scholarly journals Heat Input and Mechanical Properties Investigation of Friction Stir Welded AA5083/AA5754 and AA5083/AA7020

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 68 ◽  
Author(s):  
Mohamed M. Z. Ahmed ◽  
Sabbah Ataya ◽  
Mohamed M. El-Sayed Seleman ◽  
Abdalla M. A. Mahdy ◽  
Naser A. Alsaleh ◽  
...  
Keyword(s):  
Heat Input ◽  
Joint Strength ◽  
Cold Deformation ◽  
High Strength ◽  
Hardness Profile ◽  
Dissimilar Joints ◽  
Friction Stir ◽  
Wide Range ◽  
Strength Alloy ◽  
Fsw Parameters

The current work presents a detailed investigation for the effect of a wide range friction stir welding (FSW) parameters on the dissimilar joints’ quality of aluminum alloys. Two groups of dissimilar weldments have been produced between AA5083/AA5754 and A5083/AA7020 using tool rotational rates range from 300 to 600 rpm, and tool traverse speeds range from 20 to 80 mm/min. In addition, the effect of reversing the position of the high strength alloy at the advancing side and at retreating side has been investigated. The produced joints have been investigated using macro examination, hardness testing and tensile testing. The results showed that sound joints are obtained at the low heat input FSW parameters investigated while increasing the heat input results in tunnel defects. The hardness profile obtained in the dissimilar AA5083/AA5754 joints is the typical FSW hardness profile of these alloys in which the hardness reduced in the nugget zone due to the loss of the cold deformation strengthening. However, the profile of the dissimilar AA5083/AA7020 showed increase in the hardness in the nugget due to the intimate mixing the high strength alloy with the low strength alloy. The sound joints in both groups of the dissimilar joints showed very high joint strength with efficiency up to 97 and 98%. Having the high strength alloy at the advancing side gives high joint strength and efficiency. Furthermore, the sound joints showed ductile fracture mechanism with clear dimple features mainly and significant plastic deformation occurred before fracture. Moreover, the fracture in these joints occurred in the base materials. On the other, the joints with tunnel defect showed some features of brittle fracture due to the acceleration of the existing crack propagation upon tensile loading.

scholarly journals Comprehensive Analysis of the Microstructure and Mechanical Properties of Friction-Stir-Welded Low-Carbon High-Strength Steels with Tensile Strengths Ranging from 590 MPa to 1.5 GPa

2021 ◽  
Vol 11 (12) ◽  
pp. 5728
Author(s):  
HyeonJeong You ◽  
Minjung Kang ◽  
Sung Yi ◽  
Soongkeun Hyun ◽  
Cheolhee Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Joint Strength ◽  
Solid Phase ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
Friction Stir ◽  
Welding Processes

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels.

Investigations on the Mechanical Properties and Formability of Friction Stir Welded Tailored Blanks

2007 ◽  
Vol 344 ◽  
pp. 143-150 ◽  
Author(s):  
Gianluca Buffa ◽  
Livan Fratini ◽  
Marion Merklein ◽  
Detlev Staud
Keyword(s):  
Mechanical Properties ◽  
Stress Condition ◽  
Research Effort ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Tests ◽  
Friction Stir ◽  
Tailored Blanks ◽  
Sheet Stamping ◽  
Wide Range

Tight competition characterizing automotive industries in the last decades has determined a strong research effort aimed to improve utilized processes and materials in sheet stamping. As far as the latter are regarded light weight alloys, high strength steels and tailored blanks have been increasingly utilized with the aim to reduce parts weight and fuel consumptions. In the paper the mechanical properties and formability of tailored welded blanks made of a precipitation hardenable aluminum alloy but with different sheet thicknesses, have been investigated: both laser welding and friction stir welding have been developed to obtain the tailored blanks. For both welding operations a wide range of the thickness ratios has been considered. The formability of the obtained blanks has been characterized through tensile tests and cup deep drawing tests, in order to show the formability in dependency of the stress condition; what is more mechanical and metallurgical investigations have been made on the welded joints.

