Explore the mechanism of high fatigue crack propagation rate in fine microstructure of friction stir welded aluminum alloy

被引:22
作者
Dai, Qilei [1 ]
Liang, Zhifang [2 ]
Chen, Gaoqiang [1 ]
Meng, Lichun [3 ]
Shi, Qingyu [1 ]
机构
[1] Tsinghua Univ, Dept Mech Engn, Beijing 100084, Peoples R China
[2] Tsinghua Univ, Fundamental Ind Training Ctr, Beijing 100084, Peoples R China
[3] CSR Sifang Locomot & Rolling Stock Co Ltd, Qingdao 266000, Peoples R China
来源
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 2013年 / 580卷
关键词
Aluminum alloys; Fatigue crack propagation; Fracture; Grain refinement; Friction stir welding; RESIDUAL-STRESS; GROWTH; BEHAVIOR; JOINTS; STRENGTH; SPEED; ZONE;
D O I
10.1016/j.msea.2013.05.057
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
Fatigue crack propagation (FCP) at different locations of friction stir welded AA6N01 joint was investigated. FCP experiments were performed to study crack propagation rates in the Paris region. The highest FCP rate was in the stir zone (SZ) which composed of much finer grain compared with the other areas of joint. Fracture surfaces at different locations were examined. More brittle fracture characteristic was observed in SZ. To further investigate the mechanism of high FCP rate in SZ, differential scanning calorimetry (DSC) analysis was conducted. The results showed that there was relatively high energy stored in SZ. After releasing the stored energy, the resistance of FCP in SZ improved significantly while the grain size kept the same, the fatigue fractographs had changed from quasic-leavage to plastic fatigue striation fracture. These proved that the stored energy affected fatigue crack propagation in FSW joint significantly. (C) 2013 Elsevier B.V. All rights reserved.
引用
收藏
页码:184 / 190
页数:7
相关论文
共 25 条
[1]  
Anderson T., 1995, FRACTURE MECH FUNDAM, P453
[2]   Fatigue crack growth resistant microstructures in polycrystalline Ni-base superalloys for aeroengines [J].
Boyd-Lee, AD .
INTERNATIONAL JOURNAL OF FATIGUE, 1999, 21 (04) :393-405
[3]   The role of residual stress and heat affected zone properties on fatigue crack propagation in friction stir welded 2024-T351 aluminium joints [J].
Bussu, G ;
Irving, PE .
INTERNATIONAL JOURNAL OF FATIGUE, 2003, 25 (01) :77-88
[4]   Fatigue behaviour of AA6082 friction stir welds under variable loadings [J].
Costa, J. D. ;
Ferreira, J. A. M. ;
Borrego, L. P. ;
Abreu, L. P. .
INTERNATIONAL JOURNAL OF FATIGUE, 2012, 37 :8-16
[5]   Influence of welding speed on the fatigue of friction stir welds, and comparison with MIG and TIG [J].
Ericsson, M ;
Sandström, R .
INTERNATIONAL JOURNAL OF FATIGUE, 2003, 25 (12) :1379-1387
[6]   Fatigue crack growth in 2024-T351 friction stir welded joints: Longitudinal residual stress and microstructural effects [J].
Fratini, L. ;
Pasta, S. ;
Reynolds, A. P. .
INTERNATIONAL JOURNAL OF FATIGUE, 2009, 31 (03) :495-500
[7]   Grain size effects on the fatigue response of nanocrystalline metals [J].
Hanlon, T ;
Kwon, YN ;
Suresh, S .
SCRIPTA MATERIALIA, 2003, 49 (07) :675-680
[8]   Fatigue crack propagation behavior of friction stir welded Al-Mg-Si alloy [J].
Hong, Seongjin ;
Kim, Sangshik ;
Lee, Chang Gil ;
Kim, Sung-Joon .
SCRIPTA MATERIALIA, 2006, 55 (11) :1007-1010
[9]   Weld tool travel speed effects on fatigue life of friction stir welds in 5083 aluminium [J].
James, MN ;
Hattingh, DG ;
Bradley, GR .
INTERNATIONAL JOURNAL OF FATIGUE, 2003, 25 (12) :1389-1398
[10]   Friction-stir welding effects on microstructure and fatigue of aluminum alloy 7050-T7451 [J].
Jata, KV ;
Sankaran, KK ;
Ruschau, JJ .
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 2000, 31 (09) :2181-2192