Intermetallic formation and mechanical properties of Ni-Ti diffusion couples
Intermetallic formation and mechanical properties of Ni-Ti diffusion couples
复制标题
Ni-Ti扩散偶的金属间化合物形成和机械性能
DOI：
10.1016/j.matdes.2017.05.055
复制
发表时间：
2017-09-15
影响因子：
8.4
通讯作者：
Shi, Fangrong
中科院分区：
文献类型：
--
作者：
Hu, Lifang;Xue, Yongzhi;Shi, Fangrong
在真空度为10（-1）Pa的炉中热压制备了Ni-Ti扩散偶样品。扫描电子显微镜（SEM）研究表明，在650摄氏度下，Ni-Ti界面形成了三种金属间化合物，即NiTi 2、NiTi和Ni 3 Ti。由于Ti向Ni中的扩散，Ni 3 Ti首先在Ni基体上生长，随后出现NiTi 2，最后在NiTi 2-Ni 3 Ti界面之间形成NiTi。随着扩散层厚度的增加，一部分Ni 3 Ti也被Ti消耗以形成NiTi。在900 ℃下，电流改变了界面的微观结构.柱状晶体最初形成在Ni 3 Ti基体内部，其紧邻NiTi，并且该晶体随后在垂直于接头平面的方向上伸长。Ni_3Ti消失，最终生成纯Ti。所观察到的强度变化进行了讨论，界面微观结构。剪切实验表明，在650 ℃下制备的样品在Ni 3 Ti中观察到断裂。对于在900 ℃下制备的样品，在NiTi 2中检测到断裂。
Samples of Ni-Ti diffusion couples were prepared by hot pressing in a furnace with a vacuum of 10(-1) Pa. Scanning electron microscopy (SEM) investigations indicated that three intermetallic compounds, namely, NiTi2, NiTi, and Ni3Ti, were formed at the Ni-Ti interface at 650 degrees C. Ni3Ti first grew at the Ni substrate because of the diffusion of Ti into Ni, NiTi2 subsequently appeared, and NiTi finally developed between the NiTi2-Ni3Ti interface. As the thickness of the diffusion layers increased, a part of Ni3Ti was also consumed by Ti to form NiTi. The interfacial microstructure was changed by the current at 900 degrees C. A columnar crystal initially formed inside the Ni3Ti matrix, which was immediately adjacent to NiTi, and this crystal then elongated at a direction perpendicular to the plane of the joint. Ni3Ti vanished, and pure Ti was finally produced. The observed strength variations were discussed in relation to interfacial microstructures. Shear experiments showed that fractures were observed in Ni3Ti for the sample prepared at 650 degrees C. For the sample prepared at 900 degrees C, fractures were detected in NiTi2.