Effect of tool pin-tip profiles on material flow and mechanical properties of friction stir welding thick AA7075-T6 alloy joints

2016 ◽  
Vol 88 (1-4) ◽  
pp. 949-960 ◽  
Author(s):  
Mao Yuqing ◽  
Ke Liming ◽  
Liu Fencheng ◽  
Chen Yuhua ◽  
Xing Li
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Material Flow ◽  
Friction Stir ◽  
Tool Pin

Numerical Study of the Tool Rake Angle Effect on the Material Flow in Friction Stir Welding Process

2007 ◽  
Author(s):  
Hosein Atharifar ◽  
Radovan Kovacevic
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Numerical Study ◽  
Welding Process ◽  
Rake Angle ◽  
Heat Transfer Analysis ◽  
Tool Geometry ◽  
Friction Stir ◽  
Tool Pin ◽  
Welding Processes

Minimizing consumed energy in friction stir welding (FSW) is one of the prominent considerations in the process development. Modifications of the FSW tool geometry might be categorized as the initial attempt to achieve a minimum FSW effort. Advanced tool pin and shoulder features as well as a low-conductive backing plate, high-conductive FSW tools equipped with cooling fins, and single or multi-step welding processes are all carried out to achieve a flawless weld with reduced welding effort. The outcomes of these attempts are considerable, primarily when the tool pin traditional designs are replaced with threaded, Trifiute or Trivex geometries. Nevertheless, the problem remains as to how an inclined tool affects the material flow characteristics and the loads applied to the tool. It is experimentally proven that a positive rake angle facilitates the traverse motion of the FSW tool; however, few computational evidences were provided. In this study, numerical material flow and heat transfer analysis are carried out for the presumed tool rake angle ranging from −4° to 4°. Afterwards, the effects of the tool rake angle to the dynamic pressure distribution, strain-rates, and velocity profiles are numerically computed. Furthermore, coefficients of drag, lift, and side force and moment applied to the tool from the visco-plastic material region are computed for each of the tool rake angles. Eventually, this paper confirms that the rake angle dramatically affects the magnitude of the loads applied to the FSW tool, and the developed advanced numerical model might be used to find optimum tool rake angle for other aluminum alloys.

scholarly journals The Effect of Tool Pin Size and Taper Angle on the Thermal Process and Plastic Material Flow in Friction Stir Welding

2021 ◽  
Author(s):  
Jie Chen ◽  
Lei Shi ◽  
Chuansong Wu ◽  
Yuanning Jiang
Keyword(s):  
Friction Stir Welding ◽  
Shear Layer ◽  
Layer Thickness ◽  
Material Flow ◽  
Horizontal Plane ◽  
Thermal Process ◽  
Plastic Material ◽  
Taper Angle ◽  
Friction Stir ◽  
Tool Pin

Abstract Friction stir welding (FSW) tool pin, as a critical component of FSW tool, plays an important role in determining the final joint properties by affecting the heat generation, plastic material flow, welding loads and so on. However, the influence of tool pin on heat and mass transfer in FSW are not elucidated. In the present study, a validated model was adopted to quantitatively analyze the effects of pin size and taper angle on the thermal process and plastic material flow in FSW. It reveals that the torque and transverse force imposed on the pin are increased with the increase of the pin diameters (including its root diameter, its tip diameter and its size in condition of constant taper angle), while the total tool torque various a little for the tool pin diameter considered in this study. When the pin diameters increase, the viscosity of the materials near the pin is decreased, while the temperature as well as the flow velocity is increased. More plastic material near the tool could rotate around the tool with an increase of the pin diameter. The TMAZ boundary is enlarged with larger pin diameters in FSW. Particularly, the shear layer thickness of the same horizontal plane in the range of 1 mm < z < 5 mm is significantly enlarged with an increase of pin root diameters. However, the shear layer thickness of the same horizontal plane in the region of z < 5 mm is increased when using a larger pin tip diameter. In addition, maximum width of TMAZ boundary at the top surface of workpiece was not affected by pin diameters. The model is validated by experimental results. It lays solid foundation for optimizing the tool pin size and taper angle in FSW.

scholarly journals Influence of Tool Pin Profile and Tool Rotating Speed on Mechanical Properties of Al6082 Alloy

