37. Machining of High-Quality Microchannels on Ti6Al4V Using Ultra-Short Pulsed Laser

Design and development of microscale features are found to be an evolving field of interest in various manufacturing industries including aerospace, automobile, spacecraft, and biomedical. Even though there are various advancements in ultraprecision machining techniques, accomplishment of microscale features with higher geometrical quality is still found to be the critical area of research, which needs to be explored as it affects the performance of the micro-components. Hence, in the present work a detailed investigation on the lasing parameter with respect to the surface integrity of microfeature has been carried out, and it is discussed in detail. Microfeatures in the form of channels and circular profile were machined on Ti6Al4V using ultra-short pulsed laser trepanning technique at various scan speeds. All the laser processed surfaces were analyzed using an optical microscope and 3D profilometer to evaluate the formation of heat-affected zone. Experimental results show a significant reduction in the width of heat-affected zone with the increase in scan speed from 2 to 2000 mm/s. Further analysis on the profile of the microfeature depicted the occurrence of higher order distortions at scan speed of 2 mm/s, which can be attributed to the occurrence of re-solidification layer and debris entrapment. A benchmark can be set from the current observations for the future investigations in selecting the optimal scan speed for achieving high-quality microfeatures on Ti6Al4V.