Simulation and experimental study on deformation during micro-aluminum powder ball milling process
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 power-law 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 R2 is 0.999 46,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.
万方数据
维普
