A Study on Grain Size, Mechanical Properties and First Mode of Metal Transfer in Underwater Friction Stir Welded AA5052-O

2018 ◽  
Vol 775 ◽  
pp. 466-472 ◽  
Author(s):  
K. Tejonadha Babu ◽  
S. Muthukumaran ◽  
C. Bharat Kumar
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Metal Transfer ◽  
Welding Parameters ◽  
Friction Stir ◽  
Second Mode ◽  
Underwater Friction Stir Welding

Friction stir welding (FSW), a new joining process is finding extensive use in the welding of aluminum alloy sheets. The metal transfer modes in the FSW cause the quality of the weld and its properties. The first mode of metal transfer is accomplished by the tool and shoulder, while the second mode occurs around the pin. In the present study, two different welding conditions, which were friction stir welding in the air (CFSW) and underwater friction stir welding (UWFSW) carried out at various welding parameters to weld the AA5052-O aluminum alloy sheets and determine the consequence of the first mode on the tensile strength of welded joints. Considerable grain refinement and enhanced mechanical properties were obtained in UWFSW joints. It Is observed that the first mode affect the tensile strength of the joint, also found that a linear correlation between the first mode and the tensile strength.

scholarly journals Effect of process parameters on mechanical properties of AA5052 joints using underwater friction stir welding

2020 ◽  
Vol 14 (1) ◽  
pp. 6259-6271
Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanish Paramaguru ◽  
Mokhtar Awang ◽  
Hamed Mohebbi ◽  
Sharma V Korada
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Welding Parameters ◽  
Fracture Characterization ◽  
Friction Stir ◽  
Weld Joints ◽  
Underwater Friction Stir Welding

Underwater Friction Stir Welding (UFSW) is a solid-state joining technique which uses a non-consumable tool to weld metals. The objective of this investigation is to evaluate the mechanical properties of the AA5052 Aluminium alloy joints prepared by UFSW. The effect of different type of welding tools and welding parameters on the weld joint properties are studied. Square, tapered cylindrical and taper threaded cylindrical type of welding tools have been used to produce the joints with the tool rotational speed varying from 500 rpm to 2000 rpm while the welding speed varying from 50 mm/min to 150 mm/min. Tensile strength, micro-hardness distribution, fracture features, micro-and macrostructure of the fabricated weld joints have been evaluated. The effect of welding process parameters that influences the mechanical properties and fracture characterization of the joints are explained in detail. A maximum Ultimate Tensile Strength (UTS) value of 222.07 MPa is attained with a gauge elongation of 14.78%. Microstructural evaluation revealed that most of the fracture are found on the thermal mechanically affected zone (TMAZ)adjacent to the weld nugget zone (WNZ) due to bigger grain sizes. It is found that most of the joints exhibit ductile characteristics in failure. Fractography analysis has been used to find the behavior of weld joints in failure.

scholarly journals Tensile Strength, Micro-hardness and Microstructure of Friction-Stir-Welding AA6061-T4 Joints

2018 ◽  
Vol 25 (4) ◽  
pp. 50-55
Author(s):  
Najeeb S. Abtan ◽  
Ataalah Hussain Jassim ◽  
Mustafa S. M. Al-Janabi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Base Metal ◽  
High Hardness ◽  
Welding Parameters ◽  
Micro Hardness ◽  
Friction Stir ◽  
Wide Range

Welding of aluminum alloys by traditional welding methods creates some defects such as hot cracks, porosity, and void that led to decreasing of mechanical properties. Friction Stir Welding (FSW) gives good mechanical properties of aluminum alloy welds. In this paper, FSW worked in 4 mm thick plate of 6061-T4 aluminum alloy, with two welding parameters are used (tool rotational speed and feed rate) was investigated, were analyzed the microstructure and mechanical properties by carried out microstructural, micro-hardness, and tensile strength tests. From results are found defect-free of welds at a wide range of parameters. Stir zone shows a fine-equiaxed grain and high hardness, not significantly change between heat affected zone and base metal in size grain. Tensile strength of welds was lower than base metal and fracture location was occurred at a low hardness region for the welds.

