粉末压制中粉末形状对粉体力学行为的影响  

Influence of powder shape on mechanical behavior of powder in powder compaction

作　　者：张炜 袁传牛 萧伟健 陈荣昕 张宁 刘焜[3] Zhang Wei;Yuan Chuanniu;Xiao Weijian;Chen Rongxin;Zhang Ning;Liu Kun(School of Mechanical and Automotive Engineering,Fujian University of Technology,Fuzhou 350118,China;Fujian Key Laboratory of Intelligent Machining Technology and Equipment,Fujian University of Technology,Fuzhou 350118,China;Institute of Tribology,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]福建工程学院机械与汽车工程学院,福建福州350118 [2]福建工程学院福建省智能加工技术及装备重点实验室,福建福州350118 [3]合肥工业大学摩擦学研究所,安徽合肥230009

出　　处：《锻压技术》2023年第7期138-148,共11页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51975174);福建省自然科学基金资助项目(2020J01869)。

摘　　要：针对粉末压制中的粉末形状与粉体力学行为的关联问题,基于离散单元法建立了铁基粉末的单轴压制模型,分析了压制中粉末形状对致密化特征、微观接触力以及宏观应力等力学行为的影响规律。结果表明:在压制过程中粉体的孔隙率随形状系数AR的减小而降低,配位数随形状系数AR的减小而增加。粉体接触力各向异性随形状系数AR的减小而逐渐增强,而各形状粉体的接触各向异性系数a_(c)、a_(n)、a_(t)均经历从突增过渡到稳定阶段的变化过程。此外,粉体的压制应力快速增加阶段所占比例会随形状系数AR的减小而增大;粉末形状系数AR越小,体系内应力的分布范围越集中。将进一步拓展粉末压制中力学行为的研究理论基础,为改善粉末零件的致密性提供方法指引。For the relationship problem between powder shape and powder mechanical behavior in powder compaction,a uniaxial compaction model of iron-based powder was established based on discrete element method,and the influence laws of powder shape on mechanical behaviors such as densification characteristics,microscopic contact force and macroscopic stress during compaction process were analyzed.The results show that during the compaction process,the porosity of powder decreases with the decreasing of shape coefficient AR,and the coordination number increases with the decreasing of shape coefficient AR.The anisotropy of powder contact force gradually increases with the decrease of the shape coefficient AR,while the contact anisotropy coefficients a_(c),a_(n) and a_(t) of powders with various shapes all undergo a change process from a sudden increase to a stable stage.In addition,the proportion of rapid increase stage in the compression stress of powder increases with the decreasing of shape coefficient AR,and the smaller the powder shape coefficient AR,the more concentrated the distribution of the internal stress in the system.Thus,the research theoretical basis of the mechanical behavior in powder compaction is further expanded to provide method guidance for improving the compactness of powder parts.

关 键 词：粉末颗粒形状 粉末压制 离散元法 接触力 应力 

分 类 号：TF121[冶金工程—粉末冶金]