关键词: 颗粒增强金属基复合材料, 应变梯度, 切削温度, 位错

Abstract: In order to gain a deeper understanding of the cutting processes of particle reinforced aluminum matrix composites, a constitutive model was established based on the strain gradient theory for 45%-SiCp/Al composites through multiphase modeling. Through the secondary development of simulation software ABAQUS, the established constitutive equation and B-W fracture criterion describing fracture were programmed into the user subroutine VUMAT using programming language, and then imported into ABAQUS for simulation analysis. Based on the cutting experiments and simulation analysis results, the changes in surface temperature, internal stress and strain, and dislocations of SiCp/Al composite materials with different cutting depths at the same cutting speed were studied. The results indicate that the modified constitutive model is more consistent with the experimental ones compared to the traditional Johnson-Cook model, and it is found that an increase in cutting depth will trigger a high-temperature gradient. The internal stress of the material will form stress concentration near the particles. A large number of dislocations appear in areas with high strain on the machining surfaces, which increases the difficulty of machining particle reinforced metal matrix composites.

Key words: particle reinforced metal matrix composite, strain gradient, cutting temperature, dislocation