摘要
粉末冶金材料由于其制造工艺的特点,强度和寿命对微缺陷(夹杂、气孔、表面划伤)十分敏感,导致了粉末冶金材料的破坏具有较大的分散性,使得寿命预测更为困难.本文根据国内粉末材料中缺陷的分布特点,基于文献[7～9]中概率断裂分析的思路,对原有方法进行了修正和推广,重新给出了缺陷在表面、亚表面以及内部时的定义及缺陷在这些不同位置时出现概率断裂的确定方法,建立了一个可考虑缺陷形状、大小、位置等分布特征的粉末冶金材料寿命预测概率模型,并基于此计算了不同尺寸缺陷位于不同位置时材料的失效概率及总失效概率.分析表明:所给出的方法可以很好的表征国内工艺条件下粉末冶金材料缺陷的概率特征对强度寿命的影响,方法是有效的.
Due to manufacturing characteristic, the strength and life of powder metallurgy alloy are sensitive to micro defects,such as nonmetallic inclusion ,pores,and nicks on the surface. A distinct character of failure of this kind of material is scatter,which makes life prediction more difficult. In this paper,based on the defect populations of domestic PM alloy and some probability failure methods established in reference [7- 9] ,definition of the probability for the presence of a defect inside the surface,sub-surface and internal region is given first, and then a probabilistic model is set up, which can calculate the failure probability caused by defects having different shapes and different sizes, being in different regions, and also can calculate the total failure probability. It is concluded that the method can describe the effect of probabilistic character of defects on the strength and life of PM alloy,and it is proved to be valid.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2005年第6期951-957,共7页
Journal of Aerospace Power
关键词
航空
航天推进系统
粉末冶金
缺陷
临界尺寸
概率
aerospace propulsion system
probabilistic powder metallurgy
defects
critical size
probabilistic
