scholarly journals The Effects of In-Process Cooling during Friction Stir Welding of 7475 Aluminium Alloy

2021 ◽  
Vol 50 (9) ◽  
pp. 2743-2754
Author(s):  
Ashish Jacob ◽  
Sachin Maheshwari ◽  
Arshad Noor Siddiquee ◽  
Abdulrahman Al-Ahmari ◽  
Mustufa Haider Abidi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Welded Joints ◽  
Positive Impact ◽  
Welding Process ◽  
Fusion Welding ◽  
Friction Stir ◽  
Cooling Conditions ◽  
Zero Degree ◽  
Welding Technique

Certain age hardenable alloys such as AA7475 cannot be joined with perfection using fusion welding techniques. This requires non-conventional welding technique such as friction stir welding process to join these ‘difficult to weld’ alloys. In this study, three different cooling conditions i.e. cryogenic, sub-zero, and zero-degree Celsius temperature conditions have been analyzed to understand its impact on the welding process. In-process cooling was found to behave effectively and also enhanced the mechanical properties of the welded joints. A stable microstructure was clearly seen in the images observed under the metallurgical microscope. The weld efficiencies were found to be good in each of the samples which are indicative of a strong metallic joint. The effective cooling conditions employed had an overall positive impact on the joint.

scholarly journals Mechanical Properties and Microstructural Characterization of Dissimilar Friction Stir Welded AA5083 and AA6061 Aluminium Alloys

Mechanika ◽  
2020 ◽  
Vol 26 (6) ◽  
pp. 545-552
Author(s):  
Sasi Lakshmikhanth RAJASEELAN ◽  
Subbaiah KUMARASAMY
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Welded Joints ◽  
Aluminium Alloys ◽  
Microstructural Analysis ◽  
Testing Machine ◽  
Welding Process ◽  
Fusion Welding ◽  
Friction Stir

Solidification is one of the major issues that was faced during the fusion welding of dissimilar non-heat treatable and heat treatable aluminium alloys. To overcome this issue Friction Stir Welding played a very vital role, since it is a solid state welding process. In the current study, dissimilar friction stir welding was carried out between non heat-treatable aluminium alloy AA5083-H111 and heat-treatable aluminium alloy AA6061-T6. The microstructural analysis and the mechanical properties of the dissimilar friction stir welded aluminium alloy AA5083-H111 and AA6061-T6 have been investigated. Both optical microscopy and scanning electron microscopy was used to evaluate the microstructural features. The elemental analysis was carried out using SEM-EDX. The tensile properties are studied using Universal Testing Machine. Hardness at various zones of the welded joints was measured using Vicker’s Hardness Testing Machine. The mechanical properties of the friction stir welded joints were correlated with the microstructure of the dissimilar welded joints.

scholarly journals Comparative investigation of friction stir welding and fusion welding of 6061 T6 – 5083 O aluminum alloy based on mechanical properties and microstructure

2014 ◽  
Vol 62 (4) ◽  
pp. 791-795 ◽  
Author(s):  
S. Jannet ◽  
P.K. Mathews ◽  
R. Raja
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Welded Joints ◽  
Welding Process ◽  
Hardness Test ◽  
Comparative Investigation ◽  
Fusion Welding ◽  
Friction Stir ◽  
Advantages And Disadvantages ◽  
Fusion Welded Joints

Abstract This paper compares, the mechanical properties of welded joints 6061 T6 and 5083 O aluminium alloys obtained using friction stir welding (FSW) at four rotation speeds namely 450,560,710 and 900 rpm and that by conventional fusion welding. FSW welds were carried out on a milling machine. The performance of FSW and Fusion welded joints were identified using tensile test, hardness test and microstructure. The properties of FSW and fusion welded processes were also compared with each other to understand the advantages and disadvantages of these processes for welding applications for Al alloys. It was seen that the tensile strength obtained with FSW was higher as compared to conventional fusion welding process. The width of the heat affected zone of FSW was narrower than Fusion welded joints. The results showed that FSW improved the mechanical properties of welded joints.

