前角对单晶镍纳米加工影响的分子动力学仿真

发布时间：2018-04-12 15:39

本文选题：分子动力学 + 单晶镍　；参考：《东北大学学报(自然科学版)》2017年10期

【摘要】：应用分子动力学仿真研究了单晶镍的纳米加工过程.通过研究加工力的变化规律,发现加工初期加工力剧烈波动与工件中产生了较大体积的层错结构有关.采用不同前角的刀具进行了一系列加工仿真,结果表明:在刀具前角的增大过程中,加工力及前刀面与切屑之间的摩擦系数逐渐减小;由于前角的增大使刀具对切屑的推挤作用与切屑的整体弯曲减弱,切屑高度增加及切屑中完好的FCC原子比也逐渐增加;工件亚表面的缺陷原子数目逐渐减少,损伤深度也呈减小趋势.采用负前角加工时,工件亚表面损伤较严重,出现了层错四面体结构和LC位错;工件内部高温原子数随刀具前角的增大而逐渐减少,并且工件的温度分布以刀具圆角为中心向工件内部辐射.
[Abstract]:The process of nanocrystalline nickel fabrication was studied by molecular dynamics simulation.By studying the changing law of machining force, it is found that the violent fluctuation of machining force at the beginning of processing is related to the formation of large volume stacking fault structure in the workpiece.A series of machining simulations were carried out with the tools with different front angles. The results show that the machining force and the friction coefficient between the cutting face and chip gradually decrease during the increase of the front angle of the cutting tool.Due to the increase of the front angle, the squeezing effect of the cutting tool on chip and the overall bending of the chip are weakened, the chip height increases and the FCC atom ratio in the chip increases gradually, and the number of defective atoms on the sub-surface of the workpiece decreases gradually.The depth of damage also tended to decrease.When the negative front angle is used, the subsurface damage of the workpiece is more serious, the laminated tetrahedron structure and LC dislocation appear, and the number of atoms at high temperature in the workpiece decreases with the increase of the cutting tool front angle.And the temperature distribution of the workpiece radiates to the inside of the workpiece with the tool corner as the center.
【作者单位】：东北大学机械工程与自动化学院;
【基金】：国家自然科学基金资助项目(51375082)
【分类号】：O614.813;TB383.1

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