The effect of annealing temperature on the morphology,phase composition,micro-hardness and corrosion resistance of Ni-W coating were investigated.The results show that an unidentified phase(2θ ≈41.4°)was presented in the as-plated Ni-W coating and then disappeared after annealing treatment.Meanwhile,NiW and Ni4W were precipitated in the annealed coating.As the annealing temperature increased,the grain size and porosity of coating gradually increased.Significant cracks were observed and W was found in the Ni-W coating annealed at 1 000 ℃.The micro-hardness of annealed Ni-W coatings were much higher than that of as-deposited coating,while an adverse corrosion performance was observed for the annealed Ni-W coatings.The corrosion resistance became worse with the increasing annealing temperature.The coating annealed at 500 ℃ showed a biggest micro-hardness value and a fairly acceptable corrosion resistance.%研究了在氢气气氛中,不同的热处理温度对Ni-W合金镀层表面状态、相结构及显微硬度和耐蚀性的影响.结果表明,镀态的Ni-W合金镀层存在一种未知相(2θ≈41.4°),热处理过程中这一未知相消失,同时镀层中析出NiW、Ni4W等沉淀相.随着热处理温度的升高,镀层的晶粒度逐渐增大,镀层在热处理过程中形成的孔隙逐渐增多.当热处理温度达到1 000 ℃后,镀层表面出现明显的裂纹,同时镀层中可还原形成单质W.Ni-W合金镀层的显微硬度经热处理后显著增大,热处理温度为500 ℃时镀层的显微硬度最大,同时镀层具有与镀态Ni-W合金相近的耐蚀性,热处理温度进一步升高后镀层的耐蚀性降低.
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