基于离散元法,综合考虑重力、接触力、阻尼、摩擦、范德华力等多种作用力的影响,建立了粉末流动温压过程中粉末堆积的数学模型,对相同材料不同粒径的二元颗粒粉末和相同粒径不同材料的二元粉末颗粒的混粉过程进行了研究。通过实验研究和数值模拟的结合。得到了一个不同数量比的二元堆积的密度规律:在大小粒子直径比为10,当小粒子是大粒子数量的300倍时,获得的最大堆积密度为0.824。通过实验验证了相同粒径不同密度的二元粉末颗粒的填充模拟过程,得到了一致的实验结果。研究结果有效地验证了离散元数学模型的正确性及相关数值模拟的实用性。
In this paper based on discrete element method, mathematic model on metal powder packing in powder warm flow compaction was founded, considering the gravity, contaeting forces, damping, friction forces and Van Der Waals Interaction (VDWI) among the particles. The powder packing processes were simulated for both the same powder particles composed of two different diameters and two different powder packing with the same diameter. In combination with experiment study, a density law for dual powder packing by a series of different numerical ratio was obtained. As the radius ratio is 10, if the number of small particles is 300 times of that of large particles, the maximum packing density is 0. 824. The experimental results are consistent with the filling simulation process for the same size but different densities of binary powder particles. The obtained results validated effectively the correctness of discrete element mathematical model and practicality of associated numerical simulation.