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.

scholarly journals A Weighting Grade-Based Optimization Method for Determining Refill Friction Stir Spot Welding Process Parameters

2019 ◽  
Vol 28 (10) ◽  
pp. 6471-6482
Author(s):  
Rafał Kluz ◽  
Andrzej Kubit ◽  
Tomasz Trzepiecinski ◽  
Koen Faes ◽  
Wojciech Bochnowski
Keyword(s):  
Process Parameters ◽  
Rotational Speed ◽  
Spot Welding ◽  
Load Capacity ◽  
Base Material ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Welding Parameters ◽  
Tool Rotational Speed ◽  
Friction Stir

Abstract The welding process used in fabricating thin-walled structures by refill friction stir spot welding (RFSSW) should be characterized by a high strength of welds and high process repeatability which is demonstrated by a small dispersion of the load capacity of the joints. The present work is designed to optimize RFSSW process parameters for 7075-T6 Alclad aluminum alloy sheets used to fabricate aircraft structures. The optimization was performed by scalarization of the objective function using the weighting grades method. The study considers the effect of process parameters, i.e., tool plunge depth, duration of welding, tool rotational speed, on the tensile/shear strength of the joints, and dispersion of the load capacity. It was found that it was possible to choose the optimal welding parameters taking into account maximization of the load capacity and minimization of the dispersion of the joint strength via a best compromise between the tool rotational speed ensuring adequate plasticization of the base material and the duration of welding ensuring that a fine-grained joint microstructure is obtained.

Process Parameters Optimization of Friction Stir Welding in Aluminium Alloy 6063-T6 by Taguchi Method

2017 ◽  
Vol 867 ◽  
pp. 97-104 ◽  
Author(s):  
T. Ganapathy ◽  
K. Lenin ◽  
K. Pannerselvam
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Taguchi Method ◽  
Axial Force ◽  
Process Parameters ◽  
Welding Speed ◽  
Rotational Speed ◽  
Process Parameter ◽  
Main Process ◽  
Friction Stir

This paper deals with the effective application of friction stir welding similar to butt joining technique.AL6063 T-6 alloys prepared in 125x 100 x 7mm thickness plate and FSW tool setup were H13 of diameter 25mm rotary tool with straight cylindrical pin profile. The maximum strength was considered for selection of combined process parameter. The process parameters were optimized using Taguchi method. The Rotational speed, welding speed, and axial speed are the main process parameter which taken into our consideration. The optimum process parameters are determined with reference to tensile strength of the joint. From the experiments, it was found the effects of welding parameter are the axial force is highest substantial parameter to determining the tensile strength of the joint. The paper which revealed the optimal values of process parameter are to acquire a maximum tensile strength of friction stir welded AL6063-T6 plates is 101.6Mpa with the combination level of rotational speed, welding speed and axial force are found to be 1100 RPM, 60 mm/min and 12.5 KN. validation test was carried out and results were nearer to the optimized results confirmed by the optimum results.

scholarly journals Surface modification of Aluminium alloy (7xxx series) by multipass friction stir processing

2021 ◽  
Vol 6 (2) ◽  
pp. 008-017
Author(s):  
P K Mandal
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Process Parameters ◽  
Friction Stir Processing ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Research Work ◽  
Dendritic Structure ◽  
Similar Process ◽  
Friction Stir

Multipass friction stir processing (MP-FSP) is a solid-state surface modification technique, which was developed based on the simple principle of FSW. Aluminium plates were subjected to MP-FSP from 1 to 14 passes along the longitudinal direction with the specified process parameters such as rotational speed of 1000 rpm and travel speed of 70 mm/min and axial force of 15 kN. Subsequently, similar process parameters had followed by doublepass friction stir processing (DP-FSP) in order to help determine the effectiveness of multipass in creating high strength of aluminium alloys. Now-a-days extensive research had focused on various process parameters such as rotational speed, traverse speed, tool design on processing of aluminium alloys and proficiently enhanced material properties. This technique has considered mostly development of green technology, which is energy efficient and environment friendly technique. Experimentally proven that the Al-Zn-Mg-Sc alloys are characterized through OM, FESEM, DSC, SEM, TEM, and mechanical properties. The tensile strength and ductility of the MP-FSP specimen improved significantly to 122.48%, and 42.55% respectively, but hardness decline to 4.84% as compared to DP-FSP. This is due to not only for refinement of cast dendritic structure and eliminate segregation in the as-cast alloy, but also to the refining of grains, such as the uniform distribution of Al3Sc and hardening precipitates. To aim of this research work is to mainly focusing on MP-FSP may enhance mechanical properties better than DP-FSP and useful for macroscale applications.

