Properties of Friction-Stir Welded Aluminum Alloys 6111 and 5083

Author(s):  
W. Gan ◽  
K. Okamoto ◽  
S. Hirano ◽  
K. Chung ◽  
C. Kim ◽  
...  

Friction-stir welding (FSW) promises joints with low porosity, fine microstructures, minimum phase transformation, and low oxidation compared with conventional welding techniques. It is capable of joining combinations of alloys not amenable to conventional welding. Certain combinations of FSW parameters were used to create FSWs of aluminum alloys 5083-H18 and 6111-T4, and the physical weld defects were measured. The mechanical behavior of FSW welds made under the most favorable choice of parameters was determined using tensile tests and hardness measurements and was correlated to the microstructures of the weld and base material. Stir zones (SZs) in the 5083 specimens were much softer than the strain-hardened base materials. SZs in the 6111 material are approximately as hard as the base material. Natural aging of 6111 FSW specimens occurred in some parts of the heat-affected zone and produced hardening for up to 12weeks after welding. Annealing of 5083 FSW specimens produced abnormal grain growth (AGG) for welds produced under certain welding conditions and in certain parts of the weld zone. AGG is more severe for low-heat conditions, i.e., higher tool travel speed but lower rotational speed. The conditions for most favorable FSW are presented, as well as the expected microstructures and mechanical properties, along with the weld conditions that promote AGG.

Author(s):  
S. M. O. Tavares ◽  
P. C. M. Azevedo ◽  
B. Emi´lio ◽  
V. Richter-Trummer ◽  
M. A. V. Figueiredo ◽  
...  

The T-joint is a common joint type frequently used in transport industries because of the importance of increasing the inertia and strength of thin skins and shells without significant weight increase. This shape can be obtained by different processes as extruding, riveting, welding or others. However, the low weldability of some aluminum alloys, when using traditional welding processes, is an obstacle to the possible full benefit of such reinforced structures. The friction stir welding (FSW) process is suitable to join most aluminum alloys and should be considered as a feasible alternative to the other processes used to produce this type of geometry. This paper reports the results obtained concerning FSW T-joints with a new configuration. These joints simulate a typical reinforcement composed by two materials in order to optimize the damage tolerance. The skin is made of a 6xxx series alloy, and the reinforcement is made of a 7xxx series alloy. Mechanical properties were obtained and micro-structural analyses of the weld zone were performed, and the results were compared with those obtained in base materials and butt joints.


2014 ◽  
Vol 936 ◽  
pp. 1735-1741
Author(s):  
Xue Cheng Song ◽  
Li Jie Guo ◽  
Xiao Song Feng ◽  
Yu Huan Yin ◽  
Fan Cui

Dissimilar barrier butt joints of AA2024 to AA6061/SiC/55p composite were fabricated by friction stir welding. Effect of the traverse speed on interface bonding, joint microstructure and tensile properties was investigated. Results revealed that, all joints possessed a tensile strength stronger than 80% that of the composite base materials, and the highest strength value was 178MPa. Macro interface can be readily identified in the weld zone between AA2024 and AA6061/SiC/55p composite, of which the area decreased and then increased as the traverse speed increased. The size and shape of SiC particles in the interface zone varied a lot due to different stirring effect and forward impact of the pin in different traverse speeds. Increasingly impairment of the composite base material near the interface was also detected with the traverse speed increasing.


