Ultraprecision ductile mode machining of glass by micromilling process

Abstract

Glass is considered as a difficult-to-machine material because of its susceptibility to brittle fracture during machining. To avoid brittle fracture and achieve superior surface finish, glass must be machined in ductile mode. Mostly, ductile mode machining is performed by a single point cutting tool. This paper presents the results of an experimental study to achieve ductile mode machining of glass by micromilling process. Fracture-free slots have been cut in soda-lime glass workpiece by micro-endmilling. Experimental results have established that fracture-free slots can be machined in glass by micromilling process within the controlled set of cutting conditions. These cutting conditions are conducive to highly compressive hydrostatic stresses developed in the cutting zone to suppress the crack propagation during machining. The feed per edge and the axial depth of the cut have been identified as the critical factors for the ductile–brittle transition in microcutting of glass by milling process.