Cutting Performance Of Laser Assisted Diamond Turning Of Calcium Fluoride With Different Crystal Orientations

Single point diamond turning of single crystal CaF2 using the mu-LAM process is studied. We focus on how crystal orientation of the workpiece can influence tool wear and efficiency of the cutting process. Cutting experiments were performed on single crystal CaF2 with < 100 >, < 111 >, and < 211 > crystal orientations. The tool failed at the smallest cutting distance for < 111 > crystal orientation, whereas tool failure on < 100 > orientation occurred at the longest cutting length. Tool life for cutting < 211 > and < 111 > crystal orientations was found to be 92% and 67%, respectively, of that of tool life during cutting < 100 > orientation. To explain the results obtained, an anisotropic model based on Schmid's law was used. It is shown that an inverse correlation between the resistance to plastic deformation and maximum cutting distance without inducing any brittle fracture can be established. (C) 2021 Optical Society of America