condition such as heat treatment or cold work.

So if we were to investigate this ourselves, we could look down a microscope at a polished and etched sample and look for grain growth (larger grains) - or we could do a micro-hardness traverse looking for hardness change on change in precipitates?

Richard Smith

Thanks for your answer i guess precipitation of unwanted alloy could change the hardness in the HAZ and give solution to our problem. but grain growth may not be a possibilty i guess. i will check it out by carrying out a Al welding.