激光重熔功率对镍基自润滑涂层组织与性能的影响

Effect of Laser Remelting Power on Microstructure and Properties of Nickel-Based Self-Lubricating Coatings

为研究重熔功率对Inconel 718镍基自润滑涂层组织与性能的影响规律,采用激光熔覆技术在27SiMn钢板材上制备Inconel 718熔覆涂层,选用三种不同的激光功率二次重熔熔覆试样。使用超景深显微镜观察熔覆层表面形貌及金相组织,使用显微硬度计检测熔覆层的显微硬度,使用销-盘式摩擦磨损试验机检验及评价熔覆层的摩擦磨损性能。结果表明,激光重熔后熔覆层的晶粒得到明显的细化,随着重熔功率的增加,熔覆层晶粒尺寸先减小后增大,重熔功率为1 260 W时,熔覆层顶部晶粒尺寸最均匀细小;重熔后熔覆层的硬度均有较大提高,相较未重熔试件硬度最高可提升22%;从磨损形貌来看,试样的磨损机理主要为磨粒磨损,经重熔后试样的摩擦系数及磨损失重均得到了明显的降低。分析摩擦磨损试验数据可知,重熔功率在1 260 W时,试件的耐磨性能最好。

In order to study the influence of remelting power on the microstructure and properties of Inconel 718nickel-based self-lubricating coating,laser cladding technology is adopted to prepare Inconel 718cladding coating on 27SiMn steel plate,and three different laser power remelting cladding samples are selected.The surface morphology and metallographic structure of the cladding layer are observed by super depth of field microscope,the microhardness of the cladding layer is measured by microhardness tester,and the friction and wear properties of the cladding layer are tested and evaluated by pin-disk friction and wear testing machine.The results show that the grain size of the cladding layer is obviously refined after laser remelting.With the increase of remelting power,the grain size of the cladding layer decreases firstly and then increases.When the remelting power is 1260W,the grain size at the top of the cladding layer is the most uniform and fine.After remelting,the hardness of the cladding layer is greatly improved,and the hardness can be increased by 22%compared with that of the specimen without remelting.From the wear morphology,the wear mechanism of the sample is mainly abrasive wear,and the friction coefficient and wear weight loss of the sample are obviously reduced after remelting.The analysis of friction and wear test data shows that the specimen has the best wear resistance when the remelting power is 1260W.