scholarly journals Wear Inducing Phase Transformation of Plasma Transfer Arc Coated Tools during Friction Stir Welding with Al Alloy

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Kuan-Jen Chen ◽  
Fei-Yi Hung ◽  
Truan-Sheng Lui ◽  
Yong-Ren Shih
Keyword(s):  
Wear Resistance ◽  
Phase Transformation ◽  
Friction Stir Welding ◽  
High Speed ◽  
Phase Transfer ◽  
Welding Process ◽  
High Speed Steel ◽  
Al Alloy ◽  
Transfer Layer ◽  
Friction Stir

The friction stir welding process (friction stir welding/processing, FSW/FSP) has wear problems related to stirring tools. In this study, the plasma transfer arc (PTA) method was used with stellite 1 powders (Co-based) to coat on the head of a SKD61 stirring tool (SKD61-ST1) in order to investigate the wear performance and phase transformation of SKD61-ST1 after FSW. Under the same experimental parameters, the wear data were compared with the high-speed steel SKH51 (tempering material SKH51-T and annealed material SKH51-A) and tungsten-carbide cobalt (TCC). Results showed the PTA coating was a γ-Co solidification matrix with M7C3 and M23C6 carbides. After FSW, the wear resistance of SKD61-ST1 was better than that of SKH51-A and SKH51-T and lower than that of TCC. The SKD61-ST1, SKH51-A, and SKH51-T stirring tools exhibited sliding wear after FSP, where the pin and shoulder of the stirring tool formed a phase transfer layer on the surface, and the peeling of the phase transfer layer caused wear weight loss. The main phase of the phase transfer layer of the SKD61-ST1 tool was Al9Co2. The affinity and adhesion energy of the Co-Al phase was lower than that of Fe-Al phase, and the phase transfer layer of the SKD61-ST1 tool was thinner and had lower coverage, thereby increasing the wear resistance of the SKD61-ST1 stirring tools during FSW.

Modeling of Friction Stir Welding of AL7075 Using Neural Networks

2012 ◽  
Vol 3 (1) ◽  
pp. 66-79 ◽  
Author(s):  
Sasidhar Muttineni ◽  
Pandu R. Vundavilli
Keyword(s):  
Neural Network ◽  
Mechanical Properties ◽  
Neural Networks ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
High Speed ◽  
Welding Process ◽  
High Speed Steel ◽  
Operating Conditions ◽  
Friction Stir

Friction stir welding (FSW) is a solid state welding process, which is used for the welding of aluminum alloys. It is important to note that the mechanical properties of the FSW process depends on various process parameters, such as spindle speed, feed rate and shoulder depth. Two different tool materials, such as High speed steel (HSS) and H13 are considered for the welding of Al 7075. The present paper deals with the modeling of FSW process using neural networks. A three layered feed forward neural network (NN) has been used to model the FSW of aluminum alloys. It is important to note that the connection weights and bias values of the NN are optimized with the help of a binary coded genetic algorithm (GA). The training of the NN with the help of GA is a time consuming process. Hence, offline training has been provided to optimize the connection weights and bias values of the neural network. Once, the training is over, the GA trained neural network will be used for online prediction of the mechanical properties of FSW process at different operating conditions.

Friction Stir Welding of Aluminum Alloy 1100 and Titanium-Al Alloy

2016 ◽  
Author(s):  
B. K. Dhindaw ◽  
P. S. De ◽  
Priyadarshini Jayashree
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
High Speed ◽  
High Speed Steel ◽  
Al Alloy ◽  
Ti Alloy ◽  
Joint Region ◽  
Friction Stir ◽  
Shoulder Region ◽  
Material Mixing

A intercalating joint between Al and Ti alloy is friction stir welded using a high speed steel tool. The material mixing occurs mainly in the shoulder region while the pin region shows nominal mixing. Microscopy and hardness experiments indicate sporadic formation of intermetallic compounds. The joint region near the shoulder and to some extent below it shows increase in hardness compared to the base Ti alloy.

