Dynamics and stability analysis in end milling of aero-engine casings considering material removal effect

During the milling of thin-walled parts, the dynamic characteristics of the process system constantly vary with the material removal, which also have a significant impact on the chatter stability of the process system. The influence of material removal effect on the dynamics and stability in end milling of aero-engine casings is studied. Firstly, the material removal process is divided into several cutting lines and several cutting segments by analyzing the geometry and processing technology of the workpiece. Secondly, the calculation methods of the dynamic evolution and stability limits are developed. And the material removal effect is investigated in one single cutting line as well as in different cutting lines. The results show that the dynamic characteristics of the workpiece have a small reduction in a single cutting line but have a big change in different cutting lines, and the stability lobe diagram will have a small offset towards the left inferior side in a single cutting line but present a staggered case in different cutting lines. Then it is difficult to optimize the cutting parameters for the entire milling process. Therefore, an optimal selection approach of cutting parameters based on single line toolpath is proposed to suppress cutting chatter in the whole material removal process. Finally, several milling and hammer impact tests are carried out to validate the feasibility and effectiveness of the presented method.