Interface energy and its influence on interface fracture between metal and ceramic thin films in nanoscale
Interface energy and its influence on interface fracture between metal and ceramic thin films in nanoscale
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DOI：
10.1063/1.3501090
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发表时间：
2010-10
影响因子：
3.2
通讯作者：
L. Liang;X. You;Hansong Ma;Yanping Wei
中科院分区：
文献类型：
--
作者：
L. Liang;X. You;Hansong Ma;Yanping Wei
通过考虑基于热力学表达式的化学键贡献和基于力学特性的结构应变贡献，建立了两种不同材料薄膜之间界面能随尺寸变化的理论模型。界面能随薄膜厚度的减小而减小，由两种材料的熔化熵、熔化焓、剪切模量等热力学和力学参数决定。基于该模型预测的部分金属/MgO和金属/Al2O3界面能与分子力学计算结果一致。进一步比较了基于原子模拟的Ag/MgO和Ni/Al2O3的界面断裂性能。界面能越小，界面的断裂强度和韧性越低。通过引入界面势和界面应力，讨论了界面能、界面强度和断裂韧性之间的内在关系。微观界面断裂韧性在纳米尺度上等于结构界面能，微观断裂强度与断裂韧性成正比。(C) 2010年美国物理研究所。(doi: 10.1063/1.3501090)
A theoretical model about the size-dependent interface energy between two thin films with different materials is developed by considering the chemical bonding contribution based on the thermodynamic expressions and the structure strain contribution based on the mechanical characteristics. The interface energy decreases with reducing thickness of thin films, and is determined by such available thermodynamic and mechanical parameters as the melting entropy, the melting enthalpy, the shear modulus of two materials, etc. The predicted interface energies of some metal/MgO and metal/Al2O3 interfaces based on the model are consistent with the results based on the molecular mechanics calculation. Furthermore, the interface fracture properties of Ag/MgO and Ni/Al2O3 based on the atomistic simulation are further compared with each other. The fracture strength and the toughness of the interface with the smaller structure interface energy are both found to be lower. The intrinsic relations among the interface energy, the interface strength, and the fracture toughness are discussed by introducing the related interface potential and the interface stress. The microscopic interface fracture toughness is found to equal the structure interface energy in nanoscale, and the microscopic fracture strength is proportional to the fracture toughness. (C) 2010 American Institute of Physics. [doi:10.1063/1.3501090]