The composition of electroless Ni-W-P alloy plating bath was optimized by orthogonal test using resistivity as the evaluation index. The obtained optimal composition of bath and process parameters are as follows: NiSO4·6H2O 15 g/L, NaH2PO2H2O 25 g/L, Na2WO4·2H2O 10 g/L, Na3C6H5O7·2H2O 60 g/L, C3H6O3 5 mL/L, NH4C1 30 g/L, temperature 88 ℃, pH 9, and time 2 h. The properties of Ni-W-P alloy coating such as surface morphology, structure, and microhardness were studied by scanning electron microscope, X ray diffractometer, micro-hardness tester, etc. Using the said bath composition under optimal process conditions, the electroless Ni-W-P plating rate is 6.9 μm/h. The obtained Ni-W-P alloy coating has a resistivity of 204.7 mΩ·cm and is typically amorphous with different-sized and compact cell structure distributing uniformly on the surface. The coating bonds firmly to the substrate and has higher microhardness and better resistance to wear and corrosion than a Ni-P coating.%以电阻率为性能指标,采用正交试验对化学镀Ni-W-P的镀液配方进行优化,得到最优配方与工艺为:NiSO4·6H2O 15 g/L,NaH2PO2·H2O 25 g/L,Na2WO4·2H2O 10g/L,Na3C6H5O7·2H2O60 g/L,C3H6O3 5 mL/L,NH4C1 30g/L,pH=9,温度88℃,时间2h.采用扫描电镜、X射线衍射仪、显微硬度计等研究了Ni-W-P合金镀层的表面形貌、结构、显微硬度等性能.在最佳配方与工艺下,化学镀Ni-W-P的镀速为6.9 μm/h,所得Ni-W-P合金镀层的电阻率为204.7 mΩ·cm,为典型的非晶态结构,表面均匀分布着大小不一、致密的胞状结构,镀层与基体之间结合力牢固,显微硬度高于Ni-P镀层,耐磨性和耐蚀性均优于Ni-P镀层.
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