Surface integrity enhancement of ZL109 aluminum-silicon piston alloy employing the forward and reverse finish cutting method

The machined surface integrity has significance on fatigue life. The step-by-step feed cutting is put forward and adopted to machine ZL109 aluminum-silicon piston alloy. In addition, the forward and reverse finish cutting is also proposed to improve the machined quality and fatigue life. The result indicates that the step-by-step feed cutting can effectively avoid scratching and decrease surface roughness, bring about the compressive residual stress, and improve machined quality. Moreover, there is smaller elastic-plastic recovery and thermal expansion on the machined surface, when the step-by-step feed cutting is adopted, so that the machining dimension accuracy can be ensured perfectly. The forward and reverse finish cutting can effectively decrease the surface roughness and the tensile residual stress due to the thermal stress. So the larger the cutting thickness is, the smaller surface residual stress is, when the cutting depth is 0.15–0.30 mm in the forward and reverse finish cutting. It can improve the machined quality of ZL109 aluminum-silicon piston alloy and the fatigue life when the reasonable cutting parameter is adopted. Those results have an important practical significance.