Precision turning of SiCp/Al composite material surface with ultrasonic elliptical vibration and its surface physical and mechanical properties

Aluminum matrix silicon carbide (SiCp/Al) composite is a typical high brittle-hard material, which is prone to surface defects such as matrix tearing and particle breakage during the machining process. In this study, ultra-precision turning was carried out on SiCp/Al composite with a volume fraction of 35%. The influence laws of two machining conditions—conventional precision turning and ultrasonic elliptical vibration-assisted turning (UEVAT)—on the surface hardness, thickness of the metamorphic layer, morphology and microhardness of the metamorphic layer after machining were investigated. The results show that, compared with conventional precision turning, UEVAT can ensure the surface hardness of workpieces to a certain extent. Within the parameter range studied, the surface hardness is increased by approximately 9.5%–17.7% with the change of spindle speed, 3.5%–13.4% with the change of feed rate, and 6.2%–10.1% with the change of tool nose radius. Additionally, this method reduces the thickness of the metamorphic layer, ensures the morphology and microhardness of the metamorphic layer.