scholarly journals Friction stir welding of Aluminium matrix composites – A Review

2018 ◽  
Vol 144 ◽  
pp. 03002 ◽  
Author(s):  
Prabhu Subramanya ◽  
Murthy Amar ◽  
Shettigar Arun ◽  
Herbert Mervin ◽  
Rao Shrikantha
Keyword(s):  
Friction Stir Welding ◽  
Welding Process ◽  
Fusion Welding ◽  
Aluminium Matrix ◽  
Future Research ◽  
Matrix Composites ◽  
Aluminium Matrix Composites ◽  
Friction Stir ◽  
Tool Profiles ◽  
Welding Technique

Friction stir welding (FSW) is established as one of the prominent welding techniques to join aluminium matrix composites (AMCs). It is a solid state welding process, takes place well below the melting temperature of the material, eliminates the detrimental effects of conventional fusion welding process. Although the process is capable to join AMCs, challenges are still open that need to be fulfill to widen its applications. This paper gives the outline of the friction stir welding technique used to join AMCs. Effect of process variables on the microstructure and mechanical properties of the joints, behavior of reinforcing materials during welding, effect of tool profiles on the joint strength are discussed in detail. Few improvements and direction for future research are also proposed.

Influence of Tool Rotational Speed on the Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

2016 ◽  
Vol 857 ◽  
pp. 228-231
Author(s):  
Ho Sung Lee ◽  
Ye Rim Lee ◽  
Kyung Ju Min
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Space Shuttle ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Welding Parameters ◽  
Friction Stir ◽  
Mechanical And Microstructural Properties ◽  
Tool Rotation

Aluminum-Lithium alloys have been found to exhibit superior mechanical properties as compared to the conventional aerospace aluminum alloys in terms of high strength, high modulus, low density, good corrosion resistance and fracture toughness at cryogenic temperatures. Even though they do not form low-melting eutectics during fusion welding, there are still problems like porosity, solidification cracking, and loss of lithium. This is why solid state friction stir welding is important in this alloy. It is known that using Al-Cu-Li alloy and friction stir welding to super lightweight external tank for space shuttle, significant weight reduction has been achieved. The objective of this paper is to investigate the effect of friction stir tool rotation speed on mechanical and microstructural properties of Al-Cu-Li alloy. The plates were joined with friction stir welding process using different tool rotation speeds (300-800 rpm) and welding speeds (120-420 mm/min), which are the two prime welding parameters in this process.

Evaluating the Strength of the Friction Stir Welded Joints at Various Rotational Speeds

2013 ◽  
Vol 446-447 ◽  
pp. 312-315
Author(s):  
Ramaraju Ramgopal Varma ◽  
Abdullah Bin Ibrahim ◽  
B. Ravinder Reddy
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Yield Strength ◽  
Welded Joints ◽  
Rotational Speed ◽  
Testing Machine ◽  
Friction Stir ◽  
Universal Testing ◽  
Welding Technique

The present research paper aims in evaluating the strength of the welded AA6351 alloy plates of 6 mm thick by using friction stir welding technique at different rotational speeds The applied welding technique is capable of achieving the mechanical properties of the alloy close to that of the original alloy. In the present investigation, the speeds of the spindle were varied from 1100 rpm to 1500 rpm with a constant transverse speed of 20 mm/min. The tensile strength of the joints is determined by an universal testing machine. The results from the present investigation show that the values of the yield strength were very much closer to the values of the AA6351Alloy prior to welding. It has been found from the experiments that the strength of the joints increases with the increase in the rotational speed; however, the same is decreasing after achieving certain speed.

