摘要
研究了不同Ce添加量对压铸AZ91D合金高周疲劳性能的影响。在应力比R=0.1条件下对不同Ce含量的镁合金进行高周疲劳试验,利用升降法计算合金的疲劳强度。结果表明:随着Ce的添加,AZ91D合金的组织细化,合金中孔隙的数量降低,分布趋于均匀;在循环基数Nf=1×107条件下,合金的室温疲劳强度从96.7 MPa分别提高到106.3 MPa(1%Ce)和105.5 MPa(2%Ce);疲劳裂纹萌生于合金内部的孔隙和夹杂位置,并沿着晶粒边界扩展;合金中添加Ce后,疲劳裂纹扩展区出现疲劳条纹,疲劳断口呈现出准解理和韧窝断裂的混合特征。
The effect of different contents of Ce addition on high cycle fatigue behavior of die-cast magnesium alloy AZ91D was investigated. Mechanical fatigue tests were conducted at the stress ratio of R = 0.1, and fatigue strength was evaluated using up-and down loading method. The results show that the grain size of of poro AZ91D alloy is refined remarkably, the amount sity addition of decreases and distributes evenly with the Ce. The fatigue strength of AZ91D alloy at room temperature increases from 96.7 up to 116.5 MPa （ 1% Ce） and 105.5 MPa （ 2% Ce ） respectively at the number of cycles to failure, Nf = 1×10^7. The fatigue crack of AZ91D alloy initiates at porosities and inclusions, and propagates along grain boundaries. The fatigue striations on fractured surface appear with Ce addition. The fatigue fracture surface of test specimens shows hybrid-fracture characteristics of quasicleavage and dimple.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2006年第5期605-609,共5页
Journal of the Chinese Society of Rare Earths
基金
国家"十五"科技攻关项目(2001BA311A07-2)资助
关键词
压铸镁合金
铈
高周疲劳
断口分析
稀土
die-cast magnesium alloy
cerium
high cycle fatigue
fracture surface analysis
rare earths
作者简介
杨友（1972-），男，吉林长春人，博士研究生，副教授；研究方向：汽车材料.通讯联系人（E-mail：yangyou_0825@163．com）
