scholarly journals Optimum Rotational and Traverse Speeds of Al-Cu Joints Welded by FSW Based on the Formability of The Joint

Author(s):  
Hammed T. Elmetwally ◽  
Hani Nagiub SaadAllah ◽  
M.S. Abd-Elhady ◽  
Ragab K. Abdel-Magied

Abstract Joining of aluminum to copper using Friction Stir Welding (FSW) is a primary manufacturing process that is in most applications followed by a secondary forming process. The objective of this research is to determine the optimum rotational and traverse speeds of Al-Cu Welded by FSW based on the formability of the joint. The formability and strength of Al-Cu joined by FSW are investigated under different operating conditions. Aluminum and copper blanks are welded at three different rotational speeds that are 910, 1280 and 1700 rpm, under three different traverse speeds, which are 16, 29 and 44 mm/min. The base metal used in this study is Aluminum (Al-1050) and copper under two conditions, i.e. as received and annealed. The mechanical properties of base metals and produced joints are evaluated by tensile and hardness tests. The Al-Cu joints by FSW are drawn into flangeless U and cup shapes in order to examine the formability of the joint. The maximum tensile load, punch load and forming index were obtained when Al is welded to annealed Cu at 1700 rpm and 16 mm/min, i.e. highest rotational and lowest traverse speeds, and that is due to the strain hardening of the joint. However, the ductility was maximum at 1280 rpm and 44 mm/min, i.e. moderate rotational and highest traverse speed. It can be concluded that if the Al-Cu joint by FSW will be used further in a forming process, it should be welded at a moderate rotational and high traverse speed in order to avoid strain hardening and improve the ductility of the joint.

2015 ◽  
Vol 236 ◽  
pp. 53-61
Author(s):  
Wojciech Jurczak

The paper presents the results of investigations on mechanical properties and electrochemical potential distribution within arc welded (TIG) and friction stir welded (FSW) joints subjected to slow strain rate tests. The materials investigated were high-strength 7xxx series (7020 and its modification 7020M) aluminum alloys intended for shipbuilding. The objectives were joint quality assessment and comparison of the advantages of new FSW method with the traditional TIG methods commonly utilized in shipbuilding industry. Joint quality was evaluated based on mechanical investigations, hardness distribution tests and simultaneous electrochemical corrosion potential measurements at various locations within the welded joints.Initiation of corrosion processes on TIG and FSW joints was identified as a radical decrease in corrosion potential related to load followed by oxide layer cracking. Arc welded (TIG) joints of 7xxx series alloys undergo corrosion at lower values of tensile load applied as compared to the FSW joints. Superior mechanical properties and higher corrosion resistance of the FSW joints make this technology well-suited for joining high-strength 7xxx series alloys.


Author(s):  
Sumit Jain ◽  
R.S. Mishra

In this research, a defect-free dissimilar weld joint of AA7075-T6 and AA6061-T6 reinforced with Al2O3 nanoparticles was fabricated via friction stir welding (FSW). The influence of tool rotational speed (700, 900 and 1100 rpm), traverse speed (40, 50 and 60 mm/min) with varying volume fractions of Al2O3 nanoparticles (4%, 7% and 10%) on microstructural evolution and mechanical properties were investigated. The augmentation of various mechanical properties is based on the homogeneity of particle dispersion and grains refinement in the SZ of the FSWed joint. The findings revealed that the remarkable reduction in grain size in the SZ was observed owing to the incorporation of Al2O3 nanoparticles produces the pinning effect, which prevents the growth of grain boundaries by dynamic recrystallization (DRX). The increasing volume fraction of Al2O3 nanoparticles enhanced the mechanical properties such as tensile strength, % elongation and micro-hardness. Agglomeration of particles was observed in the SZ of the FSWed joints produced at lower tool rotational speed of 700 rpm and higher traverse speed of 60 mm/min due to unusual material flow. Homogenous particle dispersion and enhanced material mixing ensue at higher rotational speed of 1100 rpm and lower traverse speed of 40 mm/min exhibit higher tensile strength and micro-hardness.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1937 ◽  
Author(s):  
Tomasz Machniewicz ◽  
Przemysław Nosal ◽  
Adam Korbel ◽  
Marek Hebda

The paper describes the influence of the friction stir welding travel speed on the mechanical properties of the butt joints of copper plates. The results of static and fatigue tests of the base material (Cu-ETP R220) and welded specimens produced at various travel speeds were compared, considering a loading applied both parallel and perpendicularly to the rolling direction of the plates. The mechanical properties of the FSW joints were evaluated with respect to parameters of plates’ material in the delivery state and after recrystallisation annealing. The strength parameters of friction stir welding joints were compared with the data on tungsten inert gas welded joints of copper plates available in the literature. The results of microhardness tests and fractographic analysis of tested joints are also presented. Based on the above test results, it was shown that although in the whole range of considered traverse speeds (from 40 to 80 mm/min), comparable properties were obtained for FSW copper joints in terms of their visual and microstructural evaluation, their static and especially fatigue parameters were different, most apparent in the nine-fold greater observed average fatigue life. The fatigue tests turned out to be more sensitive criteria for evaluation of the FSW joints’ qualities.


