基于液相烧结过程的硬质合金表面Al2O3/TiC涂层一步制备机理研究

项目名称： 基于液相烧结过程的硬质合金表面Al2O3/TiC涂层一步制备机理研究

项目编号： No.51302023

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 杨梅

作者单位： 成都理工大学

项目金额： 25万元

中文摘要： Al2O3具有高热稳定性、化学稳定性、高硬度、抗氧化与扩散磨损能力，被广泛用作高速切削领域中的硬质合金刀具涂层。采用气相沉积法和溶胶-凝胶法时，涂层制备与硬质合金基体制备是分步进行的，两次加热过程会对硬质合金基体的微观组织与性能产生不利影响，且TiCxN1-x预涂层与Al2O3涂层难以一步完成。本项目将硬质合金生坯在Al2O3@TiO2核/壳结构溶胶中浸渍涂层，然后直接进行液相烧结，实现硬质合金表面Al2O3/TiC涂层一步制备。项目探索涂层在出现WC-Co伪二元共晶液相的硬质合金基体表面的形成机制、相变过程和生长规律；分析涂层与基体的协同烧结行为、固/液界面元素扩散与反应机理；表征界面微观组织结构、物理力学性能和残余应力状态；并与气相沉积法和溶胶-凝胶法对比，研究Al2O3/TiC 涂层的切削行为和磨损机理。本项目拓展了硬质合金Al2O3 涂层的研究领域,为新型涂层技术研究提供理论支撑。

中文关键词： 液相烧结；硬质合金；涂层；Al2O3/TiC；溶胶-凝胶

英文摘要： Due to high thermal stability, chemical stability, high hardness, oxidation resistance and diffusion wear resistance, Al2O3 has been widely used as coating materials of cemented carbide cutting tools for high speed machining. As for the preparation of Al2O3 coating by vapor deposition method and sol-gel method, the preparation processes of cemented carbide substrates and coatings are separated, and heating twice will do harm to the microstructure and properties of the substrate. Further more, the TiCxN1-x film and Al2O3 film are hard to be fabricated at one time. In the project, the cemented carbide green bodies are dip coated in Al2O3@TiO2 core-shell sols, the coated green bodies are directly sintered to achieve the Al2O3/TiC coated cemented carbide. The forming mechanism, phase evolution, and growth mechanism of Al2O3/TiC film are investigated, the sintering behavior of Al2O3/TiC film and substrate, interface diffusion and reaction are analyzed, the microstructure, properties and residual stress are characterized；the cutting performance and wear mechanism of Al2O3/TiC coating prepared by vapor deposition method and sol-gel method are compared with the film by one step method. The project expands the research field of Al2O3 coatings on cemented carbide, the research results can act as theoretical support for no

英文关键词： Liquid phase sintering；Cemented carbide；Coating；Al2O3/TiC；Sol-gel