Development of new bunding alloys for diamond by estimating wettability

金刚石具有许多优异的物理性能，如高硬度、高导热系数、高声传播常数、高折射常数和高绝缘性等。近年来，随着掺杂元素的加入，金刚石对半导体产生了浓厚的兴趣。为了将金刚石用作工业材料，研究金刚石与金属的润湿性是很重要的，因为金刚石通常与金属结合在一起。本文采用座滴法研究了液态Al、Cu、Au及含钛合金对金刚石的润湿性。研究结果总结如下：除铜外，纯液态Al和Au对金刚石的润湿性具有温度依赖性。尤其是在Al的情况下，接触角在高温下突然减小。Al和Al-Ti合金的接触角从润湿开始就表现出与时间的关系，除了铜之外，润湿性与温度的关系已被清楚地认识到。研究发现，在Al中加入少量的钛，可显著提高其耐热性能。通过扫描电子显微镜和电子探针观察发现，在金刚石与Al或Al-Ti合金的接触界面上形成了A14C3晶体。这表明金刚石与液态金属润湿性的温度和时间与界面反应有关。连接强度估计为：Cu&lt；Au&lt；Au-Ti&lt；Al&lt；Al-Ti。

Diamond has many excellent physical properties, high hardness, high thermal conductivity, high sound propagation constant, high refraction constant and high insulator etc.. Recently, diamond is much interested in semiconductor with the addition of doping element. In order to use diamond as a industrial material, it is important to study the wettability of diamond by metals, becaouse diamond is usually joined with metals. In the present work, the wettability of diamond by liquid Al, Cu, Au and these alloys contained Ti has been researched by the sessile drop method. Summary of research results as follows :Wettability of diamond by pure liquid Al and Au, excepting Cu has shown temperature dependence. Especially in case of Al, a contact angle has been decreased abruptly at high temperature. The temperature dependence of the wettability, excepting Cu, has been clearly recognized by addition of Ti.The contact angle of Al and Al-Ti alloys has shown the time dependence from the beginning of the wetting. It has been found that a small amount of Ti in Al has improved remarkable the watt ability. A formation of A14C3 crystal has been found in a contact interface of diamond and Al or Al-Ti alloy by the observation of SEM and EPMA.It has been suggested that the temperature and time dependences of the wettability of diamond by liquid metal have related to an interfacial reaction. The strength of joining has been estimated as Cu<Au<Au-Ti<Al<Al-Ti.