Influence of Water Cooling and Post-Weld Ageing on Mechanical and Microstructural Properties of the Friction-Stir Welded 6061 Aluminium Alloy Joints

2018 ◽  
Vol 877 ◽  
pp. 163-176 ◽  
Author(s):  
Devuri Venkateswarulu ◽  
Muralimohan Cheepu ◽  
Devireddy Krishnaja ◽  
S. Muthukumaran
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminium Alloy ◽  
Rotational Speed ◽  
Optimal Path ◽  
Microstructural Characterization ◽  
Traverse Speed ◽  
Maximum Efficiency ◽  
Water Cooling ◽  
Friction Stir

A 6061-T6 aluminium alloy was friction stir welded in submerged water as well as in air cool at a constant traverse speed and different rotational speed in order to investigate the microstructural characterization and mechanical behaviour of the joints. In order to improve the tensile strength of the joints, weldments were studied at different heat treatment processes such as post weld aged condition and solutionized condition. It is observed that, water cooled joints are resulted in enhancing of both strength and ductility with the lower strain hardening ability than the air cooled joints. The width of the hardness distribution varies with the different cooling process of the joints. The highest hardness peak observed to be located in the heat affected zone of the joints. The maximum tensile strength of the joints achieved for welds under water cooled conditions in contrast to air cooled conditions. Moreover, a combination of water cooling and post weld ageing is proven to be the optimal path to improving the microstructural and mechanical properties of the joints with a maximum efficiency of 89.87% of the base metal strength. The microstructural observations of the joints revealed the presence of voids defects for the low rotational speed joints due to the insufficient heat input. The nugget of the higher tensile strength joints were free from defects and showed the fine grained material flow patterns which are constructive to obtain better mechanical properties.

Effect of Al2O3 nanoparticles on microstructure and mechanical properties of friction stir-welded dissimilar aluminum alloys AA7075-T6 and AA6061-T6

2021 ◽  
pp. 095440892110655
Author(s):  
Sumit Jain ◽  
R.S. Mishra
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Particle Dispersion ◽  
Al2o3 Nanoparticles ◽  
Tool Rotational Speed ◽  
Micro Hardness ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys

In this research, a defect-free dissimilar weld joint of AA7075-T6 and AA6061-T6 reinforced with Al2O3 nanoparticles was fabricated via friction stir welding (FSW). The influence of tool rotational speed (700, 900 and 1100 rpm), traverse speed (40, 50 and 60 mm/min) with varying volume fractions of Al2O3 nanoparticles (4%, 7% and 10%) on microstructural evolution and mechanical properties were investigated. The augmentation of various mechanical properties is based on the homogeneity of particle dispersion and grains refinement in the SZ of the FSWed joint. The findings revealed that the remarkable reduction in grain size in the SZ was observed owing to the incorporation of Al2O3 nanoparticles produces the pinning effect, which prevents the growth of grain boundaries by dynamic recrystallization (DRX). The increasing volume fraction of Al2O3 nanoparticles enhanced the mechanical properties such as tensile strength, % elongation and micro-hardness. Agglomeration of particles was observed in the SZ of the FSWed joints produced at lower tool rotational speed of 700 rpm and higher traverse speed of 60 mm/min due to unusual material flow. Homogenous particle dispersion and enhanced material mixing ensue at higher rotational speed of 1100 rpm and lower traverse speed of 40 mm/min exhibit higher tensile strength and micro-hardness.

scholarly journals Process Parameters Optimization for Producing AA6061/TiB2 Composites by Friction Stir Processing

2017 ◽  
Vol 67 (1) ◽  
pp. 101-118 ◽  
Author(s):  
Dakarapu Rao Santha ◽  
Nallu Ramanaiah
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Friction Stir Processing ◽  
Rotational Speed ◽  
Single Variable ◽  
Influence Of Process Parameters ◽  
Percentage Reinforcement ◽  
Friction Stir

Abstract Friction stir processing (FSP) is solid state novel technique developed to refine microstructure and to improve the mechanical properties and be used to fabricate the aluminium alloy matrix composites. An attempt is made to fabricate AA6061/TiB2 aluminium alloy composite (AMCs) and the influence of process parameters like rotational speed, transverse feed, axial load and percentage reinforcement on microstructure and mechanical properties were studied. The microstructural observations are carried out and revealed that the reinforcement particles (TiB2) were uniformly dispersed in the nugget zone. The Tensile strength and Hardness of composites were evaluated. It was observed that tensile strength, and hardness were increased with increased the rotational speed and percentage reinforcement of particles. The process parameters were optimized using Taguchi analysis (Single Variable) and Grey analysis (Multi Variable). The most influential parameter was rotational speed in single variable method and multi variable optimization method. The ANOVA also done to know the percentage contribution of each parameter.

