(1. 华南理工大学 应用化学系， 广州 510640;
2. 广州有色金属研究院 分析室， 广州 510651;
3. 中南工业大学 粉末冶金研究所， 长沙 410083)
摘 要: 建立了PIM脱脂过程中高分子高温裂解脱除的数学模型， 分析了生坯中的应力分布， 考察了恒加热速率、 恒失重速率、 保温处理工艺等对生坯应力的影响。结果显示， 生坯内气体压力、 径向应力、 切向应力分布呈现中高外低分布， 径向应力在生坯表面为零， 而切向应力在表面不为零。 与恒加热速率比较， 恒失重速率和保温处理工艺可以有效降低生坯应力，但热脱脂工艺时间仍较长。 采用恒应力方法对工艺进行优化设计， 既可以有效降低生坯内应力， 又可以大幅度缩短脱脂工艺时间。
关键字: PIM； 脱脂； 数学模型； 工艺优化
（1. Department of Applied Chemistry, South China University of Technology, Guangzhou 510640, P.R.China;
2. Guangzhou Nonferrous Metal Research Institute, Guangzhou 510651, P.R.China;
3. State Key Lab for Powder Metallurgy, Central South University of Technology, Changsha 410083, P.R.China）
Abstract:A numerical model of polymer debinding in PIM was proposed. The stress distribution in greenware was analyzed and the effects such as linear heating rate, holdingtime heating, mass loss ratecontrolled program on the stress was investigated. The results show that the distribution of inner gas pressure， radial and tangential stresses exhibit their maximum values at center and decrease as the position shifts away from the center to the surface. At the surface,the radial stress drops to zero, but the tangential stress does not. By comparison of holdingtime heating and mass loss ratecontrolled programs with linear heatingrate program, the maximum stresses at the center decrease much, but the process time shortens a little. The optimized parameters can be drawn by the isostress method to minimize the stresses and process time.
Key words: PIM； debinding； numerical model； optimized parameters
