氦氖激光陀螺铟封界面数值模拟及失效机理研究

发布时间：2018-07-28 17:48

【摘要】：He-Ne激光陀螺作为一种常用的惯性制导器件,在现代航空、航海、航天等国防事业领域应用广泛。电极与谐振腔的热压封接是He-Ne激光陀螺生产过程中的核心工艺之一,封接界面的失效会直接造成谐振腔内真空放电环境的改变,降低产品的有效寿命。文章基于分子动力学和第一性原理理论对阴极Al/In和阳极Cu/In界面进行数值模拟,研究了Al(001)/In(001)界面原子扩散以及屈服失效过程,分析界面的失效机理,旨在为进一步优化谐振腔与电极铟封工艺提供理论指导。主要研究内容如下:1)基于第一性原理理论,对Al、Cu、In理想晶体进行结构优化,对优化后三种晶体各低指数表面模型的弛豫状态、表面能和表面态密度进行综合分析,结果表明Al(111)、Cu(111)、In(001)三个表面最稳定。2)以稳定表面分别构建Al(111)/In(001)和Cu(111)/In(001)界面初始模型,通过对比优化后两种界面的界面能、吸附能和解离能数据,并进一步分析界面附近原子的弛豫状态,结果发现理想Cu(111)/In(001)界面比Al(111)/In(001)界面更加稳定,界面强度更高;界面的电子态密度分布显示Al/In和Cu/In原子电子态在一定能量区间出现重叠,界面电荷密度及差分电荷密度图显示界面处原子间形成共价键作用,其中Cu(111)/In(001)界面电荷转移程度更高。3)基于2NN-MEAM原子作用势,采用经典分子动力学研究了不同工艺温度及压力下Al(111)/In(001)和Cu(111)/In(001)界面拉伸强度的变化规律,计算结果表明阴极封接最佳工艺参数为463K、4MPa,阳极封接最佳工艺参数为423K、5MPa,相同温度和压力下Cu(111)/In(001)界面拉伸强度高于Al(111)/In(001)界面。4)对Al(001)/In(001)界面原子扩散以及拉伸失效过程进行分析,发现界面失效表现为界面层及铟层内部产生缺陷,进一步形成气体渗透通道,造成谐振腔内部真空环境发生改变。
[Abstract]:As a common inertial guidance device, He-Ne laser gyroscope is widely used in the fields of modern aviation, navigation, space and other defense industries. The hot pressure sealing of electrode and resonant cavity is one of the core processes in the production process of He-Ne laser gyro. The failure of sealing interface will directly cause the change of vacuum discharge environment in the resonator and reduce the product Based on the molecular dynamics and the first principle theory, the numerical simulation of the cathode Al/In and the anode Cu/In interface is carried out. The atomic diffusion and yield failure process of Al (001) /In (001) interface are studied, and the failure mechanism of the interface is analyzed. The purpose is to provide theoretical guidance for further optimization of the resonant cavity and the electrode indium sealing process. The following contents are as follows: 1) based on the theory of first principle, the structure optimization of Al, Cu, In ideal crystal is optimized. The relaxation state, surface energy and surface state density of each low index surface model of the three crystals are synthetically analyzed. The results show that Al (111), Cu (111), In (001) and the most stable.2) are constructed to stabilize the surface of Al (111) /In (001) respectively. With the initial model of Cu (111) /In (001) interface, by comparing the interfacial energy of the two interfaces, the adsorption energy and dissociation energy data are compared, and the relaxation state of the atoms near the interface is further analyzed. The results show that the ideal Cu (111) /In (001) interface is more stable than the Al (111) /In (001) boundary and the interface strength is higher; the distribution of electronic density of states of the interface shows Al/In The electron state of Cu/In overlaps in a certain energy range, the interface charge density and the difference charge density map show the covalent bond between atoms at the interface, and the charge transfer degree of Cu (111) /In (001) interface is higher.3) based on the 2NN-MEAM atom action potential, using the classical molecular dynamics to study the Al (1) under the different process temperature and pressure. 11) the variation of the tensile strength of /In (001) and Cu (111) /In (001) interface. The results show that the best process parameters of the cathodic bonding are 463K, 4MPa, and the optimum technological parameters of the sealing are 423K, 5MPa, the tensile strength of the Cu (111) /In (001) interface under the same temperature and pressure is higher than the Al (111) /In (001) interface.4). The failure process is analyzed. It is found that the interface failure shows the defects in the interface layer and indium layer, and the gas permeation channel is further formed, which causes the change of the vacuum environment inside the resonator.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN96

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