TC18表面超音速火焰喷涂WC-12Co和WC-10Co4Cr涂层的耐腐蚀性能研究

Corrosion Properties of HVOF Sprayed Coatings of WC-12Co and WC-10Co4Cr on TC18 Ti-alloy

采用HVOF技术在TC18钛合金表面制备WC-12Co和WC-10Co4Cr涂层。利用SEM和XRD分析试样微观形貌和物相组成,使用显微硬度计及纳米压痕仪分别对试样的显微硬度和塑韧性进行测量。对试样进行电化学腐蚀测试和中性盐雾腐蚀实验,并对比分析其腐蚀行为。结果表明,WC-12Co涂层和WC-10Co4Cr涂层的显微硬度分别为HV0.31177.2和HV0.31258.8,弹性模量分别为355和391 GPa,均明显高于TC18基体(HV0.3336.4、102 GPa)。WC-12Co涂层和WC-10Co4Cr涂层均能有效地提高基体的耐蚀性能,其中WC-10Co4Cr涂层耐蚀性能更优。

Coatings of WC-12 Co and WC-10 Co4 Cr were fabricated on TC18 Ti-alloy via high velocity oxygen fuel process. Their microstructure and phase composition were characterized by scanning electron microscope（SEM） and X-ray diffractometer（XRD）. The surface microhardness and plasticity-toughness of the coated alloys were measured with microhardness tester and dynamic ultra microhardness tester respectively. While the corrosion behavior of TC18 alloy without and with coatings of WC-12 Co and WC-10 Co4 Cr respectively was comparatively assessed by means of electrochemical test and salt spray test. The results showed that the microhardness and elastic modulus of WC-12 Co coating（HV0.31177.2,355 GPa） and WC-10 Co4 Cr coating（HV0.31258.8, 391 GPa） were significantly higher than that of TC18 substrate（HV0.3336.4, 102 GPa）. Both WC-12 Co coating and WC-10 Co4 Cr coating were able to effectively improve the corrosion resistance of TC18 substrate, and the WC-10 Co4 Cr coating exhibited better corrosion resistance.