激光重熔对火焰喷涂法制备Ni-WC复合涂层耐磨性能的影响

Effects of Laser Remelting on Wear Resistance of Ni-WC Composite Coatings by Flame-Spraying

利用CO2激光对火焰喷涂制备的Ni-WC复合涂层进行了重熔实验,通过扫描电镜(SEM)观察了其重熔后表面形貌,测试了含有不同WC体积分数样品重熔前后的涂层显微硬度,并分析了WC含量对涂层组织及耐磨性的影响。实验结果表明,火焰喷涂制备的涂层气孔随着WC颗粒含量增大而增多,经激光重熔后气孔明显减少;激光重熔后的涂层显微硬度比火焰喷涂的涂层显微硬度提高约20%,WC体积分数为6%时涂层显微硬度达到最大值;激光重熔处理后的涂层耐磨性随着WC含量的增加而增大,WC体积分数为6%时,其耐磨性达到最佳值。

Ni-WC composite coatings prepared by flame spraying were remelted with CO2 laser, and the morphologies of the composite coatings by laser remelting were observed with scanning electron microscopy （SEM）. The micro-hardness （HV） of samples with the different volume fraction of WC particle was tested, and the effects of WC particles on microstructure and wear resistance were analyzed. It is shown that the coating pores prepared by flame spraying increase with the content of WC particle, and the pores are reduced obviously after laser remelting; The coating hardness after laser remelting increases 20% than that by flame spraying, which attains the biggest when WC volume fraction is 6 % ; The coating resistance wear after laser remelting increases with the increase of WC content. The best wear resistance is obtained when the WC volume fraction is as high as 6%.