Research on micro-cutting mechanism of CoCrFeNiAlX high-entropy alloy fiber-reinforced aluminum matrix composites

This study aims to investigate the micro-cutting mechanism of CoCrFeNiAlX short fiber-reinforced 7A09 aluminum matrix composites. By setting different material constitutive models, material failure, and evolution criteria for each reinforcing phase, orthogonal cutting simulations were conducted at four typical angles (0 degrees, 45 degrees, 90 degrees, 135 degrees). The effects of fiber angle, volume fraction, and Al element content on cutting forces, cutting temperatures, chip morphology, and residual stresses were investigated under different cutting parameters. Micro-cutting experiments were also conducted to verify the micro-cutting of CoCrFeNiAl0 fiber-reinforced aluminum matrix composites. The results show that the cutting depth is positively correlated with cutting forces, and the increase in cutting force is approximately 51% when the cutting depth increases from 30 to 60 mu m. Both cutting forces increase and then decrease with increasing cutting speed and fiber angle. The cutting forces decrease first and then increase with the increasing Al element content in the fibers. Cutting forces are positively correlated with the volume fraction of fibers in the workpiece, and compared to the workpiece without fibers, the cutting force increases by approximately 22% at a fiber content of 15 vol%. The cutting temperature gradually increases with increasing cutting depth and cutting speed. The cutting temperature first increases and then decreases with increasing fiber angle, and when the fiber angle increases from 45 to 135 degrees, the cutting temperature decreases by 44%. The cutting temperature first decreases and then increases with the increasing Al element content in the fibers. The integrity of the cutting surface is positively correlated with cutting depth, Al content in the fibers, and fiber volume fraction. Multiple and irregular chip fractures are observed when the fiber angle is 45 degrees or 90 degrees, while the integrity of the chips improves when the fiber angle is 0 degrees or 135 degrees. The chip layer exhibits block-like fracture when the fiber volume fraction reaches 15 vol%. The peak residual compressive stress is negatively correlated with cutting depth, cutting speed, and Al content in the fibers, and the peak position moves away from the machined surface with the increase of the first two factors. The peak residual compressive stress is positively correlated with fiber angle and fiber content in the workpiece, and when the fiber angle is 135 degrees or the volume fraction is 15 vol%, the peak position is significantly away from the machined surface.