2019 ◽  
Vol 8 (12) ◽  
pp. 3342-3345
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Automatic Process ◽  
Work Piece ◽  
Milling Machine ◽  
Friction Stir ◽  
Vertical Milling ◽  
Vertical Milling Machine ◽  
Tool Pin

Friction stir welding is a solid state welding which uses non consumable welding tool. It is an automatic process which generally performs on the vertical milling machine. In this type of welding, the relative motion between the tools and work piece creates heat which uses the region of work piece to be welded get softened and to joint the two work pieces. Friction stir welding process is more reliable for the materials which are generally non heat treatable. In this present investigation it will observe that how the rotational speeds of the tool and different shapes of the tool pins effects the mechanical properties of the aluminium alloy 6082. For this purpose three tools with different profiles, i.e triangular, cylindrical and square was designed and fabricated. At three different rotational speeds of 560 rpm, 900 rpm, 1800 rpm work pieces are joined using vertical milling machine. Specimens are prepared and tested for mechanical properties, tensile, impact, and hardness tests are performed and to detect the defects and voids x-ray test performed on the weld joints. And it was observed that highest tensile strength was presented when the square pin tool used at 560 rpm. The rotational speed increased mechanical properties are reducing significantly.

scholarly journals Numerical Studies on Temperature and Material Flow During Friction Stir Welding using Different Tool Pin Profiles

2021 ◽  
Vol 83 (1) ◽  
pp. 91-104
Author(s):  
M. D. Bindu ◽  
P. S. Tide ◽  
A. B. Bhasi
Keyword(s):  
Friction Stir Welding ◽  
Temperature Distribution ◽  
Material Flow ◽  
Three Dimensional ◽  
Friction Stir ◽  
Specific Strength ◽  
Numerical Studies ◽  
Computational Fluid Dynamics Cfd ◽  
Tool Pin ◽  
Metal Hardness

A three dimensional computational fluid dynamics (CFD) model has been developed to study the effect of tool pin profile on the material flow and temperature development in friction stir welding (FSW) of high specific strength AA 7068 alloy. Numerical simulations were carried out using a RNG k-e turbulence model. Three tool pin profiles, viz. cylindrical, conical and straight cylindrical threaded were considered for the simulation. The temperature distribution and material flow pattern obtained from the simulation were compared for different pin profiles. Simulation results predicted Temperature distribution and material maxing was better in straight cylindrical tapered thread pin welds. Weld joints were fabricated using the straight cylindrical threaded pin with the same parametric combinations as in the simulation. Peak temperature measured in the experiment was less than that obtained by simulation. Hardness measurements taken at different weld regions has showed that about 71% of that of the base metal hardness is obtained with the threaded tool pin. The microstructure study revealed a defect free weld joint. Precipitates distributed in the microstructure indicate sufficient heat input to join the material without dissolving precipitates. The developed numerical model is helpful in optimising FSW process parameters.

Experimental investigation and optimization of mechanical properties on combination of higher and lower strength of aluminum alloys

2021 ◽  
pp. 095440892110606
Author(s):  
C Ganesan ◽  
K Manonmani
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Welding Speed ◽  
Rotational Speed ◽  
Axial Load ◽  
Welding Process ◽  
Process Parameter ◽  
Nugget Zone ◽  
Friction Stir ◽  
Tool Pin

Friction stir welding is a high potential technology for joining similar and dissimilar aluminum materials, utilized extensively in aerospace and automotive industrial applications to eradicate the problems like hot cracking, porosity, element loss, etc. due to the fusion welding process. This Research addresses the joining of two dissimilar materials of AA 5754 – H32 and AA 8090T6511 – Al-Li and their mechanical properties analysis with the effects of friction stir welding process parameters like tool rotational speed, welding speed and axial load on weld nugget zone formation quality. The significant roles of different tool pin profiles are also emphasized. A mathematical modeling equation was formed by using regression analysis to optimize the process parameter and found the best tool pin profile for defect-free weld nugget zone and higher tensile and hardness properties. This research also portrays the contribution of various pin profiles and each process parameter on the ultimate tensile strength by response surface methodology. The results indicate that the defect-free weld joints are observed with 1800 r/min of rotational speed, welding speed of 15 mm min−1 and 8.5 kN of axial load with hexagonal pin profile.

