scholarly journals Optimum Rotation Speed for the Friction Stir Welding of Pure Copper

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Masoud Jabbari ◽  
Cem C. Tutum

The friction stir welding (FSW) was conducted in the pure copper plates with the thickness of 4 mm in the constant traverse speed of 25 mm/min and five different rotation speeds. Analysis of metallographic images showed that the increasing of the rotation speed results in the increase of grain size in the nugget zone. Vickers hardness tests were conducted on the weld samples and the maximum hardness obtained in rotation speed of 900 rpm. Results of the tensile tests and their comparison with that of the base metal showed that the maximum strength and the minimum elongation are achieved again in this rotation speed. Yield strength and ultimate tensile strength increased with the decrease in grain size in the nugget region, and the yield strength obeyed Hall-Petch relationship. Hence, the hardness values do not follow the relationship.

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Yanni Wei ◽  
Hui Li ◽  
Peng Xiao ◽  
Juntao Zou

In this paper, 1060 aluminum and T2 pure copper were joined by friction stir welding. The influence of the rotation speed and inclination on the microstructure and mechanical properties of the joint were investigated. The microstructure and composition of the welded interface region were analyzed. The joints’ strength was tested, and the conductivity of the joints was estimated. Joints having good surface formation and defect-free cross section were successfully obtained. The cross-sectional morphologies of the Al-Cu friction stir welding joints can be divided into three zones: the shoulder impact zone, the weld nugget zone, and the interface zone. The interface zone consisted of a metallurgical reaction layer and a visible mixed structure. The reaction layers were identified as Al2Cu, Al4Cu9 phases. The tensile strength of the joints reaches maximum values of 102 MPa at a rotation speed of 950 rpm and inclination of 0°, which was approximately equal to those of 1060Al base metal. The resistivity of the Al-Cu joint was approximately equal to the theoretical resistivity. The interfacial resistance is directly affected by the joint defects, compound types, and thickness of the intermetallic compound layer.


Author(s):  
Hreetabh Kishore ◽  
Mainak Banerjee ◽  
Saruabh Rai ◽  
Rakesh Kumar ◽  
Anupam Agrawal

Abstract Micro Friction Stir welding (μFSW) has found its broader application in the area of packaging of MEMS devices, biomedical components, and joining of micro-mechanical assemblies. This study focuses on the effect of process parameters over the joint strength while joining Al6061-T6 and pure copper sheets of 0.3 mm thickness. Also, a coupled Eulerian-Lagrangian (CEL) numerical model has been developed in the finite element suite of ABAQUS®. The boundary conditions used in the numerical simulation are kept almost similar to the experimental conditions to record thermal results. Moreover, an analytical approach for finding microhardness of welded joints using the Hall-Petch equation is also presented. The process parameters like rotational tool speed and welding traverse speed were found to be dominating in order to get better joint strength. The essential μFSW process parameters combination suggested that 1100rpm rotational speed, 20mm/min. traverse speed and 0.15mm pin depth (tool) result in superior flexural, thermal, and morphological properties of the joint. A good agreement between the experimental and simulation results was found with a maximum of 8% error in the predicted temperature values. The anticipated joint strength and surface characterization of the samples revealed a complex flow and homogeneous mixture at the pin-sheet interaction zone with higher micro-hardness values.


Author(s):  
Khosro Bijanrostami ◽  
Reza Vatankhah Barenji

Underwater dissimilar friction stir welding of the AA6061 and AA7075 aluminum alloys was performed in this study. The effect of friction stir welding parameters on the grain size and hardness of the joints was studied using empirical models. The microstructure of the joints was characterized by means of light and transmission electron microscopes. The Vickers hardness test was conducted to measure the hardness of the joints. In addition, the process parameters including traverse and rotational speeds, grain size and hardness of the joints were correlated. The results revealed that the developed models predicted the hardness and grain size of the joints, precisely. Higher traverse speed and lower rotational speeds resulted in finer grain size and larger hardness. The grain boundaries and dislocations were identified as responsible for the higher hardness of the joints welded at lower heat input conditions. Moreover, the Hall–Petch relationship showed a deviation from its linear classical equation, which was due to the formation of substructures such as dislocations inside the grains.


2013 ◽  
Vol 787 ◽  
pp. 346-351
Author(s):  
Salar Salahi ◽  
Vahid Rezazadeh ◽  
Atabak Iranizad ◽  
Ali Hosseinzadeh ◽  
Amir Safari

As a novel technique for joining materials, friction stir welding (FSW) has significant advantages over the conventional welding methods and is widely applied for joining different materials including aluminum, magnesium and copper alloys. In this research, the mechanical and microstructural characteristics of friction stir welded annealed pure copper joints were investigated. The influence of the tool rotation speed, welding speed and applied load was studied. The friction stir welding (FSW) was conducted at welding speed ranged from 30 to 70 mm/ min, rotation speed ranged from 400 to 1200rpm and applied load ranged from 1000 to 1500 kg. After welding process, tensile and Vickers hardness tests were performed. It has been found that increasing the tool rotational speed and/or reducing the welding speed increases heat input and causes grain coarsening in stir zone. High applied load refines the microstructure of NZ and increases the hardness and tensile strength of NZ. An optimum heat input condition was found to reach the best mechanical properties of the joints. The tensile characteristics of the friction stir welded tensile samples depend significantly on the tool rotation speed ,welding speed and applied load.


