scholarly journals Brass Wire Forming By Friction Stir Back Extrusion: Numerical Modeling and Experiment

2021 ◽  
Author(s):  
Mostafa Akbari ◽  
Parviz Asadi
Keyword(s):  
Numerical Modeling ◽  
Cross Section ◽  
Rotational Speed ◽  
Material Flow ◽  
Upward Movement ◽  
Movement Experience ◽  
Friction Stir ◽  
Temperature Distributions ◽  
Tool Axis ◽  
Lower Strain

Abstract Friction stir back extrusion (FSBE) is used to produce brass wires and then, Numerical modeling is developed to simulate the FSBE of brass based on the Coupled Eulerian-Lagrangian technique (CEL) and verified by experiments. Next, the effects of FSBE parameters such as tool rotational and plunging speed on the strain and temperature distributions, microstructure, and patterns of material flow are studied. The results show that, the highest temperature and strain occurs near the tool/workpiece interface, but in a further distance from the tool axis. Additionally, in the cross section of a FSBE wire, the microstructure is finer in the periphery of the sample. A higher rotational speed or a lower plunging speed results in a coarser microstructure. The material flow pattern during the process is conical helix, and does not change meaningfully by the process parameters. The points at the further distance from the tool axis, along with an upward movement, experience an inward spiral movement which is amplified by higher rotational speed. However, the materials very near the tool axis almost take an upward movement and endure a very lower strain.

Superplasticity in Friction Stir Processed AZ80 Magnesium Alloy

2010 ◽  
Vol 433 ◽  
pp. 241-246 ◽  
Author(s):  
Yoshimasa Takayama ◽  
Itsuki Takeda ◽  
Toshiya Shibayanagi ◽  
Hajime Kato ◽  
Kunio Funami
Keyword(s):  
Magnesium Alloy ◽  
Cross Section ◽  
Room Temperature ◽  
Maximum Stress ◽  
Strain Rates ◽  
Friction Stir ◽  
Az80 Magnesium Alloy ◽  
Lower Strain ◽  
Elongation To Failure ◽  
Scanning Electron

Superplasticity in an AZ80 magnesium alloy subjected to friction stir processing (FSP) has been investigated. FSP was carried out at two traveling speeds of 150mm/min and 300mm/min for grain refinement. Optical microscopy on cross section to processing direction revealed obvious differences in size and feature between the stir zones at the two traveling speeds. The hardness of FSPed sample at the room temperature was about 30HV higher than that of as-received one. The maximum stress of the FSPed sample was reduced remarkably at lower strain rates compared with those of the as-received one at 573K and 673K. On the other hand, the elongation to failure of the FSPed sample showed ten to thirteen times larger than that of the as-received one at 573K and low strain rates. Further surface morphology near the fracture tip was observed by scanning electron microscopy to discuss deformation mechanism at high temperatures.

Experimental Study on Friction Stir Welding of Dissimilar Al 6061 to Trip 780/800 Steel

2014 ◽  
Author(s):  
Xun Liu ◽  
Shuhuai Lan ◽  
Jun Ni
Keyword(s):  
Friction Stir Welding ◽  
Cross Sections ◽  
Welding Speed ◽  
Rotational Speed ◽  
Maximum Temperature ◽  
Friction Stir ◽  
Al 6061 ◽  
Tool Axis ◽  
Edge Temperature ◽  
Welding Force

Friction stir welding (FSW) of dissimilar Al 6061 and TRIP 780/800 steel has been performed under different process parameters, including tool rotational speed, welding speed as well as the relative position of the tool axis to the abutting edge. Temperature and mechanical welding force was recorded during the process. Welding speed has an insignificant effect on either the maximum temperature or welding force. However, it can directly change the length of high temperature duration, which will accordingly influence temperature distribution in the weld and the microstructure. Higher rotational speed can effectively elevate weld temperature through greater amount of heat input. Metallurgical observations on weld cross sections perpendicular to the joint line was performed using both optical and scanning electron microscope. Microstructure evolution was analyzed and related to the force and temperature measurement results during the FSW process.

