Simulation study of the influence of cutting speed and tool-particle interaction location on surface formation mechanism in micromachining SiCp/Al composites

The SiC particle-reinforced aluminum matrix composites are widely employed in different fields due to their outstanding performance. An in-depth understanding of their surface formation mechanism will pave a solid foundation for the widespread application. In this paper, two-dimensional microscale finite element models composed of a SiC particle and Al2024 matrix are established. The effects of cutting speed and tool-particle interaction location on particle behavior and surface formation during micromachining process are investigated. The location is categorized into two scenarios (tool cuts the upper and the lower part of the particle) and different cutting speeds for each scenario are presented. As a result, in scenario one (tool cuts the upper of the particle), the particle fractures by brittle fracture while the depth of surface defects decreases with increase of the cutting speed; in scenario two (tool cuts the lower part), the removal way of the particle changes from being pulled out to being crushed as the speed increases. The von Mises equivalent stresses of the particle and the matrix at the two scenarios are analyzed to explain these phenomena. Experimental measurements of micromilled surfaces are compared with simulation, showing promising results.