Optimizing the Friction Stir Spot Welding Parameters to Attain Maximum Strength in Dissimilar Joints of Aluminum and Carbon Steel

2016 ◽  
Vol 3 (2) ◽  
pp. 64-76
Author(s):  
Sundaram Manickam ◽  
Visvalingam Balasubramanian
Keyword(s):  
Carbon Steel ◽  
Rotational Speed ◽  
Spot Welding ◽  
Dwell Time ◽  
Friction Stir Spot Welding ◽  
Diameter Ratio ◽  
Tool Rotational Speed ◽  
Dissimilar Joints ◽  
Friction Stir ◽  
Tool Diameter

The present investigation is aimed at optimizing the friction stir spot welding (FSSW) process parameters such as tool rotational speed, plunge rate, dwell time and tool diameter ratio, to attain the maximum strength in dissimilar joints of AA6061 aluminum and carbon steel. Experiments were conducted according to the four factor, five level central composite rotatable design matrix. Strength of the joints was evaluated by means of single lap shear test. Optimization was done by response surface method (RSM). A maximum tensile shear fracture load (TSFL) of 9.46 kN was exhibited by a joint welded using following parameters: tool rotational speed of 1000 rpm, plunge rate of 4 mm/ min, dwell time of 5 sec and tool diameter ratio of 3.0.

scholarly journals Effect of Rotational Speed and Flat Tool Diameter on the Zn Distribution of the Dissimilar Metals Friction Stir Spot Welded between Aluminum Alloy 5083 H321 and Galvanized Steel

2019 ◽  
Vol 269 ◽  
pp. 02004
Author(s):  
Bintang Adhi Guna ◽  
Nurul Muhayat ◽  
Triyono
Keyword(s):  
Rotational Speed ◽  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Galvanized Steel ◽  
Dissimilar Metals ◽  
Zn Diffusion ◽  
Friction Stir ◽  
Zn Distribution ◽  
Tool Diameter ◽  
Flat Tool

Friction stir spot welding (FSSW) was developed to join the dissimilar materials as an alternative for replacing the resistance spot welding (RSW). In the case of dissimilar metals welded between aluminum and galvanized steel, Zn can decompose and diffuse in both steel and aluminum so it can increase the joint strength. Due to this reason, it is important to explore the Zn distribution based on the parameter of the friction stir spot welding. The lap joint configuration was used in this work where aluminum plate was placed on the top of steel. Aluminum thickness was 3 mm, while steel thickness was 1 mm. The constant depth of plunge, dwell time, and penetration rate were 2.7 mm, 3 seconds, and 0.9 mm/sec respectively. Flat tool with diameters of 10 mm, 12 mm and 14 mm were used for FSSW processes and for each flat tool diameter, four levels of the rotational speed of 1000 rpm, 1200 rpm, 1600 rpm and 2000 rpm were performed. The Zn distribution was evaluated using the SEM and EDS analysis. Due to the heat generation during FSSW process, materials around the tools will soften and then flow to follow the centrifugal force. The rotational speed and the flat tool diameter affected the distance and the shape of Zn diffusion flow. The distance of Zn diffusion both horizontal and vertical direction increased as increasing the rotational speed and the flat tool diameter.

Multi Response Optimization of Process Parameters on AA8011 Friction Stir Welded Aluminium Alloys Using RSM Based GRA Coupled with DEA

2015 ◽  
Vol 813-814 ◽  
pp. 446-450 ◽  
Author(s):  
K. Palani ◽  
C. Elanchezhian
Keyword(s):  
Process Parameters ◽  
Tilt Angle ◽  
Feed Rate ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Welding Process ◽  
Fusion Welding ◽  
Gray Relational Analysis ◽  
Friction Stir ◽  
Tool Tilt Angle

The friction stir welding process is the newly developed material joining process used to join the different materials which are very difficult to join in the conventional fusion welding process. In this investigation using the specially designed straight cam profiled tool, the multiple responses of Ultimate tensile strength, Ultimate yield strength and Percentage of elongation with the process parameters of rotational speed, tool tilt angle and feed rate are optimized. The five level, three factor rotatable central composite design is selected to optimize the responses of friction stir welded AA 8011 aluminium alloys. The highest gray relational grade with the highest relative efficiency is found using the gray relational analysis coupled with the data envelopment analysis to predict the optimum parameters. It exposes that at the rotational speed of 680 rpm, the tool tilt angle of 98 degrees and the feed rate of 24 mm/min the good weld quality can be attained.

scholarly journals Influence of Tool Geometry and Process Parameters on the Properties of Friction Stir Spot Welded Multiple (AA 5754 H111) Aluminium Sheets

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1157
Author(s):  
Danka Labus Zlatanovic ◽  
Sebastian Balos ◽  
Jean Pierre Bergmann ◽  
Stefan Rasche ◽  
Milan Pecanac ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Spot Welding ◽  
Minimum Energy ◽  
Tool Geometry ◽  
Friction Stir ◽  
Minimum Energy Consumption ◽  
Punch Test ◽  
Wide Range ◽  
Lap Welding

Friction stir spot welding is an emerging spot-welding technology that offers opportunities for joining a wide range of materials with minimum energy consumption. To increase productivity, the present work addresses production challenges and aims to find solutions for the lap-welding of multiple ultrathin sheets with maximum productivity. Two convex tools with different edge radii were used to weld four ultrathin sheets of AA5754-H111 alloy each with 0.3 mm thickness. To understand the influence of tool geometries and process parameters, coefficient of friction (CoF), microstructure and mechanical properties obtained with the Vickers microhardness test and the small punch test were analysed. A scanning acoustic microscope was used to assess weld quality. It was found that the increase of tool radius from 15 to 22.5 mm reduced the dwell time by a factor of three. Samples welded with a specific tool were seen to have no delamination and improved mechanical properties due to longer stirring time. The rotational speed was found to be the most influential parameter in governing the weld shape, CoF, microstructure, microhardness and weld efficiency. Low rotational speeds caused a 14.4% and 12.8% improvement in joint efficiency compared to high rotational speeds for both tools used in this investigation.

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