作　　者： ; ; ; ; ;

机构地区： 福州大学材料科学与工程学院

出　　处： 《材料热处理学报》 2009年第2期146-151,共6页

摘　　要： 基于涂层部分熔化(PM)区比例,孔隙率和结合强度,通过系列实验得到最佳喷涂工艺参数。利用XRD衍射仪,扫描电镜和透射电镜研究等离子喷涂纳米结构Al2O3-13wt%/TiO2(AT13)复合涂层的微观结构;对涂层的显微硬度和断裂韧性进行了Weibull统计,通过磨损实验建立了磨损图。研究表明,涂层存在全熔化(FM)区和PM区,关键等离子喷涂参数(CPSP)的增大促进PM区比例的减小及涂层结合强度的增大。喷涂过程中物相发生了反应,涂层中FM和PM区分别由完全和部分熔化的粒子形成。PM区存在纳米尺寸的晶体和非晶态物质,粒子间发生液相烧结。Weibull统计表明涂层显微硬度和断裂韧性的统计分布存在对应于组织的双态分布。PM区的平均显微硬度低于FM区的,而其显微硬度的分散性更大;PM区的平均断裂韧性及其分散性大于FM区。 The optimal spray parameters were determined by experiments, based on the partially melted（PM） zone percentage, porosity and bond strengh of the coatings. Microstructure of the nanostructured Al2O3-13wt % TiO2 （AT13） compound coating sprayed with the optimal spray parameters was analyzed by XRD, SEM and TEM. Microhardness and fracture toughness of the coating were studied by Weibull distribution and wear map was established by wear experiments. The results show that, nanostructured coating contains fully melted （FM）zone and PM zone, the increasing of the critical plasma spray parameter（CPSP） promote the discreasing of the PM zone percentage and the increasing of the bond strength of the coatings. The component phases of the powder reacts each other during the plasma spraying process. FM and PM zone results from fully melted droplets and partially melted particles, respectively. Nanosized crystals and amorphous particles exist in the PM zone, liquid phase sintefing operates in the PM zone. The Weibull distribution analysis shows that the distribution of microhardness and fracture toughness of the coating present a hi-modal distribution, which is correspond to the bi-modal microstructnre of the nanostructured coating. The mean value of microhardness of PM zone is higher than that of FM zone, while the dispersity is higher. The mean value and the dispersity of fracture toughness of PM zone are both higher than that of FM zone.

关 键 词： 纳米涂层 等离子喷涂 组织性能

领　　域： [金属学及工艺] [金属学及工艺]