Effects of Process Parameters on Friction Stir Spot Welding of Aluminum Alloy to Advanced High-Strength Steel

2016 ◽  
Author(s):  
Kai Chen ◽  
Xun Liu ◽  
Jun Ni
Keyword(s):  
Aluminum Alloy ◽  
Cross Sections ◽  
Spot Welding ◽  
Dwell Time ◽  
High Strength ◽  
Friction Stir Spot Welding ◽  
Thin Layers ◽  
Weld Strength ◽  
Friction Stir ◽  
Alloy 6061

Friction stir spot welding (FSSW) process has been successfully applied for joining aluminum alloy 6061 to TRIP 780/800 steel. Effects of tool plunge speed and dwell time on the weld strength were studied through design of experiments and analysis of variance. It is shown that dwell time is a more dominant parameter in affecting the weld strength than plunge speed. Cross sections of weld specimens show the formation of hook with a swirling structure. Higher magnified SEM view with EDS analysis reveals the swirling structure to be composed of alternating thin layers of steel and Al-Fe intermetallic compounds (IMCs). During tensile shear test, cross nugget failure is the only failure mode. Cracks are initiated in the swirling structure at the tensile side of the weld nugget and cleavage feature can be observed on the fractured surface.

Effects of Process Parameters on Friction Stir Spot Welding of Aluminum Alloy to Advanced High-Strength Steel

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Kai Chen ◽  
Xun Liu ◽  
Jun Ni
Keyword(s):  
Aluminum Alloy ◽  
Process Parameters ◽  
Cross Sections ◽  
Spot Welding ◽  
Dwell Time ◽  
Friction Stir Spot Welding ◽  
Thin Layers ◽  
Weld Strength ◽  
Friction Stir ◽  
Lap Shear

This paper studies a friction stir spot welding (FSSW) process that has been successfully applied to join aluminum alloy 6061-T6 to transformation-induced plasticity steel (TRIP) 780/800 steel. Cross sections of weld specimens show the formation of a hook with a swirling structure. A higher magnified scanning electron microscope (SEM) view of the swirling structure with energy dispersive X-ray spectroscopy (EDS) analysis reveals that it is composed of alternating thin layers of steel and Al–Fe intermetallic compounds (IMCs). To check the effect of different process parameters on the weld strength, the effects of tool plunge speed and dwell time were studied through the design of experiments (DOE) and analysis of variance (ANOVA) method. It shows that dwell time is a more dominant parameter in affecting the weld strength than plunge speed. Furthermore, investigation of failure using a lap shear tests reveals that cross nugget failure is the only failure mode. It also shows that cracks are initiated in the swirling structure at the tensile side of the weld nugget. After failure, a cleavage feature can be observed on the fractured surface.

Experimental Investigation on Joining Dissimilar Aluminum Alloy 6061 to TRIP 780/800 Steel Through Friction Stir Welding

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Xun Liu ◽  
Shuhuai Lan ◽  
Jun Ni
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Cross Sections ◽  
Failure Modes ◽  
High Strength ◽  
Tensile Tests ◽  
Weld Strength ◽  
Friction Stir ◽  
Aluminum Alloy 6061 ◽  
Alloy 6061

Friction stir welding (FSW) technique has been successfully applied to butt joining of aluminum alloy 6061-T6 to one type of advanced high strength steel (AHSS), transformation induced plasticity (TRIP) 780/800 with the highest weld strength reaching 85% of the base aluminum alloy. Mechanical welding forces and temperature were measured under various sets of process parameters and their relationships were investigated, which also helped explain the observed macrostructure of the weld cross section. Compared with FSW of similar aluminum alloys, only one peak of axial force occurred during the plunge stage. Three failure modes were identified during tensile tests of weld specimens, which were further analyzed based on the microstructure of joint cross sections. Intermetallic compound (IMC) layer with appropriate thickness and morphology was shown to be beneficial for enhancing the strength of Al–Fe interface.

