Formation mechanism of the segregation layer of reactive metals to the bonding interface in brazing alloy joining for metal/ceramics and structure cotrol of joining

(1)利用陶瓷/金属复合材料在高温下产生类似热激电流（TSC）。金属材料采用Al、Cu、Ti、Pt、W和Mo，陶瓷材料采用SiC、Al_2O_3、ZrO_2、Si_3N_4、AlN和ZrB_2。这些陶瓷/金属偶在高温下产生的电动势与传统的热电动势具有不同的特征。这些温度从陶瓷电导率的升高到接近。这些极化曲线一直依赖于温度，但一直是最大电动势。在1100 k时，电动势始终保持在陶瓷的负电位。(2)在陶瓷的界面上使用钎焊分离活性元素，其中包括活性金属，如VI， Ti, Zr, Hf。(3)为了解释这些偏析机理，我们假设这些电动势是在钎焊温度下产生的驱动力。然后从偶体外侧加入电场。陶瓷制成正极，消除了活性金属的偏析。反向是隔离的。因此，我们解释了陶瓷界面的偏析是由于陶瓷/金属界面偶对产生特殊的热电动势引起的。(4)分离层厚度由小电流的外加电场控制。即，层的厚度正比于电流和时间的因素。临时的，不依赖。

(1) Generation of like thermally stimulated current (TSC) was observed by using the couple was consisted ceramics/metal at elvated temperature. Metals were used Al, Cu, Ti, Pt, W and Mo. Ceramicses were used SiC, Al_2O_3, ZrO_2, Si_3N_4, AlN and ZrB_2. These ceramics/metal couples are generated electromotive force which is differntly character as conventional thermally EMF at elevate temperature. These temperature were observed from adjacent to increasing of electroconductivity of ceramics. These polarization curves has been depended temperature but has been maximum EMF. EMF are held always negative potential on side of ceramics above brazing TEMP. As 1100 k.(2) Reactive element are segregated on the interface of ceramics by using brazers which is included reactive metal such as VI a family Ti, Zr, Hf.(3) For explain these segregation mechanism, we are assumed that these EMF be made make driving force are generated ag brazing TEMP. . Then we are added electric field from out side of couple. Segregation of reactive metals are disappeared by ceramics are made positive pole. Reverse are segregated. Therefore, we are explained that segregation to the interface of ceramics are caused by generation of peculiary thermally EMF on interface ceramics/metal couple.(4) Thickness of segragation layer are controlled by outside electric field with small current. Namely, thickness of layer are propotionaly depended by factors of current and time. TEMP. Are not depended.