scholarly journals Fatigue Behavior of Conventional and Stationary Shoulder Friction Stir Welded EN AW-5754 Aluminum Alloy Using Load Increase Method

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1510
Author(s):  
Abootorab Baqerzadeh Chehreh ◽  
Michael Grätzel ◽  
Jean Pierre Bergmann ◽  
Frank Walther
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Aluminum Alloys ◽  
Efficient Method ◽  
Fatigue Behavior ◽  
Friction Stir ◽  
Stationary Shoulder ◽  
Aluminum Sheets ◽  
Load Increase ◽  
Weld Seams

The load increase method, which is highly efficient in rapidly identifying the fatigue performance and strength of materials, is used in this study to investigate friction stir welded (FSW) EN AW-5754 aluminum alloys. Previous investigations have demonstrated the accuracy and efficiency of this method compared to Woehler tests. In this study, it is shown that the load increase method is a valid, accurate and efficient method for describing the fatigue behavior of FSW weld seams. The specimen tests were performed on 2 mm thick aluminum sheets using conventional and stationary tool configurations. It is shown that an increase in fatigue strength of the FSW EN AW-5754 aluminum alloys can be achieved by using the stationary shoulder tool configuration rather than the conventional one.

scholarly journals On the Fatigue Performance of Friction-Stir Welded Aluminum Alloys

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4246
Author(s):  
Sergey Malopheyev ◽  
Igor Vysotskiy ◽  
Daria Zhemchuzhnikova ◽  
Sergey Mironov ◽  
Rustam Kaibyshev
Keyword(s):  
Residual Stress ◽  
Fatigue Strength ◽  
Aluminum Alloys ◽  
Fatigue Behavior ◽  
Base Material ◽  
Fatigue Performance ◽  
Coarse Grained ◽  
Original Material ◽  
Friction Stir ◽  
Macro Scale

This work was undertaken in an attempt to ascertain the generic characteristics of fatigue behavior of friction-stir welded aluminum alloys. To this end, different alloy grades belonging to both the heat-treatable and non-heat-treatable types in both the cast and wrought conditions were studied. The analysis was based on the premise that the fatigue endurance of sound welds (in which internal flaws and surface quality are not the major issues) is governed by residual stress and microstructure. Considering the relatively low magnitude of the residual stresses but drastic grain refinement attributable to friction-stir welding, the fatigue performance at relatively low cyclic stress was deduced to be dictated by the microstructural factor. Accordingly, the fatigue crack typically nucleated in relatively coarse-grained base material zone; thus, the fatigue strength of the welded joints was comparable to that of the parent metal. At relatively high fatigue stress, the summary (i.e., the cyclic-plus residual-) stress may exceed the material yield strength; thus, the fatigue cracking should result from the preceding macro-scale plastic deformation. Accordingly, the fatigue failure should occur in the softest microstructural region; thus; the fatigue strength of the welded joint may be inferior to that of the original material.

scholarly journals Effect of Corrosion and Surface Finishing on Fatigue Behavior of Friction Stir Welded EN AW-5754 Aluminum Alloy Using Various Tool Configurations

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3121 ◽  
Author(s):  
Abootorab Baqerzadeh Chehreh ◽  
Michael Grätzel ◽  
Jean Pierre Bergmann ◽  
Frank Walther
Keyword(s):  
Climate Change ◽  
Aluminum Alloy ◽  
Fatigue Behavior ◽  
Salt Spray ◽  
Base Material ◽  
Fatigue Properties ◽  
Surface Finishing ◽  
Friction Stir ◽  
Stationary Shoulder ◽  
Root Surfaces

