陈燕飞, 肖莺, 许荣, 朱政强, 艾凡荣, 邹冬华, 胡罗斌, 李克, 王志刚. NiTi神经介入导丝微连接接头组织演变规律及其超弹性保持机制[J]. 金属学报, DOI: 10.11900/0412.1961.2026.00150.
Yanfei CHEN, Ying XIAO, Rong XU, Zhengqiang ZHU, Fanrong AI, Donghua ZOU, Luobin HU, Ke LI, Zhigang WANG. Microstructural Evolution and Superelasticity Retention Mechanism of Micro-resistance Butt Welded Joints for NiTi Neurointerventional Guidewires[J]. Acta Metall Sin, 0, (): 0-.

摘要 相关文章 Metrics 全文: PDF(4242 KB)   摘要: 针对神经介入导丝分段制造中近端刚性与远端柔顺性的性能梯度调控难题，采用微电阻对焊实现了350 μm超细径NiTi形状记忆合金导丝的高质量连接，并系统研究了焊接热循环作用下接头组织演化、B2/B19’相变行为及超弹性保持机制。研究结果表明，微电阻焊接头形成了典型的熔化区-热影响区-母材分层组织，其中熔化区宽度约95 μm，热影响区约140 μm，接头内部未发现明显气孔与裂纹缺陷。EBSD结果显示，热影响区晶粒发生一定程度粗化，而熔化区在快速凝固作用下形成了细化的重熔组织。TEM分析表明，焊接接头整体仍以B2奥氏体为主，并存在少量B19’马氏体，仅观察到极少量NiTi2纳米析出物，且并未形成明显的第二相聚集或连续析出结构，说明瞬时热输入与快速冷却有效抑制了扩散型第二相的大量形成，同时焊接热循环诱导局部晶格畸变并形成亚稳态B19’马氏体结构。纳米压痕结果显示，母材区、热影响区和熔化区的硬度及弹性模量总体保持在相近水平，焊接热循环未导致接头发生明显的局部力学性能退化。拉伸结果表明，焊接接头仍保留了与母材接近的应力诱导马氏体相变平台，其平台应力约为570.0 MPa；同时，接头抗拉强度达821.9 MPa，为母材的78.3%，延伸率维持在11.5%。上述结果表明，微电阻对焊能够实现超细径NiTi合金的高强度连接与接头超弹性保持，为梯度功能神经介入导丝的设计提供理论支撑。 关键词 ： 镍钛合金,  介入导丝,  微电阻对焊,  B2/B19’相变,  超弹性     Abstract：To address the challenge of performance-gradient regulation between proximal rigidity and distal flexibility during the segmented fabrication of neurointerventional guidewires, high-quality joining of 350 μm ultra-fine NiTi shape memory alloy wires was achieved via micro-resistance butt welding (RBW). The microstructural evolution, B2/B19’ phase transformation behavior, and superelasticity retention mechanism under welding thermal cycling were systematically investigated. The results indicate that the welded joint exhibited a typical hierarchical structure consisting of a fusion zone (FZ), a heat-affected zone (HAZ), and the base metal (BM). The fusion zone width was approximately 95 μm, while the HAZ width was about 140 μm, and no obvious pores or cracks were observed within the joint. EBSD analysis revealed grain coarsening in the HAZ, whereas the FZ exhibited a refined remelted structure due to the rapid solidification. TEM characterization demonstrated that the joint microstructure remained dominated by B2 austenite and contained a small amount of B19’ martensite. Only a trace amount of NiTi2 nanoparticles was observed, without significant second-phase aggregation or continuous precipitation, indicating that the transient heat input and rapid cooling effectively suppressed extensive diffusion-controlled second-phase formation. Meanwhile, the welding thermal cycle induced localized lattice distortion and the formation of metastable B19’ martensite. Nanoindentation results showed that the hardness and elastic modulus of the BM, HAZ, and FZ remained at relatively similar levels, indicating that the welding thermal cycle did not cause significant local mechanical degradation of the joint. Tensile testing demonstrated that the welded joints retained a characteristic stress-induced martensitic transformation plateau comparable to that of the base metal, with a plateau stress of approximately 570.0 MPa. The ultimate tensile strength reached 821.9 MPa, corresponding to 78.3% of that of the base metal, while the elongation remained at 11.5%. These findings demonstrate that micro-resistance butt welding can achieve high-strength joining while largely retaining the superelastic functionality of ultra-fine diameter NiTi wires, providing theoretical support for the design of gradient functional neurointervention guidewires. Key words： NiTi alloy    Neurointerventional guidewire    Micro-resistance butt welding    B2/B19’ phase transformation    Superelasticity 收稿日期: 2026-06-05      基金资助:吉安市科技计划项目(2024H100263); 国家自然科学基金青年项目C类(5250116); 江西省自然科学基金青年项目(20252BAC200638) 服务 把本文推荐给朋友 加入引用管理器 E-mail Alert RSS 作者相关文章 陈燕飞 肖莺 许荣 朱政强 艾凡荣 邹冬华 胡罗斌 李克 王志刚 44.8K 链接本文: https://www.ams.org.cn/CN/10.11900/0412.1961.2026.00150      或      https://www.ams.org.cn/CN/Y0/V/I/0 [1] 姜江, 郝世杰, 姜大强, 郭方敏, 任洋, 崔立山. NiTi-Nb原位复合材料的准线性超弹性变形[J]. 金属学报, 2023, 59(11): 1419-1427. [2] 朱祎国,张杨,赵聃. 多晶NiTi形状记忆合金相变的细观力学本构模型[J]. 金属学报, 2013, 49(1): 123-128. [3] 贺志荣 王启 邵大伟. 时效对Ti-50.8Ni-0.3Cr形状记忆合金组织和超弹性的影响[J]. 金属学报, 2012, 48(1): 56-62. [4] 王启 贺志荣 王永善 杨军. 退火温度和应力-应变循环对Ti-Ni-Cr形状记忆合金超弹性的影响[J]. 金属学报, 2010, 46(7): 800-804. [5] 贺志荣 王芳. 热处理对Ti-Ni-Cr低温超弹性合金相变行为的影响[J]. 金属学报, 2010, 46(3): 329-333. [6] 游素琴 崔玉亭 武亮 孔春阳 马勇 杨晓红 潘复生. Ni53.2Mn22.6Ga24.2单晶的磁控形状记忆效应和磁控超弹性特性[J]. 金属学报, 2009, 45(3): 351-355. [7] 贺志荣 . Ti-50.8Ni-0.3Cr超弹性合金的相变与形变特性[J]. 金属学报, 2008, 44(9): 1076-1080 . [8] 阚前华; 康国政; 钱林茂; 刘宇杰; 王海林 . 超弹性NiTi合金相变棘轮行为的实验研究[J]. 金属学报, 2008, 44(8): 949-955 . [9] 贺志荣 . Ti-Ni形状记忆合金多阶段可逆相变的类型及其演化过程[J]. 金属学报, 2007, 43(4): 353-357 . [10] 贺志荣; 王芳; 王永善; 夏鹏举; 杨波 . V和Cr对Ti-Ni超弹性合金相变和形变特性的影响[J]. 金属学报, 2007, 43(12): 1293-1296 . [11] 贺志荣; 张永宏; 王永善 . Ti49.4Ni 50.6超弹性弹簧的相变和形变特性[J]. 金属学报, 2004, 40(1): 46-50 . Viewed Full text Abstract Cited   Shared      Discussed