Fatigue Properties of Butt Welded Aluminum Alloy and Carbon Steel Joints by Friction Stirring

6th International Conference on Fracture Fatigue and Wear

Okane, M.^1 ; Shitaka, T.^2 ; Ishida, M.^3 ; Chaki, T.^3 ; Yasui, T.^4 ; Fukumoto, M.^4

Department of Mechanical Engineering, National Institute of Technology, Toyama College, Japan^1

Advanced Course, National Institute of Technology, Toyama College, Japan^2

National Institute of Technology, Toyama College, Japan^3

Department of Mechanical Engineering, Toyohashi University of Technology, Japan^4

关键词: Cemented carbides;    Controlled conditions;    Dissimilar joints;    Effect of heat treatments;    Fatigue properties;    Friction stirring;    Heat-treated specimens;    Welding conditions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/843/1/012040/pdf
DOI  :  10.1088/1742-6596/843/1/012040

来源: IOP

【 摘 要 】

The butt dissimilar joints of Al-Mg-Si alloy JIS A6063 and carbon steel JIS S45C by means of friction stir welding were prepared for investigating fatigue properties of the joints. The joining tool used has cemented carbide thread probe and a shoulder made of alloy tool steel. All the fatigue tests were carried out under a load-controlled condition with a load ratio R=0.1 in air at room temperature. From the experimental results, it was found that hardness near the interface in A6063 was lower than that of base material. Three types of fatigue fracture occurred even in case of same welding condition. The first one was fracture at boundary between the lower hardness region and base material in A6063, the second type was initiated in the stir zone by FSW process and the last one was fracture at interface. Fatigue strength in case of the second one was lower than others. Furthermore, to investigate the effect of heat treatment on fatigue properties of the dissimilar joints, fatigue tests were also carried out with using the specimens which were heat treated under the same condition to aging process in T6 treatment. Fatigue fracture was initiated at interface between A6063 and S45C in case of the heat treated specimen, but fatigue strength was improved approximately 25% as compared with that of the non-heat treated specimen.