scholarly journals T-FSW of Dissimilar Aerospace Grade Aluminium Alloys: Influence of Second Pass on Weld Defects

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 525
Author(s):  
Mustufa Haider Abidi ◽  
Nabeel Ali ◽  
Hashmatullah Ibrahimi ◽  
Saquib Anjum ◽  
Dhruv Bajaj ◽  
...  
Keyword(s):  
Process Parameters ◽  
Aluminium Alloys ◽  
Detrimental Effect ◽  
Substantial Reduction ◽  
T Joints ◽  
Friction Stir ◽  
Weld Defects ◽  
Shoulder Diameter ◽  
Aerospace Sector

The restoration of numerous aircraft structures is achievable with effective repair of welded joints. T-joints are often utilized in these structures to provide structural stability, keeping minimal body weight. Multi-pass friction stir welding (FSW) has proved to be useful for improving the quality of aluminium alloy welds employed in the aerospace sector. However, FSW of these alloys in T-configuration has not been sufficiently addressed yet. Even rarer is the discussion of efficacy of second FSW pass, with altered process parameters for improving the weld quality in T-joints. Hence, two commonly used aerospace grade aluminium alloys, namely, AA2024 and AA7075, were friction stir welded in T-configuration, varying three process parameters, i.e., tool rotational speed, welding speed and shoulder diameter. The effect of second FSW pass, performed at an optimum set of parameters, on kissing bond and tunnelling defect was studied in detail. A substantial reduction in the detrimental effect of these weld defects was discussed via tensile testing, micro-hardness and micro-structural observations.

scholarly journals Concomitant Outcomes due to the Alterations of Process Parameters During the Friction Stir Welding of T-Joint Between Dissimilar Aluminium Alloys

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Nadeem Fayaz Lone ◽  
Amanullah Mahmood ◽  
Arbaz Ashraf ◽  
Md Masroor Alam ◽  
Homi Hussain ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Process Parameters ◽  
Aluminium Alloys ◽  
Dominant Factor ◽  
Welding Parameters ◽  
Engineering Structures ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Shoulder Diameter ◽  
Lower Tensile Strength

Dissimilar Friction Stir Welded T-joints gives auxiliary strength to engineering structures, keeping insignificantbody weight. Due to the stronger material being away from the heat source, the T-joint between AA8011 and AA5754 is very vulnerable to formation of defects which results in lower tensile strength along the skin and stringer. In this paper, two aluminium alloys, namely AA5754 and AA8011 were friction stir welded in the Tjoint configuration, and the roles of welding parameters such as the tool transverse speed, tool rotational speed, and tool shoulder diameter on the tensile strength along skin and stringer was analyzed and discussed. The relative importance of the three process parameters was also analyzed. The tool shoulder diameter is found to be the most dominant factor for the strength along the skin, whereas, tool transverse speed is found to be the most important for the strength along stringer.

scholarly journals Shoulder Related Temperature Thresholds in FSSW of Aluminium Alloys

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues
Keyword(s):  
Heat Generation ◽  
Process Parameters ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Spot Welding ◽  
Base Material ◽  
Main Process ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Diameter

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.

Effect of material properties and process parameters on quality of friction stir forming

2021 ◽  
Vol 70 ◽  
pp. 553-559
Author(s):  
Francesco Gagliardi ◽  
Mahsa Navidirad ◽  
Giuseppina Ambrogio ◽  
Wojciech Z. Misiolek
Keyword(s):  
Process Parameters ◽  
Material Properties ◽  
Friction Stir

scholarly journals Review on Friction Stir Processed TIG and Friction Stir Welded Dissimilar Alloy Joints

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 142 ◽  
Author(s):  
Sipokazi Mabuwa ◽  
Velaphi Msomi
Keyword(s):  
Friction Stir Welding ◽  
Friction Stir Processing ◽  
Aluminium Alloys ◽  
Processing Technique ◽  
Inert Gas ◽  
Tungsten Inert Gas Welding ◽  
Friction Stir ◽  
Dissimilar Alloys ◽  
The Status

