金属粉末成形过程的裂纹预测  

Forecasting the Crack in Metal Powder Forming Process

作　　者：董林峰[1] 李从心[1] 

机构地区：[1]上海交通大学塑性成形工程系,上海200030

出　　处：《上海交通大学学报》2001年第1期90-93,共4页Journal of Shanghai Jiaotong University

基　　金：上海市汽车科技发展基金资助项目! (115 9A)

摘　　要：根据金属粉末成形的工艺过程和裂纹形成原因 ,对裂纹进行了分类 ,运用损伤力学方法分析了金属粉末成形过程中出现各类裂纹的形成机理 ,使用基于 Lee金属粉末压制模型导出了缺陷预测模型 ,模型包含了瞬时应力、应变、相对密度及它们积累作用的影响 ,因此该模型不仅定量地表示瞬时的损伤状态 ,更体现了整个加载过程应力 -应变历史进程对材料产生的劣化作用 ,对单台阶零件压制进行了模拟 ,结果显示裂纹出现在应力三轴度和应变较大部位 。This paper classified the fractures systematically based on the forming stage and causes of fractures which appeared in metal powder forming process. It also analyzed the forming mechanism of fractures using the damage mechanics method. A forecasting model was derived based on Lee's metal powder compacting model and plastic theory for porous material. Considering the affection of stress, strain, stress triaxiality instantaneously and their accumulation, this model can not only show the instantaneous damage state quantitative, but also materialize the bad affection of strain-stress's course during the whole load process. The forming process of T-shaped part was simulated with the model. The results show that the fractures appear where the strain and stress triaxiality are higher, which conforms well with the experiment.

关 键 词：金属粉末 裂纹预测 成形工艺 粉末冶金 压制模型 预测模型 损伤力学 应力 应变 

分 类 号：TF124.31[冶金工程—粉末冶金]