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通过化学镀方法制备了高硬度 Ni- B合金涂层。经 XRD分析确认镀态镀层组织为过饱和固溶体与非晶态的混合组织。热处理后硬度高达 HV1 30 0。该镀层组织在不同热处理温度下 ,以 350℃为分界点 ,组织转变过程有很大差异 ,并发现转变过程中有 Ni2 B出现。应力释放、B的脱溶及 Ni2 B和 Ni3B的形成是影响镀层硬度的几个关键因素 ,尤其是 Ni2 B显对镀层硬度 -时间曲线的变化规律的影响显著。不同热处理温度下 ,硬度的峰值出现时间不同 ,有随热处理温度升高向时间缩短方向移动的趋势 ;热处理温度愈趋近 Ni- B合金的晶化温度 ,硬度随时间的变化过程愈复杂。
High-hardness Ni-B alloy coatings were prepared by electroless plating. XRD analysis confirmed that the plated coating was supersaturated solid solution and amorphous mixed microstructure. Hardness up to HV1 30 0 after heat treatment. The microstructure of the coating at different heat treatment temperature, 350 ℃ as the cut-off point, a very different process of transformation of the organization and found that during the transition Ni2B appear. The stress release, the desorption of B and the formation of Ni2B and Ni3B are the key factors affecting the hardness of the coating, especially Ni2B significant impact on the variation of the coating hardness - time curve. At different heat treatment temperatures, the peaks of hardness appear at different times, and tend to move with the increase of heat treatment temperature in the direction of shortened time. The closer the heat treatment temperature is, the more complicated the crystallization temperature and hardness of Ni-B alloy change with time.