钛合金表面Ta-W-Nb/TiN涂层的制备及表征

Titanium and related alloys, as one group of the most promising structural materials, are play increasingly more important roles in many industrial applications. However, its poor performance in extreme environments with high pressure, high temerature, thermal shock, and serious corrosion risk, has retarded the further development of Titanium alloys. In this project, multi arc ion plating will be applied to fabricate the Ta-W-Nb/TiN composite coatings for improving the corrosion resistance of Titanium alloys. Following research efforts will include, but are not limited to, be focused on the microstructure controlling and characterization of of α-phase Ta and possible interfacial phases in the coatings, thermodynamic modeling of the thermal stabilities of the Ta-W-Nb/TiN composite for effectively controlling the inter-diffusion of Ta-W-Nb/TiN/substrate; analyese on thermal plasticity of Ta-W-Nb/TiN coatings as well as interfacial bonding nature , clarification on crack nucleation mechanisms by , where and modeling of thermal shock resistance. The knowledge obtained from these researches will help provide theoretical ground and practical guidance for high temperature applications of titanium and its alloys.

随着现代工业技术的不断发展，钛和钛合金在各行各业中的用量越来越大，已成为世界各国竞相开发研究、应用的关键结构材料之一。但钛合金不耐烧蚀和冲刷等特性大大限制了其在高温、高压、高速且具烧蚀、冲刷及热震性气氛环境中的应用。本项目拟采用多弧离子镀技术在钛合金表面制备Ta-W-Nb/TiN复合涂层以提高其耐烧蚀、防冲刷性能。主要开展形成α-Ta相的微观组织调控研究，实现获得α-Ta相结构的Ta-W-Nb涂层；微观表征Ta-W-Nb/TiN/钛合金基体涂层与界面合金相微结构，建立Ta-W-Nb/TiN复合涂层α-Ta相热稳定性的热力学模型，有效控制Ta-W-Nb/TiN/基体界面元素扩散行为；研究Ta-W-Nb/TiN涂层的热塑性和与基体钛合金的原子键合机理，建立其抗热震破坏模型，揭示其抗裂纹萌生机理，为钛合金的高温应用提供理论基础和实践依据。

随着现代工业技术的不断发展，钛和钛合金在各行各业中的用量越来越大，已成为世界各国竞相开发研究、应用的关键结构材料之一。但钛合金不耐烧蚀和冲刷等特性大大限制了其在高温、高压、高速且具烧蚀、冲刷及热震性气氛环境中的应用。本项目采用多弧离子镀技术在钛合金表面成功制备了结构为α-Ta相的Ta-10W /TiN复合涂层，涂层均匀、致密，厚度5-45μm可控，与基体结合紧密，可满足工程应用。同时对真空下钛合金/Ta-10W/TiN涂层体系从650-1000℃时的界面反应及元素扩散行为、涂层抗热震行为及界面处微裂纹扩展模型进行了系统的研究，结果表明Ta-10W/TiN复合涂层可以有效保护基体，使得钛合金能够在600℃-900℃的高温环境中正常使用，超过900℃时，涂层与基体发生剧烈而快速的界面反应而导致涂层失效，同等条件下TiN过渡层的存在可以显著抑制Ta-10W涂层与钛合金的界面反应和元素扩散，延缓涂层失效；涂层的抗热震性能良好，经10次热震后未发生脱落现象，并且Ta-10W/TiN复合涂层的抗热震性能优于Ta-10W涂层。研究结果可为Ta-10W/TiN涂层体系在高温、高压、高速烧蚀气氛中的工程应用提供理论依据和实践指导。