Microstructure and Mechanical Properties of Friction Stir Welding Joint of Pure Copper

2011 ◽  
Vol 418-420 ◽  
pp. 1520-1523
Author(s):  
Yong Zhao ◽  
You Li Ye ◽  
Keng Yan ◽  
Li Long Zhou
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
High Speed ◽  
Bonding Temperature ◽  
Pure Copper ◽  
High Speed Steel ◽  
Weld Nugget ◽  
Nugget Zone ◽  
Friction Stir ◽  
Welding Joint

Microstructures and mechanical properties of pure copper weld joints are discussed under different parameters of friction stir welding. The results reveal that it is conducive to the formation of compact joint in friction stir welding by applying high speed steel tool with high anti-bonding temperature. The friction stir welding joint with compact and defect-free microstructure could be obtained when the tool rotation rate is 1250- 1650 r/min and the tool traverse speed is 20-50 mm/min. Intensively plastic deformation occurs in the soften materials of the weld nugget zone and numerous crystal particles are broken under the influence of tool stirring. The microstructure of weld nugget zone is composed of tiny isometric crystals, which is due to the dynamic recrystallization of broken crystal particles. The structure of thermo-mechanical affected zone on both sides is asymmetric. Obvious boundary of the thermo affected zone could be seen on the advancing side, and the plastic streamline is apparent.

The Rotational Extrusion Alloying

2013 ◽  
Vol 664 ◽  
pp. 521-524
Author(s):  
Wei Ping Xu ◽  
Li Ming Ke ◽  
Li Xing
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Low Temperature ◽  
High Speed ◽  
Welding Process ◽  
Stable Phase ◽  
Dissimilar Metals ◽  
Friction Stir ◽  
Pole Figures ◽  
Extrusion Technology

The Rotating Extrusion Alloying (REA) is a process which combined friction stir welding process and extrusion technology. In the REA process, dissimilar metals are mixed, cracked, and subjected to high speed, severe pressing deformation, and therefore rapidly alloy at a low temperature. The result shows that REA technology can be alloyed Al-Ti material. Its phases are mainly composed of Al and Al3Ti, which are distributed more evenly in the aluminum. After heat treatment, its phases’ types and pole figures have no significant change, but there is a trend of transition to the non-equilibrium stable phase. Small-angle grain boundaries decrease or even disappear.

Establishing optimal friction stir welding parameters for AA2219-T87 Al-alloy using comprehensive RSM and GA approach

2021 ◽  
Author(s):  
Boddu Rajnaveen ◽  
Govada Rambabu ◽  
Kollabothina Prakash ◽  
Kotipalli Srinivasa Rao
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Welding Process ◽  
Welding Parameter ◽  
Welding Parameters ◽  
Al Alloy ◽  
Regression Equations ◽  
Corrosion Properties ◽  
Friction Stir ◽  
Aa2219 Alloy

Abstract AA2219-T87 aluminium alloy has been used in aerospace applications because of its high strength, low density and resistance to corrosion. The copper in the alloy improves the hardness and lowers melting point, which makes two sections easily joined with a process called friction stir welding of aluminium alloy. In the present work, heat-treated AA2219 alloy was butt welded by solid-state friction stir welding process. This work aims to develop a suitable combination of welding parameters for producing defect-free weld joints of AA2219 alloy to improve tensile and corrosion properties. The most influencing control parameter for optimising the friction stir welding responses was determined using sophisticated design of experiments (DOE) techniques. Ultimate tensile strength and corrosion resistance are observed as responses in this study. To achieve the desired weld responses, a three-factor, three-level Box-behneken design was used. Analysis of Variance (ANOVA) was carried out to examine the interaction effect and significant welding parameter to set the optimal level of welding conditions. Multi-response regression equations have been developed using response surface methodology (RSM) to estimate the output characteristics of weld. The Genetic algorithm (GA) was used to optimise the predicted mathematical model under given optimization constraints. The results shown that the optimum responses are obtained at input factors rotational speed 300 rpm, welding speed 80 mm/min, and axial force of 10kN.

scholarly journals Influence of material velocity on heat generation during linear welding stage of friction stir welding

2016 ◽  
Vol 20 (5) ◽  
pp. 1693-1701
Author(s):  
Alin Murariu ◽  
Darko Veljic ◽  
Dragana Barjaktarevic ◽  
Marko Rakin ◽  
Nenad Radovic ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Friction Stir Welding ◽  
Heat Generation ◽  
Welding Process ◽  
Slip Rate ◽  
Frictional Heat ◽  
Al Alloy ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Pin

