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在钛合金(Ti-6Al-4V)表面利用激光熔覆技术进行了直接熔覆Al_2O_3-13wt%TiO_2涂层的工艺研究。利用光学显微镜(OM)、扫描电子显微镜(SEM)和显微硬度计研究了激光熔覆Al_2O_3-TiO_2涂层工艺参数对熔覆涂层质量的影响,分析了熔覆过程中涂层熔池的对流现象、涂层的显微组织和显微硬度分布情况。当激光功率在2 200~2 800 W的范围内,扫描速度为500mm/min时,获得了界面结合良好的Al_2O_3-TiO_2涂层,且涂层的内部组织均匀,不存在明显的裂纹和气孔。经激光熔覆的Al_2O_3-TiO_2涂层表现出明显的流线型特征,其中的未熔颗粒分布均匀,大多以流线形式分布在涂层内部,对涂层起到了一定的增强作用。钛合金基材的硬度为360~390HV0.3,激光熔覆涂层的显微硬度为1 000~1 300 HV0.3,达到了基体硬度的3倍左右。
The technology of direct cladding Al 2 O 3-13wt% TiO 2 coating on the surface of titanium alloy (Ti-6Al-4V) was studied by laser cladding technique. The effects of laser cladding Al_2O_3-TiO_2 coating parameters on the quality of the coating were studied by optical microscope (OM), scanning electron microscopy (SEM) and microhardness tester. The effects of laser cladding coating bath Convection phenomenon, coating microstructure and microhardness distribution. When the laser power is in the range of 2 200 ~ 2 800 W and the scanning speed is 500 mm / min, the Al 2 O 3 -TiO 2 coating with good interfacial adhesion is obtained. The internal structure of the coating is even and there are no obvious cracks and pores. The laser clad Al 2 O 3 -TiO 2 coating showed obvious streamline characteristics, of which the un-melted particles were distributed evenly, mostly in the streamline distribution inside the coating, which played a certain enhancement to the coating. The hardness of titanium alloy substrate is 360 ~ 390HV0.3, laser cladding coating microhardness of 1 000 ~ 1 300 HV0.3, reaching about 3 times the hardness of the substrate.