Optimization of multi-step cutting strategies for SiCp/Al composites: A thermo-mechanical coupled simulation and experimental study

• A thermo-mechanical coupled multi-step orthogonal cutting model for SiCp/Al composites was successfully established. • The two-step cutting strategy (60–20) can achieve surface quality comparable to that of a more complex three-step process (50–25-5). • The cumulative strain at material points during the cutting process is revealed, along with the identification of the characteristics of the loading cycles Due to the low material removal rate of SiCp/Al composites, multiple cutting passes are often required to meet final dimensional requirements. Therefore, enhancing machining efficiency without compromising surface integrity has emerged as a pivotal challenge. Accordingly, this study developed a thermo-mechanical coupled multi-step orthogonal cutting model and systematically analyzed the optimization effects of multi-step cutting strategies on the machining performance through experimental validation. Six cutting schemes were designed for a total cutting allowance of 80 μm, with focused evaluation of key characteristics including surface roughness and residual stress. The model’s accuracy was verified by comparing simulation and experimental data of cutting forces, temperatures, surface defects, and chip morphology. Results indicate that among five two-step cutting strategies, the 60–20 scheme achieved the lowest surface roughness Sa (93.831 nm), comparable to the 50–25-5 three-step scheme (88.51 nm), with milder surface damage. Moreover, the sequential cutting operations generated compressive residual stresses in machined surfaces, with the 60–20 strategy producing more significant compressive residual stresses. These findings demonstrate the feasibility of replacing three-step processes with two-step cutting strategies, providing important insights for achieving high-efficiency and high-quality machining of SiCp/Al composites.