Surface integrity in micro-grinding of Ti6Al4V considering the specific micro-grinding energy

Abstract

Surface integrity is one of the most significant quality aspects of micro-grinding of difficult-to-cut materials. On the other hand, specific grinding energy is a fundamental parameter for describing the micro-grinding process. This paper addresses the surface integrity of the micro-ground surface of a titanium alloy under different cutting speeds and feed-rate-to-depth-of-cut (vw/ae) ratios at the same chip thickness. Three different cutting speeds and vw/ae ratios have been chosen and the residual stress of the workpiece, as well as the specific micro-grinding energy, have been investigated. The results showed that almost the same minimum specific grinding energy was obtained at tested cutting speed and vw/aeratio. The results of the XRD analysis showed that contrary to the specific micro-grinding energy, the residual stresses of the ground surface changed by varying the cutting speed and vw/ae ratio. Higher cutting speeds resulted in lower compressive residual stress, and higher vw/ae ratios resulted in higher compressive stresses. This can be attributed to higher temperatures in the chip-formation process compared to the plastic deformation in micro-grinding at higher cutting speeds and lower vw/ae ratios which was proved via SEM micrographs.