Effect of plasma preheating on weld quality and tool life during friction stir welding of DH36 steel

2021 ◽  
pp. 095440542199013
Author(s):  
Avinish Tiwari ◽  
Pardeep Pankaj ◽  
Saurav Suman ◽  
Piyush Singh ◽  
Pankaj Biswas ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Tool Life ◽  
Force Measurement ◽  
Deep Understanding ◽  
High Strength ◽  
Microstructural Characterization ◽  
Stir Zone ◽  
Friction Stir ◽  
Allotriomorphic Ferrite ◽  
Fsw Parameters

Friction stir welding (FSW) of high strength materials is challenging due to high tool cost and low tool life. To address this issue, the present investigation deals with an alternative of plasma-assisted friction stir welding (PFSW) of DH36 steel with WC-10%Co tool. Plasma preheating current (13 A, 15 A, and 17 A) was varied by keeping other FSW parameters as constant. During the FSW and PFSW process, force measurement and thermal history aided in a deep understanding of the process, tool degradation mechanisms, accompanied by the mechanical and microstructural characterization of the welded joints. The stir zone hardness was increased from 140 HV0.5 to about 267 HV0.5. The yield and tensile strength of weld increased from 385 MPa and 514 MPa to about 391 MPa and 539 MPa, respectively. Weld joint elongation (%) was increased from ~10% of weld 1 to ~13.89% of weld 4. During PFSW, the process temperature was increased, the cooling rate was lowered, and the weld bead was widened. The results also revealed that the plasma-assisted weld resulted in polygonal ([Formula: see text]) and allotriomorphic ferrite as the major constituents in the stir zone. Pearlite dissolution and spheroidization were observed in the ICHAZ and SCHAZ, respectively. Additionally, the plasma preheating reduced the tungsten tool’s wear by 58% compared to FSW.

Mechanical and Corrosion Behavior of Friction Stir Welded AA 6063 Alloy

2022 ◽  
pp. 206-214
Author(s):  
Radha R. ◽  
Sreekanth D. ◽  
Tushar Bohra ◽  
Surya Bhan Pratap Singh
Keyword(s):  
Friction Stir Welding ◽  
High Strength ◽  
Metallic Alloys ◽  
Fusion Welding ◽  
Corrosion Properties ◽  
Microstructural Refinement ◽  
Significant Development ◽  
Friction Stir ◽  
Mechanical And Corrosion Properties ◽  
Fsw Parameters

Friction stir welding (FSW) is considered to be the most significant development in solid state metal joining processes. This joining technique is energy efficient, environmentally friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. The project aims to join Aluminum 6063 alloy plates by FSW and emphasize the (1) mechanisms responsible for the formation of welds without any defects, microstructural refinement, and (2) effects of FSW parameters on resultant microstructure, mechanical, and corrosion properties.

scholarly journals Experimental review of thermal analysis of dissimilar welds of High-Strength Steel

2019 ◽  
Vol 58 (1) ◽  
pp. 38-49 ◽  
Author(s):  
Francois Njock Bayock ◽  
Paul Kah ◽  
Belinga Mvola ◽  
Pavel Layus
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Heat Input ◽  
Power Plants ◽  
Welding Process ◽  
Postweld Heat Treatment ◽  
High Strength ◽  
Dissimilar Welding ◽  
Dissimilar Welds ◽  
Wide Range

Abstract Dissimilar welding offers exiting benefits for a wide range of engineering applications, such as automotive bodies, piping systems of nuclear power plants, health equipment. The main advantages of dissimilarwelding applications areweight reductions, lower costs, unique properties combinations, and improved energy-efficiency. The properties of dissimilar weld depend on the type of welding process used, the accuracy of the process parameters control, the characteristics of the base metal and the heat treatment procedures. The current study reviews the scientific literature on the topic of thermal analysis of dissimilar high-strength steels (HSS) welding. The review of experimental data was carried out to analyze the variable heat input effect on dissimilar welds. The results indicate the welds mechanical properties irregularity and reduction in toughness and tensile strength due to uneven changes in the microstructure. Furthermore, postweld heat treatment (PWHT) often resulted in the formation of intermetallic compounds whose properties are dependent on the duration of treatment. The research results can be used to optimize the heat input of the HSS welding process.

scholarly journals Friction Stir Welding of Non-Heat-Treatable High-Strength Alloy 5083-O

Metals ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 208 ◽  
Author(s):  
Takashi Nakamura ◽  
Toshiyuki Obikawa ◽  
Itaru Nishizaki ◽  
Masatoshi Enomoto ◽  
Zhenglong Fang
Keyword(s):  
Friction Stir Welding ◽  
High Strength ◽  
Friction Stir ◽  
Strength Alloy

Optimization of Process Parameters for Improved Corrosion Resistance and Microstructural Exploration in Friction Stir Welding of AA2024 - AA6061

2019 ◽  
Vol 969 ◽  
pp. 589-594
Author(s):  
R. Dinesh Kumar ◽  
D. Srija ◽  
P. Suresh ◽  
S. Muthukumaran
Keyword(s):  
Corrosion Resistance ◽  
Friction Stir Welding ◽  
Optimal Parameter ◽  
Microstructural Analysis ◽  
Traverse Speed ◽  
Dissimilar Joints ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Three Stages ◽  
Fsw Parameters

