摘要

Refractory NbMoTaWVCr high entropy alloy (HEA) was fabricated by combination of mechanically alloying (MA) and spark plasma sintering (SPS) using powders of Nb, Mo, Ta, W and V as raw materials. The effects of milling time on phase composition, microstructure evolution and mechanical properties were investigated. The results show that mechanical alloying can be achieved after 40 h ball milling, and the single-phase BCC NbMoTaWVCr high entropy alloy powder is obtained. With the increase of milling time, the grain size is refined and the micro strain increases.The bulk alloy sintered by SPS at 1 500℃ consists of BCC matrix, Laves phase and oxide phase. The content of precipitated phase increases with the increase of milling time. With the increase of milling time, the compressive yield strength increases first and then decreases and the plasticity decreases gradually. The NbMoTaWVCr refractory high entropy alloy sintered from powders milled for 40 h exhibits an excellent yield strength of 3416 MPa and plastic strain of 5.3%. ? 2020, Editorial Office of Materials Science and Engineering of Powder Metallurgy. All right reserved.