Mechanical, tribological behaviors of high strength and anti-wear materials at high temperature by in situ carbide-reinforcement through hot press sintering of Ni and V2AlC

The in-situ carbide-reinforced Ni-based composites were prepared by hot pressing Ni and 10, 20 and 30 mol. % V2AlC, and their microstructures, mechanical and tribological properties, wear and fracture mechanisms at room
and high temperatures were analyzed. The sintered phases included γ, γ′, V-doped γ′, VCx and NiAl. The Ni-20V2AlC composite had superior mechanical properties due to the strengthening effect of γ′ phase, V-doped γ′
phase and in-situ carbides. (The tensile and compressive strengths were 379.34 and 864.79 MPa at 800 ◦C, respectively). Three composites exhibited excellent wear resistance with WR less than 2.8 × 10􀀀 5 mm3⋅N􀀀 1⋅m􀀀 1
at high temperatures, which was attributed to the lubricating layer comprising NiO, vanadium oxide and nickel vanadate. Two kinds of nickel vanadate were examined, and Ni3V2O8 had laminated and shear-able structure,
while Ni2V2O7 was hard to be sheared.