Temperature prediction model of bone drilling considering the effect of tool wear

Biomass bone is biologically active and sensitive to heat; excessive temperatures would destroy the biological activity of the bone tissue or even cause bone necrosis. Therefore, it is vital to control the drilling temperature in clinical surgery for internal fixation of fractures. This paper focused on the influence of tool wear on the drilling temperature during the bone drilling process. The effect of three drilling parameters, the tool diameter, machine spindle speed and tool feed speed, on three dynamic characteristics, the drilling force, drilling temperature and tool wear, was investigated through bone drilling experiments. A prediction model of the bone drilling temperature considering the effect of the amount of wear was established based on Archard wear theory and the heat source method, and was in good agreement with the experimental results. The predicted results showed that worn bits produced drilling temperatures up to 3.4°C higher than those of new bits, and the maximum error in the prediction of the drilling temperature was 11.04%. The temperature model better extended the applicability of the existing temperature models.