The heat generated during friction stir welding (FSW) process depends on plastic deformation of the material and friction between the tool and the material. In this work, heat generation is analysed with respect to the material velocity around the tool in Al alloy Al2024-T351 plate. The slip rate of the tool relative to the workpiece material is related to the frictional heat generated. The material velocity, on the other hand, is related to the heat generated by plastic deformation. During the welding process, the slippage is the most pronounced on the front part of the tool shoulder. Also, it is higher on the retreating side than on the advancing side. Slip rate in the zone around the tool pin has very low values, almost negligible. In this zone, the heat generation from friction is very low, because the material is in paste-like state and subjected to intensive plastic deformation. The material flow velocity around the pin is higher in the zone around the root of the pin. In the radial direction, this quantity increases from the pin to the periphery of the tool shoulder.

scholarly journals Temperature Based Optimization of Friction Stir Welding of AA 6061 Using GRA Synchronous With Taguchi Method

2021 ◽  
Author(s):  
Eyob Messele ◽  
Assefa Asmare Tsegaw
Keyword(s):  
Friction Stir Welding ◽  
Base Metal ◽  
Weld Zone ◽  
Welding Process ◽  
Quality Characteristic ◽  
Heat Transfer Analysis ◽  
Al Alloy ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Pin

Abstract One of the recent novel joining mechanisms in the solid-state-welding process is Friction Stir Welding (FSW). The process is extensively used in joining similar and dissimilar materials as well. This research studied and found the optimum process parameters of FSW based on the temperature simulation results on a 5 mm 6061 Al alloy sheet with a butt joint configuration. Steady-state heat transfer analysis was performed using a transient thermal workbench to predict and identify the optimum parameters grounded on the simulation welding temperature result. The parameters are optimized using the hybrid Taguchi L9 orthogonal array and Grey relation analysis method with a larger is better quality characteristic. Mechanical properties of the weld joints' such as hardness and tensile strength, were studied at an ambient temperature. The result revealed that a higher rotational speed with a minimum traverse speed and taper threaded tool pin impart the optimum parameter settings. Analysis of variance (ANOVA) was carried out also to determine the effects of each process parameter. At a 95 % confidence interval, rotational and traverse speeds show significant characteristics. The joint efficiency reached 92.25% of the base metal at a maximum welding temperature. Additionally, the microstructure of the stir weld zone of the specimen was studied as well. Metallographic Characterization carried out using Scanning Electron Microscope (SEM) revealed the microstructure of the samples after the weld did not show any significant change with the base metal. Furthermore, this study scheme can be extended to thick non-ferrous, ferrous, and metal-based composite materials, too.

Investigation and Thermal Analysis of Friction Stir Welding Process Parameters of AA6061 Plates

2016 ◽  
Author(s):  
Jalay Shukla ◽  
Raghu Echempati ◽  
Rupal Vyasa ◽  
Vishvesh Badheka
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
High Speed ◽  
Welding Process ◽  
Ansys Software ◽  
Friction Stir ◽  
Ansys Simulation ◽  
Different Shapes ◽  
Weld Parameters ◽  
Different Thickness

Friction stir welding (FSW) is a solid state welding process in which a non-consumable rotating tool with a specially designed pin and shoulder is inserted into the abutting edges of sheets or plates to be joined and subsequently traversed along the joint line. In FSW, a pin tool with different shapes spins against the edges of two metal pieces of same or different thickness positioned next to each other. As the pin travels along, it creates friction that generates heat, mixes, and joins the alloys without melting them. To optimize the process, several researchers created pins of different shape, and geometry, and used them in FSW but varied the depth, rotational speed, and tilt angle of the pins. Statistical analysis has been used to identify the most optimum combination of tool and weld parameters that could support high-speed production. Many studies support that the faster FSW is carried out, the stronger (better weld quality) the resulting welds will be. The objective of this paper is to predict the effects of some of the process parameters on the performance of the aluminum alloy components joined using ANSYS simulation tool. Although not reported in this paper, the mechanical and metallurgical properties of the welded members have been measured in the laboratory. The goal is to gain an understanding of how FSW can be used to successfully join aluminum alloys and to study the effect of the various process parameters on the process. The material used is AA6061 as it is one of the popular choices for automotive applications. Experiments have been conducted to validate some of the simulation results from ANSYS software.

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