Mechanism of the coupling effect of pulse laser remelting and ultrasonic vibration in suppressing surface/subsurface defects and improving wear resistance of Al-50Si

Abstract

Al-50Si is promising for electronic packaging and automotive lightweighting. However, Si particles cause cutting defects, reducing wear resistance. Thus, pulse laser remelting ultrasonic vibration composite cutting was developed. The key to effectively suppressing particle fracture and stress concentration, reducing surface roughness and subsurface damage, and enhancing wear resistance is to set the ultrasonic cutting depth based on the remelting layer thickness. When the laser pulse width is 120 ns, the power is 25 W, and the cutting depth is 40 μm, the roughness decreases to 0.121 μm.The residual stress drops to −9.6 MPa. The wear depth of the surface in the wear test is reduced to 4.43 μm. The wear mechanism is abrasive wear. The wear resistance is significantly improved.