Influence of aluminum content on the microstructure and properties of the in-situ TiC reinforced AlxFeCoNiCu high entropy alloy matrix composites

Abstract

TiC particles reinforced AlxFeCoNiCu multi-principal elements alloys matrix metallic composites AlxFeCoNiCu/TiC with different content aluminum were fabricated in-situ from Al-Fe-Co-Ni-Cu-Ti-C system through vacuum inductive melting method. The microstructure and properties of AlxFeCoNiCu/TiC composite has been analyzed. In-situ TiC reinforcements particles were uniformly distributed in the matrix and their interfaces with the matrix are very clean and no reaction layer at the interfaces. With the increase of aluminum content, the structure of matrix changed from FCC structure to BCC and FCC bi-phase structure, the ultensile fracture strength increases to a maxmium and then decreases. When the content of aluminum mole rate (x) increases from 0.2 to 0.6, the ultensile fracture strength of the composites increases from 502 MPa to a maxmium of 675 MPa. And then with the further increase of x to 1.0, the ultensile fracture strength decreases to 595 MPa.