Abstract
Roller burnishing (RB) and friction stir processing (FSP) were applied to a cast aluminum alloy, AC4CH-T6, to improve the fatigue properties. In order to investigate the effects of RB and FSP on the fatigue properties, fatigue tests have been performed using the roller burnished, the friction stir processed and the untreated specimens. The RB specimens exhibited higher fatigue strength than the untreated specimens. This improvement is attributed to the increase in hardness and compressive residual stress by RB. On the other hand, in the FSP specimens, fatigue strengths were also significantly improved compared with the untreated specimen due to the elimination of casting defects by the FSP.
