Oxidation behaviour of Ti6Al4V and titanium based-matrix composites (TiC/Ti6Al4V and TiB/Ti6Al4V)

¹ Photonic Center, Manufacturing Cluster, CSIR, South Africa
² Department of Chemistry, University of Limpopo, South Africa
³ Department of Mechanical Engineering Science, Faculty of Engineering and the Built Environment, University of Johannesburg, Johannesburg 2006, South Africa
⁴ Department of Material Science and Metallurgical Engineering, University of Pretoria, South Africa

^* HKgomo@csir.co.za

Abstract

This study explores the oxidation behaviour of Ti64 and titanium-based matrix composites, specifically TiC/Ti64 and TiB/Ti64. Through experimental analysis for oxidation tests using the Ultra furnace, the oxidation characteristics were examined to understand the behaviour of these materials under elevated temperatures (400ºC, 500ºC and 600ºC for 6 hours). Scanning Electron Microscopy (SEM) was used to examine the as- built and after-oxidation microstructures. X-ray Diffraction (XRD) was used to identify phases present before and after oxidation. At 400°C, all materials (Ti64, TiC/Ti64 and TiB/Ti64) exhibited minimal oxidation with no increase in mass. As the oxidation temperature increased to 500°C, Ti64 showed visible oxygen diffused zones (ODZS) on the surface under SEM, whereas TiC/Ti64 showed resistance to oxidation as no ODZs were formed on the surface. TiB/Ti64 exhibited intermediate oxidation behaviour and formed an oxide layer, TiO2 observed on XRD. At 600°C oxidation, Ti64 continued to oxidize significantly, while TiC/Ti64 and TiB/Ti64 showed increased oxidation, though to a lesser extent compared to Ti64.