基于分子动力学的金属铝纳米切削过程研究

发布时间：2018-03-11 18:41

本文选题：分子动力学　切入点：金属铝　出处：《沈阳航空航天大学》2017年硕士论文　论文类型：学位论文

【摘要】：伴随着航空航天、医疗器械及电子通讯等行业的迅速发展,对各种高精度零部件、高精度曲面及微小构件的加工精度要求也越来越高,部分精度要求已经达到纳米级别。然而,纳米级的加工机理和规律与常规条件下的加工有着本质的区别,所以,再应用宏观的切削理论来研究纳米级切削机理及规律显然是不合适的。本文应用分子动力学(Molecular dynamics,MD)的理论及方法,建立了金属铝的纳米切削分子动力学仿真(Molecular dynamics simulation,MDS)模型,对其进行纳米切削仿真,从微观角度来探究其纳米切削过程。首先,本文对纳米切削MDS的发展及研究现状进行了详细介绍,在认真学习和研究了MD的基本理论及方法后,确定了适用于金属铝的纳米切削MDS的方法及相关切削仿真参数、仿真条件,建立了其纳米切削MDS模型,并开发出相应的仿真程序。其次,对所建立的金属铝纳米切削MDS模型进行了弛豫研究,得到了弛豫时的系统势能变化曲线并给出了弛豫时间。对模型进行了纳米切削仿真,得到切削时的瞬时原子图像、切削力、切削温度等,并对切削过程中材料的去除、已加工表面的形成及切削力、切削温度、系统势能的变化规律进行了详细分析。再次,研究了在相同的仿真条件下,不同仿真参数的变化对金属铝纳米切削过程的影响。最后,研究了在相同的仿真条件下,刀具在不同位置的磨损情况下对金属铝纳米切削过程的影响,包括切削过程中的切削力、刀具温度、工件温度的变化规律等。
[Abstract]:With the rapid development of aerospace, medical devices and electronic communication industries, the machining accuracy requirements of various high-precision parts, high-precision curved surfaces and micro-components are becoming more and more high, some of which have reached the nanometer level. The mechanism and law of nanoscale processing are essentially different from those of conventional processing, so, It is obvious that it is inappropriate to apply the macroscopic cutting theory to study the mechanism and law of nanoscale cutting. In this paper, the molecular dynamics simulation model of nano-machined aluminum is established by using the theory and method of molecular dynamics molecular dynamics (MD). Nano-cutting simulation is carried out to explore the nanoscale cutting process from the micro point of view. Firstly, the development and research status of nano-cutting MDS are introduced in detail. After studying and studying the basic theory and method of MD, The method of nano-cutting MDS suitable for metal aluminum and the relevant cutting simulation parameters and simulation conditions are determined. The MDS model of nano-cutting is established and the corresponding simulation program is developed. In this paper, the relaxation of the MDS model for nanometallic aluminum cutting is studied, the curve of the system potential energy and the relaxation time are obtained. The simulation of the model is carried out, and the instantaneous atomic image and cutting force are obtained. The material removal, the formation of the machined surface, the cutting force, the cutting temperature and the system potential energy are analyzed in detail. Thirdly, under the same simulation conditions, the change of the material, the formation of the machined surface, the cutting temperature and the potential energy of the system are analyzed in detail. The influence of different simulation parameters on the process of metal aluminum nano-cutting is studied. Finally, the influence of tool wear on the process of metal aluminum nano-cutting under the same simulation conditions is studied. Including cutting force, tool temperature, workpiece temperature, etc.
【学位授予单位】：沈阳航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG501

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