The Role of Friction Stir Welding Process Parameter on Mechanical Properties of Magnesium Alloy AZ31B

2013 ◽  
Vol 849 ◽  
pp. 38-44
Author(s):  
S. Vijayan ◽  
S. Prasath
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Microstructure Evolution ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Friction Stir ◽  
Current State ◽  
Magnesium Alloy Az31b

The Friction Stir welding is a solid state welding invented in the year 1991.This welding technique is highly energy efficient, eco-friendly in joining the high strength aerospace aluminums alloys and its other alloys which are not able to weld by the conventional fusion welding process. Initially FSW is use to weld aluminums alloys and gradually it applies to all form of metals and alloys. In this review article the current state of understanding and development of FSW with respect to Magnesium alloys AZ 31 B is addressed. And particular emphasis is given to the effect of FSW process parameters on the mechanical properties, corrosion behavior and microstructure evolution. At this stage there is wide gap in understanding the mechanism of dissimilar Magnesium welds on microstructure evolution and microstructure property relationships with respect to FSW and Submersible FSW process.

scholarly journals Al-Based Surface Composites and Strengthening Of Welded Joints Through Multi-Pass FSP Technique: A Review

2021 ◽  
Vol 10 (2) ◽  
pp. 1426-1440
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Friction Stir Processing ◽  
Welded Joints ◽  
Friction Stir ◽  
Surface Composites ◽  
Uniform Dispersion ◽  
Recent Developments ◽  
Welding Technique ◽  
Made In

Friction stir processing (FSP) is a microstructural modifying technique that uses the same principles as the friction stir welding technique. FSP technique can be employed on the same surface repeatedly as desiredand this repetition is called multi-pass friction stir processing (MFSP). The recent developments have shown that MFSP technique is very useful towards uniform dispersion of reinforcement particles during fabrication of surface composites. Some studies have also demonstrated that MFSP technique can be employed on welded joints as a way of improving the mechanical properties of the welded joints. This paper reports on the progress made in using the multi-pass friction stir processing (MFSP) technique in producing aluminium-based surface composites. It further looks at the progress made in using the MFSP on aluminium-based welded joints. An effort is made to identify the gap that requires some exploration for the better utilization and understanding of this technique

Features of structure formation processes in AA2024 alloy joints formed by the friction stir welding with bobbin tool

2021 ◽  
Vol 23 (2) ◽  
pp. 98-115
Author(s):  
Alexey Ivanov ◽  
◽  
Valery Rubtsov ◽  
Andrey Chumaevskii ◽  
Kseniya Osipovich ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Structure Formation ◽  
Welded Joints ◽  
Heat Input ◽  
Welded Joint ◽  
Welding Process ◽  
Tool Material ◽  
Travel Speed ◽  
Material System ◽  
Friction Stir

Introduction. One of friction stir welding types is the bobbin friction stir welding (BFSW) process, which allows to obtain welded joints in various configurations without using a substrate and axial embedding force, as well as to reduce heat loss and temperature gradient across the welded material thickness. This makes the BFSW process effective for welding aluminum alloys, which properties are determined by their structural-phase state. According to research data, the temperature and strain rate of the welded material have some value intervals in which strong defect-free joints are formed. At the same time, much less attention has been paid to the mechanisms of structure formation in the BFSW process. Therefore, to solve the problem of obtaining defect-free and strong welded joints by BFSW, an extended understanding of the basic mechanisms of structure formation in the welding process is required. The aim of this work is to research the mechanisms of structure formation in welded joint of AA2024 alloy obtained by bobbin tool friction stir welding with variation of the welding speed. Results and discussion. Weld formation conditions during BFSW process are determined by heat input into a welded material, its fragmentation and plastic flow around the welding tool, which depend on the ratio of tool rotation speed and tool travel speed. Mechanisms of joint formation are based on a combination of equally important processes of adhesive interaction in “tool-material” system and extrusion of metal into the region behind the welding tool. Combined with heat dissipation conditions and the configuration of the “tool-material” system, this leads to material extrusion from a welded joint and its decompaction. This results in formation of extended defects. Increasing in tool travel speed reduce the specific heat input, but in case of extended joints welding an amount of heat released in joint increases because of specific heat removal conditions. As a result, the conditions of adhesion interaction and extrusion processes change, which leads either to the growth of existing defects or to the formation of new ones. Taking into account the complexity of mechanisms of structure formation in joint obtained by BFSW, an obtaining of defect-free joints implies a necessary usage of various nondestructive testing methods in combination with an adaptive control of technological parameters directly in course of a welding process.

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