Parametric Investigation and Groove Quality Mapping of Nd:YAG Laser Micro-Grooving of Ti-6Al-4 V Alloy

Laser micro machining has become the method of choice for maintaining precise dimensions in advanced difficult-to-cut materials. Laser micro grooves on hard materials receive wide promotion, investigation as well as application in the aerospace and automotive industries. Previous literatures have indicated various difficulties in machining grooves with width less than 50 μm, which are significantly essential in biomedical implant micro-patterning, aerospace and automotive surface texturing, tribological lubrication control, microfluidic channels, and micro-heat transfer applications. To overcome this shortcoming an improved experimental investigation approach for fabricating micro grooves in titanium alloy (Ti-6Al-4 V) by means of Nd-YAG direct laser machining has been carried out. Micro grooves with expected width of 30 μm are machined by varying three parameters i.e. current, assist gas pressure and scanning speed. The range of each process parameter is arranged at three different levels and the experimental sequences have been planned as per full factorial design. In this study a parametric analysis has been carried out to build up quantitative relationship in between process variables and process responses. By using scanning electron microscope equipped with energy-dispersive X-ray spectroscopy pattern, the characterization of surface morphology was also performed. The results demonstrated various surface defects during machining. Based on these, a groove quality map along with machining strategy is proposed to monitor and control the surface defects along with improvement in groove quality.