发表机构
Northwestern University（西北大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究采用NbZrW扩散阻挡层的两步瞬态液相工艺，实现NiTi与Ti-6Al-4V的异质连接，所得接头具超弹性，为不相容合金的异质键合提供可行方案。
AI 中文摘要
NiTi与Ti-6Al-4V（Ti-64）的异质连接受限于脆性Ti₂Ni的形成及NiTi功能的退化。研究开发了一种两步瞬态液相（TLP）工艺，其中难熔的NbZrW扩散阻挡层将不相容的连接对转化为两个可独立键合的界面。该阻挡层对每种合金发挥不同作用：对NiTi而言，作为反应基体溶解形成富Ti的Ni-Ti-Nb液相，该液相渗入自身晶界，并通过选择性Ti被阻挡层吸收终止；对Ti-64而言，作为惰性基体，通过牺牲Cu箔的接触熔化实现连接。两个界面均完全致密且无连续金属间化合物层。拉伸试验中，跨越两个界面的连接在350 MPa下开始相变，表现出至2.5%全局应变的应力平台（与标距段NiTi的应力诱导相变一致），并在平台后于380-410 MPa断裂。5次至460 MPa的加载-卸载循环显示出稳定的超弹性循环，伴随轻微棘轮效应。这些结果表明，扩散阻挡层可实现原本不相容合金的异质TLP连接。
英文摘要
Dissimilar joining of NiTi to Ti-6Al-4V (Ti-64) is limited by brittle Ti2Ni formation and degradation of NiTi functionality. A two-step transient liquid phase (TLP) route was developed in which a refractory NbZrW diffusion barrier converts the incompatible couple into two independently bondable interfaces. The barrier plays a different role for each alloy: a reactive substrate for NiTi, dissolving to form a Ti-rich Ni-Ti-Nb liquid that infiltrates its own grain boundaries and is terminated by selective Ti absorption into the barrier; and an inert substrate for Ti-64, joined through contact melting of a sacrificial Cu foil. Both interfaces are fully dense and free of continuous intermetallic layers. In tension, joints spanning both interfaces began transforming at 350 MPa, exhibited a stress plateau to 2.5 global strain (consistent with stress-induced transformation of the NiTi half of the gauge) and failed beyond the plateau at 380-410 MPa. Five load-unload cycles to 460 MPa showed stable superelastic loops with minor ratcheting. These results demonstrate that a diffusion barrier enables dissimilar TLP joining of otherwise incompatible alloys.
Comments20 pages, 7 figures, 1 table, 4 supplemental figures
