Co-Ti/SiC、Co-Ti/石墨体系的润湿性研究

Investigation on wettability of Co-Ti/SiC and Co-Ti/Graphite systems

设计了Co-73.3Ti(质量分数)高温钎料,并采用座滴法研究了Co-73.3Ti/SiC、Co-73.3Ti/石墨体系的润湿性以及保温时间对接触角的影响。结果表明,Co-73.3Ti/SiC体系中由于活性元素Ti的加入增加了Si和C在钎料中的溶解度,体系润湿性随保温时间的延长逐渐改善,直至钎料在SiC表面完全铺展。而由于石墨结构中存在于固液界面的外缘线前的孔洞阻止了钎料铺展,保温时间对Co-73.3Ti/石墨体系的接触角影响较小。微观形貌分析表明,Co-73.3Ti钎料与SiC和石墨的界面处都发生了元素的互扩散。

Co-73.3Ti （Co-73.3wt% Ti） high temperature brazing filler was designed and the wettability of Co- 73.3Ti/SiC and Co-73.3Ti/graphite systems was studied by the sessile drop method in this paper. The effect of dwelling time on the contact angle was also investigated. The results show that the wettability of Co-73.3Ti/SiC system is gradually improved with prolonging of dwelling time until the filler spreads completely on the SiC surface because additive Ti increases the solubility of Si and C in the filler. Whereas, the existence of cavities before the triple-line in the structure of graphite hampers spreading of the filler, leading to the fact that dwelling time has less influence on the contact angle of Co-73.3Ti/graphite system. Microstructure analysis reveals that inter-diffusion takes place at the interfaces of both Co-73.3Ti /SiC and Co-73.3Ti/graphite systems.