scholarly journals Fatigue Fracture Analysis of Dissimilar Residual Stress in Dissimilar Aluminum Alloy Friction Stir Welded Joints

Author(s):  
Xue-feng LI ◽  
Guo-qin SUN
2011 ◽  
Vol 295-297 ◽  
pp. 1896-1900 ◽  
Author(s):  
Qiu Lin Yang ◽  
Dong Po Wang ◽  
Shi Pin Wu ◽  
Sen Li

The fatigue property of friction stir welded joints in Ai7075-T651 is crucial adjective in the modern aerospace industry. Treated by the UIP (Ultrasonic impact peening) process using the self-made device, the effects are studied in this paper, and the results show that: under the stress ratio R=0.5, the fatigue life of welded joints treated by ultrasonic peening is prolonged by 8~14 times. The strengthened layer caused by the plastic variation, surface hardening and uniformity of tissue, and transversal residual stress of base metal after UIP becomeing compressive residual stress of 100 Mpa in the surface, which are the main reasons that lead to the improvement of fatigue property.


2018 ◽  
Vol 252 ◽  
pp. 69-80 ◽  
Author(s):  
W.Y. Li ◽  
Q. Chu ◽  
X.W. Yang ◽  
J.J. Shen ◽  
A. Vairis ◽  
...  

2017 ◽  
Vol 17 (2) ◽  
pp. 29-40 ◽  
Author(s):  
M. A. Tashkandi ◽  
J. A. Al-Jarrah ◽  
M. Ibrahim

AbstractThe main aim of this investigation is to produce a welding joint of higher strength than that of base metals. Composite welded joints were produced by friction stir welding process. 6061 aluminum alloy was used as a base metal and alumina particles added to welding zone to form metal matrix composites. The volume fraction of alumina particles incorporated in this study were 2, 4, 6, 8 and 10 vol% were added on both sides of welding line. Also, the alumina particles were pre-mixed with magnesium particles prior being added to the welding zone. Magnesium particles were used to enhance the bonding between the alumina particles and the matrix of 6061 aluminum alloy. Friction stir welded joints containing alumina particles were successfully obtained and it was observed that the strength of these joints was better than that of base metal. Experimental results showed that incorporating volume fraction of alumina particles up to 6 vol% into the welding zone led to higher strength of the composite welded joints as compared to plain welded joints.


2011 ◽  
Vol 399-401 ◽  
pp. 2040-2043 ◽  
Author(s):  
Da Li ◽  
Hua Ji ◽  
Yan Liu ◽  
Guo Qing Gou ◽  
Hui Chen ◽  
...  

MIG welding and laser-MIG hybrid welding have been widely used to joint aluminum alloy in recent years. Residual stress and heat cycling of MIG welding and laser-MIG hybrid welding are analyzed by SYSWELD software. The results show that the peak values of the stress in hybrid welding is 30~50% less than the results in the MIG welded joints.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4211 ◽  
Author(s):  
Anton Naumov ◽  
Iuliia Morozova ◽  
Evgenii Rylkov ◽  
Aleksei Obrosov ◽  
Fedor Isupov ◽  
...  

The objective of this study was to investigate the effect of the high welding speed on the mechanical properties and their relations to microstructural characteristics of butt friction stir welded joints with the use of 6082-T6 aluminum alloy. The aluminum sheets of 2.0 mm thick were friction stir welded at low (conventional FSW) and high welding speeds (HSFSW) of 200 and 2500 mm/min, respectively. The grain size in the nugget zone (NZ) was decreased; the width of the softened region was narrowed down as well as the lowest microhardness value located in the heat-affected zone (HAZ) was enhanced by HSFSW. The increasing welding speed resulted in the higher ultimate tensile strength and lower elongation, but it had a slight influence on the yield strength. The differences in mechanical properties were explained by analysis of microstructural changes and tensile fracture surfaces of the welded joints, supported by the results of the numerical simulation of the temperature distribution and material flow. The fracture of the conventional FSW joint occurred in the HAZ, the weakest weld region, while all HSFSW joints raptured in the NZ. This demonstrated that both structural characteristics and microhardness distribution influenced the actual fracture locations.


2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940032 ◽  
Author(s):  
Pengfei Zhu ◽  
Guoqing Gou ◽  
Zhaofu Li ◽  
Minhao Zhu ◽  
Zhongyin Zhu ◽  
...  

The welding residual stress has different effects on the mechanical properties of aluminum alloy welded joints, such as size stability, fatigue strength and stress corrosion cracking. Therefore, it is very important to evaluate the welding residual stress accurately. In this paper, the residual stress of A7N01 aluminum alloy welded joints was measured by X-ray diffraction. In contrast to the traditional method, the cos[Formula: see text] method was used in this paper, the results were compared with those obtained by the conventional [Formula: see text] method. In addition, the influence of oscillation unit on the test results of the cos[Formula: see text] method was studied.


Sign in / Sign up

Export Citation Format

Share Document