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  for Metal Finishing since 1989
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How to improve the fatigue resistance of aluminum

2007

I've heard that shot peening raises fatigue resistance significantly. Also cryogenic processing increases fatigue resistance.

Do you know the mechanism of the processes?

Material is 7075 T6 aluminum.

Thanks in advance.

Jang Houk
student - Seoul, Korea

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I do not know whether shot peening will solve your particular problem or work in your particular situation, Jang, but the principal is that by compressing the surface, shot peening can cause the surface to have compressive stresses. If the surface is under compressive stress before the imposition of the cyclic fatigue stresses, it is possible that it can remain compressive or at least low in the tensile range. And if the stress never gets significantly tensile, cracks will not propagate. I understand that things like the landing gear of aircraft are shot peened before plating.

Sorry, I do not know the mechanism of fatigue improvement which is claimed for cryogenic treatment. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007