scholarly journals Microstructural Evolution and Mechanical Properties of Friction Stir Welded Butt Joints of 5A06 Alloy Ultra-Thin Sheets

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3906 ◽  
Author(s):  
Yang Han ◽  
Xiaoqing Jiang ◽  
Tao Yuan ◽  
Shujun Chen ◽  
Dongxiao Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Grain Boundaries ◽  
Microstructural Evolution ◽  
Welding Speed ◽  
Base Material ◽  
Thin Plates ◽  
Al Alloy ◽  
Minimum Thickness ◽  
Friction Stir

Ultra-thin plates have great potential for applications in aircraft skin, the packaging industry, and packaging of electronic products. Herein, 1 mm-thick 5A06 Al alloy was welded with friction stir welding. The microstructural evolution of the welds was investigated in detail with optical microscopy, scanning electron microscopy, and electron backscatter diffraction. The results showed that the friction stir welds of 1 mm-thick 5A06 Al alloy were well formed without obvious defect and with a minimum thickness reduction of 0.025 mm. Further, the grain size and the proportion of low-angle grain boundaries decreased with decreasing welding speed, because of the increasing degree of dynamic recrystallization. Among all of the welded joints, the welding speed of 100 mm/min yielded the smallest grain size and the highest proportion of high-angle grain boundaries, and thus the best mechanical properties. Specifically, the tensile strength of the joint was greater than that of the base material, while the elongation reached 80.83% of the base material.

Investigation of Microstructure and Mechanical Properties of Friction Stir Lap Jointed Ni Base Superalloy

2012 ◽  
Vol 724 ◽  
pp. 481-485
Author(s):  
Kuk Hyun Song ◽  
Kazuhiro Nakata
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Friction Stir Welding ◽  
Base Material ◽  
Lap Joints ◽  
Stir Zone ◽  
Inconel 600 ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

This study evaluated the microstructure and mechanical properties of friction stir welded lap joints. Inconel 600 and SS 400 as experimental materials were selected, and friction stir welding was carried out at tool rotation speed of 200 rpm and welding speed of 100 mm/min. Applying the friction stir welding was notably effective to reduce the grain size of the stir zone, as a result, the average grain size of Inconel 600 was reduced from 20 μm in the base material to 8.5 μm in the stir zone. Joint interface between Inconel 600 and SS 400 showed a sound weld without voids and cracks. Also, the hook, along the Inconel 600 alloy from SS 400, was formed at advancing side, which directly affected an increase in peel strength. In this study, we systematically discussed the evolution on microstructure and mechanical properties of friction stir lap jointed Inconel 600 and SS 400.

Effects of welding speeds on the microstructural and mechanical properties of AZ91D Mg alloy by friction stir welding

2020 ◽  
Vol 11 (6) ◽  
pp. 769-782 ◽  
Author(s):  
Nagabhushan Kumar Kadigithala ◽  
Vanitha C
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Magnesium Alloy ◽  
Welding Speed ◽  
Base Material ◽  
Welding Parameters ◽  
Content Type ◽  
Friction Stir ◽  
Az91d Magnesium Alloy ◽  
Transverse Tensile

PurposeThe main purpose of the present work is to evaluate, the microstructural and mechanical properties of friction stir welded plates of AZ91D magnesium alloy with 3 mm thickness, and to determine the optimum range of welding conditions.Design/methodology/approachMicrostructure and fractographic studies were carried out using scanning electron microscopy (SEM). Vickers micro hardness test was performed to evaluate the hardness profile in the region of the weld area. The phases in the material were confirmed by X-Ray diffraction (XRD) analysis. Transverse tensile tests were conducted using universal testing machine (UTM) to examine the joint strength of the weldments at different parameters.FindingsMetallographic studies revealed that each zone shown different lineaments depending on the mechanical and thermal conditions. Significant improvement in the hardness was observed between the base material and weldments. Transverse tensile test results of weldments had shown almost similar strength that of base material regardless of welding speed. Fractographic examination indicated that the welded specimens failed due to brittle mode fracture. Through these studies it was confirmed that friction stir welding (FSW) can be used for the welding of AZ91D magnesium alloy.Research limitations/implicationsIn the present study, the welding speed varied from 25 mm/min to 75 mm/min, tilt angle varied from 1.5° to 2.5° and constant rotational speed of 500 rpm.Practical implicationsMagnesium and aluminum based alloys which are having high strength and low density, used in automotive and aerospace applications can be successfully joined using FSW technique. The fusion welding defects can be eliminated by adopting this technique.Originality/valueLimited work had been carried out on the FSW of magnesium based alloys over aluminum based alloys. Furthermore, this paper analyses the influence of welding parameters over the microstructural and mechanical properties.

