An insight into the electrical energy demand of friction stir welding processes: the role of process parameters, material and machine tool architecture

2018 ◽  
Vol 100 (9-12) ◽  
pp. 3013-3024
Author(s):  
Gianluca Buffa ◽  
Giuseppe Ingarao ◽  
Davide Campanella ◽  
Rosa Di Lorenzo ◽  
Fabrizio Micari ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Machine Tool ◽  
Process Parameters ◽  
Energy Demand ◽  
Electrical Energy ◽  
Friction Stir ◽  
Welding Processes ◽  
Insight Into

Establishing the Dependence of Output Parameters Depending on Local Process Conditions for Friction Stir Welding of Pure Copper Plates

2018 ◽  
Vol 1146 ◽  
pp. 32-37 ◽  
Author(s):  
Marius Adrian Constantin ◽  
Ana Boşneag ◽  
Eduard Niţu ◽  
Lia Nicoleta Boţilă
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Speed ◽  
Frictional Heating ◽  
Pure Copper ◽  
Fusion Welding ◽  
Process Conditions ◽  
Friction Stir ◽  
Local Process ◽  
Welding Processes

Welding copper and its alloys is usually difficult to achieve by conventional fusion welding processes because of high thermal diffusivity of the copper, which is at least 10 times higher than most steel alloys, in addition to this, there are the well-known disadvantages of conventional fusion welding represented by necessity of using alloying elements, a shielding gas and a clean surface. To overcome these inconveniences, Friction Stir Welding (FSW), a solid state joining process that relies on frictional heating and plastic deformation, is being explored as a feasible welding process. In order to achieve an increased welding speed and a reduction in tool wear, this process is assisted by another one (TIG) which generates and adds heat to the process. The research includes two experiments for the FSW process and one experiment for tungsten inert gas assisted FSW process. The process parameters that varied were the rotational speed of the tool [rpm] and the welding speed [mm/min] while the compressive force remained constant. The purpose of this paper is to correlate the evolution of temperature, tensile strength, elongation and microscopic aspect with the linear position on the joint (local process parameters) for each experimental case and then make comparisons between them, and to identify and present the set of process parameters that has the best mechanical properties for this material.

Empirical Dynamic Modeling of Friction Stir Welding Processes

2007 ◽  
Author(s):  
Xin Zhao ◽  
Prabhanjana Kalya ◽  
Robert G. Landers ◽  
K. Krishnamurthy
Keyword(s):  
Steady State ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Dynamic Models ◽  
Welding Process ◽  
Recursive Least Squares ◽  
Finite Difference Schemes ◽  
Power Relationship ◽  
Friction Stir ◽  
Welding Processes

Current Friction Stir Welding (FSW) process modeling research is concerned with the detailed analysis of local effects such as material flow, heat generation, etc. These detailed thermo-mechanical models are typically solved using finite element or finite difference schemes and require substantial computational effort to determine temperature, forces, etc. at a single point in time. Dynamic models describing the total forces acting on the tool throughout the entire welding process are required for the design of feedback control strategies and improved process planning and analysis. In this paper, empirical models relating the process parameters (i.e., plunge depth, traverse rate, and rotation speed) to the process variables (i.e., axial, traverse, and lateral forces) are developed to understand their dynamic relationship. First, the steady-state relationship between the process parameters and variables is constructed, and the relative importance of each process parameter on each process variable is determined. Next, the dynamic process response characteristics are determined using Recursive Least-Squares. The results indicate that the steady-state relationship between the process parameters and variables is well characterized by a nonlinear power relationship, and the dynamic responses are well characterized by low-order linear equations. Experiments are conducted that validate the developed FSW dynamic models.

