Fatigue design factors for ECAPed materials

Equal channel angular pressing (ECAP) was successfully performed on commercial pure aluminum, aluminum 6061 alloy and commercial pure copper by route BC. Tensile and fatigue (under constant stress) tests shows a significant enhancement in mechanical properties consisting of hardness, yield strength, ultimate tensile strength and endurance limit, but the ductility of the alloys reduced with employing this process. Two fatigue design factors Kl and Kh has been suggested to co-related fatigue data from coarse grained (CG) to ultra-fine grained (UFG) materials.

Research highlights▶ ECAPed die has been designed and manufactured. ▶ Fatigue and mechanical strength of three ECAPed materials have been investigated. ▶ Improvements of hardness, yield strength, ultimate tensile and fatigue strength have been achieved with applying ECAP operation. ▶ Two fatigue design factors Kl and Kh has been suggested to co-related fatigue data from coarse grained (CG) to ultra-fine grained materials (UFG). ▶ These factors are very useful for designers of components against fatigue when using UFG materials.