Surface Morphology and Wall Angle Comparison of Microchannels Fabricated in Titanium Alloy Using Laser-Based Processes

The increase in the usage of titanium alloys for micro-engineering applications has driven the demand for improved micromanufacturing processes. Laser-based microfabrication processes such as direct laser ablation (DLA), laser-induced plasma micromachining (LIPMM), and magnetically controlled laser-induced plasma micromachining (MC-LIPMM) are promising technologies to fill this technological gap. In this paper, we evaluate microchannels fabricated in Ti6Al4V substrates using laser ablation, LIPMM, and MC-LIPMM. Scanning electron microscope (SEM) images and 3D scans of the channels were used to compare the surface morphology and channel geometry for different feed rates and number of laser passes. Wall angle measurements show that the LIPMM processes yield channels with steeper walls and smoother walls in comparison with the channels fabricated using direct ablation. The clear morphological differences on the surface finish of the walls made by direct ablation and using laser-induced plasmas hint at the differences in material removal mechanisms between these manufacturing methods.