Zn元素含量对AgCuZn钎料在TiC金属陶瓷表面润湿性的影响

在AgCu共晶钎料中添加不同量的Zn元素熔炼成AgCuZn钎料,并在陶瓷表面进行润湿试验.结果表明,当Zn元素含量为25%(质量分数)时,钎料在陶瓷表面润湿角最小,为23.5°;从近钎料外表面到钎料/陶瓷界面,组织依次为(Cu,Ni)+Ag(s.s)+Cu(s.s)/Ag(s.s)+Cu(s.s)/(Cu,Ni)/Ag(s.s)+Cu(s.s)+TiC金属陶瓷/TiC金属陶瓷.随着钎料中Zn元素含量增加,钎料/TiC金属陶瓷界面处(Cu,Ni)固溶体形态由块状弥散分布变为层状分布;Zn元素在真空中挥发能促进界面元素的溶解和扩散,从而使固液界面张力减小、钎料表面张力增大,最终导致润湿角随着钎料中Zn元素含量增加而出现最小值.

Influence of Zn content on wettability of TiC cermet by AgCuZn alloy

Wetting experiments were performed on TiC cermet by AgCuZn alloy melted of AgCu eutectic powder and Zn powder with different ratios.It’s shown that the smallest contact angle of 23.5° was obtained when the Zn content in AgCuZn alloy is 25%.The microstructure is respectively(Cu,Ni)+Ag(s.s)+Cu(s.s)/Ag(s.s)+Cu(s.s)/(Cu,Ni)/Ag(s.s)+Cu(s.s)+TiC cermet/TiC cermet from the near exterior surface of the alloy to the cermet.With the increasing of Zn content in the alloy,the morphology of(Cu,Ni) solid solution in the interface of alloy/TiC cermet changes from dispersive blocks to a continuous layer;dissolution and diffusion of the element in the interface were improved by evaporation of Zn in vacuum,which lead to decreasing of interface tension and increasing of surface tension of the liquid,and finally leads to a minimum of contact angle with increasing of Zn content.