Mechanical and wear characteristics of spark plasma sintered titanium/multilayer graphene nanocomposites

Abstract

Owing to excellent mechanical properties, Titanium (Ti) alloys have been of great interest in recent years. However, due to their poor wear resistance application of these alloys is restricted in the areas involving wear and friction. To address such challenges, in the current work, multilayer graphene (MLG) reinforced titanium matrix composites have been fabricated via the spark plasma sintering process. The content of MLG in Ti6Al4V powder is varied between 0% and 1.2%. The present work explores the influence mechanism of MLG addition in Ti6Al4V by investigating fabricated nanocomposites’ microstructure, nanohardness and wear behaviour. Microstructural study reveals an in-situ reaction between a carbon source from MLG and Ti from the Ti6Al4V to form a secondary phase TiC. Moreover, due to the formation of TiC, an increase in the nanohardness value of sintered nanocomposites Ti6Al4V/1.2 wt.% MLG (5.39 GPa) was recorded when compared to fabricated Ti6Al4V alloy (3.23 GPa). Dry sliding wear tests were performed under loads of 3–7 kg. It was observed that Ti6Al4V/1.2 wt.% MLG nanocomposite shows the maximum wear resistance across various sliding velocities with a minimum wear rate of 15 × 10−6 g/m. It is evident from the results obtained that MLG plays a vital role in improving the microstructural, mechanical, and tribological properties of sintered nanocomposites.