Abstract
? 2022 Elsevier B.V.In this paper, the microstructure, micro zone performance and compressive properties of FeCoNi1.5CuB0.5Y0.2 high-entropy alloys under different cryogenic treatment parameters (cryogenic temperature T, holding time t and cooling rate V) are studied. The results show that there are significant lattice distortions and changes in the morphology and size of each phase under different cryogenic conditions. In the optimized sample with cryogenic treatment conditions of T = ?196 ℃, t = 36 h and V= 5 ℃/min, the number of HCP phase and M3B phase increases significantly, the size is significantly reduced and a large number of nanoparticles appear. In terms of the mechanical properties of the micro zone, the nano-hardness and elastic modulus of each phase have been significantly improved compared with the untreated sample. For the optimized sample, the nano-hardness, compressive strength and fracture toughness also reach the maximum, which are 34.4%, 44.6% and 145% higher than that of the untreated sample respectively. It is analyzed that the cryogenic treatment of HEA results in dislocation strengthening, fine-grain strengthening, nano-heterogeneous particle strengthening, which promote the simultaneous improvement of the overall strength-ductility of the HEA.
NSTL
Elsevier