Ultraprecision laser-assisted diamond machining of single crystal Ge

Abstract In this paper we present an experimental study on ultraprecision machining (UPM) of single crystal Ge using the μ-LAM process. The material is oriented with the cutting plane normal to the direction. It is shown that increased hydrostatic pressures on the surface during cutting by increasing the tool radius and negative rake angle can aid in enhancing ductile material removal from the surface. It is shown that the cutting performance can be increased by approximately 400% using the optimal tool geometry. It is also shown that the optimal tooling geometry with a steep negative rake angle, i.e. −65°, is capable of producing repeatable surface form and finish over long cutting distances. Finally, it will be shown that the laser beam used for μ-LAM, with the right amount of power, produces surfaces that are under less post machining residual stresses.