Preparation and mechanical properties of TiCx–(NiCu)3Al–CuNi2Ti–Ni hybrid composites by reactive pressureless sintering pre-alloyed Cu/Ti3AlC2 and Ni as precursor

Abstract

Ni based hybrid composites were fabricated from Ni/Cu/Ti3AlC2 powder mixtures. After pressureless sintering, almost fully dense TiCx-(NiCu)3Al-CuNi2Ti-Ni hybrid composites were obtained and the in situ formed ultrafine TiCx grains were homogeneously distributed in the metal matrix. The as prepared hybrid composites exhibited superior mechanical properties due to precipitation of submicron sized TiCx and (NiCu)3Al particles homogeneously dispersed in the matrix. The hardness, yield stress and ultimate compressive strength of the hybrid composites fabricated from 3.5Ti3AlC2/15.1Cu/81.4Ni reactant mixture attained mean values 2.66±0.10GPa, 837±36MPa and 1123±15MPa, respectively. The enhancement of the mechanical properties was attributed to a size dependent particle strengthening mechanism as well as formation of large amount of dimples.