Material flow modeling for the DSFSW of magnesium alloy

2020 ◽  
pp. 030932472097661
Author(s):  
Parviz Asadi ◽  
MohammadHosein Mirzaei
Keyword(s):  
Magnesium Alloy ◽  
Rotational Speed ◽  
Material Flow ◽  
Sheet Thickness ◽  
Maximum Temperature ◽  
Flow Modeling ◽  
Az91 Magnesium Alloy ◽  
Friction Stir ◽  
Az91 Magnesium ◽  
Tool Pin

The Coupled Eulerian Lagrangian (CEL) method is utilized to model the double shoulder friction stir welding (DSFSW) of AZ91 magnesium alloy and then the model is verified by the experiments. The effects of tool rotational speed and sheet thickness on temperature and strain distributions as well as the material flow patterns are considered at different steps of the process. The material flow pattern around the tool pin is demonstrated properly and the shoulder driven and pin driven zones are predicted very well. Results show that, the material movement in shoulder driven and pin driven zones is different, while it is from the advancing side (AS) to the retreating side (RS) in the pin driven zone, it is inverse in the shoulder driven zone. Additionally, increase in rotational speed raises the maximum temperature and strain, improves the material movement, expands the SZ width and increases the depth of shoulder driven zone. Furthermore, increase in sheet thickness results in a decrease in maximum temperature and strain as well as the material movement. In the sheets with low thickness due to the effects of two shoulders, the pin driven zone is not distinguishable, however in thicker welding sheets the pin driven zone is obvious by significantly lower strains.

Simulation of Material Flow and Heat Evolution in Friction Stir Processing Incorporating Melting

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
H. W. Nassar ◽  
M. K. Khraisheh
Keyword(s):  
Friction Stir Processing ◽  
Rotational Speed ◽  
Material Flow ◽  
Heat Evolution ◽  
Heat Of Fusion ◽  
Maximum Temperature ◽  
Molten Layer ◽  
Local Melting ◽  
Friction Stir ◽  
Microstructure Refinement

Friction stir processing (FSP) is a relatively new technology for microstructure refinement of metallic alloys. At high processing speeds, excessive heating due to severe plastic deformation and friction may result in local melting at the interface between the FSP tool and the workpiece. In this work, a computational fluid dynamics (CFD) approach is applied to model material flow and heat evolution during friction stir processing of AZ31B magnesium alloy, taking into consideration the possibility of local melting in the stirring region. This is achieved by introducing the latent heat of fusion into an expression for heat capacity and accounting for possible effects of liquid formation on viscosity and friction. Results show that the temperature in the stirring region increases with the increase in rotational speed and drops slightly with the increase in translational speed. As liquid phase begins to form, the slope of temperature rise with rotational speed decreases and the maximum temperature in the stirring region stabilizes below the liquidus temperature at high rotational speeds. It is also shown that the formation of a semi-molten layer around the tool may result in a reduction in the shearing required for microstructure refinement.

scholarly journals Study of Temperature Distribution and Material Flow in Friction Stir Welding of AA6061-T6

2020 ◽  
Author(s):  
Manoj Kumar ◽  
Ramesh Kumar ◽  
Sachin D Kore
Keyword(s):  
Temperature Distribution ◽  
Rotational Speed ◽  
Material Flow ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Tool Geometry ◽  
Low Velocity ◽  
Friction Stir ◽  
Tool Geometries ◽  
Velocity Magnitude

Abstract A fully-coupled 3-D model of FSW was developed for 4 mm plates of AA6061-T6 aluminum alloy based on the Finite Volume Method (FVM) in ANSYS Fluent 14.5 software. Two types of the model; one with the tool and another without tool was developed for different tool geometry and analysis was done for temperature distribution in the workpiece as well as in tool using system coupling for first model and workpiece only in later one. A parametric study was performed at different tool rotational speed regarding temperature distribution, and material flow analysis was carried out for all tool geometries at a single rotational speed. The material behaves differently when passes through the different tool and it was affected by thermal history, viscosity and strain rate for particular tool geometry. Temperature-dependent material properties and a user-defined function (UDF) code of viscosity have been incorporated in the model considering the workpiece as a non-Newtonian viscous fluid. A better material mixing observed in case of threaded pin geometry by using a steady-state laminar flow model. All tapered tool geometries were unable to mix material properly just below and around the pin tip due to very low-velocity magnitude in this region, which may lead to a kind of defect. An asymmetric temperature distribution observed in the workpiece and at higher rotational speed peak temperature observed higher in the workpiece, and the flow of heat was more in tool. Validation of the model was done by performing experiments.

scholarly journals Study of Temperature Distribution and Material Flow in Friction Stir Welding of AA6061-T6

