An integrated toolpath and process parameter optimization for high-performance micro-milling process of Ti-6Al-4V titanium alloy

Titanium alloys such as Ti-6Al-4V offer biocompatibility, corrosion resistance, and superb mechanical properties and are considered the most important metallic biomaterial for medical applications. However, mechanical machining of titanium alloys is still highly difficult and even more challenging for micro-scale machining such as micro-milling. Severe burr formation and rapid tool wear create significant problems such as poor surface roughness. In order to improve the performance of micro-milling Ti-6Al-4Valloy, this study proposes an integrated method in selecting the toolpath and optimum process parameters which can meet micro-machining requirements and constraints. Controlled micro-end-milling experiments for measuring burr formation and surface roughness, finite element simulations for predicting forces and tool wear, and mathematical modeling and optimization techniques have been utilized for determining optimum toolpath strategy and process parameters. Based on the micro-end-milling tests on a circular thin rib feature, process optimization results are validated and indicate a significant improvement in process performances in terms of minimizing burr formation, maximizing tool life, and surface quality.