文献类型：期刊文献

英文题名：Ti-content-regulated microstructural evolution and mechanisms underlying room-temperature compressive strength–plasticity synergy in NbMoTaWTi? refractory high-entropy alloys

作者：Hu, Jiezhen[1,3]; Zhong, Shenghao[1]; Geng, Baoyu[1,3]; Deng, Peichang[2,3]; Li, Youchi[1]; Wen, Cheng[1]

机构：[1] School of Mechanical Engineering, Guangdong Ocean University, Zhanjiang, 524088, China; [2] College of Chemistry and Environment, Guangdong Ocean University, Guangdong, Zhanjiang, 524088, China; [3] Zhanjiang Key Laboratory of Corrosion and Protection of Ocean Engineering Equipment, Guangdong, Zhanjiang, 524088, China

年份：2026

卷号：1081

外文期刊名：Journal of Alloys and Compounds

收录：EI(收录号：20263821511298)、Scopus(收录号：2-s2.0-105050739288)

语种：英文

外文关键词：Binary alloys - Compressive strength - Crystal microstructure - Dendrites (metallography) - Elastic moduli - Entropy - Fracture - Fracture toughness - Hardness - Mechanical testing - Niobium alloys - Plasticity - Solid solutions - Tantalum alloys - Ternary alloys - Titanium - Titanium alloys - Tungsten alloys

外文摘要：To reveal the effects of Ti content on the phase stability, microstructural evolution, and room-temperature compressive behavior of NbMoTaW-based refractory high-entropy alloys, a series of as-cast NbMoTaWTi? (x = 0, 0.5, 1, 2, and 4) alloys were fabricated and systematically investigated through microstructural characterization, mechanical testing, and first-principles calculations. The results show that all the alloys retain a single-phase BCC solid-solution structure without detectable secondary phases; with increasing Ti content, the lattice parameter increases from 3.2266 ? to 3.2528 ?, the dendritic microstructure is progressively refined, and elemental partitioning becomes more pronounced. The hardness decreases from 552.5 HV to 463.4 HV, whereas the ultimate compressive strength and fracture strain increase from 1230 MPa and 5.2% to 2210 MPa and 36.8%, respectively. First-principles calculations based on representative SQS models indicate that Ti addition reduces the bulk modulus, shear modulus, Young's modulus, and theoretical hardness, while weakening directional bonding and enhancing metallic bonding characteristics, suggesting Ti-induced elastic softening and reduced resistance to shear deformation. The simultaneous improvement in ultimate compressive strength and fracture strain is attributed to the retained stability of the BCC solid-solution, dendrite refinement, and the load-bearing and deformation-coordination mechanism between Ta/W-enriched dendrite cores and Ti/Nb-enriched interdendritic regions. These findings clarify the mechanisms underlying the Ti-content-regulated room-temperature compressive strength–plasticity synergy in NbMoTaWTi? refractory high-entropy alloys. ? 2026 Elsevier B.V.