摘要
采用有限元软件Marc中的Shima-Oyane屈服准则,对NiFe2O4基金属陶瓷粉末在冷压过程中压坯的相对密度、应力-应变分布进行有限元模拟,分析了相对密度分布不均匀的原因以及相对密度梯度对产生压制缺陷的影响,建立了压坯相对密度和断裂韧性之间的关系,并进行了相关的试验验证。结果表明,在不同压制力下得到的压坯最终相对密度大概可分为3个区域,随着压制力的增大,3个区域的相对密度和相对密度差均增大,且相对密度差的增大促进了生坯缺陷的产生。试验结果证明了模拟结果的准确性,压制力越大,产生的缺陷越严重,压制产生缺陷的区域最有可能出现在两个相对密度差较大的过渡处以及应力、应变较大处。
The Shima-Oyane yield criteria within Marc finite element software was used to simulate variation and distribution of relative density and stress-strain in NiFez 04 matrix cermet powder cold pressing process. Causes for the nonuniform distribution of relative density and influence of relative density gradient to defects were analyzed. The relationship between relative density and fracture toughness was established, and it was experimentally validated. The results show that there three different regions of relative density exist in compact under different pressing force. The relative density and relative density difference of those three regions increase with the pressing force increasing, and the vast of relative density difference promotes green defects. The simulation result is verified by the test. The greater pressing force,defects becomes more obvious and serious. The defects of compact are most likely to appear in the transitive region where the relative density difference or stress-strain is large.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2014年第12期141-145,共5页
Materials Reports
基金
国家自然科学基金(51175445)
科技部国际合作专项(2010DFA52130)
关键词
粉末压制
有限元
屈服准则
数值模拟
缺陷
powder compaction, finite element, yield criteria, numerical simulation, defects
