In-depth understanding of material flow behavior and refinement mechanism during bobbin tool friction stir welding

2021 ◽  
pp. 103816
Author(s):  
Q. Chu ◽  
W.Y. Li ◽  
D. Wu ◽  
X.C. Liu ◽  
S.J. Hao ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Flow Behavior ◽  
Friction Stir ◽  
Refinement Mechanism

Influence of Tool Geometry and Contact Condition on Friction Stir Welding of Al-Cu Laminated Composites

2013 ◽  
Vol 856 ◽  
pp. 16-21
Author(s):  
R. Beygi ◽  
Mohsen Kazeminezhad ◽  
A.H. Kokabi ◽  
S. Mohammad Javad Alvani ◽  
D. Verdera ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Laminated Composites ◽  
Flow Behavior ◽  
Tool Geometry ◽  
Contact Conditions ◽  
Friction Stir ◽  
Tool Geometries ◽  
Welding Procedure ◽  
Sem Analyses

In this study friction stir welding of Al-Cu laminated composites were carried out by two different tool geometries. Welding procedure was carried out from both sides of Al and Cu. Analyzing cross section of welds showed that different contact conditions between shoulder and material, offers different material flow behavior which is dependent on the tool geometry. SEM analyses showed that mixing of materials in nugget region is more pronounced in the advancing side. Also XRD results indicated that welding from Cu side, leads to intermetallic formation in mixed regions.

Material Flow Behavior during Friction Stir Welding of Copper and Steel

2011 ◽  
Vol 138-139 ◽  
pp. 842-847 ◽  
Author(s):  
Chun Ping Huang ◽  
Wen Liang Chen ◽  
Li Ming Ke ◽  
Huang Lu
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Flow Behavior ◽  
Dissimilar Metals ◽  
Screw Thread ◽  
Friction Stir ◽  
Different Shapes ◽  
Welding Joints ◽  
Flow Morphology ◽  
Main Factor

The joining of dissimilar metals, T2 copper and Q235 mild steel was carried out by friction stir welding. The material flow of different shapes of the probe and different forms of welding joints were studied, the material flow behavior on different locations from the probe was also analyzed. The experimental results showed that the screw thread in probe is the main factor in driving material flow along the thickness direction of the weld during FSW of copper and steel, the flow morphology of the weld is significantly different with vary forms of welding joints, and the material flow on different locations from the probe are quite different from each other. Instantaneous cavity will form at the upper of the weld with the use of left screw thread probe during FSW, and if not promptly and adequate padding, it is prone to appear hole-type defects.

scholarly journals Material-flow behavior during friction-stir welding of 6082-T6 aluminum alloy

2016 ◽  
Vol 87 (1-4) ◽  
pp. 1115-1123 ◽  
Author(s):  
Yongxian Huang ◽  
Yaobin Wang ◽  
Long Wan ◽  
Haoshu Liu ◽  
Junjun Shen ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Material Flow ◽  
Flow Behavior ◽  
Friction Stir

A Study of Material Flow Behavior in Thickness Direction in Friction Stir Welding of 7075 Alloy Plate

2013 ◽  
Vol 652-654 ◽  
pp. 2315-2319
Author(s):  
Zheng Hua Guo ◽  
Wen Long Liu ◽  
Cheng Zhong Li ◽  
Jun Hua Cui ◽  
Gang Yao Zhao
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Rotation Speed ◽  
Flow Behavior ◽  
Dissimilar Materials ◽  
Thickness Direction ◽  
Alloy Plate ◽  
Friction Stir ◽  
Tool Pin ◽  
Welding Processes

Friction stir welding, which is considered to be a solid-state welding, possesses several advantages over conventional welding processes, is an effective approach to weld high-strength, large thickness and dissimilar materials. Material flow behavior on FSW was generally acknowledged to have effects on weld property. The material flow behavior in thickness direction of advancing and retreating side was analyzed by a numerical model established with cone-shape tool pin. Numerical results indicate that there exist material flow in thickness direction on both sides and the behavior was affected by welding and tool pin rotation speed. Decrease welding speed or increase rotation speed would make material deformation intensified, and increase the fluidity of the material.

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.

scholarly journals Study on the Relationship between Root Metal Flow Behavior and Root Flaw Formation of a 2024 Aluminum Alloy Joint in Friction Stir Welding by a Multiphysics Field Model

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 913
Author(s):  
Jian Luo ◽  
Jiafa Wang ◽  
Hongxin Lin ◽  
Lei Yuan ◽  
Jianjun Gao ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Material Flow ◽  
Welded Joint ◽  
Yield Criterion ◽  
Flow Behavior ◽  
Metal Flow ◽  
Bottom Surface ◽  
Line Defect ◽  
Friction Stir

In friction stir welding (FSW), many defects (such as kissing bond, incomplete penetration, and weak connection) easily occur at the root of the welded joint. Based on the Levy–Mises yield criterion of the Zener–Hollomon thermoplastic constitutive equation, a 3D thermal–mechanical coupled finite element model was established. The material flow behavior and the stress field at the root area of a 6 mm thick 2024-T3 aluminum alloy FSW joint were studied. The influence of pin length on the root flaw was investigated, and the formation mechanism of the “S line” defects and non-penetration defects were revealed. The research results showed that the “S line” defect forms near the bottom surface of the pin owing to the insufficiently mixed material from the advancing side (AS) and retreating side (RS) near the weld center. The non-penetration defect forms near the bottom surface of the workpiece owing to the insufficient driving force to make the material flow through the weld center. With the continual increase of pin length, the size of the “S line” defect and non-penetration defect reduces, and finally, the defect-free welded joint can be obtained with an optimized suitable length of the pin in this case.

scholarly journals Effect of Modified Pin Profile and Process Parameters on the Friction Stir Welding of Aluminum Alloy 6061-T6

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
J. C. Verduzco Juárez ◽  
G. M. Dominguez Almaraz ◽  
R. García Hernández ◽  
J. J. Villalón López
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Material Flow ◽  
Flow Behavior ◽  
Tensile Tests ◽  
Welding Parameters ◽  
Friction Stir ◽  
Aluminum Alloy 6061 ◽  
Alloy 6061

This work deals with the effect of a new “bolt-head” pin profile on the friction stir welding performance of the aluminum alloy 6061-T6, compared to traditional pin profiles. Friction stir welding parameters such as the tool rotation speed and the welding speed were investigated together with the different pin profiles; the results show that the new “bolt-head” pin profile leads to better mechanical properties of welded specimens. The pin profiles used in this work were the straight square (SS), straight hexagon (SH), taper cylindrical (TC), and the straight hexagon “bolt-head” (SHBH). It was found that the last pin profile improves the material flow behavior and the uniform distribution of plastic deformation and reduces the formation of macroscopic defects on the welded zone. Mechanical tensile tests on welded specimens were performed to determine the tensile strength: the specimens welded with the SHBH pin profile have shown the highest mechanical properties. An approach is presented for material flow on this aluminum alloy using the SHBH pin profile, which is related to the improvement on the resulting mechanical properties.

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