Rolling Al0.3CrFeNiCu1.5 alloy guided by hot simulation and fracture toughness of rolling alloy sheet

Abstract

In order to strengthen high-entropy alloys with both good hot deformation processing property and fracture toughness, and avoid property damage caused by microstructure defects, optimized AlCrFeNiCu alloy is designed and prepared. The hot deformation curve of the alloy is studied, the constitutive equation of hot compression is deduced, the hot processing map is drawn, and the microstructure evolution and fracture toughness under the optimum hot deformation conditions are studied. The results show that the alloy has not high diffusion activation energy (=70.39 KJ/mol), high stress index (=13.11), high power dissipation factor and large hot processing zone. All show that the alloy has good deformation processing ability, and deformation processing can enhance the mechanical properties of the alloy. The hot processing zone is identified to be 940 C-1060 C, 0.01 s-0.04 s. After rolling and homogenization annealing, the alloy is composed of BCC+FCC dual-phase solid solution. After rolling deformation, discontinuous DRX is caused, forming a soft BCC phase (disordered A2 phase), and the disordered A2 phase squeezes each other to improve the bearing capacity. Dislocation strengthening effect is obvious. The preferred growth direction of the dendrite is either along <100> or along <110>. The fracture toughness value is high, reaching 54.20 MPa⋅m. The dendrite is tangent to the notch, which prevents the crack propagation from forming a barrier and helps to enhance the fracture toughness of the alloy.