【作者】 齐剑钊；

【导师】 乔培新； 龙伟民；

【作者基本信息】 机械科学研究总院 ， 材料加工工程， 2011， 硕士

【摘要】 本文选用Cu-Zn-Sn-Ni合金粉状钎料,通过加入-300目WC和-20目～+30目WC,调整其流动性和耐磨性,采用钎剂保护的炉中加热工艺,在Q235A钢表面制备WC颗粒增强的铜基耐磨复合钎涂涂层。通过正交试验法及单因素试验法对影响涂层成型性能的工艺因素进行分析。研究中,通过金相显微分析、扫描电镜分析、显微硬度分析、拉伸试验以及磨损试验,研究WC颗粒增强的铜基耐磨复合钎涂涂层的组织结构、力学性能、结合强度及其耐磨性能,并对其耐磨涂层的磨损机理进行分析,最终对钎涂工艺进行优化,得到了优质的耐磨涂层。通过对涂层制备工艺因素的分析可知：对涂层成型性能影响较大的因素主要有涂层的加热温度、保温时间以及涂层中-300目WC的含量。其中,通过加入-300目WC,原有钎料中的针状组织转变为以枝状晶为主的组织,提高加热温度、延长保温时间有利于涂层的熔合,可提高涂层的致密度,但是当涂层加热温度升至910℃时,将增加涂层内部产生气孔的风险。通过数据分析并结合试验验证,确定了-300目WC含量为6wt.%,-20目～+30目WC含量为30wt.%、40wt.%、50wt.%,涂层加热温度为870℃,保温10min的工艺可得到组织结构比较致密的涂层,并通过一系列力学性能测试及磨损试验,可知：WC颗粒增强的铜基耐磨复合钎涂涂层可以显著提高母材的表面耐磨性能,其中,-20目～+30目WC含量越高,涂层耐磨性能越好。更多还原

【Abstract】 The wear resistant composite coating of two classes of different sized WC particles (-300 mesh and -20～+30 mesh) with Cu-Zn-Sn-Ni filler metals was prepared on the surface of Q235A steel by furnace brazing and protected by flux. Through orthogonal test and one-factor experiment, the factors on coating-forming properties were analyzed. With the aid of microscope SEM and wear test, the coating was analyzed on the microstructure, mechanical properties, bonding strength, wear resistance and mechanism of the Cu-based brazing coating reinforced with WC particles, which process have been optimized.Through analying the factors on coating-forming properties, the result showd, heating temperature and time,-300 mesh WC content had a significant effect on the coating, adding -300 mesh WC, the original microstructure of the coating was changed from needle to dendrite; raising the temperature and extending the time in the heat, the consistency of the coating was improved; but to 910℃, it would produce pores.Optimized results showed:the microstructure of the coating, with 6 wt.%-300 mesh WC,30 wt.%,40 wt.% or 50 wt.% -20～+30 mesh WC, for 10min in 870℃, achieved the lowest porosity. Through analying mechanical properties, bonding strength, wear resistance, it showed, the Cu-based brazing coating reinforced with WC particles could greatly improve the wear-resisting performance of the matrix surface, and the more-20～+30 mesh WC in the coating, the better the wear resistant.更多还原