Study on modification of joining layer structures of ceramic/metal bondings with heat treatment

为了生产具有耐热性和高断裂强度的陶瓷/金属结合，实验研究了五个项目，总结如下：从抑制热残余应力的焊料和中间层材料的筛选试验中，Ti的三层结构最终选择了（1.5um）- Cu（20 um）-Ni（部分镍中间层）和Ni（t）-W（t= 1 mm）-Ni（t= 1 mm）作为候选焊料和中间层材料。当中间层厚度为1.3mm时，室温下的断裂强度最高可达240 MPa。该断裂强度随试验温度的升高而增加，在400 ℃时达到290 MPa左右，然后逐渐降低，但在800 ℃时仍高于180 MPa。在真空中1000 ℃加热100小时后，接头的断裂强度和界面结合层结构几乎没有变化。在氧化气氛中，如在空气中，发现这种结合的高断裂强度是K ...更多信息 当温度达到600 ℃时，由于钨层的选择性氧化，断裂强度迅速下降。采用超声波显微镜对陶瓷与金属连接时产生的热残余应力进行了无损检测。该方法的原理是测量泄漏声表面波的速度，其变化依赖于应力条件，即速度随拉应力而减小，压应力则相反。这种新技术使我们能够测量陶瓷/金属结合界面附近的应力分布。所得结果是合理的，除了几个新的发现，这是无法解释的现有知识。为了理解这些新的结果，进一步的理论和实验研究应该是必需的，我们的实验室正在进行中。少

To produce ceramic/metal bondings with heat resistance and high fracture strength, five items were experimentally investigated and could be summarized as follows: From screening tests of solder and interlayer materials for depression of thermal residual stress, triplex layer structures of Ti(1.5um)- Cu(20um)-Ni(a part of nickel interlayer) and of Ni(t)-W(t=1mm)-Ni(t=1mm) were finally selected as candidate solder and interlayer materials. It was found that a maximum fracture strength of 240MPa was obtained at room temperature when a thickness of nickel interlayer is about 1.3mm. This fracture strength increased with increase in test temperatures and reached about 290MPa at 400ﾟC and then decreased gradually, but it is still higher than 180MPa at 800ﾟC. The bonding was heated at 1000ﾟC up to 100hr in vacuum and showed little change in fracture strength and raction bonding layer structures. In oxidizing atmospheres as in air it was found that a high fracture strength of this bonding was k … More ept up to 600ﾟC and above this critical temperature a fracture strength decreased rapidly due to the selective oxidation of the tungsten layer. Instead of tungsten an interlayer with anti-oxidation property has to be developed and is now under progress.A ultra-sound microscope was used for non-destructive evaluation of thermal residual stress developed on the ceramic surface when it was joined to metals. The principle of this method is to measure velocity of leaky surface acoustic wave, which changes dependent on stress conditions, namely, the velocity decreases with tension stress and the reverse case is for compressive stress. This novel technique enables us to measure stress distribution in the vicinity of ceramic/metal bonding interface. The results obtained are reasonable, except several new findings which is unexplainable using existing knowledges. In order to understand these new results further theoretical and experimental investigations should be required and are under progress in our laboratory. Less