Microstructural and Mechanical Properties of TiCX–Ni3(Al,Ti)/Ni Functionally Graded Composites Fabricated from Ti3AlC2 and Ni Powders

In this paper, a novel type of functionally graded material (FGM) was successfully fabricated from pure Ni and Ti 3 AlC 2 powder mixtures by hot-press sintering route at 1200 °C and 17 MPa. In each layer, Ti 3 AlC 2 particles transformed into TiC x phase, while the additional Al–Ti atoms decomposed from Ti 3 AlC 2 diffused into the Ni matrix, giving rise to the formation of γ′-Ni 3 (Al,Ti). Part of the submicron TiC x and Ni 3 (Al,Ti) particles were uniformly distributed in the Ni matrix, while some of the TiC x maintained the original Ti 3 AlC 2 plate-like morphology. Both TiC x and Ni 3 (Al,Ti) content decreased from 60Ti 3 AlC 2 /Ni layer to 10Ti 3 AlC 2 /Ni layer in a stepwise manner was fabricated. The microstructural analysis indicates that no cracks, delamination and step-type abrupt changes occured in the graded layer of the manufactured FGM. Flexural strength and Vickers hardness enhanced with the increasing Ti 3 AlC 2 content except for fracture strain and toughness. The overall fracture toughness and the flexural strength of FGM can reach 21.76 MPa m 1/2 and 1329 ± 34 MPa, respectively. The prepared FGM, herein, with a hard ceramic surface on one side to resist local plastic deformation, and a ductile metallic surface on the other side to provide toughness. Graphic Abstract