Effect of Milling Parameters on Surface Roughness for High-Speed Milling of Pre-Sintering Zirconia

Zirconia has been widely concerned in dental restoration duo to its excellent properties, but its high hardness make direct milling inefficient, while pre-sintering zirconia has good machinability. By single factor experiment in high-speed finish milling on 900°C pre-sintering zirconia, effect of four milling process parameters’ change on surface roughness was analyzed, and process sensitivity and relative sensitivity were put forward to compare the effect degree and to optimize milling parameters’ domains respectively. Roughness models are established on each parameter, and analysis results show the effect degree in order of spindle speed, feed engagement, cutting width, and cutting depth, spindle speed in them is a main factor. Based on relative sensitivity, milling parameters stability domain and instability domain are presented.