Microhardness and Microstructural Studies on Underwater Friction Stir Welding of 5052 Aluminum Alloy

2017 ◽  
Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanis Paramaguru ◽  
Mokhtar Awang
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Plate Thickness ◽  
Base Material ◽  
Friction Stir ◽  
Underwater Friction Stir Welding ◽  
Void Area ◽  
Average Size ◽  
Microstructural Studies

As compared to normal Friction Stir Welding (FSW) joints, the Underwater Friction Stir Welding (UFSW) has been reported to be obtainable in consideration of enhancement in mechanical properties. A 5052-Aluminum Alloy welded joints using UFSW method with plate thickness of 6 mm were investigated, in turn to interpret the fundamental justification for enhancement in mechanical properties of material through UFSW. Differences in microstructural features and mechanical properties of the joints were examined and discussed in detail. The results indicate that underwater FSW has reported lower hardness value in the HAZ and higher hardness value in the intermediate of stir zone (SZ). The average hardness value of underwater FSW increases about 53% greater than its base material (BM), while 21% greater than the normal FSW. The maximum micro-hardness value was three times greater than its base material (BM), and the mechanical properties of underwater FSW joint is increased compared to the normal FSW joint. Besides, the evaluated void-area fraction division in the SZ of underwater FSW joint was reduced and about one-third of the base material (BM). The approximately estimated average size of the voids in SZ of underwater FSW also was reduced to as low as 0.00073 mm2, when compared to normal FSW and BM with approximately estimated average voids size of 0.0024 mm2 and 0.0039 mm2, simultaneously.

Heat Transfer Simulations and Analysis of Joint Cross-Sectional Microstructure on Friction Stir Welding between Steel and Aluminium

2020 ◽  
Vol 863 ◽  
pp. 85-95
Author(s):  
Truong Minh Nhat ◽  
Truong Quoc Thanh ◽  
Tu Vinh Thong ◽  
Tran Trong Quyet ◽  
Luu Phuong Minh
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Thermal Contact ◽  
Welding Process ◽  
Welding Parameters ◽  
Thermal Imager ◽  
Sem Images ◽  
Cross Sectional ◽  
Friction Stir

This study presents conducted heat simulations and experimental jointing flat-plate of aluminum alloy 6061 and SUS 304. Temperature is simulated by the COMSOL software in three states: (1) Preheat the Friction Stir Welding (FSW) by TIG welding, (2) Thermal contact resistance between Aluminium and steel, and (3) The welding process using stiring friction is simulated. The simulations intended to predicting the temperature which is used for preheat and welding process to ensuring the required solid-state welding. The temperature is also determined and checked by a thermal imager comparing with simulation results. Besides, the results of tensile strength is carried out. The Box - Behnken method is used to identify the relationship between the welding parameters (rotation, speed and offset), temperature and tensile strength. The maximum tensile strength is 77% compared to the strength of aluminum alloy. The optimal set of parameters for the process is n = 676 rpm, v = 46 mm / min and x = 0.6 mm. The optimizing welding parameters to achieving good quality of welding process are described. SEM images to determine some properties of welding materials. This is also the basis for initial research to identify some defects in welding of two different materials (IMC thickness and interconnected pores) and the cause of these defects.

Analysis of process parameters effects on underwater friction stir welding of aluminum alloy 6082-T6

2018 ◽  
Vol 233 (6) ◽  
pp. 1700-1710 ◽  
Author(s):  
Mohd Atif Wahid ◽  
Zahid A Khan ◽  
Arshad Noor Siddiquee ◽  
Rohit Shandley ◽  
Nidhi Sharma
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Rotational Speed ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Underwater Friction Stir Welding ◽  
Optimal Setting

In friction stir welding of heat treatable aluminum alloys, the thermal cycles developed during the joining process result in softening of the joints which adversely affect their mechanical properties. Underwater friction stir welding can be a process of choice to overcome this problem due to low peak temperature and short dwell time involved during the process. Consequently, this article presents a study pertaining to the underwater friction stir welding of aluminum alloy 6082-T6 with an aim to develop a mathematical model to optimize the underwater friction stir welding process parameters for obtaining maximum tensile strength. The results of the study reveal that the tool shoulder diameter (d), tool rotational speed (ω), welding speed (v), and second-order term of rotational speed, that is, ω2, significantly affect the tensile strength of the joint. The maximum tensile strength of 241 MPa which is indeed 79% of the base metal strength and 10.7% higher than that of conventional (air) friction stir welding joint was achieved at an optimal setting of the underwater friction stir welding parameters, that is, tool rotational speed of 900 r/min, the welding speed of 80 mm/min, and a tool shoulder of 17 mm. The article also presents the results of temperature variation, the macrostructural and microstructural investigations, microhardness, and fractography of the joint obtained at the optimal setting for underwater friction stir welded (UFSWed) joint.

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