Fatigue characteristics and microcosmic mechanism of Al-Si-Mg alloys under multiaxial proportional loadings

• Published in: International journal of minerals, metallurgy and materials Vol. 18; no. 4; pp. 437 - 443
• Main Authors: Jiang, Xiao-song, He, Guo-qiu, Liu, Bing, Zhu, Zheng-yu, Zhang, Wei-hua
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.08.2011; Springer Nature B.V; School of Material Science and Engineering, Tongji University, Shanghai 200092, China%National Power Traction Key Laboratory, Southwest Jiaotong University, Chengdu 610031, China
• Subjects: Alloys; Aluminum base alloys; Amplitudes; Automobile industry; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Corrosion and Coatings; Dislocations; Equivalence; Fatigue (materials); Fatigue life; Fatigue tests; Glass; Heat treating; Low cycle fatigue; Magnesium; Materials Science; Metal fatigue; Metallic Materials; Natural Materials; Silicon; Strain; Surfaces and Interfaces; Thin Films; Tribology; Weight reduction; 低周疲劳寿命; 多轴; 微观机制; 比例; 疲劳特性; 载荷; 透射电子显微镜; 铝硅镁合金; fatigue; proportional loadings; microstructure; aluminum alloys
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-011-0459-0

With the increasing use of Al-Si-Mg alloys in the automotive industry,the fatigue performance of Al-Si-Mg alloy has become a major concern with regard to their reliability.The fatigue characteristics and microcosmic mechanism of an Al-Si-Mg alloy under multiaxial proportional loadings were investigated in this research.As low cycle fatigue life and material strengthening behavior are closely related,the effect of equivalent strain amplitude on the multiaxial fatigue properties was analyzed.Fatigue tests were conducted to determine the influence of equivalent strain amplitude on the multiaxial proportional fatigue properties.The fatigue life exhibits a stable behavior under multiaxial proportional loadings.The dislocation structures of the Al-Si-Mg alloy were observed by transmission electron microscopy（TEM）.The dislocation structure evolution of the Al-Si-Mg alloy under multiaxial proportional loadings during low cycle fatigue develops step by step by increasing fatigue cycles.Simultaneously,the dislocation structure changes with the change in equivalent strain amplitude under multiaxial proportional loadings.The experimental evidence indicates that the multiaxial fatigue behavior and life are strongly dependent on the microstructure of the material,which is caused by multiaxial proportional loadings.