摘要
采用SHS反应火焰喷涂技术,把Al-TiO2-B2O3铝热反应剂引入喷涂材料中,采用机械球磨和聚乙烯醇(PVA)造粒制成喷涂复合粉末,在镁合金AZ31B表面制备Al2O3基复相陶瓷涂层。利用XRD和SEM分析了喷涂复合粉末和复合陶瓷涂层的组成及形貌,并对涂层的热震性能、致密性、显微硬度和耐磨性进行测试。结果表明:复合粉末经12 h球磨后发生铝热反应,粉末呈球形及少量片状,造粒后形成相互包覆的球形结构。涂层中生成TiB2、MgAl2O4等新相。该复合涂层熔化较充分,涂层与基体结合紧密,界面处Mg元素有扩散。复合涂层热震次数可达45次,清漆封孔后,孔隙率为0%,致密性很好,最大显微硬度值达1224 HV0.1,耐磨性比镁合金基体提高8倍以上。涂层热震性能、致密性、显微硬度和耐磨性明显优于普通热喷涂陶瓷涂层。
With SHS reaction flame spraying,Al2O3-based multiphase ceramic coating was prepared on AZ31B magnesium alloy by introducing Al-TiO2-B2O3 thermite into spraying composite powder,which was prepared by mechanical ball milling and PVA granulation.XRD and SEM were used to analyze the composition and morphology of the composite powder and composite ceramic coating.The thermal shock,compactness,microhardness and wear resistance of the composite ceramic coating were investigated.The results show that thermite reaction happens in composite powder after 12 hours ball milling and globular structure coated each other is formed after granulation.TiB2,MgAl2O4 and other new phases are found in the coating.The melting rate of composite ceramic coating is high and the combination of the coating and matrix is well.Diffusion of Mg element take place in the interface of composite coating.The thermal-shock times of this coating can reach 45 times,the porosity is 0% after hole sealing with varnish,the maxima microhardness value reaches 1224 HV0.1 and wear resistance of this coating is 8 times more than that of the magnesium alloy substrate.The thermal shock performance,compactness,microhardness and wear properties of this coating are significantly better than these of the common spraying coating.
出处
《金属热处理》
CAS
CSCD
北大核心
2010年第11期50-56,共7页
Heat Treatment of Metals
基金
辽宁省教育厅创新团队项目(2009T044)
辽宁工程技术大学研究生科研立项资助项目(Y201000301)
