原位XRD研究热处理Ni-P化学镀合金的结构

In Situ XRD Investigation on Structure Change of Electroless Ni-P Alloys

通过改变镀液的CNi2+/CH2PO2-比例,在乙酸 柠檬酸体系中,获得组成分别为Ni 7.8P(质量比)和Ni 11.7P的镍磷化学镀层。用程序升温原位XRD分析了镀层在40～500℃之间的结构变化。镀态时Ni 7.8P为微晶结构而Ni 11.7P为非晶结构。在20℃/min升温速度下,Ni 7.8P在200℃后发生晶化,直接析出稳定的Ni3P和Ni相。Ni 11.7P在300℃后晶化,先析出介稳的Ni5P2相,375℃后转变为平衡的Ni3P和Ni相。

The electroless Ni\|7.8P and Ni\|11.7P (wt%) alloys were obtained by altering the ratios of CNi2+/CH2PO-2 in the bath of acetic\|citric acids mixed solution. The structure change of plating during program temperature elevating from 40 ℃ to 500 ℃ was investigated by in situ X\|ray diffraction (XRD). The as\|deposit structure of Ni\|7.8P plating was microcrystalline while the Ni\|11.7P plating was amorphous. During program temperature elevating, the Ni\|7.8P alloy crystallized at a temperature over 200 ℃ and directly formed stable Ni3P and Ni phases. The Ni\|11.7P alloy crystallized at a temperature over 300 ℃ and formed metastable Ni5P2 phase, then transformed to the Ni5P2 and Ni phases at temperature over 375 ℃.