Simultaneous five-axis milling of titanium alloys for turbomachinery components

The high cost of manufacture led the aerospace industry to look for high performance machining techniques for difficult-to-cut materials like titanium alloys. Although considerable progress was obtained in the past regarding the machining rate, the results remain behind expectations. The poor cutting performance is mainly caused by the low thermal conductivity and extremely high thermal stability of these materials. In this context, simultaneous five-axis milling offers large technological and economical potential for flexible manufacturing of sculptured surfaces. Due to its specific characteristics such as adjusting constant and favorable tool load by guaranteeing constant cutter engagements and an optimal fit of the milling tool to the contour, low machining times can be realized with high surface qualities. This paper focuses on the development of these potentials for manufacturing titanium engine blades based on various investigations at the Fraunhofer IPT. Special interest is pointed to the systematic analysis of the correlation between machining parameter and surface integrity properties including the verification of theoretical approaches and FEM simulation.