Ag45CuZn钎料表面刷镀锡的试验研究

Experimental Research of Tin Brush Electro-Plated on Ag45CuZn Brazing Filler Metal

以Ag45CuZn钎料为基体,在其表面刷镀锡制备AgCuZnSn钎料,考察电流密度、阴阳极相对运动速度、镀液温度、刷镀电压和时间对刷镀电流效率和AgCuZnSn钎料中Sn含量的影响,采用扫描电镜（SEM）和润湿试验炉分析锡镀层的表面形貌和钎料的润湿性.结果表明,随着电流密度、刷镀电压及镀液温度的升高,电流效率和Sn含量先增大后减小;随着阴阳极相对运动速度的增加,电流效率逐渐降低,Sn含量先升高后下降;随着刷镀时间的延长,Sn含量逐渐增加,电流效率无显著变化.无定向锡颗粒平行于Ag45CuZn钎料表面方向的生长方式优于垂直其表面方向的生长方式,此时镀层表面平整、致密,孔隙率小（0.82％）,锡晶粒的尺寸为0.3～1.8 μm.与基体Ag45CuZn钎料相比,刷镀2.38％（质量分数）金属Sn之后,其润湿面积提高19.5％,制备的Ag43.92Cu28.65Zn25.05Sn2.38钎料具有良好的润湿性.

The AgCuZnSn brazing filler metal was prepared on the Ag45CuZn brazing filler metal by brush electro-plating tin.The effect of current density,relative velocity of cathode and anode,bath electrolyte temperature,voltage and time on current efficiency and tin content of AgCuZnSn brazing filler metal were investigated.The surface morphology of tin coating and the brazing filler metal wettability were observed using scanning electron microscopy （SEM） and wetting test furnace.The results indicate that current efficiency and tin content initially increase and then decrease with the increase of the current density,brush electro-plating voltage and temperature.As the increase of the relative velocity of anode and cathode,the current efficiency gradually reduces,and the tin content initially increases and then decreases.With the increase of the brush electro-plating time,the current efficiency has no significant change,but the content of tin increases.SEM images show that a smooth and uniform surface morphology of the tin coating with tin grain size of about 0.3～1.8 μm and porosity of 0.82% is obtained.The non-directional tin granular parallel to the surface direction of Ag45CuZn brazing filler metal growth is better than that of perpendicular to the surface of the growth.Compared to Ag45CuZn brazing filler metal matrix,when 2.38 wt.% metal tin is brush electro-plated on Ag45CuZn brazing filler metal,the wetting area of Ag45CuZn brazing filler metal increases by about 19.5 %,and the Ag43.92Cu28.65Zn25.05Sn2.38 brazing filler metal possesses a good wettability.