Investigation on generation and features of burn defect in Ti6Al4V milling

Owing to the low thermal conductivity and elasticity, cutting burn defect is easy to produce in machining titanium alloy Ti6Al4V. Since the excessive cutting temperature caused by tool wear is the key factor for cutting burn, the relationship between the tool wear rate and cutting burn was studied. In this research, the dynamic process of cutting burn was investigated through wear experiments of cutting tool. The relationship between the tool wear and cutting burn defect were also studied. Then, the microhardness of workpiece was evaluated to analyze the unfavorable effect when the burn defect is occurred. Finally, the microstructure of titanium alloys was observed by scanning electron microscope (SEM) in the dynamic process of burn defect. The α phase particles are coarsened and the mechanical properties of materials are degenerated.