scholarly journals Numerical Simulation of Material Flow and Analysis of Welding Characteristics in Friction Stir Welding Process

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 621 ◽  
Author(s):  
Haitao Luo ◽  
Tingke Wu ◽  
Peng Wang ◽  
Fengqun Zhao ◽  
Haonan Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Friction Stir Welding ◽  
Finite Element Model ◽  
Material Flow ◽  
Welding Process ◽  
Element Model ◽  
Welding Seam ◽  
Friction Stir ◽  
Tool Pin ◽  
The Finite Element Model

Friction stir welding (FSW) material flow has an important influence on weld formation. The finite element model of the FSW process was established. The axial force and the spindle torque of the welding process were collected through experiments. The feasibility of the finite element model was verified by a data comparison. The temperature field of the welding process was analyzed hierarchically. It was found that the temperature on the advancing side is about 20 °C higher than that on the retreating side near the welding seam, but that the temperature difference between the two sides of the middle and lower layers was decreased. The particle tracking technique was used to study the material flow law in different areas of the weld seam. The results showed that part of the material inside the tool pin was squeezed to the bottom of the workpiece. The material on the upper surface tends to move downward under the influence of the shoulder extrusion, while the material on the lower part moves spirally upward under the influence of the tool pin. The material flow amount of the advancing side is higher than that of the retreating side. The law of material flow reveals the possible causes of the welding defects. It was found that the abnormal flow of materials at a low rotation speed and high welding speed is prone to holes and crack defects. The forming reasons and material flow differences in different regions are studied through the microstructure of the joint cross section. The feasibility of a finite element modeling and simulation analysis is further verified.

An Experimental Investigation on Mechanical Properties and Microstructure of Friction Stir Welding of AA5052

2014 ◽  
Vol 592-594 ◽  
pp. 48-52 ◽  
Author(s):  
C. Chanakyan ◽  
P. Dinesh Babu ◽  
M.P. Jenarthanan ◽  
K. Jagathesh
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Friction Stir Welding ◽  
Traverse Speed ◽  
Special Focus ◽  
Nugget Zone ◽  
Friction Stir ◽  
Before And After ◽  
Property Changes ◽  
Tool Pin

The aim of this project is to study the micro-structural and mechanical property changes during friction stir welding [FSW] with a special focus on AA5052. The objective of this project is to experimentally investigate the influence of tool pin profiles (straight cylinder, fluted cylinder and pentagonal cylinders) and welding input parameters (rotational speed and traverse speed) on microstructure and mechanical properties (tensile strength, hardness) of AA5052 Al in FSW process. The detailed micro-structural analyses are carried out on the base metal and welded zone (nugget zone), Thermo mechanically affected zone and heat affected zone. The mechanical properties such as, tensile and hardness are studied before and after FSW process.

Effect of Friction Stir Welding pin Shape on Mechanical Properties of AA6061 Alloy Weldment

2013 ◽  
Vol 465-466 ◽  
pp. 1309-1313
Author(s):  
Mohd Hasbullah Idris ◽  
Mohd Shamsul Husin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Material Flow ◽  
Weld Line ◽  
Butt Joint ◽  
Hardness Distribution ◽  
Plunge Depth ◽  
Friction Stir ◽  
Joint Properties

The present study is aimed to determine the effect of friction stir welding pin; square and diamond shape on mechanical properties of butt joint AA6061 weldment. Welding was carried out at different plunge depths of 0.0, 0.2, 0.3 and 0.4 mm together with rotation and transverse speeds of 500 rpm and 40 mm/min, respectively. Material flow, tensile strength and hardness of the weldment were evaluated. The results indicated that joint properties were significantly affected by tool design. It was found that material flow was higher for diamond pin tool compared to that of square pin resulting in considerable increased in tensile strength of the joint. In addition, the highest tensile strength was obtained on the samples welded with square shape pin at 0.4 mm plunge depth whilst the lowest was by diamond shape at the plunge depth of 0.0 mm. Regardless of pin shape and plunge depth; asymmetrical hardness distribution was observed for all weldments. The highest hardness was found to be close to the weld line produced by the diamond shaped pin at 0.0 mm plunge depth.

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