Evaluating weld properties of conventional and swept friction stir spot welded 6061-T6 aluminium alloy

2019 ◽  
Vol 9 (8) ◽  
pp. 851-860 ◽  
Author(s):  
S. Suresh ◽  
K. Venkatesan ◽  
Elango Natarajan ◽  
S. Rajesh ◽  
Wei Hong Lim
Keyword(s):  
Shear Strength ◽  
Aluminium Alloy ◽  
Rotational Speed ◽  
Shear Fracture ◽  
Shear Loading ◽  
Tool Rotational Speed ◽  
Lap Shear Strength ◽  
Friction Stir ◽  
Lap Shear ◽  
Weld Properties

6061-T6 aluminium alloy is a tempered grade aluminium material that is extensively used, particularly in space and automotive applications. The conventional and swept friction stir spot welding (FSSW) joints are prepared by varying tool rotational speed at four different levels. The mechanical properties, microstructure and mode of failure in both types of FSSW are evaluated and reported. The high plastic deformation and fine grains influenced the increase in hardness of the weld joints based on the Hall-Petch equation. The highest lap shear strength of 5.31 kN is observed in swept FSSW sample prepared at 1400 rpm. Interestingly, 1600 rpm decreased the lap shear strength due to insufficient friction between base metal and tool in the higher tool rotational speed. The minimum microhardness is noticed in heat-affected zone (HAZ) of both cases. Conventional FSSW samples showed shear fracture, nugget pullout fracture and circumferential fracture under lap shear loading, whereas swept FSSW showed only the circumferential fracture.

Friction Stir Spot Welding of AZ31B Magnesium Alloy

2017 ◽  
Vol 867 ◽  
pp. 105-111
Author(s):  
S. Ramesh Babu ◽  
M. Nithin ◽  
S. Pavithran ◽  
B Parameshwaran
Keyword(s):  
Shear Strength ◽  
Magnesium Alloy ◽  
Rotational Speed ◽  
Spot Welding ◽  
Dwell Time ◽  
Friction Stir Spot Welding ◽  
Resistance Welding ◽  
Hardness Distribution ◽  
Tool Rotational Speed ◽  
Friction Stir

The Electrical Resistance Welding (ERW) of Magnesium and Aluminium is more difficult than steel because the welding machines must provide high currents and exact pressures in order to provide the heat necessary to melt the magnesium for proper fusion at the interface in order to produce a sound weld. Further, resistance welding of magnesium requires a backup plate made of steel to conduct the heat to the workpiece material. To overcome this problem, Friction Stir Spot Welding (FSSW) has been developed. In this study, the hardness distribution and the tensile shear strength of FSSW welds in the AZ31B Magnesium alloy has been investigated and it has been found that tool rotational speed and dwell time plays a major role in determining the weld strength. From the experimental study, a tool rotational speed of 1100 rpm and dwell time of 20 s produced good shear strength of 2824 N and the corresponding grain size was 4.54 μm. This result is very well supported by microstructural examinations and hardness distribution studies.

scholarly journals Parameters optimization for friction spot welding of AZ31 magnesium alloy by Taguchi method

2012 ◽  
Vol 17 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Leonardo Contri Campanelli ◽  
Uceu Fuad Hasan Suhuddin ◽  
Jorge Fernandez dos Santos ◽  
Nelson Guedes de Alcântara
Keyword(s):  
Shear Strength ◽  
Magnesium Alloy ◽  
Rotational Speed ◽  
Spot Welding ◽  
Dwell Time ◽  
Az31 Magnesium Alloy ◽  
Lap Shear Strength ◽  
Plunge Depth ◽  
Friction Spot Welding ◽  
Lap Shear

Friction spot welding (FSpW) is a solid state welding process suitable for producing spot-like joints, especially in lightweight materials, which are particularly interesting due to the weight saving potential. The plunging of an especially designed non-consumable and rotating tool creates a connection between overlapped sheets through frictional heat and plastic deformation. Minimum material loss is observed, and therefore a fully consolidated joint with flat surface (no keyhole) is obtained. In the current study, the effect of FSpW parameters, such as rotational speed, plunge depth and dwell time, on lap shear strength of AZ31 magnesium alloy joints was investigated. The optimization of input process parameters was carried out through Taguchi approach of DOE. Analysis of variance was applied to determine the individual importance of each parameter. Main effect plots were used to indicate the best levels for maximizing lap shear strength. The results show that tool plunge depth has the higher effect on the weld strength, followed by rotational speed and dwell time.

scholarly journals Effect of Tool Rotational Speeds on Friction Stir Welded AA6082-T6 Aluminium Alloy Joints

2020 ◽  
Vol 9 (1) ◽  
pp. 62-67
Keyword(s):  
Tensile Strength ◽  
Aluminium Alloy ◽  
Rotational Speed ◽  
Mechanical Characteristics ◽  
Weld Zone ◽  
Grain Structure ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Average Grain Size ◽  
Equiaxed Grain

