Abstract: To optimize the parameters of plunge milling of titanium alloys and provide an experimental basis for milling force control, mathematical models of threedirection milling forces for plunge milling of titanium alloy TC11 are built by three factors and four levels orthogonal experimental method, and multivariable linear regression method is used to conduct the numerical fitting. Based on these models, the absolute and relative sensitivities of threedirection milling force with respect to milling speed, feed per tooth and milling depth are analyzed. The effect of milling parameters on milling forces is studied. The results show that in plunge milling of titanium alloy TC11, the threedirection milling forces increase with increasing milling speed, feed per tooth and milling depth, but the influence degree is different. The zdirection milling force is more sensitive to all milling parameters variations than the xdirection and ydirection milling force. The threedirection milling forces are all more sensitive to milling depth than feed per tooth,least sensitive to milling speed.

Key words: sensitivity analysis, titanium alloys, plunge milling, milling force, milling parameters