Assessment of the Fatigue Behaviour of Friction Stir Welded Joints: Aluminium Alloy 6082-T6

2007 ◽  
Vol 348-349 ◽  
pp. 209-212 ◽  
Author(s):  
Pedro Miguel Guimarães Pires Moreira ◽  
A.M.P. de Jesus ◽  
A.S. Ribeiro ◽  
Paulo Manuel Salgado Tavares de Castro
Keyword(s):  
Aluminium Alloy ◽  
Welded Joints ◽  
Base Material ◽  
Welding Process ◽  
Growth Curves ◽  
Fatigue Behaviour ◽  
Fatigue Properties ◽  
Friction Stir ◽  
Crack Propagation Resistance ◽  
Strength And Ductility

A study on the fatigue behaviour of friction stir butt welds of 3mm thick 6082-T6 aluminium alloy was carried out. Monotonic tensile and cyclic tests of welded joints and base material were performed to understand the influence of the welding process on the static and fatigue properties. Microhardness profiles were measured and fatigue crack growth curves were determined for cracks growing in different locations of the weldments. Friction stir material exhibited lower strength and ductility properties than the base material. However, an enhanced crack propagation resistance is observed.

Fatigue Behaviour of Friction Stir Welded Steel Joints

2014 ◽  
Vol 891-892 ◽  
pp. 1488-1493 ◽  
Author(s):  
José Azevedo ◽  
Virgínia Infante ◽  
Luisa Quintino ◽  
Jorge dos Santos
Keyword(s):  
Base Material ◽  
Welding Process ◽  
Steel Structures ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Welded Steel ◽  
Shipbuilding Industry ◽  
Friction Stir ◽  
Steel Joints

The development and application of friction stir welding (FSW) technology in steel structures in the shipbuilding industry provide an effective tool of achieving superior joint integrity especially where reliability and damage tolerance are of major concerns. Since the shipbuilding components are inevitably subjected to dynamic or cyclic stresses in services, the fatigue properties of the friction stir welded joints must be properly evaluated to ensure the safety and longevity. This research intends to fulfill a clear knowledge gap that exists nowadays and, as such, it is dedicated to the study of welded steel shipbuilding joints in GL-A36 steel, with 4 mm thick. The fatigue resistance of base material and four plates in as-welded condition (using several different parameters, tools and pre-welding conditions) were investigated. The joints culminate globally with defect-free welds, from which tensile, microhardness, and fatigue analyses were performed. The fatigue tests were carried out with a constant amplitude loading, a stress ratio of R=0.1 and frequency between 100 and 120 Hz. The experimental results show the quality of the welding process applied to steel GL-A36 which is reflected in the mechanical properties of joints tested.

scholarly journals A Method for Comparing the Fatigue Performance of Forged AZ80 Magnesium

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1290
Author(s):  
Andrew Gryguć ◽  
Seyed Behzad Behravesh ◽  
Hamid Jahed ◽  
Mary Wells ◽  
Bruce Williams ◽  
...  
Keyword(s):  
Base Material ◽  
Fatigue Behaviour ◽  
Fatigue Properties ◽  
Closed Die Forging ◽  
Geometry Configuration ◽  
Automotive Suspension ◽  
Process Structure ◽  
Durability Performance ◽  
Strength And Ductility ◽  
Structure Properties

A closed die forging process was developed to successfully forge an automotive suspension component from AZ80 Mg at a variety of different forging temperatures (300 °C, 450 °C). The properties of the forged component were compared and contrasted with other research works on forged AZ80 Mg at both an intermediate forging and full-scale component forging level. The monotonic response, as well as the stress and strain-controlled fatigue behaviours, were characterized for the forged materials. Stress, strain and energy-based fatigue data were used as a basis for comparison of the durability performance. The effects of the starting material, forging temperature, forging geometry/configuration were all studied and aided in developing a deeper understanding of the process-structure-properties relationship. In general, there is a larger improvement in the material properties due to forging with cast base material as the microstructural modification which enhances both the strength and ductility is more pronounced. In general, the optimum fatigue properties were achieved by using extruded base-material and forging using a closed-die process at higher strain rates and lower temperatures. The merits and drawbacks of various fatigue damage parameters (FDP’s) were investigated for predicting the fatigue behaviour of die-forged AZ80 Mg components, of those investigated, strain energy density (SED) proved to be the most robust method of comparison.

scholarly journals Forming and Properties of Friction Stir Welding Process for Dissimilar Mg Alloy

2015 ◽  
Vol 9 (1) ◽  
pp. 859-864
Author(s):  
Tielong Li ◽  
Zhenshan Wang
Keyword(s):  
Magnesium Alloy ◽  
Process Parameters ◽  
Welded Joints ◽  
Defect Formation ◽  
Base Material ◽  
Welding Process ◽  
Fracture Initiation ◽  
Line Defect ◽  
Influence Of Process Parameters ◽  
Friction Stir

For hot extrusions of magnesium alloy sheets, Dissimilar AZ80 and AZ31 were used, in which AZ80 was placed on advancing side and AZ31 on retreating side, using friction stir butt welding with different process parameters. Some defect-free welded joints with good weld surfaces could be obtained with some suitable welding conditions. The maximum tensile strength of welded joint which is 225.5 MPa can reach 98% that of the AZ31 base material. Influence of process parameters on defects, weld shaping and mechanical property were discussed systematically. And the microstructure of different zones was compared. The fracture of the welded joints takes place at the junction of mechanical heat affected zone and nugget zone in AZ31 magnesium alloy set retreating side, since existing difference in metallographic structure of alloy diversely suffered by heat, pressure and depositing impurities. Fracture initiation site may be the P line defect which should be eliminated, and the P line defect formation was analyzed.