In the current work, an attempt has been made to investigate the effect of tool rotational speed on microstructural and mechanical properties of friction stir welded AA6082-T6 aluminium alloy. Four different tool rotational speeds such as 500, 700, 900 and 1100 rpm were used to produce the joints while keeping the other process parameters constant. The tool used to fabricate the welded samples was tungsten carbide with straight cylindrical pin profile. The microstructural properties were examined using an optical and scanning electron microscope and found that the 700 rpm produced joint showed equiaxed grain structure with 14.3 µm average grain size. The mechanical characteristics such as tensile strength, impact strength and microhardness were evaluated and found the highest tensile strength of 265 MPa, impact energy of 10 J and micro hardness of 76 HV in the weld zone for the sample prepared with 700 rpm tool rotational speed. The fractographic studies were also carried out to study the mode of failure.

scholarly journals Optimization of Process Parameters for Friction Stir Welding of Dissimilar Aluminium Alloy AA6061 to AA5183 using TOPSIS Technique

2019 ◽  
Vol 8 (9S3) ◽  
pp. 1315-1319
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Rotational Speed ◽  
Transverse Velocity ◽  
Welding Process ◽  
Fusion Welding ◽  
Welding Parameters ◽  
Optimum Process ◽  
Tool Rotational Speed ◽  
Friction Stir

Friction stir welding has proven to be the most promising solid state joining process. It can be used to get high weldability in joining of high strength aerospace aluminium alloys and other metallic alloys which used to be low with traditional fusion welding process. This paper emphasises on finding the optimum process parameter for friction stir welding of dissimilar aluminium alloy AA6061 to AA5183 using multi criteria decision making method (MCDM). Friction stir welding was done at different tool rotational speed and transverse velocity and mechanical properties such as tensile strength, percentage elongation and hardness were studied for each weld specimen. Finally optimization was done using TOPSIS (Techniqueof Ordered Preference by Similarity to Ideal Solution). The result revealed that the tool rotational speed of 1200 rpm and welding speed of 80mm/min are the optimum welding parameters.

Comparative assessment on weldability of Al 6061 to polycarbonate for dissimilar sheets placement in friction stir lap welding using sensor signals

2021 ◽  
pp. 095440622110426
Author(s):  
Nisith Goswami ◽  
Kamal Pal
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Rotational Speed ◽  
Weight Ratio ◽  
Weld Interface ◽  
Fusion Welding ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Joint Efficiency ◽  
Welding Processes

The thermoplastic polymers and precipitation hardened aluminium alloys are highly popular in the aerospace and automobile sectors as a replacement of metallic materials to improve the strength to weight ratio. Thus, the unlike aluminium alloy to polycarbonate assembled structures are often necessary for which mechanical fastening and adhesive bonding are the primary methods for joining as fusion welding processes are inadequate. However, the dissimilar joint efficiency is found to be less. Thus, the ultrasonic and friction welding processes are developed. The friction stir welding is one such advanced material stirring technique without any melting of base materials. The present work addresses metallic aluminium (Al6061) to polycarbonate sheet materials joining using friction stir welding in overlap configuration using tapered H13 tool steel. The thrust force with associated tool stirring torque has been acquired in real time during plunging followed by welding phase. The weld bead profile with respective force-torque signals was analysed for the process monitoring. The tensile test has been carried out on the lap welds. The weld interface of the unlike sheets have also been scrutinised. Initially, the aluminium sheet was partially overlapped on polycarbonate for the parametric study. The highest joint efficiency was found to be 40.2% at 1400 rpm tool rotational speed and 75 mm/min traverse speed due to improper material mixing at the weld interface. Therefore, the feasibility of the process have been tested by placing thermoplastic polycarbonate over aluminium alloy through which the joint efficiency was further improved (48.57%) at comparatively low tool rotational speed (1100 rpm) with lower welding speed (55 mm/min) as the minute metallic particles uniformly mixed with melted and solidified polycarbonate due to more uniform torque in the welding phase. The tool stirring torque and axial thrust was found to be higher in this overlap position.

Lap shear strength and fatigue life of friction stir spot welded AZ31 magnesium and 5754 aluminum alloys

2012 ◽  
Vol 556 ◽  
pp. 500-509 ◽  
Author(s):  
S.H. Chowdhury ◽  
D.L. Chen ◽  
S.D. Bhole ◽  
X. Cao ◽  
P. Wanjara
Keyword(s):  
Shear Strength ◽  
Fatigue Life ◽  
Aluminum Alloys ◽  
Lap Shear Strength ◽  
Friction Stir ◽  
Lap Shear ◽  
Spot Welded
Sign in / Sign up

Export Citation Format

Share Document