【摘要】 为了观察A356-SiCp铝基复合材料的疲劳裂纹扩展机理。对在不同栽荷下的试件进行取样分析和显微观察。实验分析结果表明:在低载条件下,SiC颗粒将阻碍裂纹的扩展,改变裂纹的扩展方向。裂纹避开SiC颗粒在基体中作之字形扩展,而降低裂纹的宏观扩展速度,使材料的疲劳寿命得到提高。更多还原

【Abstract】 In order to confirm the mechanism of fatigue growth of an aluminum alloy A356-SiCp composite, some micrographic observations were taken to an interior plane of the fatigue test specimens cracked but unbroken. The results of this work have reveals the different fatigue growth mechanism in the high cycle fatigue and in the low cycle fatigue. In the high cycle fatigue or low stress level,the fatigue crack growth principally in the matrix and tend to avoid cutting through SiC particles. In the low cycle fatigue or high stress level,except propagation in the matrix,fatigue crack can propagate throughout the particles,or along the particle/matrix interface. In the case of low stress level,the main fissure is brought to go round particles and take thus a more sinuous path in the CMMp than that in the unreinforced alloy.更多还原