Mechanical Behaviour of Al-Li Alloy Joints by Different Friction Stir Welding Parameters

2014 ◽  
Vol 1051 ◽  
pp. 799-807 ◽  
Author(s):  
Dan Dan Zhang ◽  
Wen Qing Qu ◽  
Qun Bo Lv ◽  
Yang Yang Liu ◽  
Wei Yan Li ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Base Material ◽  
Welding Process ◽  
Fatigue Properties ◽  
Welding Parameters ◽  
Fatigue Lifetime ◽  
Friction Stir ◽  
The Relationship ◽  
Microstructure And Mechanical Property ◽  
Made In

In this study, the Al-Li alloy plates were friction stir welded (FSW) at different welding parameters, and the effect of welding parameters on the hardness, tensile and fatigue properties of the butted and lapped FSWed joints were investigated. The experimental results showed that the ultimate strength and elongation of butted joints decreased as the heat input increasing, and the maximum ultimate strength of the joints was equivalent to 83% that of the base material. By comparison of the heat inputs during welding process at different parameter combinations, the relationship between the microstructure and mechanical property of FSWed joints was established. For the overlapped welds made in 2mm thick plates of Al-Li-S4 and 2099 alloys, the hooking defect was a typical and inevitable defect appearing on the TMAZ of both advancing and retreating sides, which would adversely damage the mechanical properties of overlapped joints. Furthermore, the length of pin significantly affected the tensile property of overlapped joints, when the length of pin varies from 2.8mm to 2.5mm, the ultimate strength increased 14% to 20%. In addition, the fatigue lifetime of overlapped joints was lower than that of butted joints and base metal.

scholarly journals Load Controlled Fatigue Behaviour of Microplasma Arc Welded Thin Titanium Grade 5 (6Al-4V) Sheets

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5128
Author(s):  
Jaroslaw Szusta ◽  
Nail Tüzün ◽  
Özler Karakaş
Keyword(s):  
Welded Joints ◽  
Arc Welding ◽  
Experimental Studies ◽  
Welding Process ◽  
Fatigue Behaviour ◽  
Fatigue Properties ◽  
Metal Fatigue ◽  
Grade 5 ◽  
Titanium Grade ◽  
Weld Area

The current study investigates the load controlled fatigue properties of the microplasma arc welded thin titanium Grade 5 (6Al-4V) sheets. In order to explore the effect of weld geometry on the fatigue, two different welded joints were used in the experimental studies. Load controlled fatigue test results were evaluated to present an outlook on the behaviour of microplasma welded titanium alloy Grade 5 sheets under cyclic loading. Even though the previously published monotonic tests showed successful use of microplasma arc welding to join thin titanium Grade 5 sheets with mechanical properties comparable to the base metal, fatigue life of the welded joints was lower than the lives of samples without welds. In particular, the fatigue performance of overlap joints was very poor. This was presumed to be due to the changed material properties of the heat affected zone which was formed by the excess heat of the welding process as fractures often occurred at such locations. Based on experimental findings and fractographic observations, a clear adverse effect of welding process in material behaviour was discovered. Despite the concentrated heat of microplasma arc welding, post-weld heat treatment of the weld area is recommended to improve the mechanical behaviour of the welded joints.

scholarly journals Fatigue of Friction Stir Welded Aluminum Alloy Joints: A Review

2018 ◽  
Vol 8 (12) ◽  
pp. 2626 ◽  
Author(s):  
Hongjun Li ◽  
Jian Gao ◽  
Qinchuan Li
Keyword(s):  
Growth Rate ◽  
Fatigue Life ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Process Parameters ◽  
Welded Joints ◽  
Welding Process ◽  
Life Assessment ◽  
Fatigue Properties ◽  
Friction Stir

The application fields of friction stir welding technology, such as aerospace and transportation, has high safety requirements and fatigue is the dominant failure mode for weldments. It is of great significance to understand the fatigue properties of friction stir welded joints. This paper provides an overview of the fatigue mechanism, influencing factors, crack growth rate, and fatigue life assessment. It is found that the fatigue performance of friction stir welded joints can be affected by welding process parameters, test environment, stress ratio, residual stress, and weld defect. The optimized process parameters can produce high quality weld and increase the weld fatigue life. Laser peening is an effective post weld treatment to decrease fatigue crack growth rate and improve material fatigue life.

