摘要
采用激光熔覆技术在钛合金(Ti-6Al-4V)表面制备了Al2O3/TiO2涂层,研究了添加不同含量WC对熔覆层裂纹和组织性能的影响。利用光学显微镜(OM)、扫描电镜(SEM)、X射线能谱仪(EDAX)、X射线衍射分析仪(XRD)和显微硬度计研究了激光熔覆涂层的显微结构,分析了涂层的裂纹率、成分分布、相组成和显微硬度分布情况。结果表明:当WC含量为0%20%(质量分数)时,随着WC的增加,涂层表面裂纹明显减少;添加20%WC时,熔覆层表面无裂纹,涂层与基体结合良好;添加30%WC时,熔覆层表面裂纹明显增多,涂层与基体结合区产生较大裂纹,并伴有一些细小的气孔。熔覆层内有许多未熔的Al2O3颗粒,同时,随着WC含量的增加,涂层的晶粒越来越细化,组织分布更加均匀,涂层的显微硬度明显增大。
Al2O3/TiO2 coating was fabricated on Ti-6A1-4V titanium alloy substrate by laser cladding.Effects of different contents of WC on the crack and microstructure of the clad layer were studied.The microstructure,ratio of cracks,chemical distribution,phase composition and microhardness distribution of the composite coating were investigated by optical microscope (OM),scanning electron microscope (SEM),X-ray energy spectrometer (EDAX),X-ray diffraction (XRD),and Vickers microhardness tester,respectively.The results show that cracks on the surface of the coating decrease obviously with the increase of WC content from 0%to 20%(mass fraction).When the content of WC is 20%,the cracks on the surface of the clad layer eliminate gradually,and the Al2Oa/TiOEcoating is well combined with the substrate.The surface cracks in the clad layer increase obviously with the addition of 30%WC,and relative large crack occurs in the interface layer between the clad layer and the substrate with small pores.The unmelted particles of A1203are distributed in the clad layer. Meanwhile,with the increase of WC content,the grains of the A12OJTiO2coating are becoming more and more refined,the distribution of the microstructure is more uniform,and the microhardness of the coating increases obviously.
作者
孙帅
李崇桂
李帅
张群森
Sun Shuai;Li Chonggui;Li Shuai;Zhang Qunsen(School of Materials Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;Shanghai Research &Development Center for Key Technologies of Intelligent Equipments of Ultra-Intense Laser Processing,Shanghai 201620,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2018年第12期78-82,共5页
Heat Treatment of Metals
基金
国家自然科学基金(51402189)
上海工程技术大学研究生创新项目(17KY0503)
上海市“创新行动计划”部分地方院校能力建设专项计划(16030501100)
