Atomic simulation study on the effect of defects on nano-cutting mechanism of single crystal copper

Due to the high surface roughness of the parts produced by additive manufacturing (AM), the subsequent mechanical processing is required. The combination of additive manufacturing and micro/nano processing is the development trend of hybrid manufacturing in the future. In this work, the molecular dynamics simulation is used to study the effect and mechanism of different types of defects on copper cutting performance, including pore, Cr precipitate and diamond inclusion. The results show that the presence of defects leads to a decrease in the quality of the machined surface, while pore and diamond inclusion could lead to the appearance of deep holes on the machined surface. The phenomenon of sticking knife caused by stress concentration and high temperature at the tool tip is observed during the simulation in the model with Cr precipiate. The addition of defects causes a change in the horizontal cutting force. The highest force emerges during the simulation in the model with diamond inclusion. Defects in the copper substrate could reduce surface quality. Precipitate and inclusion could increase the stress near the tool so as to exacerbate tool wear and reduce tool life. Therefore, it 's necessary to decrease the number of defects in the matrix and to improve its cutting resistance.