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利用横流CO2激光器在TA15钛合金表面通过优化的激光熔覆工艺制备出原位自生的多种颗粒增强钴基复合涂层,以增强表面的耐磨性和硬度。利用X射线衍射(XRD)、金相、扫描电镜(SEM)、硬度测试机和磨损试验机等方法对熔覆层进行分析。结果表明,熔覆层的显微结构主要由γ-Co、α-Ti固溶体和弥散分布的原位自生TiB2,、Cr5Si3,、TiC、WB、SiC、Co3Ti、NiC颗粒组成,这些多种颗粒增强相弥散分布在细小的树枝晶组织之间。熔覆层的显微硬度比基体提高很多,HV达到10000 MPa左右,约为基体硬度的3倍。与钛合金相比,熔覆层的耐磨性也有显著提高,其磨损率约为钛合金的1/12。熔覆层的磨损机理具有粘着磨损和磨粒磨损的混合特征。
The cross-flow CO2 laser was used to prepare in-situ self-reinforced cobalt-based composite coating on the surface of TA15 titanium alloy by the optimized laser cladding process to enhance the wear resistance and hardness of the surface. The coatings were analyzed by X-ray diffraction (XRD), metallography, scanning electron microscopy (SEM), hardness tester and wear tester. The results show that the microstructure of the coating mainly consists of γ-Co, α-Ti solid solution and dispersed self-generated TiB2, Cr5Si3, TiC, WB, SiC, Co3Ti and NiC particles. Phase dispersed in the distribution of small dendritic tissue. The microhardness of cladding layer is much higher than the matrix, HV reaches about 10000 MPa, about 3 times of the substrate hardness. Compared with the titanium alloy, the wear resistance of the cladding also significantly increased, the wear rate of about 1/12 of the titanium alloy. The wear mechanism of the cladding layer has a combination of adhesive wear and abrasive wear.