典型材料刻划过程的仿真分析与试验研究

发布时间：2018-09-14 11:03

【摘要】：微纳米刻划是测试薄膜、涂层和聚合物等材料抗摩擦磨损性的重要手段，也是加工微纳米器件结构的重要方法。材料的宏观性能是由其内部微观力学行为所决定的，并且刻划过程中试样在探针强大的耦合作用下，亚表面层材料会产生相变、塑性变形、位错和断裂等不同微观力学行为。纳米刻划过程中的这些力学行为对材料力学性能测试结果和刻划加工沟槽质量有重要联系。因而，如何提高材料的可加工性和材料性能保持性成为研究微纳米刻划过程研究的关键。同时，材料在刻划加工过程中会受到材料表面性质和刻划工艺参数等方面因素影响。因此，针对以上问题，本文讨论了不同加工条件和不同表面状态对刻划加工沟槽质量的影响，用压入测试比较了单晶硅不同晶面和在不同压入温度下的硬度；为验证前文的仿真以及突破对国外进口微纳米刻划测试仪器的依赖，，本文设计了微纳米刻划测试装置，开展了相应的制造、集成、检测调试和针对典型材料的刻划试验。具体内容表现在如下几个方面：（1）建立了典型材料无氧铜的光滑粒子流模型，设定了光滑粒子流模型的模拟参数；针对表面残余应力对刻划加工沟槽的影响，本文对无氧铜切削表面和完整表面进行了仿真。通过对比，分析了残余应力对刻划切屑、刻划加工沟槽质量和刻划力的影响。（2）提出了多针刻划的新刻划方法，建立了单晶铜的传统单针连续刻划和双针刻划的分子动力学模型，并设定了分子动力学模拟参数。通过对比不同刻划进给量、刻划深度和刻划晶向下多针刻划与传统单针刻划创成的沟槽表面质量，Von Mise应力分布和切向、侧向刻划力。通过仿真对比，双针刻划方法不但能提高材料刻划加工的沟槽质量，还能提高材料加工效率。（3）建立了单晶硅的压入测试分子动力学模型，并结合晶体缺陷分析技术、晶体结构和纳米力学理论分析了纳米压入过程中金刚石压针下方亚表面层单晶硅的相变过程。对比了单晶硅压入阶段三个晶面的静水压力、相变原子数、载荷-位移曲线和Von Mise应力，建立了单晶硅宏观硬度和微观相变、塑性变形之间的联系。针对刻划过程中的摩擦热，本文研究了压痕温度对单晶硅硬度的影响，并解释了压痕卸载阶段单晶硅的粘连行为。（4）在仿真分析基础上，本文提出了一种可与奥林巴斯显微镜集成的卧式结构微纳米刻划测试装置。利用双剪切梁结构和八片应变片设计了二轴微力传感器，并对其进行了校核计算，标定解耦分析和静态特性分析。本文对该装置的关键部件如精密驱动单元、精密检测单元和整机进行了有限元静力学分析，并分析了该装置的误差来源和整机性能。最后，利用自制的装置开展了单晶硅和单晶铜在不同刻划深度下的刻划试验，分析了单晶硅和单晶铜刻划去除机理，以及刻划深度对两种材料加工沟槽质量的影响。
[Abstract]:Micro-nano characterization is an important means of testing the friction and wear resistance of thin films, coatings and polymers, and is also an important method of fabricating the structures of micro / nano devices. The macroscopical properties of the material are determined by its internal micromechanical behavior. In the process of characterization, different micromechanical behaviors such as phase transition, plastic deformation, dislocation and fracture will occur in the subsurface layer material under the strong coupling of the probe. These mechanical behaviors are related to the mechanical properties of materials and the quality of grooves. Therefore, how to improve the processability and performance retention of materials has become the key to the study of micro-nano characterization process. At the same time, the material is affected by the surface properties and process parameters. Therefore, the effects of different processing conditions and different surface states on the quality of grooves are discussed, and the hardness of monocrystalline silicon in different crystal planes and at different indentation temperatures is compared by indentation test. In order to verify the above simulation and break through the dependence on imported micro-nano-scale test instruments, this paper designs a micro-nano profiling testing device, and develops the corresponding manufacturing, integration, testing and debugging, as well as characterization tests for typical materials. The specific contents are as follows: (1) the smooth particle flow model of typical material oxygen free copper is established, and the simulation parameters of the smooth particle flow model are set up, and the influence of surface residual stress on the marking of grooves is discussed. In this paper, the cutting surface and the complete surface of oxygen free copper are simulated. Through comparison, the influence of residual stress on chip, grooves quality and scratching force is analyzed. (2) A new method of multi-needle scratching is proposed. The molecular dynamics models of single crystal copper with single needle continuous characterization and double needle delineation were established and the molecular dynamics simulation parameters were set up. The surface quality of grooves generated by different feed rates, depth and grain down and conventional single needle are compared. The distribution of Von Mise stress, tangential force and lateral force are obtained by comparing the surface quality of grooves created by conventional single needle method. By simulation and comparison, the double-needle method can not only improve the groove quality of material marking, but also improve the processing efficiency of material. (3) the molecular dynamics model of single crystal silicon indentation test is established, and the crystal defect analysis technique is combined. The crystal structure and nanomechanical theory were used to analyze the phase transition process of monocrystalline silicon under diamond pin in the process of nanocrystalline indentation. The hydrostatic pressure, atomic number of phase transition, load-displacement curve and Von Mise stress of three crystal planes in the process of single crystal silicon indentation are compared. The relationship between macro hardness and micro phase transformation and plastic deformation of single crystal silicon is established. In this paper, the effect of indentation temperature on the hardness of monocrystalline silicon is studied, and the adhesion behavior of monocrystalline silicon during indentation unloading is explained. (4) on the basis of simulation analysis, In this paper, a kind of horizontal structure micro-nano scribing testing device which can be integrated with Olympus microscope is presented. A two-axis micro-force sensor was designed using a two-shear beam structure and eight strain gauges, and its calibration, decoupling analysis and static characteristic analysis were carried out. In this paper, the finite element statics analysis of the key parts of the device, such as precision drive unit, precision detection unit and the whole machine, is carried out, and the error source and performance of the device are analyzed. Finally, the experiments of single crystal silicon and single crystal copper at different scratching depths were carried out by using a self-made device. The removal mechanism of single crystal silicon and single crystal copper as well as the effect of etching depth on the grooves quality of the two materials were analyzed.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

【参考文献】