Surface Texture Investigation in High Speed Flat End Milling of Ti- 6Al-4V

Aerospace alloy Ti-6Al-4V is classified as “difficu lt-to-cut” material. But with their low mass, high strength, and excellent resistance to corrosion, ti tanium alloys solve many engineering challenges. In this study, high speed end milling of Ti-6Al-4V was applied as a pot ential machining technique for obtaining better sur face finish using small diameter tools applying high rpm to fa cilitate the application of micro-meter level feed and depth of cut to ensure super finishing that could avoid the need of further grinding and polishing. Machining was p erformed on a Vertical Machining Centre (VMC) with a high speed attachment (HES 510), using cutting speed, depth of cut, and feed as machining variables. Three level full facto rial designs were followed for machining operations . Minimum average surface roughness ( Ra) value of 0.13 µm was obtained which is within the acceptable range of avoiding grinding and polishing operations. Surface texture was investigated and no alternation in microstructu res was observed and there was no presence of white layer o n the machined surface. A strain hardened zone was observed beneath the machined surface with a small temperatu re-softened zone just below the machined surface.