摘要
研究了重力铸造镁合金AZ91在应力比R=0.1条件下的高周疲劳性能。显微组织观察表明,AZ91合金中主要存在-αMg基体和-βMg17Al12两种相。力学性能测试表明,在室温条件下,AZ91合金的抗拉强度、伸长率、硬度和条件疲劳强度分别为128 MPa、2.3%、HB 63和58 MPa。疲劳断口SEM形貌分析表明,可以观察到疲劳源区、疲劳裂纹扩展区和瞬断区三个区域,断口上有较多的撕裂棱,同时也可以看到韧窝的存在,表现为准解理和韧性断裂的混合特征。
A study on high cycle fatigue properties of gravity-casting magnesium alloy AZ91 at fatigue ratio of 0.1 was investigated. Microstructural observation indicates that the alloy AZ91 chiefly contains α-Mg matrix and β-Mg17Al12 phase. The mechanical properties testing indicates that the values of tensile strength, elongation, hardness and conditional fatigue strength of gravity-casting AZ91 alloys are 128 MPa, 2.3%, HB 63 and 58 MPa. SEM analysis shows that the crack initiation site, the fatigue crack propagation area and the fatigue fracture area can be observed. The fatigue fracture surfaces exist a lot of rip edges and dimples, and they are quasi-cleavage and toughness fracture.
出处
《铸造》
EI
CAS
CSCD
北大核心
2006年第12期1280-1282,共3页
Foundry
基金
"十五"国家科技攻关项目(2001BA311A05-2)。
关键词
重力铸造
镁合金
高周疲劳
疲劳断口
gravity-casting
magnesium alloy
high cycle fatigue
fatigue fracture surface
