Microstructure and properties of FeCoNi1.5CrCu/2024Al composites prepared by microwave sintering

In this investigation, FeCoNi1.5CrCu high-entropy alloy (HEA) was prepared by mechanical alloying, following which HEA particles reinforced 2024 aluminum matrix composites were obtained using a microwave with low-temperature sintering. The microstructural characterization and mechanical properties of the composites under different sintering time at isothermal temperature were investigated systematically. The results showed that HEA particles at first diffuse uniformly and then agglomerate with an increase in the sintering time. An interdiffusion (ID) layer exists between the HEA particle and the matrix, and high-density dislocations surround the interface of the HEA/2024Al composite, with a width of 80-120 nm. The hardness and elastic modulus of the interface was tested using nanoindentation technique, which presents excellent interface micro-domains with the mechanical strength reaching about 1331.1 MPa and 47.544 GPa. At 40 min of sintering time, the compressive strength, yield strength and microhardness of the composites were reaching the maximum of 248.7 MPa, 227.4 MPa and 93.1 HV, respectively.

Automated summary

The study demonstrated that with increasing sintering time, FeCoNi1.5CrCu high-entropy alloy particles in the 2024 aluminum matrix composites diffuse uniformly and then agglomerate, forming a high-density dislocation ring around the interface. Nanoindentation technique showed excellent interface micro-domains with high mechanical strength.