Author(s):  
Morteza Ghaffarpour ◽  
Mohammad Kazemi ◽  
Mohammad Javad Mohammadi Sefat ◽  
Ahmad Aziz ◽  
Kamran Dehghani

In the present study, friction stir welding (FSW) and tungsten inert gas (TIG) techniques were used to join the dissimilar aluminum alloys of 5083-H12 and 6061-T6. The laboratory tests were designed using design of experiment (DOE) method. Variables for the FSW process were the rotational speed, traverse speed, shoulder diameter, and pin diameter. They changed in ranges of 700–2500 r/min, 25–400 mm/min, 10–14 mm, and 2–4 mm, respectively. In the case of TIG process, the variables were current intensity, traverse speed, and tilt angle. These parameters varied from 80 to 90 A, 200 to 400 mm/min, and 3° to 12°, respectively. The optimum amounts of parameters were obtained using response surface methodology (RSM). The RSM-based model was developed to predict ultimate tensile strength (UTS) of the welds produced. In FSW, the difference between predicted and measured UTS was about 1.28% and in TIG it was 1.78%. The good agreement between experimental and predicted results indicates the high accuracy of the developed model. Mechanical properties and also the microstructure of the welds were compared after optimizing both welding processes using RSM. The results showed that the welds produced by FSW indicated a considerably higher quality and also improved mechanical properties compared to TIG. Properties of the joints obtained by FSW in single-sided joints were more desirable. In the double-sided welds obtained by FSW these differences were of an even higher significance.


2018 ◽  
Vol 877 ◽  
pp. 20-25
Author(s):  
P.K. Mandal

The cast Al-Zn-Mg 7000 alloy has become one of the most potential structural materials in many engineering fields such as aircraft body, automotive casting due to their high strength to weight ratio, strong age hardening ability, competitive weight savings, attractive mechanical properties and improvement of thermal properties. The cast aluminium alloy has been modified of surface layer through a solid-state technique is called friction stir process (FSP). But basic principle has been followed by friction stir welding (FSW). This process can be used to locally refine microstructures and eliminate casting defects in selected locations, where mechanical properties improvements can enhance component performance and service life. However, some specified process parameters have adopted during experimental works. Those parameters are tool rotation speed (720 rpm), plate traverse speed (80 mm/min), axial force (15 kN), and tool design (i.e., pin height 3.5 mm and pin diameter 3.0 mm), respectively. The main mechanism behind this process likely to axial force and frictional force acting between the tool shoulder and workpiece results in intense heat generation and plastically soften the process material. The specified ratio of rotational speed (720 rpm) to traverse speed (80 mm/min) is considered 9 as low heat input during FSP and its entails low Zn vaporization problem results as higher fracture toughness of aluminium alloy. It is well known that the stirred zone (SZ) consists of refine equiaxed grains produced due to dynamic recrystallization. FSP has been proven to innovatively enhancing of various properties such as formability, hardness and fracture toughness (32.60 MPa√m). The hardness and fracture toughness of double passes AC+FSP aluminium alloy had been investigated by performing Vicker’s hardness measurement and fracture toughness (KIC)(ASTM E-399 standard) tests. Detailed observations with optical microscopy, Vicker’s hardness measurement, SEM, TEM, and DTA analysis have conducted to analyse microstructure and fracture surfaces of double passes FSP aluminium alloy.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1634-1639 ◽  
Author(s):  
LIHONG ZHAO ◽  
SHUYONG JIANG ◽  
ZHENG YI REN ◽  
HAIPING YU ◽  
YUYING YANG

The criterion and research technique of auto body panels stiffness are introduced in this work, and the finite element models (FEM) of cylindrical shallow shell that could represent auto body panels are established. Simulations of forming, springback and stiffness on cylindrical shallow shell are carried out. The simulations show great accuracy with the experimental results. Extensive simulated results of the influence laws of material mechanical properties on stiffness are achieved, such as yield strength, strain-hardening exponent, Young's modulus, anisotropy parameter and strength coefficient. With comparison of the weight coefficient of material mechanical properties on stiffness, it can be concluded that the Yong's modulus, strain-hardening exponent and yield strength are key influencing factors of stiffness. With the analysis of distribution of the strain after cylindrical shallow shell forming, plastic deformation during the forming process resulting in work-hardening of the material is one of the main reasons for increasing stiffness.


2021 ◽  
Vol 15 (3) ◽  
pp. 8332-8343
Author(s):  
Oyindamola Kayode ◽  
Esther Titilayo Akinlabi

Joining of aluminium and magnesium alloys frequently pose significant challenges to the extent where joining may seem impossible, due to differences in the physical, metallurgical, and chemical properties of the materials. Friction stir welding is a solid-state welding technique which uses a non-consumable tool to join metals. This study examines the dissimilar friction stir welding of 3 mm thick AA1050 and AZ91D alloy sheets. Successful defect-free joints were achieved at rotational speeds of 400 rpm and 600 rpm, and a constant traverse speed of 50 mm/min. The metallurgical investigations used to characterize the microstructure of the welds are optical microscopy (OM), scanning electron microscope (SEM) and X-ray diffraction (XRD). The microstructures of the samples show distinct morphology attributed to their different rotational speeds. However, Al3Mg2 intermetallics (IMCs) phase was detected in the white bands present in both weld samples. The IMCs were formed through solid-state diffusion. The mechanical properties characterizations includes the microhardness profiles and tensile testing. The variation in the rotational speeds do not have a significant effect on the microhardness distribution of the weld samples. The tensile strength of the dissimilar weld improved substantially with the presence of an interpenetration feature (IPF).


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