【作者】 赵丹；

【导师】 刘志东；

【作者基本信息】 南京航空航天大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 钛合金具有密度小、比强度高、抗腐蚀性好等优异性能,其在航空航天行业中被广泛应用。但钛合金的低硬度和较差的抗耐磨性能严重地限制了其应用。本课题目的主要是研究如何通过涂层手段提高TC4的抗耐磨性能。具体研究内容包括涂层设计、实验过程和测试分析。涂层材料方面采用普通微米级和纳米结构的Al2O3+13wt.%TiO2粉末进行对比;工艺方面选择等离子喷涂工艺为预置方式,然后进行激光熔覆,并与未经激光熔覆的涂层进行对比。实验结果的测试分析结合了本课题实验目的,进行了实验的设计并制造了相应的试验辅助装备,主要分为涂层微观组织检测分析和力学性能检测分析。前者采用SEM扫描电镜对涂层的表面和横截面的进行观察,分析其形貌、结构和微观特征,同时采用XRD物相分析对涂层的物相组织进行观察分析。后者则分别通过显微硬度仪、点磨损实验、面磨损试验、拉伸试验对其涂层的显微硬度、耐磨性、结合性能进行检测分析。通过实验结果的测试分析,阐述涂层形成的过程、机理和规律,同时进一步修正实验的工艺参数,从而得到符合要求且性能更加优异的钛合金表面涂层,达到提高钛合金TC4表面耐磨性等相关性能的目标。更多还原

【Abstract】 Titanium and its alloys are widely used in avigation, aerospace and chemical industry due to their exceptionally physical and chemical properties such as low density, high specific strength and exceptional corrosion resistance. The use of titanium alloys is limited for its poor wear resistance and low hardness. The research in this dissertation is to improve the surface properties of titanium alloys by using some surface techniques. The fabrication design and tests of the coatings were implemented The Conventional micronstructured Al2O3+13wt.%TiO2 was compared with the nanostructured Al2O3+13wt.%TiO2 in the coating material research; and laser cladding was compared with the plasma spraying in the technics research. Microstructure and composition of the coating samples were achieved by means of X-ray diffraction (XRD), scanning electron microscopy (SEM). Microhardness, wear resistance and binding properties were also tested by the corresponding test facilities. The results show that the properties of the samples with ceramic coating were greatly improved, and the nanostructured ceramic coating was also exhibited a better performance than the normal coating. In addition, plasma sprayed coating with laser remelting could significantly enhance the mechanical properties by comparison with coating without treatment.更多还原