超音速火焰喷涂WC-10Co-4Cr涂层的微观组织与摩擦磨损性能

采用超音速火焰(High Velocity Oxygen Fuel,HVOF)喷涂技术在Q235钢基体上制备WC-10Co-4Cr涂层。利用透射电子显微电镜、扫描电子显微电镜、X射线衍射仪、显微硬度计、摩擦磨损试验机等手段对涂层的微观组织结构和摩擦磨损性能进行研究。结果表明:采用HVOF喷涂技术制备的WC-10Co-4Cr涂层结构致密,与基体结合良好,孔隙率为0.67%。涂层中的物相以WC为主,此外还含有少量W2C相和非晶相。涂层的平均显微硬度为1230HV0.3。WC-10Co-4Cr涂层具有良好的耐摩擦磨损性能,累计磨损量(14.4mg)仅为Cr12MoV冷作模具钢的2/5。磨粒磨损为WC-10Co-4Cr涂层的主要磨损机制。

Microstructure,Friction and Wear Properties of HVOF Sprayed WC-10Co-4Cr Coating

WC-10Co-4Cr coating was prepared on Q235 steel substrate by high velocity oxygen fuel (HVOF)spray process.The microstructure and wear properties of the WC-10Co-4Cr coating were in-vestigated by transmission electron microscopy(TEM),scanning electron microscopy(SEM),X-ray diffraction(XRD),microhardness tester and friction-abrasion testing machine.The results show that the coating exhibits dense structure with the porosity of 0.67% and compact bonding with the sub-strate.The coating is mainly composed of WC,and a small amount of W2C and amorphous phases as well,and the average microhardness of the coating is 1230HV0.3.The cumulative mass loss of WC-10Co-4Cr coating is only 2/5 of the cold work die steel Cr12MoV,which indicates the WC-10Co-4Cr coating exhibits better abrasive properties.The abrasive wear is the main wear mechanism for the coating.