化学镀Ni-Co-P合金的晶化行为研究

Crystallizing of Electroless Plating Ni-Co.-P Alloy

为了改善镀液性能 ,扩大Ni-Co -P合金的应用范围 ,以硼酸为缓冲剂 ,柠檬酸钠为配位体化学镀Ni-Co -P合金 ,用扫描电镜 (SEM )、差示扫描量热 (DSC)和X射线衍射 (XRD)等技术研究了Ni-Co -P合金镀层表面的微观形貌和晶化行为。结果表明 ,Ni-Co -P合金镀层在镀态时呈多晶态结构 ,有立方Ni-Co合金相和非晶相 (以非晶相为主 ) ,镀层于 339.4℃时转化为Ni3 P相 ,其晶化行为与氨性缓冲介质中得到的Ni-Co -P合金有明显差异。Ni-Co -P合金在镀态时其表面有许多直径为 1.9～ 4 .8μm的圆形小颗粒 ;5 0 0℃处理后的镀层表面有一些直径为 6～ 7μm的圆形大颗粒 ,表面呈胞状结构 ,每一胞状物由许多 5 0～ 10 0nm的颗粒形成。

Electroless NiCo-P alloy plating was achieved which used boric acid as buffer solution and sodium citrate as ligand to avoid the disadvantage of ammoniac buffer.The morphology and crystallizing of Ni-Co-P alloy plating were investigated by using SEM,DSC and XRD.Results show that Ni-Co-P alloy plating is multi-crystalline structure containing cubic Ni-Co alloy phase and amorphous phase in mainly.The plating translates into Ni_3P at 339.4 ℃,and its crystallizing behavior is difierent from the Ni-C0-P alloyin ammoniac buffer solution.There are many small circular particles with diameter 1.9～4.8μm on the surface of Ni-Co-P alloy under plating.but are large circular particles with diameter 6～7 μm after treatment at 500 ℃ and the surface is cystic structure that every cyst is composed of many particles with 50～100 nm size.The technology has the characteristics of rapid deposit rate and good stability of bath.