Micromechanical insights into hard rock cutting by single diamond grains in surface-set diamond core bits: a numerical simulation study

Abstract To investigate the influence of different process parameters on the grinding of hard rock by a single diamond grain in a surface-set diamond bit and to understand the microscopic material removal mechanisms, a three-dimensional simulation of a single diamond grain scratching rock was conducted using finite element analysis software to simulate the actual cutting process and the reliability of the model was verified through single-grain cutting experiments. The study explored the variation patterns of cutting force and specific energy with rock under different influencing factors, such as grain shape, grain size, and cutting depth. Additionally, a microscopic analysis of the rock material removal mechanism during the cutting process was performed, based on the cutting force and specific energy with rock, range analysis and variance analysis were conducted. The results indicate that: (1) The cutting depth is not directly proportional to the cutting efficiency, the optimal ratio of cutting depth to grain size for regular octahedra and truncated octahedra abrasive particles is around 0.15, while for cubic abrasive particles it is around 0.167. (2) The order of the influence of different influencing factors on rock breaking specific energy is grain shape, cutting speed, cutting depth and grain size, successively. (3) Within the parameter range specified in the simulation, the optimal parameter combination is: cutting depth of 0.2 mm, grain size of 1.6 mm, cube diamond and cutting speed of 0.2 m s − 1 . Among them, the ratio of cutting depth to grain size is around 0.125.