Prediction of mechanical properties and optimization of process parameters in friction-stir-welded dissimilar aluminium alloys

2020 ◽  
Vol 17 (4) ◽  
pp. 519-526 ◽  
Author(s):  
Senthilnathan T. ◽  
Sujay Aadithya B. ◽  
Balachandar K.
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Process Parameters ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Tool Rotational Speed ◽  
Content Type ◽  
Friction Stir ◽  
Grey Relational

Purpose This study aims to predict the mechanical properties such as equivalent tensile strength and micro-hardness of friction-stir-welded dissimilar aluminium alloy plates AA 6063-O and AA 2014-T6, using artificial neural network (ANN). Design/methodology/approach The ANN model used for the experiment was developed through back propagation algorithm. The input parameter of the model consisted of tool rotational speed and weld-traverse speed whereas the output of the model consisted of mechanical properties (tensile strength and hardness) of the joint formed by friction-stir welding (FSW) process. The ANN was trained for 60% of the experimental data. In addition, the impact of the process parameters (tool rotational speed and weld-traverse speed) on the mechanical properties of the joint was determined by Taguchi Grey relational analysis. Findings Subsequently, testing and validation of the ANN were done using experimental data, which were not used for training the network. From the experiment, it was inferred that the outcomes of the ANN are in good agreement with the experimental data. The result of the analyses showed that the tool rotational speed has more impact than the weld-traverse speed. Originality/value The developed neural network can be used to predict the mechanical properties of the weld. Results indicate that the network prediction is similar to the experiment results. Overall regression value computed for training, validation and testing is greater than 0.9900 for both tensile strength and microhardness. In addition, the percentage error between experimental and predicted values was found to be minimal for the mechanical properties of the weldments. Therefore, it can be concluded that ANN is a potential tool for predicting the mechanical properties of the weld formed by FSW process. Similarly, the results of Taguchi Grey relational analysis can be used to optimize the process parameters of the weld process and it can be applied extensively to ascertain the most prominent factor. The results of which indicates that rotational speed of 1,270 rpm and traverse speed of 30 mm/min are to be the optimized process parameters. The result also shows that tool rotational speed has more impact on the mechanical properties of the weld than that of traverse speed.

Prediction and optimization of mechanical properties of PA6/NBR/graphene nanocomposites fabricated by friction stir processing

2021 ◽  
pp. 009524432110200
Author(s):  
Ali Ghorbankhan ◽  
Mohammad Reza Nakhaei ◽  
Ghasem Naderi
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Differential Scanning Calorimetric ◽  
Butadiene Rubber ◽  
Friction Stir ◽  
Graphene Nanocomposite ◽  
Graphene Nanoparticles ◽  
Input Variables

The friction stir process (FSP) method used to prepare polyamide 6 (PA6)/nitrile-butadiene rubber (NBR) nanocomposites with 1 wt% Graphene nanoparticles. Response surface methodology (RSM) and Box-Behnken design were used to study the effects of four input variables including tool rotational speed (ω), shoulder temperature (T), traverse speed (S), and the number of passes (N) on tensile strength and impact strength of PA6/NBR/Graphene nanocomposite. In order to investigate the dispersion state of Graphene and the morphology of the PA6/NBR blend in the presence of Graphene, wide x-ray patterns (WAX), scanning electron microscopy (SEM) were performed. Furthermore and differential scanning calorimetric (DSC) was used to investigate the thermal properties of PA6/NBR containing 1 wt% Graphene nanoparticles. The results confirmed that at the optimum range of input variables, PA6/NBR/Graphene nanocomposite provided good thermal stability as well as the highest tensile strength, and impact strength. This is caused by the large surface area to volume ratio of the dispersed layered Graphene in PA6/NBR blends. Under optimal conditions of the rotational speed of 1200 rpm, traverse speed of 20 mm/min, shoulder temperature of 125°C, and number pass of 3, the maximum tensile strength and impact strength are 70.4 MPa and 70.3 J/m, respectively.

