Stress and grain size dependence of fatigue fracture mechanisms in 6063 aluminum alloy

摘要

The purpose of the present study is to creste a better understanding of the fatigue behaviour in 6063 aluminium alloy. Rotating bending fatigue teats have been conducted using smooth specimens in laboratory air at ambient temperature. It was found that crack initiation site and small crack growth path depended strongly on stress level. Particularly, the stress dependence of crack initiation site largely changed at a certain stress level, which appeared to be related to the morphological change of the S-N curve. Additional fatigue tests were performed using materials with different grain sizes and the grain size dependence of fracture mechanisms and associated S-N characteristics are further discussed.