A Theoretical Analysis on Bone Drilling Temperature Field of Superhard Drill

To overcome strong drilling force and over high temperature during orthopedic surgery, the four medical drills with different geometrical shapes by using superhard materials were designed. The bone drilling temperature field of superhard drill was theoretical analyzed. Results showed that brazed step drill has the most ideal drilling temperature. It controls the maximum bone temperature below 47°C even under dry drilling. The maximum bone temperature of brazed twist drill is a little higher than 47°C. With appropriate cooling method, brazed twist drill also could provide ideal effect. On the contrary, drilling temperatures of common twist drill, brazed abrasive drill and brazed PCBN superhard drill increase successively. All of them are far higher than the critical temperature of osteonecrosis. The maximum temperatures of brazed step drill, brazed twist drill, common twist drill, brazed abrasive drill and brazed PCBN superhard drill under steady state at about 45.9°C, 61.5°C, 70.5°C, 101.2°C and 113.2°C, respectively. Brazed step drill shows the lowest drilling temperature, followed by brazed twist drill, standard twist drill, brazed abrasive drill and brazed PCBN superhard drill successively.