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很多参数都决定着热喷涂涂层的质量,如喷涂粉末性质、供粉状态、粉末的形貌、动力系统以及喷涂环境等。但在这些因素中,涂层与基材间的结合力是最基本的评价指标。为了使涂层和基材间具有良好的结合力,需要对基材进行表面清洁和预处理。通常使用有机溶剂对基材除油去污,并进行喷砂处理增大基材的表面粗糙度。但由于基材(如陶瓷)本身的性质以及形状,机械处理易造成基材的剥落或对整体性能产生不利影响。为获取一种合适的预处理工艺,科研工作者开展了大量预处理方式的研究,如水射流技术,干冰喷射清理,热处理等。其中激光烧蚀法是进行基材预处理的有效技术手段。此工作的目的是为了研究持续时间为10ns的Q开关Nd:YAG近红外激光发射的单束或复合式脉冲激光所引发的改性效应以及对界面结合力的影响,以陶瓷基复合材料上喷涂的氧化铝涂层为研究对象。结果表明,激光处理手段可引发材料的机械效应(锥形结构的形成)和化学效应,对涂层的结合性能可以起到良好的改性作用。
Many parameters determine the quality of the thermal spray coating, such as the nature of the spray powder, the state of the powder, the morphology of the powder, the power system, and the spray environment. However, among these factors, the binding force between the coating and the substrate is the most basic evaluation index. In order to have a good bond between the coating and the substrate, the substrate needs to be surface cleaned and pretreated. Usually use organic solvent degreasing the substrate, and sandblasting to increase the surface roughness of the substrate. However, due to the nature and shape of the substrate (eg, ceramic) itself, mechanical handling can easily cause the substrate to peel off or adversely affect the overall performance. In order to obtain a suitable pretreatment process, researchers carried out a large number of pretreatment methods, such as water jet technology, dry ice jet cleaning, heat treatment and so on. Among them, laser ablation method is an effective technique for substrate pretreatment. The purpose of this work was to investigate the modification effect caused by a single-beam or complex pulsed laser with a Q-switched Nd: YAG near-infrared laser with a duration of 10 ns and its effect on the interfacial adhesion to a ceramic matrix composite Alumina coating as the research object. The results show that laser treatment can induce the mechanical effect (the formation of tapered structure) and the chemical effect of the material, and can improve the bonding property of the coating.