Experimental Study and Numerical Modeling of Friction Stir Spot Welding of Pure Copper Lap Joint

2014 ◽  
Author(s):  
Ahmed Kamal Mahgoub ◽  
Abdelaziz Bazoune ◽  
Fadi A. A. Al-Badour ◽  
Abdelrahman Shuaib ◽  
Gihad Mohamed Karrar
Keyword(s):  
Experimental Study ◽  
Spot Welding ◽  
Dwell Time ◽  
Pure Copper ◽  
Friction Stir Spot Welding ◽  
Fusion Welding ◽  
Weld Strength ◽  
Tool Rotational Speed ◽  
Lap Joint ◽  
Friction Stir

Friction stir spot welding (FSSW) is an appropriate process to join materials that are difficult to weld using fusion welding, such as copper. In this paper, an experimental study to weld lap joint of pure copper plates having a dimensions of 100 × 30 × 2 mm is performed, successful spot weld is obtained at tool rotational speed of 1200 rpm, feed rate of 20 mm/min for dwell time of 2 seconds. The tool used in the FSSW has a threaded pin of 5 mm diameter, length of 3.7 mm, and a scrolled shoulder of 11.52 mm diameter. Tensile test and microhardness were performed for the joint and it showed reasonable weld strength. In addition, a numerical model was developed, and the estimated temperatures as well as weld macrostructure matched very well with experimental results.

scholarly journals Study the microstructure and mechanical properties of dissimilar friction stir spot welding of carbon steel 1006 to aluminum alloy aa2024-t3

2018 ◽  
Vol 7 (4.1) ◽  
pp. 3037
Author(s):  
Isam Tareq Abdullah ◽  
Zaman Khalil Ibrahim ◽  
Ahmed Ibrahim Razooqi
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Carbon Steel ◽  
Spot Welding ◽  
Dwell Time ◽  
Dissimilar Materials ◽  
Friction Stir Spot Welding ◽  
Shear Load ◽  
Tensile Shear ◽  
Friction Stir

Friction stir spot welding-FSSW has been suggested as effectual process to welding difficult materials such as dissimilar materials and thin sheet of metal alloys. In this study, using dissimilar materials were welded carbon steel-1006 on upper plate and aluminum alloy AA2024-T3 on lower plate. Macrostructure, micro-structural analysis and mechanical properties of the joints are done. The effect of penetration depth, dwell time and spindle speed on tensile shear load are investigated with invariable of other parameter during welding process. The maximum tensile shear load (3.31KN) was occurred when using 0.4mm of penetration depth, 10 sec of dwell time and 1400 rpm of spindle speed. Also, two type of failure shape was observed interfacial fracture of carbon steel sheet and pull-out fracture of AA2024-T3 sheet.

Study of friction stir spot welding for thermotolerant engineering thermoplastic polyimide joints

2021 ◽  
pp. 095440542199561
Author(s):  
Jicheng Gao ◽  
Jiachen Dong ◽  
Sunyi Zhang ◽  
Liang Yu ◽  
Huiming Jin ◽  
...  
Keyword(s):  
Shear Strength ◽  
Spot Welding ◽  
Dwell Time ◽  
Rotation Speed ◽  
Mixing Time ◽  
Friction Stir Spot Welding ◽  
Scanning Calorimetry ◽  
Friction Stir ◽  
Base Materials ◽  
Engineering Plastics

In this research, thermoplastic polyimide (TPI) were welding via friction stir spot welding (FSSW) in order to evaluate the feasibility of the technology. The welding tool with a tri-flute pin was used for keeping the welding effectiveness. The effect of the rotation speed and dwell time on the microstructure and shear strength was studied. The results shows that the number of gap defects between the shoulder affect zone and the pin affect zone decreased with the increase of the rotation speed. The boundary of the shoulder affect zone and the pin affect zone was no clear when increasing the dwell time from 10 s to 20 s. Long dwell time could increase the mixing time and reduce the materials viscosity, which made the structure was denser. The maximal shear strength was obtained 85.5% of the base materials. The differential scanning calorimetry (DSC) results indicated that the melting behaviour of different regions was no obvious difference. It indicated that FSSW had a feasible and potential technology to join the high temperature resistant engineering plastics.

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