2013 ◽  
Vol 773-774 ◽  
pp. 803-811 ◽  
Author(s):  
K.M. Adel

Friction stir welding of AA 7020-T6 aluminum alloys, 5 mm thick plate is an Al-Zn-Mg grade alloy of 7XXX series heat treatable of medium strength alloys and employed for welded engineering structural components. The effect of FSW parameters (rotational speeds and travel speeds) on joint strength and welding zone dimensions have been investigated experimentally. Four different rotational speeds are used: 450, 560, 710 and 900 r.p.m. with three travel speeds 16, 25 and 40 mm.min-1. The experimental investigation included tensile test and weld pool geometry determination. It was found the that best welding conditions for FSW was the weldments which have 247 Mpa yield strength, 340 MPa ultimate tensile strength, 7.3% elongation, 11020N bending forces for both face and root and hardness value ranging from (133-138) Hv 0.05 for the different welding regions under the optimal welding conditions at a rotational speed of 900 r.p.m. and travel speed of 25mm.min-1.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3110
Author(s):  
Kaveripakkam Suban Ashraff Ali ◽  
Vinayagam Mohanavel ◽  
Subbiah Arungalai Vendan ◽  
Manickam Ravichandran ◽  
Anshul Yadav ◽  
...  

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.


Friction Stir Welding (FSW) is a topical and propitious solid-state joining process producing economical and strengthened joints of age-hardened and heat-treatable Aluminium Alloy AA 6082-T6. Mechanical and fractural behaviour of weldments were investigated in order to find crack initiation and necking on the weld zone thereby perceiving the complete behaviour of fracture occurred near the weld zone. Weldments are fabricated by employing four tool pin profiles namely MX-TRIVEX, A-SKEW, Three flat threaded and Concave shouldered MX-TRIFLUTE tools at various rotational speeds 1000 rpm, 1200 rpm and 1400 rpm at single traverse speed 25 mm/min. EXCETEX-EX-40 CNC wire cut EDM with 0.25 mm brass wire diameter has been employed to perform the extraction of tensile test specimens from the weldments according to ASTM E8M-04 standard. Tensile test was performed on elctromechanically servo controlled TUE-C-200 (UTM machine) according to ASTM B557-16 standards Maximum Ultimate Tensile Strength (UTS) of 172.33 MPa (55.5% of base material) and 0.2% Yield Stress (YS) of 134.10 MPa (51.5% of base material) were obtained by using A-SKEW at 1400 rpm, 25 mm/min and maximum % Elongation (%El) of 11.33 (113.3% of base material) was obtained at MX-TRIVEX at 1000 rpm, 25 mm/min. Minimum UTS of 131.16 MPa (42.30% of base material) and 0.2% YS of 105.207 MPa (40.46% of base material )were obtained by using Concave shouldered MX-TRIFLUTE at 1400 rpm, 25 mm/min. Minimum % El of 5.42 ( 54.2% of base material) was obtained by using A-SKEW at 1000 rpm, 25 mm/min.


2018 ◽  
Vol 15 (4) ◽  
pp. 449-454
Author(s):  
Baghdad Science Journal

This work aims to investigate the tensile and compression strengths of heat- cured acrylic resin denture base material by adding styrene-butadiene (S- B) to polymethyl methacrylate (PMMA). The most well- known issue in prosthodontic practice is fracture of a denture base. All samples were a blend of (90%, 80%) PMMA and (10%, 20%) S- B powder melted in Oxolane (Tetra hydro furan). These samples were chopped down into specimens of dimensions 100x10x2.5mm to carry out the requirements of tensile tests. The compression strength test specimens were shaped into a cylinder with dimensions of 12.7mm in diameter and 20mm in length. The experimental results show a significant increase in both tensile and compression strengths when compared to control (standard) results for the preparation material.


Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 933
Author(s):  
SeongHwan Park ◽  
YoungHwan Joo ◽  
Myungchang Kang

