Integrated Analyses on Creation-Structure-Deformation of Functional Thin-Film Materials Using Molecular Dynamics Method and Assessment of Their Integrity

薄膜涂层材料在功能上有着广泛的应用。然而，在工程应用过程中，必须保证其完整性。本项目系统分析了涂层薄膜和衬底在涂层过程中的微结构变化，以及与微结构变化相关的后续变形特性。采用射频溅射工艺，在硼硅酸盐玻璃衬底上涂覆金属铝、氧化铝（Al_2O_3）和碳化硅（SiC）陶瓷，制备了多种薄膜涂层材料。对制备的材料的力学性能进行了研究，研究的性能包括：表面粗糙度、孔隙率、涂层硬度和涂层材料的抗弯强度。澄清了这些性能之间的相互关系，包括与涂层条件的关系。建立了一种基于分子动力学（MD）的新方法，可以对溅射过程、膜结构和涂层材料的强度特性进行综合分析。用该方法对铝在硅衬底上的溅射进行了分析。发现随着入射能量的增大，被涂膜中原子的占据率增加。采用平行于膜与基体界面方向加载的方法，研究了铝涂层材料的抗拉强度。分析结果表明，涂层过程中孔隙的形成导致了强度的降低。结果表明，低密度、高孔隙率涂层材料抗压痕变形能力较弱。分析结果与实验结果的对比表明，本文提出的MD方法对薄膜涂层材料的加工、结构和变形分析是有效的，可用于薄膜涂层材料的完整性评价。少

Thin-film coated materials have a wide application in their functional usages. It is required, however, that the integrity should be guaranteed during their engineering applications, In this project, systematic analyses have been made on variations in microstructures of coated thin-films and substrates during coating processes as well as their properties of the subsequent deformation associated with the microstructural variations.By an RF sputtering procedure, various thin-film coated materials were prepared by coating aluminum metal, alumina (Al_2O_3) and silicon carbide (SiC) ceramics on borosilicate glass substrates. Mechanical properties of the prepared materials were investigated, and investigated properties are as follows, surface roughness, porosity, hardness of coated films and bending strength of coated materials. Interrelations among these properties were clarified including the relations with coating conditions.A new procedure using molecular dynamics (MD) was established so … More that integrated analyses could be executed on sputtering processes, the resultant film-structures as well as the strength properties of coated materials. The sputtering of Al on silicon (Si) substrate was analyzed by using the proposed procedure. The occupancy ratio of atoms in the coated film was found to increase for larger incident energy. The tensile strength of Al coated material was examined by loading in the direction parallel to the interface between film and substrate. The analytical result showed the reduction in strength caused by the pore formation during coating process. It was clarified that the material coated by the film with lower density and higher porosity had lower resistance to the indentation deformation. By comparison between analytical and experimental results, it was concluded that the proposed MD procedure was effective to the analyses of processing, structure and deformation of thin-film coated materials and was suggested to be applicable to the integrity evaluation of such materials. Less