2020 ◽  
Author(s):  
Manoj Kumar ◽  
Ramesh Kumar ◽  
Sachin D Kore
Keyword(s):  
Temperature Distribution ◽  
Rotational Speed ◽  
Material Flow ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Tool Geometry ◽  
Low Velocity ◽  
Friction Stir ◽  
Tool Geometries ◽  
Velocity Magnitude

Abstract A fully-coupled 3-D model of FSW was developed for 4 mm plates of AA6061-T6 aluminum alloy based on the Finite Volume Method (FVM) in ANSYS Fluent 14.5 software. Two types of the model; one with the tool and another without tool was developed for different tool geometry and analysis was done for temperature distribution in the workpiece as well as in tool using system coupling for first model and workpiece only in later one. A parametric study was performed at different tool rotational speed regarding temperature distribution, and material flow analysis was carried out for all tool geometries at a single rotational speed. The material behaves differently when passes through the different tool and it was affected by thermal history, viscosity and strain rate for particular tool geometry. Temperature-dependent material properties and a user-defined function (UDF) code of viscosity have been incorporated in the model considering the workpiece as a non-Newtonian viscous fluid. A better material mixing observed in case of threaded pin geometry by using a steady-state laminar flow model. All tapered tool geometries were unable to mix material properly just below and around the pin tip due to very low-velocity magnitude in this region, which may lead to a kind of defect. An asymmetric temperature distribution observed in the workpiece and at higher rotational speed peak temperature observed higher in the workpiece, and the flow of heat was more in tool. Validation of the model was done by performing experiments.

scholarly journals Study of Temperature Distribution and Material Flow for different pin profile in Friction Stir Welding of AA6061-T6

2020 ◽  
Author(s):  
Manoj Kumar ◽  
Ramesh Kumar ◽  
Sachin D Kore
Keyword(s):  
Temperature Distribution ◽  
Rotational Speed ◽  
Material Flow ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Tool Geometry ◽  
Low Velocity ◽  
Friction Stir ◽  
Tool Geometries ◽  
Velocity Magnitude

Abstract A fully-coupled 3-D model of FSW was developed for 4 mm plates of AA6061-T6 aluminum alloy based on the Finite Volume Method (FVM) in ANSYS Fluent 14.5 software. Two types of the model; one with the tool and another without the tool was developed for different tool geometry and analysis was done for temperature distribution in the workpiece as well as in tool using system coupling for the first model and workpiece only in later one. A parametric study was performed at different tool rotational speed regarding temperature distribution, and material flow analysis was carried out for all tool geometries at a single rotational speed. The material behaves differently when passes through the different tools and it was affected by thermal history, viscosity, and strain rate for particular tool geometry. Temperature-dependent material properties and a user-defined function (UDF) code of viscosity have been incorporated in the model considering the workpiece as a non-Newtonian viscous fluid. A better material mixing was observed in the case of threaded pin geometry by using a steady-state laminar flow model. All tapered tool geometries were unable to mix material properly just below and around the pin tip due to very low-velocity magnitude in this region, which may lead to a kind of defect. An asymmetric temperature distribution observed in the workpiece and at higher rotational speed peak temperature observed higher in the workpiece, and the flow of heat was more in tool. Validation of the model was done by performing experiments.

scholarly journals Prediction of Hardness in Friction Stir Processing by Artificial Neural Networks

2021 ◽  
Author(s):  
Kartikeya Bector ◽  
◽  
Ravi Butola ◽  
Ranganath M. Singari ◽  
S L Bhandarkar ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Material Flow ◽  
Ann Model ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Subsequent Decrease ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
Tool Pin ◽  
Learning Data

This research focuses on the use of Artificial Neural Network (ANN) for the prediction of the microhardness of friction stir processed aluminium based metal matrix composite (AA6061+Al2O3). Different specimens were obtained by using rotating speeds of 1100, 1210, 1320 and 1430 rpm and travelling speeds of 36, 48, 60, 72 mm/min. The microhardness value (HV) of the processed surface of each of the samples was measured and the data collected from the specimens was used as learning data for ANN. Higher rotational speed and lower transversal speeds resulted in higher hardness value since processing at higher tool rotational speed causes high material flow and good resistance to the tool pin profile. A uniform increase in microhardness was observed up to 1320 RPM and a subsequent decrease on any further increments of tool rotational speed. Subsequently, the highest values of microhardness were observed with a square mandrel at 1320 RPM and 36 mm/min. The calculated results were satisfactorily compliant with the measured data and the ANN model was successful in predicting the microhardness.

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