High effective laser assisted diamond turning of binderless tungsten carbide

Abstract

Laser assisted diamond turning is a potential approach to increase the surface finish quality on the hard and brittle materials and to improve diamond tool life. A high effective laser assisted turning (HE-LAT) method is proposed in this article, which guides the laser beam refracts at rake face, cutting edge, and total reflects at flank face. The HE-LAT method possesses effectively improved laser heating efficiency and can be employed to achieve the homogeneous optical surfaces on hard and brittle materials. The theoretical thermomechanical analysis and systematical experimental investigations are conducted to optimize the machining parameters of the proposed HE-LAT method. The nanoscale constitutive model of binderless WC has been obtained based on the high-temperature nanoindentation tests, which facilitates the workpiece thermal filed prediction cooperating with the relevant HE-LAT FEA model. The experimental results indicate that the HE-LAT method can help to eliminate the surface fluctuation effectively, thereby achieving better surface finish quality down to 0.92 nm in Sa on binderless WC. The diamond local graphitization can also be prevented owing to the lower essential laser power and suppressed chip adhesion problem. Furthermore, the workpiece residual stress can be greatly decreased owing to the smaller thermal-affected area of HE-LAT method.