A study on the effect of cooling on microstructure and mechanical properties of friction stir-welded AA5086 aluminum butt and lap joints

2017 ◽  
Vol 233 (6) ◽  
pp. 1156-1165 ◽  
Author(s):  
Adel Sedaghati ◽  
Hamed Bouzary
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Feed Rate ◽  
Rotational Speed ◽  
Lap Joints ◽  
Tensile Behavior ◽  
Water Cooling ◽  
Friction Stir ◽  
Microstructural Behavior ◽  
Constant Feed Rate

In this paper, the effect of water cooling on mechanical properties and microstructure of AA5086 aluminum joints during friction stir welding is investigated. For doing so, the mechanical and microstructural behavior of samples welded both in air and in water was analyzed. Tests were performed involving both butt and lap welds and the results were compared. The effect of rotational speed at constant feed rate of 50 mm/min and changing rotational speed ranging from 250 to 1250 r/min was investigated. The results showed a significant change in the tensile behavior of the butt-welded specimens due to water cooling. In addition, welding was performed at constant spindle speed of 800 r/min and various traverse speeds (25 mm/min to 80 mm/min) to determine the effect of feed rate. The strength increases at first, but then decreases dramatically along with the feed rate which is due to the occurrence of a groove defect. Results showed some generally positive impacts of water cooling which are discussed in terms of tensile results, hardness distributions and microstructure analysis.

Effect of FSP on Strength and Fracture Toughness of Aluminium Alloy 7000

2018 ◽  
Vol 877 ◽  
pp. 20-25
Author(s):  
P.K. Mandal
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Aluminium Alloy ◽  
Axial Force ◽  
Weight Ratio ◽  
High Strength ◽  
Hardness Measurement ◽  
Traverse Speed ◽  
Age Hardening ◽  
Friction Stir

The cast Al-Zn-Mg 7000 alloy has become one of the most potential structural materials in many engineering fields such as aircraft body, automotive casting due to their high strength to weight ratio, strong age hardening ability, competitive weight savings, attractive mechanical properties and improvement of thermal properties. The cast aluminium alloy has been modified of surface layer through a solid-state technique is called friction stir process (FSP). But basic principle has been followed by friction stir welding (FSW). This process can be used to locally refine microstructures and eliminate casting defects in selected locations, where mechanical properties improvements can enhance component performance and service life. However, some specified process parameters have adopted during experimental works. Those parameters are tool rotation speed (720 rpm), plate traverse speed (80 mm/min), axial force (15 kN), and tool design (i.e., pin height 3.5 mm and pin diameter 3.0 mm), respectively. The main mechanism behind this process likely to axial force and frictional force acting between the tool shoulder and workpiece results in intense heat generation and plastically soften the process material. The specified ratio of rotational speed (720 rpm) to traverse speed (80 mm/min) is considered 9 as low heat input during FSP and its entails low Zn vaporization problem results as higher fracture toughness of aluminium alloy. It is well known that the stirred zone (SZ) consists of refine equiaxed grains produced due to dynamic recrystallization. FSP has been proven to innovatively enhancing of various properties such as formability, hardness and fracture toughness (32.60 MPa√m). The hardness and fracture toughness of double passes AC+FSP aluminium alloy had been investigated by performing Vicker’s hardness measurement and fracture toughness (KIC)(ASTM E-399 standard) tests. Detailed observations with optical microscopy, Vicker’s hardness measurement, SEM, TEM, and DTA analysis have conducted to analyse microstructure and fracture surfaces of double passes FSP aluminium alloy.

