scholarly journals Effect of Welding Speed on Defect Features and Mechanical Performance of Friction Stir Lap Welded 7B04 Aluminum Alloy

Metals ◽  
2016 ◽  
Vol 6 (4) ◽  
pp. 87 ◽  
Author(s):  
Huijie Zhang ◽  
Min Wang ◽  
Xiao Zhang ◽  
Zhi Zhu ◽  
Tao Yu ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Welding Speed ◽  
Mechanical Performance ◽  
Friction Stir

Study on the Microstructure and Mechanical Properties of Welding Joints of 7A05 Aluminum Alloy by FSW

2014 ◽  
Vol 496-500 ◽  
pp. 110-113
Author(s):  
Dong Gao Chen ◽  
Jin He Liu ◽  
Zhi Hua Ma ◽  
Wu Lin Yang
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Welding Speed ◽  
Welded Joint ◽  
Optical Microscope ◽  
Nugget Zone ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Welding Joints

The7A05 aluminum alloy of the 10mm thickness was welded by the friction stir welding. The microstructure and mechanical Properties of the welded joint was researched by the optical microscope, etc. The results showed: the microstructure of the weld nugget zone and the thermal mechanically affected zone were refined as the welding speed increasing when the rotate speed is constant. As the welding speed increasing the strength of extension of the welded joint is increasing at first and then stable basically. but the yield strength had no obvious change.

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.

Joint Formation and Mechanical Performance of Friction Self-Piercing Riveted Aluminum Alloy AA7075-T6 Joints

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Yun Wu Ma ◽  
Yong Bing Li ◽  
Zhong Qin Lin
Keyword(s):  
Aluminum Alloy ◽  
Failure Mode ◽  
Feed Rate ◽  
Shear Failure ◽  
Mechanical Performance ◽  
Shear Fracture ◽  
Peak Load ◽  
Spindle Speed ◽  
Friction Stir ◽  
Lap Shear

AA7xxx series aluminum alloys have great potentials in mass saving of vehicle bodies due to pretty high specific strength. However, the use of these high strength materials poses significant challenges to the traditional self-piercing riveting (SPR) process. To address this issue, a novel process, friction self-piercing riveting (F-SPR), was applied to join aluminum alloy AA7075-T6 sheets. The effects of the spindle speed and rivet feed rate on F-SPR joint cross section geometry evolution, riveting force, and energy input were investigated systematically. It was found that the rivet shank deformation, especially the buckling of the shank tip before penetrating through the top sheet, has significant influence on geometry and lap shear failure mode of the final joint. A medium rivet feed rate combined with a high spindle speed was prone to produce a defect-free joint with sound mechanical interlocking. F-SPR joints with the failure mode of rivet shear fracture were observed to have superior lap shear peak load and energy absorption over the joints with mechanical interlock failure. The optimized F-SPR joint in this study exhibited 67.6% and 13.9% greater lap shear peak load compared with SPR and refill friction stir spot welding joints, respectively, of the same sheets. This research provides a valuable reference for further understanding the F-SPR process.

Vertical Compensation Friction Stir Welding of 6061-T6 Aluminum Alloy

2016 ◽  
Vol 35 (8) ◽  
pp. 843-851 ◽  
Author(s):  
Shude Ji ◽  
Xiangchen Meng ◽  
Jingwei Xing ◽  
Lin Ma ◽  
Shuangsheng Gao
Keyword(s):  
Adverse Effect ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Welding Speed ◽  
Rotational Velocity ◽  
Weld Zone ◽  
Strengthening Effect ◽  
Fracture Surface Morphology ◽  
Friction Stir

AbstractVertical compensation friction stir welding (VCFSW) was proposed in order to solve the adverse effect caused by a big gap at the interface between two welded workpieces. VCFSW was successfully applied to weld 6061-T6 aluminum alloy with the thickness of 4 mm, while 2024-T4 aluminum alloy was selected as a rational compensation material. The results show that VCFSW is difficult to get a sound joint when the width of strip is no less than 1.5 mm. Decreasing the welding speed is beneficial to break compensation strip into pieces and then get higher quality joint. When the width of strip is 1 mm, the tensile strength and elongation of joint at the welding speed of 50 mm/min and rotational velocity of 1,800 rpm reach the maximum values of 203 MPa and 5.2%, respectively. Moreover, the addition of 2024-T4 alloy plays a strengthening effect on weld zone (WZ) of VCFSW joint. The fracture surface morphology of joint consisting of amounts of dimples exhibits ductile fracture.

Process Window for Friction Stir Lap Welding of Aluminum Alloy 6061

2014 ◽  
Vol 783-786 ◽  
pp. 2839-2844
Author(s):  
Simon Larose ◽  
Maxime Guérin ◽  
Priti Wanjara
Keyword(s):  
Aluminum Alloy ◽  
Mechanical Performance ◽  
High Strength ◽  
Butt Joint ◽  
Process Window ◽  
Tool Geometry ◽  
Transportation Industry ◽  
Friction Stir ◽  
Planar Surfaces ◽  
Lap Welding

Precipitation-hardenable 6xxx series aluminum alloys are incorporated in many structural components with due consideration of their good combination of properties including a relatively high strength, outstanding extrudability and excellent corrosion resistance. Accordingly, AA6061 has been identified as a very good candidate material for structural lightweighting of transportation vehicles. However, the weldability of aluminum alloy (AA) 6061 by means of conventional technologies such as GMAW and GTAW methods is limited by sensitivity to solidification cracking. In this respect, friction stir welding (FSW) presents a tremendous potential for assembly of aluminum structures for the transportation industry due to the low heat involved that can mitigate crack formation and, thus, translate into improved mechanical performance of the assembly. In this work, FSW of 3.18 mm thick AA6061-T6 sheets in the lap joint configuration was investigated. This configuration is considered to be more challenging for assembly by FSW than the butt joint type due to the orientation of the interface with respect to the welding tools and the necessity to break the oxide layer on two aluminium alloy planar surfaces. Weld trials were performed to examine the influence of the FSW tool geometry and process parameters on the welding defects, microstructure, hardness and bend performance. Unacceptable material expulsion and/or significant thinning in one of the two overlapped sheets were produced under most conditions. A set of FSW tool geometries leading to a viable process operational window under which the risk of defects could be mitigated and/or eliminated was identified in this study.

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