Precipitates formation and its impact in friction stir welded and post-heat-treated Inconel 718 alloy

2011 ◽  
Vol 1363 ◽  
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Inconel 718 ◽  
Rotation Speed ◽  
Base Material ◽  
Post Heat Treatment ◽  
Inconel 718 Alloy ◽  
Friction Stir ◽  
Heat Treated

ABSTRACTIn order to investigate the formation of precipitates such as MC carbides and intermetallic compounds in the friction stir welded and post-heat-treated Inconel 718 alloy, this work was carried out. Furthermore, the microstructural and mechanical properties of welds and post-heat-treated material were evaluated to identify the effect on precipitates formed during post-heat-treatment. Friction stir welding (FSW) was performed at a rotation speed of 200 rpm and welding speed of 150 mm/min; heat treatment was performed after welding at 720 °C for 8 hours in vacuum. As a result, the grain size due to FSW was notably refined from 5–20 μm in the base material to 1–3 μm in the stir zone; this was accompanied by dynamic recrystallization, which resulted in enhancements in the mechanical properties as compared to the base material. In particular, applying heat treatment after FSW led to improvements in the mechanical properties of the welds—the microhardness and tensile strength increased by more than 50% and 40% in fraction, respectively, as compared to FSW alone.

Friction Stir Lap Joining of AC4C Cast Aluminum Alloy and Zinc-Coated Steel

2008 ◽  
Vol 580-582 ◽  
pp. 371-374 ◽  
Author(s):  
Y.C. Chen ◽  
T. Komazaki ◽  
Y.G. Kim ◽  
Takuya Tsumura ◽  
Kazuhiro Nakata
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Intermetallic Compounds ◽  
Welding Speed ◽  
Base Material ◽  
Cast Aluminum Alloy ◽  
Coated Steel ◽  
Cast Aluminum ◽  
Friction Stir ◽  
Zinc Coated Steel

AC4C cast aluminum alloy and zinc-coated steel were friction stir lap welded, and the microstructures and mechanical properties of the joints were examined and analyzed. Experimental results show that the welding speeds have a significant effect on the tensile properties and fracture locations of the joints at a rotational speed of 1500 rpm. When the welding speed is higher than 60 mm/min, the joints fracture in the zinc-coated steel base material and the tensile strength is equal to that of the zinc-coated steel; when the welding speed is lower than 60 mm/min, the joints fracture in the interface and the shear strength is about 50 MPa. The change of the fracture locations is attributed to the presence of large quantity intermetallic compounds adjacent to the interface of the joints. The composition and formation mechanism of the intermetallic compounds and its effect on the mechanical properties of the joints were discussed.

Microstructure and Mechanical Properties of Friction Stir Welded Al-Zn-Mg-Cu Alloy

2014 ◽  
Vol 628 ◽  
pp. 7-11
Author(s):  
Sheng Dan Liu ◽  
Yun Dai ◽  
Yu Long Wu ◽  
Bin Chen ◽  
Xin Ming Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Base Material ◽  
Optical Microscope ◽  
Alloy Sheet ◽  
Grain Structure ◽  
Hardness Profile ◽  
Friction Stir ◽  
Cu Alloy ◽  
Microstructure And Mechanical Properties

The microstructure and mechanical properties of friction stir welded Al-Zn-Mg-Cu alloy sheet were investigated by means of hardness and tensile tests, optical microscope and scanning electron microscope. The hardness profile of the weld exhibits a W shape with the lowest value in the thermo-mechanically affected zone on the advancing side. The tensile strength and elongation of the weld are about 71% and 72% that of the base material. In the nugget zone, there are a number of fine recrystallized grains and dispersed precipitates at grain boundaries. In the thermo-mechanically affected zone, the grain size is not uniform and there are a number of precipitates at grain boundaries. In the heat affected zone, the grain structure is similar to the base material.

scholarly journals Microstructural evolution during high-temperature tensile creep at 1,500°C of a MoSiBTiC alloy

2020 ◽  
Vol 39 (1) ◽  
pp. 136-145 ◽  
Author(s):  
Sojiro Uemura ◽  
Shiho Yamamoto Kamata ◽  
Kyosuke Yoshimi ◽  
Sadahiro Tsurekawa
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Microstructural Evolution ◽  
Grain Boundary Sliding ◽  
Primary Creep ◽  
Tensile Creep ◽  
Tertiary Creep ◽  
Continuous Dynamic Recrystallization ◽  
Continuous Dynamic ◽  
Creep Regime