Effect of Process Parameters on the Joint Integrity in Friction Stir Welding of Ti-6Al-4V Lap Joints

2013 ◽  
Vol 554-557 ◽  
pp. 1083-1090 ◽  
Author(s):  
Gianluca Buffa ◽  
Livan Fratini ◽  
Matthias Schneider ◽  
Marion Merklein
Keyword(s):  
Friction Stir Welding ◽  
Titanium Alloys ◽  
Process Parameters ◽  
Lap Joints ◽  
Fusion Welding ◽  
Main Process ◽  
Filling Material ◽  
Friction Stir ◽  
Wide Range ◽  
Welding Processes

Friction Stir Welding (FSW) is a solid state welding process patented in 1991 by TWI; initially adopted to weld aluminum alloys, is now being successfully used also for magnesium alloys, copper and steels. The wide diffusion the process is having is due to the possibility to weld materials traditionally considered difficult to be welded or “unweldable” by traditional fusion welding processes due to peculiar thermal and chemical material properties. Additionally, the process allows welding a wide range of sheet thickness (up to 50mm) avoiding typical fusion welding processes defects, like cavities and porosities, with no shielding gas, filling material or joint preparation. Recently, research is focusing on titanium alloys thanks to the high interest that such materials are getting from the industry due to the extremely high strength-weight ratio together with good corrosion resistance properties. Welding of titanium alloys by traditional fusion welding techniques presents several difficulties due to high material reactivity resulting in bonding with oxygen, hydrogen, and nitrogen with consequent embrittlement of the joint. In this way FSW can represent a cost effective and high quality solution. A few studies have been developed on the FSW of titanium alloys butt joints, while there is a complete lack of knowledge as far as different joint morphologies are regarded (lap joints, T joints, etc.). In the paper the results of an experimental campaign on lap joints made out of thin Ti-6Al-4V sheets are presented. The effect of the main process parameters on the micro and macro mechanical properties has been investigated and related to the microstructural transformations occurring during the process because of the thermo-mechanical action of the tool.

scholarly journals Influence of Tool Tilt Angle on Material Flow and Defect Generation in Friction Stir Welding of AA2219

2018 ◽  
Vol 68 (5) ◽  
pp. 512-518 ◽  
Author(s):  
Suresh Meshram ◽  
Madhusudhan Reddy
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Tilt Angle ◽  
Material Flow ◽  
Critical Role ◽  
Welding Process ◽  
Fusion Welding ◽  
Friction Stir ◽  
Tool Tilt Angle ◽  
Welding Processes

Heat treatable aluminium alloy AA2219 is widely used for aerospace applications, welded through gas tungsten and gas metal arc welding processes. Welds of AA2219 fabricated using a fusion welding process suffers from poor joint properties or welding defects due to melting and re-solidification. Friction stir welding (FSW) is a solid-state welding process and hence free from any solidification related defects. However, FSW also results in defects which are not related to solidification but due to improper process parameter selection. One of the important process parameters, i.e., tool tilt angle plays a critical role in material flow during FSW, controlling the size and location of the defects. Effect of tool tilt angle on material flow and defects in FSW is ambiguous. A study is therefore taken to understand the role of tool tilt angle on FSW defects. Variation in temperature, forces, and torque generated during FSW as a result of different tool tilt angles was found to be responsible for material flow in the weld, controlling the weld defects. An intermediate tool tilt angle (1o-2o) gives weld without microscopic defect in 7 mm thick AA2219 for a given set of other process parameters. At this tool tilt angle, x-force, and Z- force is balanced with viscosity and the material flow strain rate sufficient for the material to flow and fill internal voids or surface defects in the weld.

Friction Stir Riveting: Impact of Process Parameters on Joint Performance

2005 ◽  
Author(s):  
Robin Stevenson ◽  
P.-C. Wang
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Rotational Speed ◽  
Joint Strength ◽  
Penetration Rate ◽  
Joint Performance ◽  
Friction Stir ◽  
Resistance Spot Welds ◽  
Joining Process ◽  
Insight Into

The Friction Stir Riveting (FSR) process consists of rapidly rotating a suitably shaped rivet, bringing it into contact with the workpieces to be joined and slowly driving the rotating rivet into the workpieces. The process, which borrows some features of Friction Stir Welding results in heating the workpieces through friction, thereby locally softening the workpieces and enabling the insertion of the rivet under reduced force. While conceptually simple the details and subtleties of the joining process have not been studied, thus little insight into the influence of processing characteristics has been generated and knowledge of procedures for enhancing joint strength is lacking. The intent of this study is to investigate the influence of rivet composition, rotational speed and penetration rate on joint performance and to compare overall joint performance with that obtained using conventional resistance spot welds.

