Evaluating the Subsurface Microstructure of Machined Ti-6Al-4V

Engineering the desired surface properties of a machined component enables lightweight design and improved functional performance. This research reports on the results of microstructural, mechanical and residual stress investigations of machined Ti- 6Al-4 V under varying cutting conditions. The performance of a machined component depends on the resulting microstructure influenced by the mechanical and thermal loads during machining operations. Microstructural analysis through optical microscopy of the subsurface of the machined edge is evaluated and compared to depth profiles of residual stress induced in the subsurface of the component. The effect of cutting parameters on microstructure is assessed by varying the cutting speed and cut depth, while keeping the feed rate constant. The near surface deformation angle and deformation depth was found to be a function of cutting speed and cut depth.