EDM Effects on Fatigue Strength
EDM Effects on Fatigue Strength
(OP)
I'm looking to find if anyone has any background or can point me in a direction to find a resource that addresses the effects of wire and/or plunge EDM on the fatigue strength of high strength materials.





RE: EDM Effects on Fatigue Strength
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: EDM Effects on Fatigue Strength
EDM identifications have been known to cause failure of carbide punches and other die tooling parts.
One study my company did shows a 50% reduction in cycle life with EDM vs PhotoEtching. (resonant dwell double bend testing)
nick
RE: EDM Effects on Fatigue Strength
this way there is no reduction in properties.
regards
richard
RE: EDM Effects on Fatigue Strength
Yes thats how our carbide tools are made. However at one time the identification of the details was also edm into the surface. this often times caused a critical failure of the component.
nick
RE: EDM Effects on Fatigue Strength
There are two practical ways to combat the effects of the EDM white layer. The method that you choose will depend upon the material in question and the limitations of your design. As suggested above, a final grind of the part after EDM will remove the white layer, and eliminate the problem. Another method that is commonly used on hardened high speed and tool steel parts that cannot be surface ground after EDM is to stress relieve the parts. This usually amounts to tempering back the white layer to give it some amount of ductility. As long as a suitable temperature is selected, it should not significantly reduce the hardness of the part.
What material are you using, and at what hardness? This information may allow us to provide you with some more detailed recommendations.
Maui
RE: EDM Effects on Fatigue Strength