Thin sheets of lightweight aluminum alloys, which are increasingly used in automotive, aerospace, and electronics industries to reduce the weight of parts, are difficult to weld. When applying micro-friction stir welding (μ-FSW) to thin plates, the heat input to the base materials is considerably important to counter the heat loss to the jig and/or backing plate. In this study, three different backing-plate materials—cordierite ceramic, titanium alloy, and copper alloy—were used to evaluate the effect of heat loss on weldability in the μ-FSW process. One millimeter thick AA6061-T6 and AA5052-H32 dissimilar aluminum alloy plates were micro-friction stir welded by a butt joint. The tensile test, hardness, and microstructure of the welded joints using a tool rotational speed of 9000 rpm, a welding speed of 300 mm/min, and a tool tilting angle of 0° were evaluated. The heat loss was highly dependent on the thermal conductivity of the backing plate material, resulting in variations in the tensile strength and hardness distribution of the joints prepared using different backing plates. Consequently, the cordierite backing plate exhibited the highest tensile strength of 222.63 MPa and an elongation of 10.37%, corresponding to 86.7% and 58.4%, respectively, of those of the AA5052-H32 base metal.


Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1024 ◽  
Author(s):  
Robert Kosturek ◽  
Lucjan Śnieżek ◽  
Janusz Torzewski ◽  
Marcin Wachowski

The aim of this research was to investigate the effect of friction stir welding (FSW) parameters on microstructure and mechanical properties of Sc-modified AA2519 extrusion joints. The workpiece was welded by FSW in non-heat-treated condition with seven different sets of welding parameters. For each obtained joint macrostructure and microstructure observations were performed. Mechanical properties of joints were investigated using tensile test together with localization of fracture location. Joint efficiencies were established by comparing measured joints tensile strength to the value for base material. The obtained results show that investigated FSW joints of Sc-modified AA2519 in the non-heat-treated condition have joint efficiency within the range 87–95%. In the joints obtained with the lowest ratio of the tool rotation speed to the tool traverse speed, the occurrence of imperfections (voids) localized in the stir zone was reported. Three selected samples were subjected to further investigations consisting microhardness distribution and scanning electron microscopy fractography analysis. As the result of dynamic recrystallization, the microhardness of the base material value of 86 HV0.1 increased to about 110–125 HV0.1 in the stir zone depending on the used welding parameters. Due to lack of the strengthening phase and low strain hardening of used alloy the lack of a significantly softened zone was reported by both microhardness analysis and investigation of the fractured samples.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1937 ◽  
Author(s):  
Tomasz Machniewicz ◽  
Przemysław Nosal ◽  
Adam Korbel ◽  
Marek Hebda

The paper describes the influence of the friction stir welding travel speed on the mechanical properties of the butt joints of copper plates. The results of static and fatigue tests of the base material (Cu-ETP R220) and welded specimens produced at various travel speeds were compared, considering a loading applied both parallel and perpendicularly to the rolling direction of the plates. The mechanical properties of the FSW joints were evaluated with respect to parameters of plates’ material in the delivery state and after recrystallisation annealing. The strength parameters of friction stir welding joints were compared with the data on tungsten inert gas welded joints of copper plates available in the literature. The results of microhardness tests and fractographic analysis of tested joints are also presented. Based on the above test results, it was shown that although in the whole range of considered traverse speeds (from 40 to 80 mm/min), comparable properties were obtained for FSW copper joints in terms of their visual and microstructural evaluation, their static and especially fatigue parameters were different, most apparent in the nine-fold greater observed average fatigue life. The fatigue tests turned out to be more sensitive criteria for evaluation of the FSW joints’ qualities.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3672
Author(s):  
Guodong Liu ◽  
Qunying Yang ◽  
Yongshan Cheng

Because of the tensile strength decreasing of the friction stir welded wrought magnesium (Mg) alloy compared to the base material, the reasons for the failure of weld has been focused on. After the fracture in transverse tension, the crack went through the welded joint from the center of the weld to the transition zone between the thermal-mechanical affected zone and weld zone. In the present study, the microstructure characteristics and its effect on the facture in the triple junction region is investigated. Based on the metallography and the electron back-scattered diffraction (EBSD) technology, it was observed that a twin band extended from the triple junction region to the middle of weld. The profuse twinning in the twin band was considered to play an important role on the crack propagation from the stir zone edge to the crown zone.


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