Al_2O_3陶瓷/Ni-Ti钎料反应界面形成的微观机理

Microscopic Mechanism of Formation of Reaction

通过透射电镜、扫描电镜、Ｘ射线研究了Ｎｉ－Ｔｉ高温钎料对Ａｌ２Ｏ３陶瓷与金属Ｎｂ的连接机理。发现在Ａｌ２Ｏ３一侧的反应层中，富集了高浓度的Ｏ原子和Ｔｉ原子，形成了极其细小的微晶ＴｉＯ薄层，其平均晶粒尺寸小于２７ｎｍ，ＴｉＯ以ＦＣＣ结构和ＢＣＣ结构两种晶相混合在一起。反应界面中的Ｏ原子由表层Ａｌ２Ｏ３陶瓷通过扩散脱附而获得。根据反应界面的Ｏ原子与Ｔｉ原子的扩散特点，提出了Ａｌ２Ｏ３陶瓷与活性Ｔｉ原子之新的界面反应机理。并对反应过渡区各相的结构进行了标定，确定了反应界面复合过渡层的微观结构及相的类型。

The mechanism of joining alumina to niobium with a Ni-Ti high temperature filler metal is investigated by the use of X-ray diffractometer(XRD), scanning electron microscope(SEM) and transmission electron microscope(TEM). The experimental result shows that in the interface to the alumina side, it is rich in oxygen and titanium atoms which form a very thin layer of TiO with an average grain size of less than 27nm and two types of crystalline structures of f.c.c. and b.c.c.. The oxygen atoms in the reaction interface results from alumina ceramic through diffusion process. Interface reaction mechanism between alumina and titanium is suggested in accordance with the diffusion behavior of oxygen and titanium atoms.