Statistical Analysis of Surface Roughness in Meso Scale Ultrasonic Vibrations Assisted End-Milling (UVAEM) of Titanium Alloy (Ti-6Al-4V) under Dry, Flooded, MQL and Cryogenic Environments

Titanium is a prominent material in major industries for production of high reliability parts and components to be used under extreme conditions. However, despite unique properties, it is characterized as a difficult-to-machine element. Ti-6Al-4V is highly utilized & researched α + β alloy of titanium having various machinability challenges. Nowadays, miniaturized micro and meso scale devices and components are in demand but surface finish issues are being experienced. Thus, the analysis of surface roughness is essential for optimization and minimization of post machining processes. The hazards of cutting fluids have shifted the attention on the way to latest cooling and machining methods to reduce or eradicate them. In current research, Surface Roughness of machined Ti-6Al-4V during meso-scale UVAEM under Dry, Flooded, MQL & Cryogenic conditions is examined at various levels of machining inputs including cutting speed, feed per tooth, depth of cut (DoC), amplitude of ultrasonic vibrations and cooling conditions. The analysis showed that surface roughness is significantly influenced by machining conditions, the cooling medium, and ultrasonic vibrations. The DoC proved to be the leading factor, contributing 48.49% to surface roughness. Cryogenic cooling remained the best cooling environment to minimize surface roughness. Surface roughness is reduced by 11.76% under UVAEM in comparison with the Conventional Machining (CM), however, the effect of ultrasonic vibrations amplitude is non-linear and also results in a negative effect when it exceeds a certain threshold. For optimal results with least surface roughness, cryogenic environment along with higher cutting speed, lower feed per tooth, lower DoC and optimum ultrasonic vibrations amplitude should be adopted.