材料科学
金属间化合物
巴黎法
体积分数
断裂力学
合金
扫描电子显微镜
裂缝闭合
冶金
应力集中
杂质
相(物质)
曲折
复合材料
压力(语言学)
多孔性
哲学
有机化学
化学
语言学
作者
M. Vratnica,Z. Cvijović,Katarina Gerić,Zijah Burzić
出处
期刊:Materials Science Forum
日期:2007-09-01
卷期号:555: 553-558
被引量:6
标识
DOI:10.4028/www.scientific.net/msf.555.553
摘要
The aim of the present work is to determine the role of intermetallic (IM) phases in the fatigue crack propagation behavior of hot-forged Al-Zn-Mg-Cu alloys in T73 condition. To generate differences in the volume fraction and coarseness of various IM particles, the (Fe+Si) impurity level is varied from 0.23 to 0.37 mass%. The fatigue crack propagation tests are conducted in air at ambient temperature and a stress ratio R of 0.1. Characterization of the fatigue fracture surfaces is performed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Quantified IM particles data for each alloy are then related to the fatigue properties and fractographic analysis results. It was found that almost all particles of the Fecontaining phases (primarily (Cu,Fe,Mn)Al3 and Al7Cu2Fe) are broken and not effective in hindering fatigue crack propagation. On the other hand, the Mg2Si and soluble phase particles smaller than those of the Fe-containing phases contribute beneficially to fatigue life. These particles increase the tortuosity of the crack path and retard the crack growth rate. The crack growth rate decreases as the volume fraction of coarse Fe-containing particles increases, because more secondary cracks are produced decreasing the effective stress intensity at the main crack tip.
科研通智能强力驱动
Strongly Powered by AbleSci AI