scholarly journals The Preliminary Exploration of Micro-Friction Stir Welding Process and Material Flow of Copper and Brass Ultra-Thin Sheets

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2401
Author(s):  
Changqing Zhang ◽  
Zhuo Qin ◽  
Chen Rong ◽  
Wenchen Shi ◽  
Shuwen Wang
Keyword(s):  
Friction Stir Welding ◽  
Flow Behavior ◽  
Pure Copper ◽  
Weld Zone ◽  
Metal Flow ◽  
Welding Process ◽  
Process Conditions ◽  
Friction Stir ◽  
Plastic Metal ◽  
Tool Pin

In the friction stir welding (FSW) of ultra-thin dissimilar metal sheets, different physical material properties, the reduction of plastic metal in the weld zone, and insufficient plastic metal flow lead to poor weld seam shapes and joint qualities. Therefore, it is necessary to study the flow behavior during the FSW of ultrathin sheets. In this study, micro friction stir welding (μFSW) was conducted and analyzed for the butt welding of 0.6-mm-thick ultrathin brass (H62-H) and pure copper (T2-Y) sheets. By analyzing the electric signals of the temperature and force during the welding process, testing the mechanical properties, and analyzing the metallography of the joint, the influences of the process parameters on the metal flow behavior during μFSW were studied. In the proper process conditions, the material preferentially migrated and concentric vortex flow occurred in the vicinity of the shoulder and tool pin action areas. The copper was pushed from the retreating side (RS) to the advancing side (AS) of the weld, allowing it to flow more fully. A mixture of both materials formed at the bottom of the weld nugget, and less migration occurred in the heat-affected zone of the AS at this time. The highest tensile strength can reach 194 MPa, accounting for 82.6% of the copper. The presence of brittle phases Cu5Zn8, AgZn3 and AgZn caused the hardness to fluctuate slightly.

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.

Material Flow Visualization of Dissimilar Friction Stir Welding Process Using Nano-CT

2018 ◽  
Author(s):  
Xun Liu ◽  
Sheng Zhao ◽  
Jun Ni
Keyword(s):  
Friction Stir Welding ◽  
Heat Input ◽  
Material Flow ◽  
Volume Fraction ◽  
Flow Behavior ◽  
Weld Zone ◽  
Process Conditions ◽  
Rotating Speed ◽  
Friction Stir ◽  
Small Tool

In this study, Friction stir welding (FSW) of aluminum alloy 6061-T6511 to TRIP 780 steel are analyzed under various process conditions. Two FSW tools with different sizes are used. To understand the underlying joining mechanisms and material flow behavior, nano-CT is applied for a 3D visualization of material distribution in the weld. With insufficient heat input, steel fragments are generally scattered in the weld zone in large pieces. This is observed in a combined condition of big tool, small tool offset and low rotating speed or a small tool with low rotating speed. Higher heat input improves the material flowability and generates a continuous strip of steel. The remaining steel fragments are much finer. When the volume fraction of steel involved in the stirring nugget is small, this steel strip can be in a flat shape near the bottom, which generally corresponds to a better joint quality and the joint would fracture in the base aluminum side. Otherwise, a hook structure is formed and reduces the joint strength. The joint would fail with a combined brittle behavior on the steel hook and a ductile behavior in the surrounding aluminum matrix.

3-D Finite Element Simulation of Friction Stir Welding Process of Non Similar Aluminum-Copper Sheets

2011 ◽  
Vol 312-315 ◽  
pp. 953-958 ◽  
Author(s):  
A. Alimoradi ◽  
M. Loh-Mousavi ◽  
R. Salekrostam
Keyword(s):  
Finite Element ◽  
Friction Stir Welding ◽  
Heat Input ◽  
Three Dimensional ◽  
Welding Process ◽  
Process Conditions ◽  
Friction Stir ◽  
Two Parameters ◽  
Tool Pin ◽  
The Relationship

The Friction Stir Welding (FSW), a relatively new welding process, was developed in 1991 at the Welding Institute near Cambridge, England. There are two tool speeds to be considered in friction-stir welding; how fast the tool rotates and how quickly it traverses the interface. These two parameters have considerable importance and must be chosen with care to ensure a successful and efficient welding cycle. The relationship between the welding speeds and the heat input during welding is complex. In this paper the friction stir welding (FSW) process of stainless steel alloys has been modeled using a three dimensional finite element method. A coupled thermal viscoplastic model was used for the simulation. Tool speeds and temperature distribution are coupled and solved together using this method. The relationship between the welding speeds and the heat input during welding is obtained by numerical analysis, and the stress contour occurred by temperature field and tool force is surveyed. In addition, the effects of FSW process conditions on heating mainly near the tool pin are investigated in this paper.

Effect of Friction Stir Welding Parameters on Thermal and Tensile Behavior of Aluminum Weldments Using Double Shoulder Tools

2012 ◽  
Vol 622-623 ◽  
pp. 323-329
Author(s):  
Ebtisam F. Abdel-Gwad ◽  
A. Shahenda ◽  
S. Soher
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Tensile Behavior ◽  
Frictional Heat ◽  
Welding Parameters ◽  
Friction Stir ◽  
Aluminum Base ◽  
Tool Pin ◽  
Strength And Ductility

Friction stir welding (FSW) process is a solid state welding process in which the material being welded does not melt or recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters and tool pin profile play major roles in deciding the weld quality. In this investigation, an attempt has been made to understand effects of process parameters include rotation speeds, welding speeds, and pin diameters on al.uminum weldment using double shoulder tools. Thermal and tensile behavior responses were examined. In this direction temperatures distribution across the friction stir aluminum weldment were measured, besides tensile strength and ductility were recorded and evaluated compared with both single shoulder and aluminum base metal.