In this study, fatigue behavior of surface finished and precorroded friction stir welded (FSW) specimens using various tool configurations were comparatively investigated by the load increase method. The FSW using conventional, stationary shoulder and dual-rotational configurations was carried out by a robotized tool setup on 2 mm EN AW-5754 aluminum sheets in butt joint formation. After extraction of the specimens, their weld seam and root surfaces were milled to two different depths of 200 µm and 400 µm to remove the surface and the FSW tool shoulder effects. This surface finishing process was performed to investigate the effect of the surface defects on the fatigue behavior of the FSW EN AW-5754 aluminum alloy sheets. It was found that material removal from the weld and root surfaces of the specimens, increased the fracture stresses of conventional and dual-rotational FSW from 204 to 229 MPa and 196 to 226 MPa, respectively. However, this increase could not be detected in stationary shoulder FSW. Specimens with finished surfaces, which showed superior properties, were used in salt spray and cyclic climate change test to investigate the effect of corrosion on the fatigue behavior of FSW specimens. It was shown that cyclic climate change test reduced the fatigue properties of the base material, conventional, stationary shoulder and dual-rotational FSW approximately 1%–7%. This decrease in the fatigue properties was greater in the case of the salt spray test, which was 7% to 21%.

scholarly journals Fatigue Modeling and Numerical Analysis of Re-Filling Probe Hole of Friction Stir Spot Welded Joints in Aluminum Alloys

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2171
Author(s):  
Armin Yousefi ◽  
Ahmad Serjouei ◽  
Reza Hedayati ◽  
Mahdi Bodaghi
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Element Model ◽  
Plastic Strain Amplitude ◽  
Friction Stir ◽  
Probe Hole ◽  
Good Agreement

In the present study, the fatigue behavior and tensile strength of A6061-T4 aluminum alloy, joined by friction stir spot welding (FSSW), are numerically investigated. The 3D finite element model (FEM) is used to analyze the FSSW joint by means of Abaqus software. The tensile strength is determined for FSSW joints with both a probe hole and a refilled probe hole. In order to calculate the fatigue life of FSSW joints, the hysteresis loop is first determined, and then the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted. The results were verified against available experimental data from other literature, and a good agreement was observed between the FEM results and experimental data. The results showed that the joint’s tensile strength without a probe hole (refilled hole) is higher than the joint with a probe hole. Therefore, re-filling the probe hole is an effective method for structures jointed by FSSW subjected to a static load. The fatigue strength of the joint with a re-filled probe hole was nearly the same as the structure with a probe hole at low applied loads. Additionally, at a high applied load, the fatigue strength of joints with a refilled probe hole was slightly lower than the joint with a probe hole.

Experimental Study of Stationary Shoulder Friction Stir Welded 7N01-T4 Aluminum Alloy

2016 ◽  
Vol 25 (3) ◽  
pp. 1228-1236 ◽  
Author(s):  
S. D. Ji ◽  
X. C. Meng ◽  
Z. W. Li ◽  
L. Ma ◽  
S. S. Gao
Keyword(s):  
Experimental Study ◽  
Aluminum Alloy ◽  
Friction Stir ◽  
Stationary Shoulder

Tribological characterization of friction stir welded dissimilar aluminum alloy AA6061–AA5083 reinforced with CeO2 and La2O3 nanoparticles

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Arun M. ◽  
Muthukumaran M. ◽  
Balasubramanian S.
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Environmental Conditions ◽  
Tribological Characteristics ◽  
Dissimilar Joints ◽  
Content Type ◽  
Reinforcing Effect ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys ◽  
Mechanical And Tribological Characteristics

Purpose Dissimilar materials found applications in the structural fields to withstand the different types of loads and provide multi-facet properties to the final structure. Aluminum alloy materials are mostly used in aerospace and marine industries to provide better strength and safeguard the material from severe environmental conditions. The purpose of this study is to develop new material with superior strength to challenge the severe environmental conditions. Design/methodology/approach In the present investigation, friction stir welding (FSW) dissimilar joints were prepared from AA6061 and AA5083 aluminum alloys, and the weld nugget (WN) was reinforced with hard reinforcement particles such as La2O3 and CeO2. The tribological and mechanical properties of the prepared materials were tested to analyze the suitability of material in the aerospace and marine environmental conditions. Findings The results showed that the AA6061–AA5083/La2O3 material exhibited better mechanical and tribological characteristics. The FSW dissimilar AA6061–AA5083/La2O3 material exhibited lower wear rate of 7.37 × 10−3 mm3/m and minimum friction coefficient of 0.31 compared to all other materials owing to the reinforcing effect of La2O3 particles and the fine grains formed by FSW process at WN region. Further, FSW dissimilar AA6061–AA5083/La2O3 material displayed a maximum tensile strength and hardness of 378 MPa and 118 HV, respectively, among all the other materials tested. Originality/value This work is original and novel in the field of materials science engineering focusing on tribological characteristics of friction stir welded dissimilar aluminum alloys by the reinforcing effect of hard particles such as La2O3 and CeO2.

