scholarly journals Friction stir welding of dissimilar Al alloys: effect of process parameters on mechanical properties

2016 ◽  
pp. 125-132 ◽  
Author(s):  
Jitender Kundu ◽  
Hari Singh
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Al Alloys ◽  
Friction Stir

scholarly journals Friction Stir Welding Parameters: Impact of Abnormal Grain Growth during Post-Weld Heat Treatment on Mechanical Properties of Al–Mg–Si Welded Joints

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1607
Author(s):  
Amir Hossein Baghdadi ◽  
Zainuddin Sajuri ◽  
Mohd Zaidi Omar ◽  
Armin Rajabi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Friction Stir Welding ◽  
Grain Growth ◽  
Precipitation Hardening ◽  
Al Alloys ◽  
Abnormal Grain Growth ◽  
Post Weld Heat Treatment ◽  
Welding Parameters ◽  
Friction Stir

Friction stir welding (FSW) is an alternative method to join aluminum (Al) alloys in a solid-state condition. However, the coarsening or dissolution of precipitation hardening phases in the welding zone causes strength reduction or softening behavior in the welded area of age-hardened Al alloys. Therefore, this research aimed to improve the mechanical properties of an FSW Al–Mg–Si alloy via post-weld heat treatment (PWHT) and the possibility of controlling the abnormal grain growth (AGG) using different welding parameters. FSW was performed with different rotational and travel speeds, and T6 heat treatment was carried out on the FSW samples as the PWHT. The results showed a decrease in the strength of the FSW samples compared with that of the base material (BM) due to the dissolution of precipitation hardening particles in the heat-affected zone. However, the emergence of AGG in the microstructure after the T6-PWHT was identified as the potential event in the microstructure of the PWHT samples. It is found that the AGG of the microstructure in similar joints of Al6061(T6) was governed by the welding parameters. The results proved that PWHT was able to increase the tensile properties of the welded samples to values comparable to that of Al6061(T6)-BM. The increased mechanical properties of the FSW joints were attributed to a proper PWHT that resulted in a homogeneous distribution of the precipitation hardening phases in the welding zones.

Prediction and optimization of the mechanical properties of dissimilar friction stir welding of aluminum alloys using design of experiments

2016 ◽  
Vol 232 (8) ◽  
pp. 1384-1394 ◽  
Author(s):  
R Palanivel ◽  
RF Laubscher ◽  
S Vigneshwaran ◽  
I Dinaharan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Ultimate Tensile Strength ◽  
Design Of Experiments ◽  
Process Parameters ◽  
Welding Process ◽  
Friction Stir ◽  
Friction Stir Welding Process

Friction stir welding is a solid-state welding technique for joining metals such as aluminum alloys quickly and reliably. This article presents a design of experiments approach (central composite face–centered factorial design) for predicting and optimizing the process parameters of dissimilar friction stir welded AA6351–AA5083. Three weld parameters that influence weld quality were considered, namely, tool shoulder profile (flat grooved, partial impeller and full impeller), rotational speed and welding speed. Experimental results detailing the variation of the ultimate tensile strength as a function of the friction stir welding process parameters are presented and analyzed. An empirical model that relates the friction stir welding process parameters and the ultimate tensile strength was obtained by utilizing a design of experiments technique. The models developed were validated by an analysis of variance. In general, the full impeller shoulder profile displayed the best mechanical properties when compared to the other profiles. Electron backscatter diffraction maps were used to correlate the metallurgical properties of the dissimilar joints with the joint mechanical properties as obtained experimentally and subsequently modeled. The optimal friction stir welding process parameters, to maximize ultimate tensile strength, are identified and reported.

A Numerical and Experimental Analysis of Microstructural Aspects in AA2024-T3 Friction Stir Welding

2013 ◽  
Vol 554-557 ◽  
pp. 1022-1030 ◽  
Author(s):  
Pierpaolo Carlone ◽  
Gaetano S. Palazzo
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Heat Generation ◽  
Process Parameters ◽  
Fluid Dynamic ◽  
Weld Line ◽  
Work Piece ◽  
Viscoplastic Material ◽  
Influence Of Process Parameters ◽  
Friction Stir

In recent years, remarkable interest has been focused on the Friction Stir Welding (FSW) process, by academic as well as industrial research groups. Conceptually, the FSW process is quite simple: a non-consumable rotating tool is plunged between the adjoining edges of the parts to be welded and moved along the desired weld line. Frictional and viscous heat generation increases the work piece temperature, softening the processing material and forcing it to flow around the pin. Although FSW has been effectively applied in welding of several materials, such as copper, steel, magnesium, and titanium, considerable attention is still focused on aluminum welding, in particular for transport applications. Recent literature clearly evidenced microstructural variations in the stir zone, imputable to continuous dynamic recrystallization phenomena, leading to the formation of a finer equiaxed grains. Moreover, depending on the specific alloy, thermal cycles can induce coarsening or dissolution of precipitates in the thermo-mechanically affected zone (TMAZ) and in the heat affected zone (HAZ). The influence of the aforementioned microstructural aspects on mechanical properties and formability of FSWed assemblies is also well recognized. The aim of this paper is to numerically and experimentally investigate the influence of process parameters, namely rotating speed and welding speed, on microstructural aspects in AA2024-T3 friction stir butt welds. A three-dimensional Computational Fluid Dynamic (CFD) model has been implemented to simulate the process. A viscoplastic material model, based on Wright and Sheppard modification of the constitutive model initially proposed by Sellars and Tegart has been implemented in the commercial package ANSYS CFX, considering an Eulerian framework. Tool-workpiece interaction has been modeled assuming partial sticking/sliding condition, and incorporating both frictional and viscous contributions to the heat generation. Microstructural aspects have been numerically predicted using the Zenner-Holloman parameter and experimentally measured by means of conventional metallographic techniques. Satisfactory agreement has been found between simulated and experimental results. The influence of process parameters on mechanical properties has also been highlighted.

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