高硅SiCp/Al复合材料的表面敏化

Surface sensitization of the SiCp/Al composite with a high SiC volume fraction

高硅SiCp/Al复合材料化学镀镍是其表面金属化的关键步骤,化学镀前的敏化工艺易造成该复合材料表面Al合金的过度腐蚀,形成腐蚀孔洞缺陷,金属化后的试样表面粗糙度增加,并对后续的钎焊工艺产生不利影响。本文采用SnCl2+HCl溶液对高硅SiCp/Al复合材料进行敏化处理,研究了敏化时间和敏化液浓度对试样表面质量的影响。结果表明,敏化0.5min后试样表面Al合金腐蚀程度小,沉积的Sn(OH)2颗粒数量少。敏化1.5min以上,试样表面Sn(OH)2颗粒数量多,但Al合金完全腐蚀,留下大而深的腐蚀孔洞;降低敏化液浓度也不能明显提高敏化试样的表面质量。敏化1.0min后,试样表面Al合金连续分布,无大而深的腐蚀孔洞,Sn(OH)2颗粒数量适中。经过1min敏化的高硅SiCp/Al复合材料试样表面化学镀层质量良好。

Nickel electroless-plating is a key process for surface metallization of high volume SiC p/ Al composite.Excessive corrosion of the Al alloy of the composite likely occurs in the surface sensitization process before the electroless plating process.It leads to the formation of corrosion holes and the increase of surface roughness of the metalized composite,afterwards,has a negative effect on the soldering process of the composite samples.Surface sensitization of the high volume SiC p/ Al composite was carried out in a Sn Cl2+ HClsensitizing solution in this work,and effects of the sensitizing solution concentration and the sensitizing time on the surface quality of the composite samples were also investigated.The results show that after sensitizing for 0.5 min,Al alloy on the surface of the composite samples is slightly etched,however,the amount of the Sn(OH)2precipitates is much small.After sensitizing for 1.5 min and longer,the amount of the Sn(OH)2 precipitates on the surface of the composite samples increases significantly,but the Al alloy has been etched completely to leave behind some big and deep corrosion holes there.The surface quality cannot be apparently improved through reducing the sensitizing solution concentration.After sensitizing for 1.0 min,the Al alloy is still distributed continuously on the surface of the composites samples,no big or deep corrosion holes are formed,and the amount of the Sn(OH)2precipitates is also appropriate.The surface quality of the electroless plating coating on the high volume SiC p/ Al composite is very well after sensitized for 1.0 min.