Mechanical behavior of nanoparticulate TiO2 reinforced magnesium matrix composite

Abstract

In this study, nano-sized titanium dioxide particulate reinforced pure magnesium matrix composite has been fabricated by powder metallurgy technique for five different weight fractions of reinforcement such as 4 wt%, 8 wt%, 12 wt%, 16 wt%, and 20 wt% respectively. Samples of these compositions are iso-statically cold compacted into cylindrical specimens of diameter and length each 15 mm respectively, followed by sintering and hot extrusion with an extrusion ratio of 1.56:1. SEM micrographs of blended composite powders before compaction confirmed the uniform distribution of reinforcement throughout the matrix without any agglomeration. Microstructural analysis of extruded specimens revealed the refined matrix grains and grain boundary. The reinforcement may interrupt the matrix grain growth on grain boundaries during extrusion. Targeting for biomedical applications like bone implants, kneecap surgery etc., the mechanical behavior of the composite such as microhardness, and compressive strength have been studied. It was observed from the study that the mechanical properties have been significantly improved by adding reinforcement compared to pure magnesium and better mechanical behavior have been noticed for composite with higher contribution of reinforcement.