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利用激光熔覆工艺在Ti-6Al-4V合金表面制备出原位自生TiC-Cr7C3-Ti-Ni金属复合陶瓷涂层,以改善材料表面的综合性能。采用X射线衍射(XRD)、扫描电镜(SEM)、能量分散仪(EDS)、电子探针显微分析仪(EPMA)等手段对复合涂层微观组织结构进行研究。结果表明,复合涂层主要由-βTi,-γNi固溶体及分布于晶间的Ti/TiC或Ti/Cr7C3共晶组成;晶内为贫Ni,C的-βTi固溶体组织,晶间为富Ti,C的Ti/TiC和Ti/Cr7C3共晶组织;随着复合涂层成分的变化,激光熔覆原位合成物的量发生相应的变化,涂层熔区内晶体生长形态从网络状晶向树枝晶、等轴晶过渡;复合涂层显微硬度值较基体有显著提高。
In-situ TiC-Cr7C3-Ti-Ni metal composite ceramic coatings were prepared on the surface of Ti-6Al-4V alloy by laser cladding to improve the overall surface properties. The microstructure of the composite coating was studied by XRD, SEM, EDS and EPMA. The results show that the composite coating consists of -βTi and -γNi solid solution and Ti / TiC or Ti / Cr7C3 eutectic distributed in the intergranular phase. The intragranular β-Ti solid solution is lean Ni and C, C Ti / TiC and Ti / Cr7C3 eutectic microstructure. With the composition of the composite coating changes, the amount of laser cladding in situ changes in the amount of the composition of the coating crystal growth zone morphology from the network-like crystal to the branches Crystal, equiaxed crystal transition; composite coating microhardness values significantly increased compared with the substrate.