Investigation on fatigue property of the A6N01 high strength aluminum alloy

摘要

The fatigue fracture and the microstructure of A6N01 high strength aluminum alloy were observed by OM, SEM and TEM, and the low cycle fatigue properties were tested and analyzed. The results of experimentation show that the low cycle fatigue life of A6N01 high strength aluminum alloy is 1.061 x105 cycle in R=0.1, f=97Hz, and δmax=0.75δb. The tensile strength is 308MPa. The fatigue fracture is composed of the initiation zone, the propagation zone, and the sudden fracture zone, which is characteristic of a mixedtype fatigue fracture. The fatigue crack initiates in the surface of A6N01 aluminum alloy sample, while there is no fatigue striation in fatigue crack propagation zone. The β (Mg2Si) transitional strengthening phases are precipitated in A6N01 aluminum alloy, and mostly distributed in grain boundary. The diameter of p strengthening phase is fine, about is l0nm. There is none precipitated zone in width nearby the grain boundary.