HVOF制备方法对纳米结构WC-10Co-4Cr涂层抗空蚀性能的影响  

Influence of HVOF Process on Cavitation Erosion Resistance of Nanostructured WC-10Co-4Cr Coatings

作　　者：余翔[1] 丁彰雄[1] 丁翔[2] 李超[1] 程旭东[2] YU Xiang;DING Zhang-xiong;DING Xiang;LI Chao;CHENG Xu-dong(School of Energy and Power Engineering,Wuhan University of Technology,Wuhan 430063,China;State Key Laboratory of Advanced Technology for Materials and Processing,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学能源与动力工程学院,武汉430063 [2]材料复合新技术国家重点实验室,武汉理工大学,武汉430070

出　　处：《热喷涂技术》2017年第1期12-18,共7页Thermal Spray Technology

基　　金：国家自然科学基金项目(51422507;51379168)

摘　　要：采用液体燃料和气体燃料超音速火焰喷涂工艺(HVOF)分别制备了纳米结构WC-10Co-4Cr金属陶瓷涂层,使用光学显微镜(OM)、扫描电镜(SEM)和X射线衍射仪(XRD)分析了涂层的组织结构,并比较涂层的显微硬度与开裂韧性。在清水介质中进行了涂层的振动空蚀试验(CE),探讨了不同HVOF工艺方法对涂层抗空蚀性能的影响。结果表明:两种HVOF制备的WC-10Co-4Cr涂层主要由WC相和少量的W2C相组成,气体燃料HVOF制备的WC-10Co-4Cr涂层含有微量金属W;相比于气体燃料HVOF制备的涂层,液体燃料HVOF制备的涂层孔隙率降低了大约75%,显微硬度提高了20%以上;液体燃料HVOF制备的涂层具有更优异的抗空蚀性能,其空蚀率仅为气体燃料HVOF工艺制备的涂层的28%,其主要原因是喷涂过程中粒子速度更快,温度更低。The nanostructured WC-10Co-4Cr cermet coatings were respectively deposited by high velocity oxyliquidfuel spraying(HVOLF)and high velocity oxy-gas fuel spraying(HVOGF),and the coating structureswere investigated by OM,SEM,and XRD.Meanwhile,the microhardness and crack toughness of two coatingswere compared.Moreover cavitation erosion resistance of the coatings were carried out by ultrasonic vibrationcavitation equipment in fresh water medium,and influence of different HVOF process on cavitation erosionresistance of coatings was explored.Results show that the phase compositions of the two coatings are mainlycomposed of WC and a little W2C,and a bit of metallic W was discovered in the coating sprayed by HVOGF.Compared with the coating deposited by HVOGF,the porosity of HVOLF sprayed coating has decreased about75%,and the microhardness has been improved more than20%.The coating deposited by HVOLF demonstratesmore excellent cavitation erosion resistance and its cavitation rate is only28%of the coating by HVOGF.The superior cavitation resistance of the HVOLF sprayed nanostructured WC-10Co4Cr coating is attributed to thehigher particle velocity and the lower particle temperature during the spraying process.

关 键 词：HVOF工艺 WC-10Co-4Cr 抗空蚀性能 粒子速度 

分 类 号：TG174.4[金属学及工艺—金属表面处理]