Particulate-reinforced metal matrix composites (PRMMCs) are difficult to machine due to the inclusion of hard, brittle reinforcing particles. Existing experimental investigations rarely reveal the complex material removal mechanisms (MRMs) involved in the machining of PRMMCs. This paper develops a three-dimensional (3D) microstructure-based model for investigating the MRM and surface integrity of machined PRMMCs. To accurately mimic the actual microstructure of a PRMMC, polyhedrons were randomly distributed inside the matrix to represent irregular SiC particles. Particle fracture and matrix deformation and failure were taken into account. For the model’s capability comparison, a two-dimensional (2D) analysis was also conducted. Relevant cutting experiments showed that the established 3D model accurately predicted the material removal, chip morphology, machined surface finish, and cutting forces. It was found that the matrix-particle-tool interactions led to particle fractures, mainly in the primary shear and secondary deformation zones along the cutting path and beneath the machined surface. Particle fracture and dilodegment greatly influences the quality of a machined surface. It was also found that although a 2D model can reflect certain material removal features, its ability to predict microstructural variation is limited.

由于包含硬而脆的增强颗粒，因此难以加工颗粒增强的金属基复合材料（PRMMC）。现有的实验研究很少揭示出加工PRMMC所涉及的复杂材料去除机制（MRM）。本文开发了一种基于三维（3D）微观结构的模型，用于研究机加工的PRMMC的MRM和表面完整性。为了准确模拟PRMMC的实际微观结构，多面体随机分布在基体内，以代表不规则的SiC颗粒。考虑了颗粒破裂和基体变形和破坏。为了比较模型的功能，还进行了二维（2D）分析。相关的切割实验表明，已建立的3D模型可以准确预测材料的去除，切屑形态，机加工表面光洁度和切削力。结果发现，基体-颗粒-工具的相互作用导致了颗粒的破裂，主要发生在沿切割路径和机加工表面下方的一次剪切和二次变形区域。颗粒的破裂和渗出严重影响了加工表面的质量。还发现尽管2D模型可以反映某些材料去除特征，但其预测微观结构变化的能力有限。