There is growing demand for micro and meso scale devices in the field of optics, semiconductors and bio-medical devices. In response to this demand, mechanical micro-cutting (e.g. micro-turning, micro-milling) is emerging as a viable alternative to lithography based micromachining techniques. However, certain factors limit the types of workpiece materials that can be processed using mechanical micromachining methods. For difficult-to-machine materials such as mold and die steels, limitations in cutting tool stiffness and strength are major impediments to the use of mechanical micromachining methods. This paper presents a Laser Assisted Mechanical Micromachining (LAMM) process that involves highly localized thermal softening of the hard material by focusing a solid-state continuous wave/pulsed laser beam in front of a miniature (100μm–1mm wide) cutting tool. By suitably controlling the laser power, location and spot size, it is possible to cause a sufficiently large decrease in the strength of the work material and thereby minimize catastrophic tool failure and lower tool forces and deflection. This paper presents the results of experimental characterization of the LAMM process. Micro scale grooving experiments are conducted on H-13 mold steel (42 HRc) in order to understand the influence of the laser variables (laser power, beam location with respect to tool) and cutting parameters (depth of cut, cutting speed and tool width) on the cutting forces and surface finish. The results show that, for a given cutting condition, these process responses are significantly influenced by the laser variables. Plausible explanations for the observed trends are given.
