Microstructural Evolution and Dry Sliding Wear Properties of Doping W in Ti–10 vol.% TiC Composite Foams

Abstract

Herein, novel Ti–TiC(W) composite foams were designed to address the low wear resistance of porous Ti-based alloys. Inexpensive TiH₂ was used instead of Ti powder, and the Ti–10 vol.% TiC matrix was doped with 1 vol.% nanoscale W powder, using 40 vol.% NaCl as the spacer. Ti–TiC(W) composite foams were fabricated through spark plasma sintering, dissolution, and post-heat treatment (PHT) at 900 and 1200°C for 1 h. The influence of W doping on the microstructure and tribological properties of the composite foams before and after PHT was investigated. After posttreatment, the material matrix relative density exceeded 0.9686, with a maximum microhardness of 582.36 HV_0.2 at a PHT temperature of 1200°C. After PHT at 900°C, the W particles gradually diffused into the Ti matrix, forming a diffusion zone. However, some W particles remained undissolved at the center of the diffusion zone, forming a Ti–W corona. After PHT at 1200°C, W formed a uniform mesh structure in the matrix, significantly enhancing the density and microhardness of the matrix by strengthening the strength of precipitation. The coefficients of friction of the materials ranged from 0.1565 to 0.2234, with mild wear observed after PHT at 1200°C and a minimum wear rate of 0.27 ∙ 10^–12 m³· N^–1 ∙ m^–1. The network precipitated phasesynergized to inhibit the formation of wear marks, significantly improving wear resistance. This strategy can enhance the wear resistance of porous Ti-based materials.