活性燃烧高速燃气喷涂WC-CoCr涂层的微观组织及性能

利用活性燃烧高速燃气(AC-HVAF)喷涂技术在0Cr13Ni5Mo不锈钢表面制备了WC-CoCr涂层,并利用XRD、SEM、滑动磨损以及电化学试验分析了涂层的微观组织以及耐磨耐蚀性.结果表明,涂层具有优异的微观结构以及良好的耐磨耐蚀性.XRD分析未发现其他喷涂技术普遍存在的W2C以及W相,AC-HAVF喷涂技术可以有效抑制WC的分解;涂层致密且与基体结合良好,孔隙率仅为0.75%.滑动磨损试验表明,涂层具有很低的磨损率.其主要原因为涂层硬度极高、WC颗粒细小和没有W2C相.电化学试验表明,WC-CoCr涂层的耐蚀性优于基体0Cr13Ni5Mo不锈钢,Cr的加入、W的缺少以及孔隙率低是WC-CoCr涂层耐蚀性优异的重要原因.

Microstructure and properties of AC-HVAF sprayed WC-CoCr coating

WC-CoCr coating was prepared on 0Crl3Ni5Mo stainless steel by activated combustion HVAF spray,the microstructure and properties were investigated by XRD, SEM, sliding wear and electrochemistry tests. The results show that the WC-CoCr coating has excellent microstructure and high wear and corrosion resistance. W2 C and W phases are not found in the AC-HVAF sprayed coating examined by XRD,it means that the AC-HVAF spraying technology can control the decomposition of WC effectively and improve the fracture toughness and wear resistance. The observation of SEM shows that the coating is compact with low porosity about 0.75% and well combined with the substrate. Sliding wear test shows that the WC-CoCr coating has good wear resistance,it attribute to the high hardness, fine WC grain and no W2C phase. Electrochemistry tests show that the corrosion resistance of the WC-CoCr coating is better than that of the 0Crl3NiSMo stainless steel,because of adding Cr,no W phases and low porosity in the coating.