scholarly journals Influence of Mx-Trivex, A-Skew, Three Flat Threaded and Concave Shouldered Mx-Triflute Tool Pin Profiles on Tensile Properties and Fractural Behaviour of Aa 6082-T6 Weldments During Friction Stir Welding

2020 ◽  
Vol 9 (4) ◽  
pp. 1376-1384
Keyword(s):  
Friction Stir Welding ◽  
Tensile Test ◽  
Weld Zone ◽  
Base Material ◽  
Traverse Speed ◽  
Friction Stir ◽  
Tool Pin ◽  
Solid State Joining ◽  
Joining Process ◽  
Brass Wire

Friction Stir Welding (FSW) is a topical and propitious solid-state joining process producing economical and strengthened joints of age-hardened and heat-treatable Aluminium Alloy AA 6082-T6. Mechanical and fractural behaviour of weldments were investigated in order to find crack initiation and necking on the weld zone thereby perceiving the complete behaviour of fracture occurred near the weld zone. Weldments are fabricated by employing four tool pin profiles namely MX-TRIVEX, A-SKEW, Three flat threaded and Concave shouldered MX-TRIFLUTE tools at various rotational speeds 1000 rpm, 1200 rpm and 1400 rpm at single traverse speed 25 mm/min. EXCETEX-EX-40 CNC wire cut EDM with 0.25 mm brass wire diameter has been employed to perform the extraction of tensile test specimens from the weldments according to ASTM E8M-04 standard. Tensile test was performed on elctromechanically servo controlled TUE-C-200 (UTM machine) according to ASTM B557-16 standards Maximum Ultimate Tensile Strength (UTS) of 172.33 MPa (55.5% of base material) and 0.2% Yield Stress (YS) of 134.10 MPa (51.5% of base material) were obtained by using A-SKEW at 1400 rpm, 25 mm/min and maximum % Elongation (%El) of 11.33 (113.3% of base material) was obtained at MX-TRIVEX at 1000 rpm, 25 mm/min. Minimum UTS of 131.16 MPa (42.30% of base material) and 0.2% YS of 105.207 MPa (40.46% of base material )were obtained by using Concave shouldered MX-TRIFLUTE at 1400 rpm, 25 mm/min. Minimum % El of 5.42 ( 54.2% of base material) was obtained by using A-SKEW at 1000 rpm, 25 mm/min.

Proposing a new relation for selecting tool pin length in friction stir welding process

Measurement ◽  
2018 ◽  
Vol 129 ◽  
pp. 112-118 ◽  
Author(s):  
Noor Zaman Khan ◽  
Arshad Noor Siddiquee ◽  
Zahid A. Khan
Keyword(s):  
Friction Stir Welding ◽  
Welding Process ◽  
Friction Stir ◽  
Friction Stir Welding Process ◽  
Tool Pin

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.

scholarly journals Material Flow Visualization of Dissimilar Friction STIR Welding Process Using Nano-Computed Tomography

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Xun Liu ◽  
Sheng Zhao ◽  
Kai Chen ◽  
Jun Ni
Keyword(s):  
Computed Tomography ◽  
Friction Stir Welding ◽  
Heat Input ◽  
Material Flow ◽  
Volume Fraction ◽  
Weld Zone ◽  
Process Conditions ◽  
Rotating Speed ◽  
Friction Stir ◽  
Small Tool

In this study, the friction stir welding (FSW) of aluminum alloy 6061-T6511 to TRIP 780 steel is analyzed under various process conditions. Two FSW tools with different sizes are used. To understand the underlying joining mechanisms and material flow behavior, nano-computed tomography (nano-CT) is applied for a 3D visualization of material distribution in the weld. With insufficient heat input, steel fragments are generally scattered in the weld zone in large pieces. This is observed in a combined condition of big tool, small tool offset, and low rotating speed or a small tool with low rotating speed. Higher heat input improves the material flowability and generates a continuous strip of steel. The remaining steel fragments are much finer. When the volume fraction of steel involved in the stirring nugget is small, this steel strip can be in a flat shape near the bottom, which generally corresponds to a better joint quality and the joint would fracture in the base aluminum side. Otherwise, a hook structure is formed and reduces the joint strength. The joint would fail with a combined brittle behavior on the steel hook and a ductile behavior in the surrounding aluminum matrix.

A Study on the Thermal Deformation of Fillet Joint Friction Stir Welding

2020 ◽  
Author(s):  
Sungwook Kang ◽  
Jaewoong Kim ◽  
Donghyun Kim ◽  
Kwangjin Lee ◽  
Yoonchul Jung
Keyword(s):  
Friction Stir Welding ◽  
Heat Source ◽  
Welding Process ◽  
Frictional Heat ◽  
Process Conditions ◽  
Joint Friction ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Shape ◽  
Fillet Joint

Abstract In this study, experiments and simulations were performed for fillet joint friction stir welding according to tool shape and welding conditions. Conventional butt friction stir welding has good weldability because heat is generated by friction with the bottom of the tool shoulder. However, in the case of fillet friction stir welding, the frictional heat is not sufficiently generated at the bottom of the tool shoulder due to the shape of the tool and the shape of the joint. Therefore, it is important to sufficiently generate frictional heat by slowing the welding speed as compared to butt welding. In this study, experiments and simulations were carried out on an aluminum battery housing made by friction stir welding an extruded material with a fillet joint. The temperature of the structure was measured using thermocouple during welding, and the heat source was calculated through correlation analysis. Thermal elasto-plastic analysis of the structure was carried out using the calculated heat source and geometric boundary conditions. It is confirmed that the experimental results and the simulation results are well matched. Based on the results of the study, the deformation of the structure can be calculated through simulation even if the tool shape and welding process conditions change.

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