2011 ◽  
Vol 410 ◽  
pp. 206-215 ◽  
Author(s):  
K. Kandasamy ◽  
Satish V. Kailas ◽  
Tirumalai S. Srivatsan

The axial force during friction stir welding is sensitive to plunge depth of the tool and is one of the prime factors, which exercises control over heat generation during welding. Consequently, the plunge depth for a given tool rotation speed, traverse speed, material and test machine needs to be optimized so as to get a defect-free weld. In this paper, we present and briefly discuss the results of an elaborate and enriching investigation aimed at understanding the extrinsic influence of plunge depth of the tool on weld formation in aluminium alloy 7020-T6 for a range of rotation rate and traverse speed and using two different tools. The critical need for use of a scientific approach to optimize plunge depth for a given tool material and test machine in fewer number of steps is emphasized. Key Words: Friction Stir Welding, Tool Plunge, Rotation speed, Traverse speed, Aluminium Alloy 7020


2012 ◽  
Vol 602-604 ◽  
pp. 608-611
Author(s):  
Di Qiu He ◽  
Rui Lin Lai ◽  
Shao Hua Xu ◽  
Kun Yu Yang ◽  
Shao Yong Ye ◽  
...  

In this study, Cu-Cr-Zr alloy joints are successfully fabricated by friction stir welding (FSW). Defect-free weld are produced on 12mm thick Cu-Cr-Zr alloy plate useing a non-consumable tool with a specially designed and shoulder with a constant rotation speed and a fixed traverse speed. The effect of friction stir welding (FSW) on the microstructure and mechanical properties of Cu-Cr-Zr alloy joints are investigated in details: The joints showed the presence of various zones such as nugget zone (NZ) and thermo-mechanically affected zone (TMAZ) and base metal (BM), the microhardness and the tensile strength of welded joints are lower than that of the base material.


Author(s):  
C Patel ◽  
Sumitesh Das ◽  
R Ganesh Narayanan

The main aim of the present work is to develop a cellular automata finite element –artificial neural network (CAFE-ANN) hybrid model to predict the evolution of grain size and yield strength during friction stir welding. The CAFE model was developed by linking CA cells with elements in ABAQUS, a finite element code. Then a neural network was developed and trained appropriately by using the data obtained from the validated CAFE model that predicts the grain size and yield strength. The ANN results are validated. Finally it has been demonstrated that ANN can be used as a ‘virtual machine’ to examine the effect of rotational speed, welding speed, axial force and shoulder diameter on the variation in grain size and yield strength. The temperature and strain-rate distribution predicted by the thermal and strain-rate models are consistent with the existing results. The CAFE model grain size predictions are also accurate as compared to experiments. The grain size and yield strength predictions from ANN coincide well with the experimental values and CAFE model predictions. It has been demonstrated that CAFE-ANN hybrid model can be used as a ‘virtual machine’ to predict and analyze the effect of above said parameters on the grain size and yield strength evolution. The predicted influence is found to agree with some of the available results. In few cases, a slight deviation in the trend is witnessed as compared to literature results.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Mohamed M. Z. Ahmed ◽  
Nabil Jouini ◽  
Bandar Alzahrani ◽  
Mohamed M. El-Sayed Seleman ◽  
Mohammad Jhaheen

This study investigated the effect of the friction stir welding rotation rate and welding speed on the quality and properties of the dissimilar joints between aluminum and carbon steel. Plates of 4 mm thickness from both AA2024 and AISI 1018 were successfully friction stir butt welded at rotation speeds of 200, 250, and 300 rpm and welding speeds of 25, 50, and 75 mm/min. The joint quality was investigated along the top surface and the transverse cross-sections. Further investigation using scanning electron microscopy was conducted to assess the intermetallic layers and the grain refining in the stir zone. The mechanical properties were investigated using tensile testing for two samples for each weld that wire cut perpendicular to the welding direction and the hardness profiles were obtained along the transverse cross-section. Both the top surface and the transverse cross-section macrographs indicated defect free joints at a rotation rate of 250 rpm with the different welding speeds. The intermetallic compounds (IMCs) formation was significantly affected by the heat input, where there is no formation of IMCs at the Al/steel interfaces when higher traverse speed (75 mm/min) or lower rotation speed (200 rpm) were used, which gave the maximum tensile strength of about 230 MPa at the low rotation speed (200 rpm) along with 3.2% elongation. This is attributed to the low amount of heat input (22.32 J/mm) experienced. At the low traverse speed (25 mm/min and 250 rpm), a continuous layer of Al-rich IMCs FeAl3 is formed at the joint interface due to the high heat input experienced (79.5 J/mm). The formation of the IMCs facilitates fracture and reduced the tensile strength of the joint to about 98 MPa. The fracture mechanism was found to be of mixed mode and characterized by a cleavage pattern and dimples. The hardness profiles indicated a reduction in the hardness at the aluminum side and an increase at the steel side.


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