There is an increase in reducing the weight of structures through the use of aluminium alloys in different industries like aerospace, automotive, etc. This growing interest will lead towards using dissimilar aluminium alloys which will require welding. Currently, tungsten inert gas welding and friction stir welding are the well-known techniques suitable for joining dissimilar aluminium alloys. The welding of dissimilar alloys has its own dynamics which impact on the quality of the weld. This then suggests that there should be a process which can be used to improve the welds of dissimilar alloys post their production. Friction stir processing is viewed as one of the techniques that could be used to improve the mechanical properties of a material. This paper reports on the status and the advancement of friction stir welding, tungsten inert gas welding and the friction stir processing technique. It further looks at the variation use of friction stir processing on tungsten inert gas and friction stir welded joints with the purpose of identifying the knowledge gap.

scholarly journals Mould Filling Ability Characterisation of Cast Aluminium Alloys Using Design of Experiments

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Samavedam Santhi ◽  
S. B. Sakri ◽  
Dharwada Hanumantha Rao ◽  
Srinivasan Sundarrajan
Keyword(s):  
Process Parameters ◽  
Aluminium Alloys ◽  
Metal Flow ◽  
Filling Ability ◽  
Mould Filling ◽  
Liquid Metal Flow ◽  
Factor Combination ◽  
Flow Heat ◽  
Heat Transfer And Solidification

Mould filling ability characteristic has been influencing the liquid metal flow, heat transfer, and solidification there by affecting the quality of aerospace castings. Mould filling is a critical parameter in the production of sound and quality castings, especially in the case of complex-shaped castings where section thickness is varying considerably. The mould filling ability of aluminium alloys LM6 and LM25 has been studied in the present investigation. Experimentation has been carried out using orthogonal array experimental layout. The process parameters studied in the present investigation are alloy composition, sand fineness, mould coating, and pouring temperature. The mould filling ability of selected aluminium alloy has been studied using pin test piece with cylindrical cores. The results from experimentation are analyzed to find the influence of the process parameters on mould filling ability. Based on the above, LM6 alloy has been found to have better mould filling ability characteristics and the analysis of variance has also revealed the same optimum factor combination.

In-Plane Plane-Strain Formability Investigation of Friction Stir Welded Sheets Made of Dissimilar Aluminium Alloys

2013 ◽  
Vol 446-447 ◽  
pp. 301-305
Author(s):  
Mukesh Kumar ◽  
Satish V. Kailas ◽  
R. Ganesh Narayanan
Keyword(s):  
Plane Strain ◽  
Heat Input ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Traverse Speed ◽  
Al Alloys ◽  
Welding Parameters ◽  
Strain Hardening Exponent ◽  
Friction Stir ◽  
Shoulder Diameter

In the present work, the influence of shoulder diameter, traverse speed, and rotational speed on the formability of friction stir welded sheets made between sheets of AA6061T6 and AA5052H32 Al alloys has been studied. In-Plane Plane-Strain formability tests are conducted for this purpose. It is understood from the results that the formability of welded sheets can be improved by optimizing the welding and tool parameters. A larger shoulder diameter, higher traverse speed, and lower rotational speed are favorable for improved formability, and strain hardening exponent of weld region. This is due to the fact that the heat input and subsequent microstructure evolved depends on the heat input, which depends on the welding parameters.

The Effects of Friction Stir Welding Parameters on the Characteristics of Banded Structure for Aluminum Alloys

2016 ◽  
Vol 710 ◽  
pp. 155-159
Author(s):  
Mariem Zoghlami ◽  
Mohammad Jahazi ◽  
Victor Songmene
Keyword(s):  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Process Parameters ◽  
Mechanical Characteristics ◽  
Research Work ◽  
Welding Parameters ◽  
Processing Conditions ◽  
Influence Of Process Parameters ◽  
Friction Stir

Since the invention of the friction stir welding, several studies have been conducted to understand the influence of process parameters on the microstructural, thermal and mechanical characteristics to improve the weld quality. Banded structures better known under the name of "onion rings" are one of phenomena that appear in the microstructure during this process. The welding parameters leading to their appearance as well as their effect on the quality of the joint are still subject to much research with different conclusions. In this context, the objective of this research work is to determine various characteristics of the ‘onion rings’ and correlate them to processing conditions.

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