Precision micromachining of cemented carbide using picosecond pulsed laser (Zero-cut-combined machining for forming three-dimensional microstructures)

Abstract

A simulation technique adaptable to calculating a laser-machined profile was proposed to develop microfabrication techniques for a cemented carbide using a focused picosecond pulsed laser. An experiment to obtain a defocus diagram, which shows the relationship between defocus and removal depth, was conducted by shifting the focal point upward to the work surface. The concept of zero cut, in which the laser beam was scanned repeatedly in the same path, was proposed, and it was verified using the proposed simulation technique that zero cut is useful for residual stock removal. In addition, a simulation technique adaptable to calculating both the laser-machined profile and the machining process conditions was developed using the defocus diagram as a machining condition. It was verified through a machining test by fabricating half-cut columns with radii of 30 and 50 μm formed on the upper half of a large base column that the dimensional error of the columns was less than 1% and the surface roughness was less than 0.1 μmRz. This means that the simulation technique using the defocus diagram as a machining condition is useful for the microfabrication of the cemented carbide using the focused picosecond pulsed laser.

Keywords

• picosecond pulsed laser
• defocus diagram
• zero cut
• simulation technique
• precision microfabrication