I received the following question:
I have an inquiries. I would like to perform steel shot peening process on Aluminum alloy 5083 with cast shot s110 and S230. Could you give me any sugguestion to control the process which required to achieve intensity and coverage as below: 1. with s230, intensity=0.28mm coverage=200% 2. with s110, intensity=0.20mm coverage=200% Does cast shot contiminate aluminum alloy. any suggestion to clean the contamination? Thanks

I would advise to be careful with such combination. If any iron oxide is present in your shot you may have a fire risk (termite like reaction).

In AMS2430 section 3.5.4 it is specified that aluminum alloy peened with steel shot has to be cleaned with a suitable method. One option you could use is an etch dip.

Steel shot would not be expected to react chemically with an aluminium alloy. There will, however, be physical contamination as fragmented steel particles become embedded in the aluminium alloy - these are extremely difficult to remove. Aluminium is known to reduce iron oxide - the "Thermite Process". This can only be initiated at very high temperatures - such as are induced by igniting a magnesium strip in a mixture of iron oxide and aluminium particles.