The Influence of Metallurgical Pores on Fatigue Behaviors of Fusion Welded AA7020 Joints
文献类型：期刊论文
| 作者 | Song, Z; Wu, SC; Hu, YN; Kang, GZ; Fu, YN; Xiao, TQ |
| 刊名 | ACTA METALLURGICA SINICA
 |
| 出版日期 | 2018 |
| 卷号 | 54期号:8页码:1131-1140 |
| 关键词 | CAST-ALUMINUM ALLOY X-RAY MICROTOMOGRAPHY CRACK INITIATION 3D CHARACTERIZATION POROSITY DEFECTS MICROPORES MECHANISMS SURFACE GROWTH |
| ISSN号 | 0412-1961 |
| DOI | 10.11900/0412.1961.2017.00448 |
| 文献子类 | 期刊论文 |
| 英文摘要 | With the rapid development of Chinese high-speed railway system, the urgent demand for lighter weight structures is increasing, and aluminum alloys are widely applied into manufacturing the railway train and critical safety components. As a medium strength aluminum alloy, the 7020 aluminum alloy shows a great potential. Hybrid laser welding has currently become one of the most important welding techniques for medium and high strength aluminum alloys. Nevertheless, intrinsic defects such as pores and shrinkages physically determine the fatigue resistance of the welded joint. Based on in situ synchrotron radiation X-ray computed microtomography (SR-mCT), the population, location and size of gas pores within AA7020 hybrid welded joints are firstly identified and counted. The critical size of gas pores, affecting the fatigue properties of welded joints, is acquired by combining the statistical results of the pores and the average grain size of the hybrid weld. Meanwhile, the qualitative relationship between pore size, effective stress and fatigue life is discussed through in situ fatigue life data via SR-mCT and fracture morphology. By using the finite element analysis, detailed works have been performed on the stress state near the pores of different positions inside the joint. Through the simulation analysis, the stress concentration coefficient around the pores firstly increases, then decreases, and finally tends to a stable trend as the location of the pore-like defect is transferred from the surface to the inside. Besides, the influence of porosity on fatigue crack initiation, fatigue crack growth and sudden breaking process is also analyzed using fatigue crack growth experiment. In conclusion, the results show that the critical pore size of hybrid laser welded joint can be qualitatively identified as 30 mm; the SR-mCT and fracture analysis show that larger surface and sub-surface pores are more likely to initiate fatigue cracks, and the fatigue crack propagation experiment further shows that the porosity has very little effect on the long crack growth but significant influence on the crack front. |
| 语种 | 英语 |
| 源URL | [http://ir.sinap.ac.cn/handle/331007/31140]  |
| 专题 | 上海应用物理研究所_中科院上海应用物理研究所2011-2017年 |
| 作者单位 | 1.Chinese Acad Sci, SSRF, Shanghai Inst Appl Phys, Shanghai 201204, Peoples R China 2.Southwest Jiaotong Univ, State Key Lab Tract Power, Chengdu 610031, Sichuan, Peoples R China |
| 推荐引用方式 GB/T 7714 | Song, Z,Wu, SC,Hu, YN,et al. The Influence of Metallurgical Pores on Fatigue Behaviors of Fusion Welded AA7020 Joints[J]. ACTA METALLURGICA SINICA,2018,54(8):1131-1140. |
| APA | Song, Z,Wu, SC,Hu, YN,Kang, GZ,Fu, YN,&Xiao, TQ.(2018).The Influence of Metallurgical Pores on Fatigue Behaviors of Fusion Welded AA7020 Joints.ACTA METALLURGICA SINICA,54(8),1131-1140. |
| MLA | Song, Z,et al."The Influence of Metallurgical Pores on Fatigue Behaviors of Fusion Welded AA7020 Joints".ACTA METALLURGICA SINICA 54.8(2018):1131-1140. |
入库方式： OAI收割
来源：上海应用物理研究所
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