Comparison of wear properties of commercially pure titanium prepared by selective laser melting and casting processes

The present study investigates the wear properties of commercially pure titanium (CP-Ti) parts produced using selective laser melting (SLM) and casting. Scanning electron microscopy (SEM) investigations show that SLM-produced CP-Ti parts have martensitic (α΄) microstructure, whereas cast-produced CP-Ti samples exhibit plate-like (α) microstructure. SEM studies on the wear surfaces at moderate loads (15 N) show shallow ploughing grooves at certain regions and some delamination cracks for both SLM and cast CP-Ti samples. On increasing the load to 30 N, deeper ploughing grooves were observed in both samples along with delamination of material at certain regions. However, ploughing grooves were found to be very shallow in SLM samples compared with the cast parts. Although both SLM and cast CP-Ti exhibited similar wear mechanisms, SLM CP-Ti showed better wear resistance due to its martensitic microstructure, finer grain size and superior microhardness.