Microstructural characteristics and mechanical properties of friction stir lap welding joint of Alclad 7B04-T74 aluminum alloy

2015 ◽  
Vol 78 (9-12) ◽  
pp. 1415-1425 ◽  
Author(s):  
Huijie Liu ◽  
Yunqiang Zhao ◽  
Yanying Hu ◽  
Shixuan Chen ◽  
Zhe Lin
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Lap Welding ◽  
Microstructural Characteristics ◽  
Friction Stir ◽  
Welding Joint ◽  
Lap Welding

scholarly journals Microstructural Characteristics and Mechanical Properties of Friction Stir Spot Welded 2A12-T4 Aluminum Alloy

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Huijie Liu ◽  
Yunqiang Zhao ◽  
Xingye Su ◽  
Lilong Yu ◽  
Juncai Hou
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Fracture Mode ◽  
Heat Input ◽  
Tensile Shear ◽  
Microstructural Characteristics ◽  
Friction Stir ◽  
Welding Heat Input ◽  
Mixed Fracture ◽  
Spot Welded

2A12-T4 aluminum alloy was friction stir spot welded, and the microstructural characteristics and mechanical properties of the joints were investigated. A softened microstructural region existed in the joint, and it consisted of stir zone (SZ), thermal mechanically affected zone (TMAZ), and heat affected zone (HAZ). The minimum hardness was located in TMAZ, and the average hardness value in SZ can be improved by appropriately increasing welding heat input. The area of complete bonding region at the interface increased with increasing welding heat input because more interface metals were mixed. In a certain range of FSSW parameters, the tensile shear failure load of the joint increased with increasing rotation speed, but it decreased with increasing plunge rate or decreasing shoulder plunging depth. Two kinds of failure modes, that is, shear fracture mode and tensile-shear mixed fracture mode, can be observed in the tensile shear tests, and the joint that failed in the tensile-shear mixed fracture mode possessed a high carrying capability.

Dissimilar Friction Stir Lap Welding of AA2198 and AA7075 Sheets: Forces, Microstructure and Mechanical Properties

2021 ◽  
Author(s):  
Antonello Astarita ◽  
Fausto Tucci ◽  
Alessia Teresa Silvestri ◽  
Michele Perrella ◽  
Luca Boccarusso ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welding Process ◽  
Processing Parameters ◽  
Processing Parameter ◽  
Friction Stir Lap Welding ◽  
Friction Stir ◽  
Lap Shear ◽  
Microstructure And Mechanical Properties ◽  
Lap Welding ◽  
Factorial Design Of Experiments

Abstract This paper deals with the dissimilar friction stir lap welding of AA2198 and AA7075 sheets. The influence of processing parameters, namely welding speed and tool rotational speed on joint features, microstructure, and mechanical properties were investigated implementing a full factorial design of experiments. During the welding process, axial and transversal forces were continuously measured using a dedicated sensed fixture aiming at the correlation of this processing parameter with the quality of the achieved joints. The reported outcomes showed a very narrow processing window in which it was possible to avoid the formation of defects while the formation of an hook was observed for all the joints welded. The influence of the weld bead morphology on the lap shear strength was elucidated proving that the strength is ruled by the hook morphology. A correlation between the process parameters and the forces arising was also attempted. The final microstructure of the joints was studied and explained and also compared with the microhardness results.

Interfacial Reaction during Dissimilar Friction Stir Lap Welding of Aluminum Alloy to Stainless Steel

2014 ◽  
Vol 794-796 ◽  
pp. 389-394
Author(s):  
Tomo Ogura ◽  
Taichi Nishida ◽  
Makoto Takahashi ◽  
Hidehito Nishida ◽  
Mitsuo Fujimoto ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Aluminum Alloy ◽  
Intermetallic Compounds ◽  
Lap Joint ◽  
Friction Stir Lap Welding ◽  
Friction Stir ◽  
Transmission Electron ◽  
Lap Welding ◽  
Mixed Layers ◽  
Joining Process

