Experimental and finite element investigation of high-speed bone drilling: evaluation of force and temperature

Currently, in the world of orthopedic surgeries, bone drilling is prevalent to hold broken bones and for bone implantation. Increase of bone temperature higher than 47 °C leads to a notorious phenomenon named thermal necrosis, which eventuates in cellular death of the bone tissue. Consequently, there is a chance for a loose implant after the operation. In this paper, for the first time, a 3D thermo-mechanical finite element (FE) model of a high-speed bone drilling process was introduced to study process force and temperature. Then comparing experimental results with numerical ones, the influence of the rotational speed and feed rate on both process force and the temperature was investigated. This study revealed that in high-speed drilling of the bone with a raise in rotational speed, due to different chip deformation and reduced chip thickness, both process force and temperature reduce remarkably. According to experimental and numerical findings, the optimum bone drilling setting was achieved with a tool diameter of 2 mm, the rotational speed of 12,000 rpm, and feed rate of 50 mm/min in which force and temperature were 14.11 N and 32.45 °C, respectively. The findings of this study can be an excellent help for robotic surgeries in order to decrease drilling force and temperature and ultimately squeezing of the recovery period.