微米级铝粉球磨过程中形变的仿真和实验研究  

Simulation and experimental study on deformation during micro-aluminum powder ball milling

作　　者：张昌松[1] 张白亮 高晓阳 ZHANG Changsong;ZHANG Bailiang;GAO Xiaoyang(College of Mechanical and Electrical Engineering,Shanxi University of Science and Technology,Xi'an 710021,China)

机构地区：[1]陕西科技大学机电工程学院,西安710021

出　　处：《材料科学与工艺》2024年第5期58-66,共9页Materials Science and Technology

基　　金：西安近现代化学研究所开放合作创新基金项目(SYJJ200304).

摘　　要：小粒径的铝粉在燃烧时易形成团聚,会严重影响铝粉的燃烧效率。铝(Al)与聚四氟乙烯(PTFE)通过基于机械活化原理的行星式球磨机工艺制备出的含能材料可以有效地解决团聚问题。本文采用仿真与实验相结合的方法,研究微米级铝粉在球磨的过程中破碎前的塑性变形以及破碎后的粒径变化。由于微米级粉体与磨球尺寸跨度过大,所以采用多尺度仿真,分别对磨球的相对速度分布、粉体应力能量分布以及粉体塑性变形过程中的能量变化进行研究。结果表明:磨球相对速度的法向分量分布呈幂律分布,且77%的碰撞集中在低速区间;对比粉体的应力能量分布与塑性变形时的能量变化,可以得到粉体的形态变化以及不同状态下的粉体数量,塑性变形阶段的最高能量为1.102×10^(-9)J,且粉体应力能量在1.102×10^(-9)J以下的占比为48.75%;对球磨实验中粒径变化进行曲线拟合,其判定系数R^(2)为0.999 46,数值接近于1,具有较强的可预测性;结合破碎前的塑性变形,可以实现对球磨任意时间后的颗粒粒径的预测。Aluminum powder with small particle size is prone to agglomeration during combustion,which seriously affects the combustion efficiency of aluminum powder.Aluminum(Al)and polytetrafluoroethylene(PTFE)can effectively solve the agglomeration problem by preparing energetic materials using a planetary ball mill process based on the principle of mechanical activation.This article adopts a combination of simulation and experiment to study the plastic deformation before crushing and the particle size change after crushing of micron-aluminum powder during ball milling.Due to the large size span between micrometer-sized powders and grinding balls,multi-scale simulations were used to study the relative velocity distribution,powder stress energy distribution,and energy changes during powder's plastic deformation process of the grinding balls.The results show that the normal component distribution of the relative velocity of the grinding ball follows a powerlaw distribution,and 77% of collisions are concentrated in the low-speed range.By comparing the stress energy distribution of powders with the energy changes during plastic deformation,the morphological changes of powders and the quantity of powders in different states can be obtained.The highest energy during plastic deformation is 1.102×10^(-9)J,and the proportion of powder stress energy below 1.102×10^(-9) J is 48.75%.The curve fitting of particle size changes in ball milling experiments shows that the judgment coefficient R^(2) is 0.99946,which is close to 1 and indicates a strong predictability.By combining the plastic deformation before crushing,it is possible to predict the particle size after any given time of ball milling.

关 键 词：多尺度仿真 行星式球磨机 微米级铝粉 机械活化 形变机理 

分 类 号：TH164[机械工程—机械制造及自动化]