Microstructural Characteristics and Wear Behavior of Sintered Ni-Modified Ti–xTiB2 Composites

Abstract

Titanium matrix composites were manufactured using pulsed plasma sintering with the addition of 5 wt.% Ni and TiB2 (x = 5, 10, 15, 20 wt.%) particles at a sintering temperature of 1000 °C, a heating rate of 100 °C/min, and a holding time (300 s) at an applied pressure of 50 MPa. The study examines the densification, phase evolution, hardness, microstructure, and wear behavior of Ti–Ni alloys with different ceramic (TiB2) contents. The results show that increasing TiB2 content decreases relative density from 99 to 97% while increasing hardness from 229 to 586 HV0.1. The addition of Ni particles resulted in laminar α-Ti with well-defined β-Ti grain boundaries. Furthermore, the microstructural studies have revealed a dual-phase beta and alpha Ti phase with uniformly dispersed TiB2 content. As a result of the interactions between β-Ti and Ni during sintering, an intermetallic (Ti2Ni) eutectoid phase was formed. The presence of Ni and TiB2 particles reduces the average coefficient of friction, wear volume, and wear rate. Therefore, the reinforced titanium matrix composites wear track surfaces exhibited a combination of abrasive and adhesive wear modes.