超音速火焰喷涂TiB_(2)-Co涂层组织与性能研究

Microstructure and Properties of HVOF Sprayed TiB_(2)-Co Coatings

采用机械合金化技术制备TiB_(2)-Co金属陶瓷复合粉末,通过超音速火焰喷涂技术制备TiB_(2)-Co金属陶瓷涂层。采用扫描电子显微镜(SEM)观察TiB_(2)-Co金属陶瓷涂层的微观结构特征,并对涂层进行显微硬度、磨粒磨损和磨损形貌测试,以评价涂层的性能。结果表明,涂层表面存在完全熔化区和部分熔化区;涂层呈典型的叠层状结构,与基材结合良好;涂层的硬度明显高于基体金属,是基体金属的4.5倍;磨损失重量仅为基体金属的14;涂层磨损试样表面存在空穴和犁沟,其磨损机制主要为黏着磨损和磨粒磨损。

TiB_(2)-Co cermet composite powder was fabricated by mechanical alloying process and TiB_(2)-Co coating was prepared by means of high velocity oxy-fuel(HVOF)method.The microstructure characteristics of coatings were observed by scanning electron microscopy(SEM),whilst microhardness,abrasive wear and wear morphology of TiB_(2)-Co coating were tested to evaluate the properties of the coating.The results show that there are completely melted zones and partially melted zones on the coating surface.The coating has a typical layered structure and is well combined with the substrate.The hardness of the coating is significantly higher than that of the base metal,which is 4.5 times that of the base metal.The wear loss weight is only 14 of the base metal.There are cavities and furrows on the surface of the coating wear sample.The wear mechanisms are mainly adhesive wear and abrasive wear.