Study on the predicted model and experiment of drilling forces in drilling Ti6Al4V

Abstract

Drilling is used in a very large variety of applications, which is one of the most complex manufacturing processes and is a semi-enclosed cutting process. The use of titanium alloy Ti6Al4V in engineering applications has increased in recent years, and in many of these applications drilling is one of the most critical stages in the manufacturing process. Critical issues in drilling of Ti6Al4V are often associated with large drilling forces and short life. Understanding and predicting the drilling forces occurring during drilling of Ti6Al4V would allow extending the currently used optimization methods and proposing new tool geometries and tool materials. The current paper introduces an improved mechanistic model for predicting the drilling force distribution along the main cutting edge and chisel edge of a drill, which considered the effect of feed rate. Based on the definitions of working angles, the equivalent model of drilling is developed. The effect of feed rate on the working rake angle was also investigated. Then, the drilling force model in the main cutting edge is developed based on the oblique cutting model. However, there are two different equivalent regions in chisel edge; here the drilling force model is developed based on orthogonal cutting model and plastic extrusion model, respectively. A special drilling forces distribution experiments are carried out in drilling Ti6Al4V. Good agreement between the measured and predicted drilling forces is found.