稀土对感应重熔镍基涂层界面和摩擦性能的作用机理研究

The Ni-based alloy is one of the foremost coating materials that performs well in wear and corrosion, and the alloy is widely used in a variety of special purpose application. For investigating the coating preparation ability and the characteristics of the coating of the Ni-based alloy powders prepared by high frequency induction cladding technology, the coating was prefabricated by a kind of binder cladding on steel, and the coating was remelted by high frequency induction system, The microstructure, phase structure of the coatings were investigated with a XRD, SEM, EPMA, FEGSEM, EDS, XPS and DTA, the structure characteristics of composition diffusion layer is also studied. The influence of rare earth oxides on interface morphology and composition diffusion is investigated. In addition, effects of rare earth oxides on the mechanical properties, friction and wear characteristics will be studied by the way of examining and evaluating in hardness, wear resistance. The aim of this study is mainly focused on relationship between the structure and properties of the coatings by adding rare earth oxides, the mechanism of the effect of rare earth oxides on the properties of the coatings is also investigated, and the influence of interface morphology on the properties of the coatings is discussed. Furthermore, the advantage of the project is that the results from the project can provide theoretical support for application of rare earth elements in the field of surface engineering, it is important for the protective coating of self fluxing alloy on steel components whose surface is submitted to severe conditions to obtain wear and corrosion resistance.

镍基合金具有优异的耐磨耐蚀性能，材料表面防护和强化领域得到广泛应用，本项目采用含稀土氧化物的粘结剂冷涂法在钢表面制备含稀土氧化物镍基合金涂层，通过高频感应加热对涂层重熔处理，通过借助XRD、SEM、EPMA、FEGSEM、EDS、XPS和DTA等分析手段深入研究重熔层的微观组织、结构特征和界面冶金结合状态及扩散层组织特征，探索涂层与基材结合界面形态的特征，分析界面形态的形成影响因素，研究稀土氧化物对高频感应重熔涂层界面结合及界面形态作用机理；研究扩散层合金元素的扩散机制及稀土氧化物对合金扩散的作用机理；并对涂层硬度、摩擦磨损性能进行研究，探索稀土氧化物对涂层摩擦磨损性能的作用机制，探讨界面形态对涂层性能的影响。为拓展稀土元素在表面工程领域的作用奠定理论基础，对加强金属表面强化技术，制备耐磨、耐蚀高性能复合涂层及相关材料有重要的意义。

本项目采用改进自主研发的粘结剂制备工艺及成分，研究含稀土氧化物（氧化铈和氧化镧）粘结剂对重熔层组织性能的影响，提高粘结剂性能，使粘结剂在感应重熔过程中以渣的形式浮出重熔层，容易脱除，无残留物，而且粘接剂与粉末间不会发生反应。.利用冷涂法在钢基体材料表面制备熔覆层，借助X射线衍射（XRD）、扫描电子显微镜（SEM）、电子探针（EPMA）、场发射扫描电子显微镜（FEGSEM）及能谱仪（EDS）和光电子能谱仪（XPS）研究了研究稀土氧化物对重熔层界面结构特征、界面冶金结合及扩散层作用机理。研究重熔工艺对重熔层微观组织、结构特征和界面冶金结合状态的影响；探索重熔层与基材结合界面形态的特征，分析界面形态的形成影响因素；研究稀土氧化物对高频感应重熔涂层界面结合及界面形态作用机理；研究扩散层合金元素的扩散机制及稀土氧化物对合金扩散的作用机理。磨粒磨损试验在日本产的RFT-III型往复式摩擦磨损机上进行，滑动磨损试验在德国Optimol公司制造的SRV磨损试验机和球-盘式接触方式进行，用SEM观察了涂层磨损面的组织形貌，用EDS分析涂层磨损面的成分，并对磨损后涂层的显微组织、硬度及磨损机制进行分析，研究重熔层摩擦磨损性能及强化机理，分析稀土对重熔层摩擦磨损性能的影响。研究重熔层工艺、结构与性能之间的关系。