Influence of Homogenizing Methodology on Mechanical and Tribological Performance of Powder Metallurgy Processed Titanium Composites Reinforced by Graphene Nanoplatelets

Abstract

In the present work, 0.25 wt%GNP-Ti composites were prepared through powder metallurgy route by adopting three types of mixing modes to investigate the extent of mixing on the mechanical and tribological properties. Dry ball milling, wet ball milling, and rotator mixing were independently employed to homogenize the composite constituents. Three types of composite powders obtained were subsequently sintered into composite pellets by cold compaction followed by vacuum sintering. Morphological investigation of composite powders performed by SEM revealed better homogenization of GNPs in Ti matrix for dry ball milled composite powder, whereas wet ball milled and rotator mixed composite powders showed aggregation and bundling of GNPs. Micro Vickers hardness of composites produced via dry ball milling is 4.56% and 15.7% higher than wet ball milled and rotator mixed samples, respectively. Wear test performed by pin-on-disk tribometer showed higher wear loss for wet ball milled and rotator mixed composites in comparison to dry ball milled.