Empirical Dynamic Modeling of Friction Stir Welding Processes

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Xin Zhao ◽  
Prabhanjana Kalya ◽  
Robert G. Landers ◽  
K. Krishnamurthy
Keyword(s):  
Steady State ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Dynamic Models ◽  
Recursive Least Squares ◽  
Time Range ◽  
Power Relationship ◽  
Process Variables ◽  
Friction Stir ◽  
Welding Processes

Current friction stir welding (FSW) process modeling research is mainly concerned with the detailed analysis of local effects such as material flow, heat generation, etc. These detailed thermomechanical models are typically solved using finite element or finite difference schemes and require substantial computational effort to determine temperature, forces, etc., at a single point in time, or for a very short time range. Dynamic models describing the total forces acting on the tool throughout the entire welding process are required for the design of feedback control strategies and improved process planning and analysis. In this paper, empirical models relating the process parameters (i.e., plunge depth, travel speed, and rotation speed) to the process variables (i.e., axial, path, and normal forces) are developed to understand their dynamic relationships. First, the steady-state relationships between the process parameters and the process variables are constructed, and the relative importance of each process parameter on each process variable is determined. Next, the dynamic characteristics of the process variables are determined using recursive least-squares. The results indicate the steady-state relationship between the process parameters and the process variables is well characterized by a nonlinear power relationship, and the dynamic responses are well characterized by low-order linear equations. Experiments are conducted that validate the developed FSW dynamic models.

Procedure to find out the optimal ranges of process parameters for friction stir welding

2021 ◽  
pp. 146442072199314
Author(s):  
Shubham Verma ◽  
Joy Prakash Misra ◽  
Meenu Gupta
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Tilt Angle ◽  
Welding Speed ◽  
Rotational Speed ◽  
Optical Microscope ◽  
Graphical Analysis ◽  
Friction Stir ◽  
Steepest Ascent ◽  
Vertical Milling Machine

The present study deals with the application of sequential procedure (i.e. steepest ascent) to obtain the optimum values of process parameters for conducting friction stir welding (FSW) experiments. A vertical milling machine is modified by fabricating fixture and tool ( H13 material) for performing FSW operation to join AA7039 plates. The steepest ascent technique is employed to design the experiments at different rotational speed, welding speed, and tilt angle. The ultimate tensile strength is considered as a performance characteristic for deciding the optimal levels. The mechanical and metallurgical characteristics of the joints are studied by executing tensile and microhardness tests. It is concluded from the graphical analysis of the steepest ascent technique that the optimal maximum and minimum values are 1812–1325 r/min for rotational speed, 43–26 mm/min for welding speed, and 2°–1.3° for tilt angle, respectively. Besides, optical microscope and scanning electron microscope are utilized for microstructural and fractographic analyses for a better understanding of the process.

The Effect of Stirring Tool Surface Condition on Wear Characteristics in Friction Stir Welding (FSW) Process

2021 ◽  
Vol 880 ◽  
pp. 57-62
Author(s):  
Normariah Che Maideen ◽  
Salina Budin ◽  
Koay Mei Hyie ◽  
Nor Azirah Mohd Fohimi
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Surface Condition ◽  
Welding Process ◽  
Wear Characteristics ◽  
Rotating Speed ◽  
Friction Stir ◽  
Ticn Coating ◽  
Tool Surface

Stirring tool is one of the important factor that contribute to the successful of Friction Stir Welding (FSW). Role of tool, is to heat the welding zone and stir the material along the process. Many studies have been conducted by other researchers to improve the performance of stirring tool. Similar to this work, it is aimed to investigate and analyze the effect of stirring tool surface condition on wear characteristics in friction stir welding process. Four tools have been fabricated with pre-determined surface condition. Tool 1: H13 without heat treatment and without coating. Tool 2: H13 with heat treatment only. Tool 3: H13 with TiCN coating only and Tool 4: H13 with heat treatment and with TiCN coating. Friction stir welding was performed to test and verify the performance of fabricated tools. Process parameter used are 1270 RPM for rotating speed while 218 mm/min for welding speed. From the result, Tool 4 performed better in terms of physical wear as well as wear rate.

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