黏结层及真空退火对NiCr-30%Cr3C2金属-陶瓷喷涂层性能的影响

Effect of bond layers and vacuum annealing on sprayed NiCr-30%Cr3C2 metallic-ceramic coating properties

采用两种黏结层(电镀Ni+HVOFNiCr黏结层和电镀Ni黏结层),通过超音速火焰喷涂技术制备NiCr-30%Cr3C2(质量分数)金属-陶瓷涂层,并对含电镀Ni黏结层的涂层在不同温度(800,850,900℃)下进行真空退火处理。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、电子拉伸试验机、销盘摩擦磨损仪(BOD)以及台阶仪研究了黏结层和退火处理对涂层的物相结构、结合强度和不同载荷下摩擦性能的影响。结果表明:采用Ni黏结层涂层的结合强度达64MPa,且退火后结合强度明显提升;20N载荷下,该涂层的耐磨性优于Ni-NiCr黏结层涂层,且退火后耐磨性明显提升;在5N载荷下,两种黏结层涂层的耐磨性相近,但退火后Ni黏结层涂层的耐磨性降低。

NiCr-30%Cr3C2(mass fraction) ceramic-metallic coatings were sprayed with two types of bond layer (electro-deposited Ni+HVOF NiCr bond layer and electro-deposited Ni bond layer) by HVOF.The coating with Ni bond layer was vacuum annealed at different temperatures (800,850℃ and 900℃).Phase,microstructure and mechanical properties under different loads of coatings were characterized by X-ray diffractometer (XRD),scanning electron microscope (SEM),electron-tensile tester,ball-on-disk (BOD) and step profiler.The results show that the adhesion strength of the coat-ing with Ni bond layer reaches 64MPa and is improved obviously after annealing.The wear resistance of the coating with Ni bond layer is superior to that with Ni-NiCr bond layer and improved signific-antly under 20N loading,while the wear resistance of the two coatings is with no much difference and the wear resistance of the coating with Ni bond layer is decreased after annealing under 5N loading.