Numerical analysis of the fatigue behaviour of friction stir welded joints in aluminum bridge decks

2021 ◽  
Author(s):  
Mahmoud Trimech ◽  
Charles-Darwin Annan ◽  
Scott Walbridge ◽  
Sofiene Amira
Keyword(s):  
Bridge Decks ◽  
Welding Process ◽  
Fatigue Behaviour ◽  
Fatigue Properties ◽  
Lap Joint ◽  
Friction Stir ◽  
Notch Stress ◽  
Aluminum Extrusions ◽  
Geometrical Features ◽  
Effective Notch Stress

<p>Friction stir welding (FSW), a relatively new welding technique, has been widely used in the aero- space and manufacturing industries, showing superior mechanical and durability properties. How- ever, its application in civil engineering is very limited due to the absence of appropriate standards and quality control guidelines. FSW appears to be a promising welding solution for the fabrication of vehicular bridge decks made from aluminum extrusions, with a potential to reduce distortions and improve fatigue properties. The fatigue behaviour of common FSW joint types such as the butt FSW has extensively been investigated and documented in literature. However, certain practical configurations such as the butt-lap joint used in the fabrication of extruded aluminum bridge decks have rarely been studied, especially in the area of fatigue performance. In this context, the present research provides first an overview on the welding process of typical aluminum friction stir welded bridge deck extrusions presenting the butt-lap configuration. Then, the fatigue behaviour of butt- lap FSW joints is assessed using the effective notch stress (ENS) approach. The effect of geometrical features on the fatigue behaviour of butt-lap FSW joints is numerically investigated also by the ENS approach.</p>

scholarly journals Mechanical Properties and Microstructural Characterization of Dissimilar Friction Stir Welded AA5083 and AA6061 Aluminium Alloys

Mechanika ◽  
2020 ◽  
Vol 26 (6) ◽  
pp. 545-552
Author(s):  
Sasi Lakshmikhanth RAJASEELAN ◽  
Subbaiah KUMARASAMY
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Welded Joints ◽  
Aluminium Alloys ◽  
Microstructural Analysis ◽  
Testing Machine ◽  
Welding Process ◽  
Fusion Welding ◽  
Friction Stir

Solidification is one of the major issues that was faced during the fusion welding of dissimilar non-heat treatable and heat treatable aluminium alloys. To overcome this issue Friction Stir Welding played a very vital role, since it is a solid state welding process. In the current study, dissimilar friction stir welding was carried out between non heat-treatable aluminium alloy AA5083-H111 and heat-treatable aluminium alloy AA6061-T6. The microstructural analysis and the mechanical properties of the dissimilar friction stir welded aluminium alloy AA5083-H111 and AA6061-T6 have been investigated. Both optical microscopy and scanning electron microscopy was used to evaluate the microstructural features. The elemental analysis was carried out using SEM-EDX. The tensile properties are studied using Universal Testing Machine. Hardness at various zones of the welded joints was measured using Vicker’s Hardness Testing Machine. The mechanical properties of the friction stir welded joints were correlated with the microstructure of the dissimilar welded joints.

scholarly journals Mechanical and Microstructural Characterization of Friction Stir Welded SiC and B4C Reinforced Aluminium Alloy AA6061 Metal Matrix Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3110
Author(s):  
Kaveripakkam Suban Ashraff Ali ◽  
Vinayagam Mohanavel ◽  
Subbiah Arungalai Vendan ◽  
Manickam Ravichandran ◽  
Anshul Yadav ◽  
...  
Keyword(s):  
Wear Rate ◽  
Aluminium Alloy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Weld Zone ◽  
Base Material ◽  
Matrix Composites ◽  
Wear Properties ◽  
Friction Stir ◽  
Behavioural Aspects

This study focuses on the properties and process parameters dictating behavioural aspects of friction stir welded Aluminium Alloy AA6061 metal matrix composites reinforced with varying percentages of SiC and B4C. The joint properties in terms of mechanical strength, microstructural integrity and quality were examined. The weld reveals grain refinement and uniform distribution of reinforced particles in the joint region leading to improved strength compared to other joints of varying base material compositions. The tensile properties of the friction stir welded Al-MMCs improved after reinforcement with SiC and B4C. The maximum ultimate tensile stress was around 172.8 ± 1.9 MPa for composite with 10% SiC and 3% B4C reinforcement. The percentage elongation decreased as the percentage of SiC decreases and B4C increases. The hardness of the Al-MMCs improved considerably by adding reinforcement and subsequent thermal action during the FSW process, indicating an optimal increase as it eliminates brittleness. It was seen that higher SiC content contributes to higher strength, improved wear properties and hardness. The wear rate was as high as 12 ± 0.9 g/s for 10% SiC reinforcement and 30 N load. The wear rate reduced for lower values of load and increased with B4C reinforcement. The microstructural examination at the joints reveals the flow of plasticized metal from advancing to the retreating side. The formation of onion rings in the weld zone was due to the cylindrical FSW rotating tool material impression during the stirring action. Alterations in chemical properties are negligible, thereby retaining the original characteristics of the materials post welding. No major cracks or pores were observed during the non-destructive testing process that established good quality of the weld. The results are indicated improvement in mechanical and microstructural properties of the weld.

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