摘要
为探究2A70高强铝合金疲劳性能,开展了2A70应力比R=-1温度T=25℃与T=150℃的高周疲劳试验。结合微观组织观测、应力-寿命(S-N)曲线绘制、典型断口观测,对其疲劳性能进行了研究。结果表明:温度升高会降低2A70高强铝合金的疲劳性能,温度为25℃和150℃时的疲劳极限分别为150MPa和90MPa;在常温和高温条件下都发生表面失效,裂纹萌生于次表面夹杂;2A70在疲劳加载过程中的主要断裂模式为解理断裂,在断口表面可以观察到大量河流花样和解理台阶。
In order to investigate the fatigue properties of 2A70 high-strength aluminum alloy, a high cycle fatigue test with stress ratio R=-1 and temperature T=25℃ and T=150℃ was carried out. Combined with microstructure observation, stress-life(S-N) curve and typical fracture observation, the fatigue properties of 2A70 was investigated and the influence of temperature was analyzed. The results show that the fatigue properties of 2A70 high-strength aluminum alloy decrease with the increase of temperature, and the fatigue limit is 150 MPa and 90 MPa when the temperature is 25℃ and 150℃, respectively. The surface failure occurs at both room temperature and high temperature, and the crack initiates at the subsurface inclusions. The main fracture mode of 2A70 in the process of fatigue loading is cleavage fracture, and a large number of river patterns and cleavage steps can be observed on the fracture surface.
作者
周思奇
张虹
吴新涛
ZHOU Siqi;ZHANG Hong;WU Xintao(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China;China North Engine Research Institute,Tianjin 300400,China)
出处
《机械》
2020年第5期40-44,共5页
Machinery
