不同喷枪配置制备TiC/NiCrMo涂层组织结构及性能
Structure and performance of plasma-sprayed TiC/NiCrMo coatings prepared by different types of spraying gun
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摘要: 采用SG-100型等离子喷涂喷枪,使用亚音速(Subsonic)和马赫一(Mach I)两种不同喷枪配置,在Q235钢表面制备了TiC/NiCrMo涂层。用扫描电镜、X射线衍射仪和电子探针等分别对这两种涂层表面、截面形貌、相成分以及元素分布进行了分析。同时对两种涂层孔隙率、显微硬度及耐磨损性能进行了对比。结果表明,Mach I喷枪制备的涂层比Subsonic喷枪制备的涂层致密,孔隙率较小,涂层与基体结合良好,滑动磨损性能优于Subsonic涂层,显微硬度略高于Subsonic涂层;Subsonic喷枪制备的涂层与基体结合界面有分离现象出现,涂层中有较大空隙存在。两种涂层中TiC均发生氧化,生成TiO2;TiC与Mo也发生反应生成Mo2C。Abstract: TiC/NiCrMo coatings were prepared on the substrate of Q235 steel (low carbon steel)by using two types of SG-100 plasma spraying gun labeled by Subsonic and Mach I.Morphology and phase composition of coatings were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) utilising back scattered imaging mode (BSE)and electron probe micro-analysis(EPMA).Wear tests were performed by using a ring-on-block tester under dry sliding condition.Results show that the coating prepared by Mach I gun banded well to the substrate and no delamination appears, while detachment between coating and substrate could be observed in the coating prepared by Subsonic gun.Meanwhile, large pores can be observed in the Subsonic gun-produced coatings. The Mach I gun-produced coating shows superior wear resistance to that of the Subsonic gun-produced coating.Partial oxidation of TiC and reaction between TiC and Mo occurred in both coatings.