The aluminium alloys AA2024 and AA6061 are widely used for fabricating light weight structural member with better strength and corrosion resistance. Friction stir welding (FSW) parameters such as rotational speed, tool shoulder profile and traverse speed are used to identify the corrosion resistance and microstructural analysis in different weld region of AA2024-AA6061 dissimilar joints. In this work, Taguchi L9 orthogonal array with three variables and three stages has been used to reduce the number of experiments. Potentiodynamic polarization (PDP) testing results are optimized by ANOVA technique and obtain the corrosion rate as 5.72 mil/yr and resistance polarization as 835.28 ohm.cm2. The optimal parameter set is found to be 1000 rpm, flat shoulder and 45 mm/min. The microstructural analysis reveals localized pit dissolution in the nugget zoneThe aluminium alloys AA2024 and AA6061 are widely used for fabricating light weight structural member with better strength and corrosion resistance. Friction stir welding (FSW) parameters such as rotational speed, tool shoulder profile and traverse speed are used to identify the corrosion resistance and microstructural analysis in different weld region of AA2024-AA6061 dissimilar joints. In this work, Taguchi L9 orthogonal array with three variables and three stages has been used to reduce the number of experiments. Potentiodynamic polarization (PDP) testing results are optimized by ANOVA technique and obtain the corrosion rate as 5.72 mil/yr and resistance polarization as 835.28 ohm.cm2. The optimal parameter set is found to be 1000 rpm, flat shoulder and 45 mm/min. The microstructural analysis reveals localized pit dissolution in the nugget zone.

scholarly journals Systematic Evaluation of the Advantages of Static Shoulder FSW for Joining Aluminium

2014 ◽  
Vol 794-796 ◽  
pp. 407-412 ◽  
Author(s):  
Hao Wu ◽  
Ying Chun Chen ◽  
David Strong ◽  
Philip Prangnell
Keyword(s):  
Friction Stir Welding ◽  
Temperature Distribution ◽  
Aluminium Alloy ◽  
Surface Quality ◽  
Heat Affected Zone ◽  
Heat Input ◽  
High Strength ◽  
Temperature Gradients ◽  
Systematic Evaluation ◽  
Friction Stir

Static Shoulder Friction Stir Welding (SS-FSW) is a modification to conventional FSW that was originally developed to improve the weldability of titanium alloys by reducing through thickness temperature gradients. Surprisingly, to date, there have been no published systematic studies comparing SS-FSW to FSW for aluminium welding. This may be because the high conductivity of aluminium means the heat input produced by the shoulder is thought to be beneficial. In the work presented when welding a high strength 7050 aluminium alloy, even in a relatively thin 6 mm plate, it is shown that SS-FSW has several advantages; including a reduction in the heat input, a massive improvement in surface quality, and a more uniform through thickness temperature distribution, which leads to narrower welds with a reduced heat affected zone width and more homogeneous through thickness properties. The reasons for these benefits are discussed.

Effect of Welding Parameters on Defects and Fracture Behavior of Friction Stir Welded 2195-T8 Al-Li Alloy Joints

2018 ◽  
Vol 913 ◽  
pp. 182-189
Author(s):  
Yang Wu ◽  
Hua Mao ◽  
Qing Bo Yang ◽  
Zhi Qing Zhang
Keyword(s):  
Friction Stir Welding ◽  
Heat Input ◽  
Fracture Behavior ◽  
Sudden Change ◽  
Vertical Direction ◽  
Welding Parameters ◽  
Hardness Profile ◽  
Butt Joints ◽  
Friction Stir ◽  
Thermal Affected Zone

In this work, the ratio of rotation rate to advancing speed was fixed to 10 to fabricate friction stir welding (FSW) butt joints of 2195 - T8 plates with 7.5 mm in thickness. The results revealed that the heat input of joints along the vertical direction varied with the welding parameters though these parameters had a same ratio. 500-50 and 600-60 joints failed in the thermal affected zone and thermal mechanical affected zone (TAZ/TMAZ), while other joints all failed in stirred zone (SZ). The hardness profile across the joints showed a similar W shape, while the hardness in bottom area increased with the increasing of parameters. Lazy S and kissing - bond defects appeared in all of these joints, and over - burn defect was also found in 1000-100 joint. It is concluded that the heat input distribution gradient during FSW across the joints becomes non-uniform and a sudden change between upper and lower areas even occurs.

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