Effects of hot rolling on microstructure and properties of FeCoNi1.5CrCu/2024Al composites

Abstract

The FeCoNi1.5CrCu/2024Al composites fabricated by microwave sintering were hot rolled to investigate the effect of hot rolling reduction on microstructure, mechanical properties and macroscopic crystal structure. The results show that when the rolling reduction is 62.5%, the refining effect of reinforced particle clusters is obvious, and the large-size reinforced particle clusters have basically disappeared. Besides, it distributes homogeneously in the matrix along the rolling direction, and the grain size of matrix is significantly reduced. With the increase of reduction, the relative density and microhardness of the composites increase first and then decrease, reaching the maximum of 96.6% and 172.5HV at 62.5%, respectively. Hot rolling is conducive to improving the interface bonding between HEA particles and 2024Al matrix. And when rolled with 62.5% reduction, the micro-nanohardness and elastic modulus at the interface reach 1715 MPa and 83.93 GPa, respectively. The tensile strength of hot-rolled composites increases rapidly first and then slowly, and the elongation decreases rapidly first and then slowly. When at the optimum rolling reduction 62.5%, the tensile strength and elongation of composites reach 173.54 MPa and 12.93%, respectively. The strengthening mechanisms are mainly grain refinement strengthening, load transfer strengthening and Orowan strengthening.