镀镍石墨/NiCrW合金复合材料的微观组织和摩擦学性能

Microstructures and Wear Behavior of Nickel-Coated Graphite/NiCrW Alloy Composite

为了提高NiCrW基合金的摩擦磨损性能,采用化学镀法制备出了镀层厚度均匀且致密的镀镍石墨,分别以纯石墨和镀镍石墨为润滑剂,NiCrW合金粉为基体材料,通过粉末冶金工艺制备出了力学性能较高且具备较好自润滑性能的镍合金基自润滑复合材料并就不同含量镀镍石墨对材料微观组织及摩擦学性能的影响进行了研究。结果表明∶镀镍石墨由于在基体中具有较好的分散性和与基体较好的结合性,使复合材料的组织结构、力学性能和摩擦学性能均优于添加纯石墨的复合材料。随着石墨含量的增加,NiCrW/石墨复合材料的摩擦系数和磨损率先降低后升高,当镀镍石墨质量分数为3%时,NiCrW/镀镍石墨复合材料的摩擦学性能达到最佳,摩擦系数为0.27,磨损率为3.2×10^(-5)mm^(3)/(N·m)。

In order to improve the friction and wear properties of NiCrW-based alloys,the nickel-plated graphite with uniform thickness and compactness was prepared by electroless plating.With using pure graphite and nickel-plated graphite as lubricants and the NiCrW alloy powder as the matrix,NiCrW/graphite self-lubrication composites with high mechanical properties and good self-lubricating properties were prepared via powder metallurgy.In addition,the influences of different nickel-plated graphite content on the microstructure and tribological properties of composites were studied systematically.Results showed that because the nickel-plated graphite in composites possessed better dispersibility and better combination to the matrix,which endowed the composites with better microstructure,mechanical performance and tribological properties than those added with pure graphite.With the increase of graphite content,friction coefficient and wear rate of NiCrW/graphite composites decreased first and then increased.When the content of nickel-plated graphite was 3%(mass fraction),the as-obtained NiCrW/graphite composites possessed the optimal tribological properties,which had 0.27 of friction coefficient and 3.2×10^(-5)mm^(3)/(N·m)of wear rate.