A friction stir welded A3003 aluminum alloy /SUS304 stainless steel dissimilar lap joint was successfully produced. A sound joint that fractured at the base metal was obtained in the center region of the joint through the reaction layer of aluminum-rich intermetallic compounds with nanoorder thickness. The microstructural changes at the interface of the joint was examined by studying the hole left by the extracted welding tool produced at the end of the friction stir welding (FSW) bead using transmission electron microscopy (TEM). Mixed layers consisted of ultra-fined intermetallic compounds and stainless steel were observed. The stirred aluminum alloy flows onto the mixed layer after the tool transit and the joining was achieved. Based on the TEM observations, the joining process of the lap joint was also discussed.

scholarly journals Microstructural Characteristics and Mechanical Properties of Water Cooling Bobbin-Tool Friction Stir Welded 6063-T6 Aluminum Alloy

2018 ◽  
Vol 206 ◽  
pp. 03002 ◽  
Author(s):  
Yunqiang Zhao ◽  
Chungui Wang ◽  
Chunlin Dong
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Water Mist ◽  
Water Cooling ◽  
Microstructural Characteristics ◽  
Welding Temperature ◽  
Weld Formation ◽  
Friction Stir ◽  
Mist Cooling

In this study, a novel welding method called water cooling bobbin-tool friction stir welding (WBT-FSW) was developed. 4 mm-thick 6063-T6 aluminum alloy sheets were successfully jointed by WBT-FSW. Comparative studies on macro/microstructural characteristics and mechanical properties of the WBT-FSW and conventional bobbin-tool friction stir welding (BT-FSW) joints were carried out. The results indicated that the water mist cooling can significantly decrease the welding temperature and improve both the weld formation and the mechanical properties of the joint. The tensile strength of the WBT-FSW joint was 11.4% higher than that of BT-FSW joint.

scholarly journals Interface Characteristics and Mechanical Properties of Ultrasonic-Assisted Friction Stir Lap Welded 7075-T6 Aluminium Alloy

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5335 ◽  
Author(s):  
Changshu He ◽  
Zhiqiang Zhang ◽  
Ying Li ◽  
Jingxun Wei ◽  
Menggang Zhai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ultrasonic Vibration ◽  
Fracture Mode ◽  
Fracture Strength ◽  
Shear Fracture ◽  
Friction Stir Lap Welding ◽  
Friction Stir ◽  
Ultrasonic Assisted ◽  
Lap Welding ◽  
Cold Lap

In this work, friction stir lap welding (FSLW) and ultrasonic-assisted friction stir lap welding (UAFSLW) was applied to 6-mm-thick 7075-T6 alloy sheets using three welding tools with the same process parameters. The joint formation, microstructural characteristics, and mechanical properties of the resulting lap joints were then investigated. The results showed that ultrasonic vibration significantly promoted the flow of metal at the interface, enlarged the size of the stirred zone (SZ), and reduced the angle between the hook defect and the interface. During lap shear testing, the FSLW and UAFSLW joints fractured in a similar manner. The fracture modes included tensile fracture, shear fracture, and a mixture of both. Cold lap and hook defects may have served as crack-initiation zones within the joint. Under configuration A (i.e., upper sheet on the retreating side (RS)), all joints failed in the shear-fracture mode. The effective lap width (ELW) of the joint welded using tool T2 was the greatest. This resulted in a higher shear fracture strength. The maximum shear fracture strength of the UAFSLW joint was 663.1 N/mm. Under configuration B (i.e., upper sheet on the advancing side (AS)), the shear fracture strength was greatly affected by the fracture mode. The highest shear fracture strength of the UAFSLW joint, 543.7 N/mm, was welded by tool T3. Thus, under otherwise identical conditions, UAFSLW joints can withstand a greater fracture shear strength than FSLW joints, as ultrasonic vibration helps to mix the material at the interface, thus, enlarging the SZ and diminishing the cold lap defects.

Sign in / Sign up

Export Citation Format

Share Document