Experimental investigation of the ultra-precision turning capability of PVD ZnSe

ZnSe is widely used in infrared optical systems because of the good optical characteristics in 0.5~22μm and the good processability. Physical Vapor Deposition(PVD) of ZnSe is good at no pollution in production process, lower price, etc. Infrared optical parts should be made by single point diamond turning or single point diamond fly-cutting after the experimental investigation of the ultra-precision turning capability of PVD ZnSe. The orthogonal experiment of ultra-precision turning PVD ZnSe was done at first, then the smooth turning surface and the rough turning surface were observed by metallographic microscope and 3D profilometer, and the mechanism of the defects on the turning surface was discussed. The result shows: the quality of ultra-precision turning surface of PVD ZnSe was restricted by the grain size and the distribution of the grain which could easily cause the variegated macula at the grain size, rising the spindle speed, reducing the feed rate and reducing the cut depth could make the quality of ultra-precision turning surface better and reduce the roughness Ra value lower, the roughness Ra value of the smooth turning surface was reached 3~4nm which is enough to the infrared optical image systems currently by using the optimization of parameters.