S–N curves for fatigue life estimation of friction stir welded 19501 aluminum alloy T-joint

2018 ◽  
Vol 233 (2) ◽  
pp. 664-674
Author(s):  
Prakash Chandra Gope ◽  
Harshit Kumar ◽  
Himanshu Purohit ◽  
Manish Dayal
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Weld Zone ◽  
Stress Effect ◽  
Mean Stress ◽  
Friction Stir ◽  
Fracture Surfaces ◽  
Mean Stress Effect ◽  
Metallic Bonding

In this study, the mechanical properties and fatigue life of 19501 aluminum alloy friction stir welded T-joint is investigated. Tensile properties of friction stir welded joint show that there is a marginal reduction of about 5% in strength and ductility as compared to unwelded 19501 aluminum alloy. Fatigue test results of T-joint specimen at two stress ratios of 0 and -1 show that there is a reduction of 15% in fatigue strength due to change of stress ratio from -1 to 0. Also, higher variation is seen in fatigue strength in low cycle zone than the high cycle zone. Effect of mean stress on fatigue life is discussed on the basis of different mean stress effect models. Morrow’s mean stress effect model is found to be better than other models. Micrographs from the fracture surfaces of retreating side, mid weld zone, and advancing side of the T-joint indicates that fracture surfaces are cleavage fracture. Different sizes of inter-metallic bonding are seen in the micrographs, which indicate that fracture is initiated due to breaking of the brittle inter-metallic bonding.

scholarly journals Metallurgical and Mechanical Characterization of High-Speed Friction Stir Welded AA 6082-T6 Aluminum Alloy

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4211 ◽  
Author(s):  
Anton Naumov ◽  
Iuliia Morozova ◽  
Evgenii Rylkov ◽  
Aleksei Obrosov ◽  
Fedor Isupov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Welding Speed ◽  
Welded Joints ◽  
High Speed ◽  
Structural Characteristics ◽  
Tensile Fracture ◽  
Friction Stir ◽  
Microhardness Distribution ◽  
Aluminum Sheets

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.

Effect of rotating speed on joint morphology and lap shear properties of stationary shoulder friction stir lap welded 6061-T6 aluminum alloy

2016 ◽  
Vol 88 (5-8) ◽  
pp. 2135-2141 ◽  
Author(s):  
Zhenlu Zhou ◽  
Yumei Yue ◽  
Shude Ji ◽  
Zhengwei Li ◽  
Liguo Zhang
Keyword(s):  
Aluminum Alloy ◽  
Shear Properties ◽  
Rotating Speed ◽  
Friction Stir ◽  
Stationary Shoulder ◽  
Lap Shear ◽  
Joint Morphology

Effect of friction stir processing conditions on fatigue behavior and texture development in A356-T6 cast aluminum alloy

2015 ◽  
Vol 80 ◽  
pp. 192-202 ◽  
Author(s):  
Akiko Tajiri ◽  
Yoshihiko Uematsu ◽  
Toshifumi Kakiuchi ◽  
Yasunari Tozaki ◽  
Yosuke Suzuki ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Processing ◽  
Fatigue Behavior ◽  
Texture Development ◽  
Cast Aluminum Alloy ◽  
Processing Conditions ◽  
Cast Aluminum ◽  
Friction Stir
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