激光沉积铁基涂层微观组织与耐磨性能研究

Research on Microstructure and Properties of Fe Based Wear Resistant Coating by Laser Deposition

为适应恶劣工况条件,满足精密装备对高功率小体积复杂化的发展需求,提高中碳钢材料关键部件工作表面耐磨性能,国内外主要的解决办法是利用激光沉积耐磨涂层代替传统表面淬火。本文以42Cr Mo钢作为基材,高功率CO2激光作为热源,使用同轴送粉的填料方式在基材表面涂覆激光沉积层,选取激光功率P=2.5k W,扫描速度v=0.3m/min。用Fe106、Fe106+Ni/WC的铁基涂层和表面激光高频淬火对比研究,研究Ni/WC颗粒对激光沉积铁基涂层性能的影响规律。结果表明:WC增强相的加入可以使铁基涂层中的增强相增多,还能使涂层组织细化。与高频淬火相比,单一的Fe106沉积层晶粒粗大,耐磨性能未出现明显提高;添加Ni/WC的涂层中由于硬质颗粒相和晶粒细化的影响,使涂层耐磨性显著提高。提高程度是高频淬火的1.5倍、Fe106沉积层的1.7倍和基材的2.86倍。

In order to adapt to harsh working conditions and meet the development demand of high-precision and small volume complex equipment,the wear resistance of the key parts of medium carbon steel was improved and the traditional surface hardening was replaced by the laser deposited wear-resistant coating as the main solution. In this paper,42 Cr Mo steel was used as substrate and high-power CO2 laser as heat source. The laser deposition layer was coated on the base material by coaxial powder feeding. The laser power P=2.5 k W and scanning speed v=0.3 m/min were selected. The effect of Ni/WC particles on the properties of laser deposited iron based coatings was studied by the contrast study of Fe106 and Fe106＋Ni/WC iron based coatings and surface laser high frequency quenching. The results show that the addition of WC enhanced phase can increase the enhanced phase in the iron base coating and also make the coating fine. Compared with high-frequency quenching,the single Fe106 deposition layer had coarse grain and wear resistance had not been significantly improved. Because of hard particle phase and grain refinement,the wear resistance of Ni/WC coating was significantly improved. The degree of improvement was 1.5 times as high as that of high frequency quenching,1.7 times of the Fe106 deposition layer and 2.86 times of the base material.