Optimization of friction stir welding process parameters for AA6063-ETP copper using central composite design

2020 ◽  
Vol 17 (4) ◽  
pp. 491-507 ◽  
Author(s):  
Nitin Panaskar ◽  
Ravi Prakash Terkar
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Tool Rotational Speed ◽  
Content Type ◽  
Friction Stir ◽  
Central Composite

Purpose Recently, several studies have been performed on lap welding of aluminum and copper using friction stir welding (FSW). The formation of intermetallic compounds at the weld interface hampers the weld quality. The use of an intermediate layer of a compatible material during welding reduces the formation of intermetallic compounds. The purpose of this paper is to optimize the FSW process parameters for AA6063-ETP copper weld, using a compatible zinc intermediate filler metal. Design/methodology/approach In the present study, a three-level, three-factor central composite design (CCD) has been used to determine the effect of various process parameters, namely, tool rotational speed, tool traverse speed and thickness of inter-filler zinc foil on ultimate tensile strength of the weld. A total of 60 experimental data were fitted in the CCD. The experiments were performed with tool rotational speeds of 1,000, 1,200 and 1,400 rpm each of them with tool traverse speeds of 5, 10 and 15 mm/min. A zinc inter-filler foil of 0.2 and 0.4 mm was also used. The macrograph of the weld surface under different process parameters and the tensile strength of the weld have been investigated. Findings The feasibility of joining 3 mm thick AA6063-ETP copper using zinc inter-filler is established. The regression analysis showed a good fit of the experimental data to the second-order polynomial model with a coefficient of determination (R2) value of 0.9759 and model F-value of 240.33. A good agreement between the prediction model and experimental findings validates the reliability of the developed model. The tool rotational speed, tool traverse speed and thickness of inter-filler zinc foil significantly affected the tensile strength of the weld. The optimal conditions found for the weld were, rotational speed of 1,212.83 rpm and traverse speed of 9.63 mm/min and zinc foil thickness is 0.157 mm; by using optimized values, ultimate tensile strength of 122.87 MPa was achieved, from the desirability function. Originality/value Aluminium and copper sheets could be joined feasibly using a zinc inter-filler. The maximum tensile strength of joints formed by inter-filler (122.87 MPa) was significantly better as compared to those without using inter-filler (83.78 MPa). The optimum process parameters to achieve maximum tensile strength were found by CCD.

An investigation on the mechanical properties of friction stir welded polycarbonate/aluminium oxide nanocomposite sheets

2016 ◽  
Vol 49 (6) ◽  
pp. 498-512 ◽  
Author(s):  
Ali Doniavi ◽  
Saeedeh Babazadeh ◽  
Taher Azdast ◽  
Rezgar Hasanzadeh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Rotational Speed ◽  
Signal To Noise Ratio ◽  
Base Material ◽  
Travel Speed ◽  
Effective Parameter ◽  
Welding Parameters ◽  
Effective Parameters ◽  
Friction Stir

Although considerable progress has been made in recent years in field of polymer welding, challenges still remain in using a friction stir welding method to join polycarbonate (PC) composites. This research provides an investigation on the effect of welding parameters (tool’s travel and rotational speeds) on mechanical properties of PC nanocomposite weld lines. PC nanocomposites were prepared with different percentages of Al2O3 nanofiller using a twin screw extruder and injection moulded as sheets in order to ease the welding. Considering various parameters and their levels, optimization of Taguchi experimental design was carried out, an L16 orthogonal standard array was selected and the effective parameter was calculated using analysis of variance of the results. The results indicated that nanoalumina percentage is the most effective parameter on the tensile strength of weld and tool’s travel speed and rotational speed are next effective parameters, respectively. According to signal-to-noise ratio, maximum weld tensile strength (89.5% of base material) is revealed when nanoalumina percentage, tool’s travel speed and tool’s rotational speed were chosen as 1 wt%, 12 mm/min and 1250 r/min, respectively.

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.

Effect of Process Parameters on Defect Formation in Friction Stir Processed 6082-T6 Aluminium Alloy

2012 ◽  
Vol 232 ◽  
pp. 3-7
Author(s):  
Akinlabi Esther Titilayo ◽  
Akinlabi Stephen Akinwale
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Friction Stir Processing ◽  
Feed Rate ◽  
Rotational Speed ◽  
Defect Formation ◽  
Processing Parameters ◽  
Friction Stir

This paper reports the effects of processing parameters on defects formed during friction stir processing of 6082-T6 Aluminium Alloy. The plates were processed by varying the feed rate between 50 and 250 mm/min, while the rotational speed was varied between 1500 and 3500 rpm to achieve the best result. It was observed that the sheets processed at the highest feed rate considered in this research resulted in wormhole defect. These processed samples with defects were correlated to the tensile results and it was found that the Ultimate Tensile Strength (UTS) of these samples was relatively low compared to other samples without defects.

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