AbstractMicrostructural evolution in the TiC-reinforced Mo–Si–B-based alloy during tensile creep deformation at 1,500°C and 137 MPa was investigated via scanning electron microscope-backscattered electron diffraction (SEM-EBSD) observations. The creep curve of this alloy displayed no clear steady state but was dominated by the tertiary creep regime. The grain size of the Moss phase increased in the primary creep regime. However, the grain size of the Moss phase was found to remarkably decrease to <10 µm with increasing creep strain in the tertiary creep regime. The EBSD observations revealed that the refinement of the Moss phase occurred by continuous dynamic recrystallization including the transformation of low-angle grain boundaries to high-angle grain boundaries. Accordingly, the deformation of this alloy is most likely to be governed by the grain boundary sliding and the rearrangement of Moss grains such as superplasticity in the tertiary creep regime. In addition, the refinement of the Moss grains surrounding large plate-like T2 grains caused the rotation of their surfaces parallel to the loading axis and consequently the cavitation preferentially occurred at the interphases between the end of the rotated T2 grains and the Moss grains.

scholarly journals Effect of Stirring Pin Rotation Speed on Microstructure and Mechanical Properties of 2A14-T4 Alloy T-Joints Produced by Stationary Shoulder Friction Stir Welding

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1938
Author(s):  
Haifeng Yang ◽  
Hongyun Zhao ◽  
Xinxin Xu ◽  
Li Zhou ◽  
Huihui Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Rotation Speed ◽  
Weld Nugget ◽  
Al Alloy ◽  
Nugget Zone ◽  
T Joints ◽  
Friction Stir ◽  
Stationary Shoulder ◽  
Microstructure And Mechanical Properties

In this study, 2A14-T4 Al-alloy T-joints were prepared via stationary shoulder friction stir welding (SSFSW) technology where the stirring pin’s rotation speed was set as different values. In combination with the numerical simulation results, the macro-forming, microstructure, and mechanical properties of the joints under different welding conditions were analyzed. The results show that the thermal cycle curves in the SSFSW process are featured by a steep climb and slow decreasing variation trends. As the stirring pin’s rotation speed increased, the grooves on the weld surface became more obvious. The base and rib plates exhibit W- or N-shaped hardness distribution patterns. The hardness of the weld nugget zone (WNZ) was high but was lower than that of the base material. The second weld’s annealing effect contributed to the precipitation and coarsening of the precipitated phase in the first weld nugget zone (WNZ1). The hardness of the heat affect zone (HAZ) in the vicinity of the thermo-mechanically affected zone (TMAZ) dropped to the minimum. As the stirring pin's rotation speed increased, the tensile strengths of the base and rib plates first increased and then dropped. The base and rib plates exhibited ductile and brittle/ductile fracture patterns, respectively.

Effect of Li on Mechanical Properties and Electrical Conductivity of the Al–Zn–Cu–Mg Based Alloys

2021 ◽  
Vol 21 (9) ◽  
pp. 4897-4901
Author(s):  
Hyo-Sang Yoo ◽  
Yong-Ho Kim ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Tensile Strength ◽  
Spherical Particles ◽  
Al Alloy ◽  
High Angle ◽  
Average Grain Size ◽  
Strength Improvement ◽  
Li Content

In this study, changes in the microstructure, mechanical properties, and electrical conductivity of cast and extruded Al–Zn–Cu–Mg based alloys with the addition of Li (0, 0.5 and 1.0 wt.%) were investigated. The Al–Zn–Cu–Mg–xLi alloys were cast and homogenized at 570 °C for 4 hours. The billets were hot extruded into rod that were 12 mm in diameter with a reduction ratio of 38:1 at 550 °C. As the amount of Li added increased from 0 to 1.0 wt.%, the average grain size of the extruded Al alloy increased from 259.2 to 383.0 µm, and the high-angle grain boundaries (HGBs) fraction decreased from 64.0 to 52.1%. As the Li content increased from 0 to 1.0 wt.%, the elongation was not significantly different from 27.8 to 27.4% and the ultimate tensile strength (UTS) was improved from 146.7 to 160.6 MPa. As Li was added, spherical particles bonded to each other, forming an irregular particles. It is thought that these irregular particles contribute to the strength improvement.

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