Pd/TiAl界面结合强度和热稳定性的基础研究

项目名称： Pd/TiAl界面结合强度和热稳定性的基础研究

项目编号： No.50871124

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 龚浩然

作者单位： 中南大学

项目金额： 35万元

中文摘要： 氢分离与纯化用钯膜具有优异的氢渗透性和选择性、良好的力学性能和热稳定性等，不过钯膜与多孔支撑体之间的界面结合问题长期以来一直是困扰人们的一个科学难题。本项目选择Pd膜与TiAl支撑体之间的界面，系统研究了Pd/TiAl界面的结合强度、热稳定性以及微量元素对界面性能的影响等。采用第一性原理计算和实验手段获得Pd/TiAl界面的界面能、结合强度和热稳定性等物理性能；分别研究了Pd/TiAl界面性能与界面原子结构、电子结构和化学键的内在关系。计算与实验结果表明，Pd/TiAl界面的结合强度较高，具有负的界面能，同时在773K时是热稳定的，因而TiAl是透氢Pd膜一种不错的支撑体；C、N和O原子从能量上来说容易存在于Pd/TiAl界面，并能提高界面的结合强度和使用寿命，而Cr和V杂质原子会增加Pd/TiAl界面的界面能，因此应该将界面处Cr和V原子的含量降到最低。本项目获得了Pd/TiAl界面结合强度和热稳定性的本质规律，在APL、 Inter. J. Hydrogen Energy和Intermetallics等国际知名期刊上发表论文9篇，培养的博士生获得了教育部博士生学术新人奖。

中文关键词： Pd/TiAl界面；结合强度；热稳定性；第一性原理计算

英文摘要： Palladium membranes for hydrogen separation and purification have excellent permeability and selectivity of hydrogen, wonderful mechanical properties and thermal stability, etc. The interface cohesion between Pd and various supports, however, has become a challenging problem to the lifetime of Pd membranes. In this project, the interface between Pd and TiAl is selected for a systematic study of the cohesion property and thermal stability of Pd/TiAl interfaces, as well as the effects of trace elements on interface properties, etc. First principles calculations and various experimental methods have been conducted to obtain the physical properties of the interfaces, such as interface energy, cohesion strength and thermal stability, the intrinsic relationships between interface properties and atomic structure, electronic structure as well as chemical bonding. Computational and experimental results show that the Pd/TiAl interfaces have high cohesion strength, negative interface energy, and good thermal stability at 773K, suggesting that TiAl should be a good support for Pd membranes. It is also revealed that C, N, and O atoms are energetically favorable in Pd/TiAl interfaces and could improve the cohesion strength and lifetime of Pd/TiAl interfaces, while Cr and V impurity atoms would increase the interface energy of Pd/TiAl interface, implying that the Cr and V impurity atoms should be reduced to a minimum level. This project is a systematic study of intrinsic mechanisms of cohesion strength and thermal stability of Pd/TiAl interfaces. Under the support of this project, nine scientific papers have been published in prestigious international journals such as APL, Inter. J. Hydrogen Energy, and Intermetallics, etc, and a PhD candidate has won the Scholarship Award for Excellent Doctoral Student granted by Ministry of Education.

英文关键词： Pd/TiAl interface; Cohesion property; Thermal stability; First principles calculation