基于激光熔覆的自润滑复合涂层制备及其性能研究

Study on preparation and properties of self-lubricating composite coating based on laser cladding

为了防止H13热作模具钢在使用过程中出现的磨损失效现象,使其在工作环境下(200℃)具有自润滑能力,在H13热作模具钢表面进行激光熔覆,成功制备了具有自润滑能力的Stellite 6-Cr_(3)C_(2)-WS_(2)复合涂层。研究了Stellite 6-Cr_(3)C_(2)-WS_(2)复合涂层对熔覆涂层表面性能的影响。对熔覆涂层分别进行了X射线衍射(XRD)分析、扫描电子显微镜(SEM)组织观察、能谱(EDS)分析、显微硬度测试和摩擦磨损试验测试,系统地研究了物相组成、微观组织、显微硬度和磨损性能等。试验结果表明:熔覆涂层在激光束照射下反应生成的主要物相有γ-(Fe, Co)、Cr_(7)C_(3)硬质相、(Cr, W)C碳化物和CrS自润滑相;熔覆涂层显微组织主要由平面晶和树枝晶构成;熔覆涂层硬度是基材硬度的2~3倍,表面摩擦因数为基材表面摩擦因数的65%。因此,热作模具钢H13表面的熔覆涂层的硬度和耐磨性均得到了很大的提高。

In order to prevent the wear failure phenomenon of H13 hot die steel during use process and make it have self-lubricating ability in the working environment(200℃),the composite coating of Stellite 6-Cr 3 C 2-WS 2 with self-lubricating ability was successfully pre-pared on the surface of H13 hot die steel by laser cladding,and the influences of composite coating Stellite 6-Cr 3 C 2-WS 2 on the surface properties of the cladding coating were studied.Then,the cladding coating was conducted by X-ray diffraction(XRD)analysis,scanning electron microscope(SEM)microstructure observation,energy spectrum(EDS)analysis,microhardness test and friction and wear test,and the phase composition,microstructure,microhardness and wear resistance of cladding coating were systematically analyzed.The re-sults show that the main phases generated by the reaction of the cladding coating under the laser beam irradiation areγ-(Fe,Co),Cr 7 C 3 hard phase,(Cr,W)C carbide and CrS self-lubrication phase,and the microstructure of the cladding coating is mainly composed of plane crystals and dendrites.In addition,the hardness of the cladding coating is two to three times the hardness of the substrate,and the surface friction coefficient is 65%of the surface friction coefficient of the substrate.Thus,the hardness and wear resistance of the cladding coating on the surface of H13 hot die steel have been greatly improved.