Elliptic vibration assisted cutting of metal matrix composite reinforced by silicon carbide: an investigation of machining mechanisms and surface integrity

Abstract

This paper aims to investigate the deformation mechanisms and surface integrity of SiCp/Al composites machined by elliptic vibration assisted cutting (EVAC). Self-designed EVAC device was applied to generate the elliptical trajectory on tool tip, which is driven by three piezoelectric actuators along different directions with phase difference. A two-dimensional (2D) microstructure-based finite element (FE) model of SiCp/Al composites was also established to research the deformation mechanisms and surface integrity in the process of EVAC, including material removal mechanisms, cutting force, surface roughness and microstructure. Systematic orthogonal cutting experiments shown that the relative position of tool-particles are changed by the time-varying cutting thickness in EVAC, leading to more obvious particle fracture during SiC particles removal process. Particle fracture appears in the area of particle clusters affected by chip lifting of tool. The intermittent cutting effect not only reduces the average cutting force, but also eliminates the scratch on machined surface caused by SiC particles entering the flank face–workpiece interface, improving the machined surface quality. Limited by the volume of material removal, 2D FE model has a high prediction accuracy for the micro-removal process of composite materials. The application of elliptical vibration is able to create the special functional surfaces. In order to increase the hydrophobicity of machined surface, larger feed rate and smaller cutting depth should be selected as far as possible.

Keywords

• Elliptic vibration assisted cutting (EVAC)
• Finite element model
• Machining mechanisms
• Surface integrity
• Metal matrix composite (MMCs)