Interface configuration effect on mechanical and tribological properties of three-dimension network architectural titanium alloy matrix nanocomposites

Abstract

Strong interfacial bonding is the primarily crucial issue in titanium matrix composites (TMCs). In this study, three-dimensional (3D) network structured Ti6Al4V (TC4) matrix TMCs with 0.15 wt% few-layer graphene (FLG) were fabricated by high pressure spark plasma sintering (SPS, 200–300 MPa) at 850 ℃, 900 ℃ and 950 ℃, correspondingly producing three types of interface configuration with in-situ TiC to FLG ratio of 4:6, 7:3 and 9:1. Composites sintered under 900 ℃ displayed outstanding integrated properties, including high micro-hardness (345.2 HV), excellent ultimate tensile strength (UTS, 1041 MPa) with acceptable tensile ductility (ε, 9.3%) and wear resistance with the lower wear rate (ω, 5.3 × 10−4 mm3/Nm). The synergistic effect of moderately generated TiC reinforcements on FLG (ratio of 7:3) in 3D network boundary under 900 ℃ leads to efficient load-bearing capacity, acting as the dominant strengthening mechanism. Self-lubricating effect of FLG and debris strengthening of TiC and TiO2 are also responsible for improved wear resistance.