scholarly journals Enhancement of Mechanical Properties on Novel Friction Stir Welded Al-Mg-Zn Alloy Joints Reinforced with Nano-SiC Particles

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
L. Natrayan ◽  
M. Ravichandran ◽  
Dhinakaran Veeman ◽  
P. Sureshkumar ◽  
T. Jagadeesha ◽  
...  

Friction stir welding (FSW) is a solid-state technique used to join Al-Zn-Mg alloys effectively compared with other conventional welding methods. Al-Zn-Mg alloy was processed for welding because they significantly demanded various engineering applications. A novel method of this research work is to characterize the unique mechanical properties of Al-Zn-Mg alloy reinforced with 1 to 3 wt% of nano silicon carbide (nano-SiC) particles developed by novel interlock friction-stir welding. The process parameters chosen for welding are rotational tool speed 1100 rpm, weld speed 25 mm/min, and triangular pin profile. The weld joint properties such as tensile strength, yield strength, and hardness were tested per ASTM standard. The microstructure of weld joints was studied with XRD and optical and scanning electron microscopy. The existence of silica particles in the weld joints and uniformed and homogeneous distribution of the particulates in the weld was verified by EDS analysis and microstructure. Al-Zn-Mg reinforced with nano-SiC joints has better static properties due to intensive softening in the stir region. Al-Zn-Mg with 3 wt% nano-SiC exhibits maximum tensile strength, yield strength, and nugget hardness of 191 MPa, 165 MPa, and 171 HV. Weld microstructures showed a pinning mechanism because nano-SiC particles were used as reinforcement during friction stir welding.

2013 ◽  
Vol 446-447 ◽  
pp. 312-315
Author(s):  
Ramaraju Ramgopal Varma ◽  
Abdullah Bin Ibrahim ◽  
B. Ravinder Reddy

The present research paper aims in evaluating the strength of the welded AA6351 alloy plates of 6 mm thick by using friction stir welding technique at different rotational speeds The applied welding technique is capable of achieving the mechanical properties of the alloy close to that of the original alloy. In the present investigation, the speeds of the spindle were varied from 1100 rpm to 1500 rpm with a constant transverse speed of 20 mm/min. The tensile strength of the joints is determined by an universal testing machine. The results from the present investigation show that the values of the yield strength were very much closer to the values of the AA6351Alloy prior to welding. It has been found from the experiments that the strength of the joints increases with the increase in the rotational speed; however, the same is decreasing after achieving certain speed.


Author(s):  
J.C. Verduzco Huarez ◽  
R. Garcia Hernandez ◽  
G. M. Dominguez Almaraz ◽  
J.J. Villalón López

This research work focuses on the study of the improvement of mechanical properties, specifically the tensile strength of 6061-T6 aluminum alloy on prismatic specimens with 9.5 mm thickness that has been subjected to friction stir welding process and two heat treatments; solubilized and aging before or after the welding process. Three cases studied and evaluated were, welding of the base material without heat treatment (BMW), solubilized heat treatment and partial aging of the base material before welding (HTBW), and heat treatment of solubilized and aging of the base material after welding (HTAW). The obtained results show an increase of about 10% (20 MPa) of tensile strength for the HTBW process, compared to BMW case. In addition, for the case of HTAW, the obtained tensile resistance presents a joint efficiency of 96%, which is close to the tensile strength of the base material (»310 MPa).


Author(s):  
Md. Aleem Pasha ◽  
Dr. P. Ravinder Reddy ◽  
Dr. P. Laxminarayana ◽  
Dr. Ishtiaq Ahmad Khan

<div><p><em>Welding of magnesium alloys influence a great effect on magnesium application expansion, especially in marine and aerospace where large-size, complex components are required. Due to specific physical properties of magnesium, its welding requires great control. In general, the solid-state nature of friction stir welding (FSW) process has been found to produce a low concentration of defects. Mechanical properties of  friction stir welded joints are decreases than base material, so to enhance the mechanical properties of welded portion, In the present research additional SiC particulates were incorporated in the weld interface of friction stir welding of Magnesium alloy AZ31B. Silicon Carbide has been added as reinforcement by creating separate geometry, at the edges where the welding is interface with 4 different volume proportions such as 10%, 15%, 25% and 30%. Tool Steel of H13 grade has been used as friction stir welding tool. Rotational Speed of 1400 RPM and Transverse Speed of 25 mm/min were selected. Joined Mg Alloy AZ31B alloy plates were evaluated for their mechanical properties under two different conditions, i.e in the un-reinforced welded condition and reinforced welded conditions. The results of the study revealed that the mechanical properties of the SiC particulates added Mg alloy AZ31B welded joints are superior in all four proportions of SiC, compared to un-reinforced Mg alloy AZ31B welded joints. Microstructural examination of the welded joints was conducted using Optical microscope and revealed that distribution of SiC particles producing increased weld strength. The comparison of the microstructures and mechanical properties of unreinforced Friction stir welded AZ31 with those of SiC reinforced FS-welded joints showed that the addition of SiC particles decreased the grain size and increased the strength.</em></p></div>


2020 ◽  
Vol 14 (1) ◽  
pp. 6259-6271
Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanish Paramaguru ◽  
Mokhtar Awang ◽  
Hamed Mohebbi ◽  
Sharma V Korada

Underwater Friction Stir Welding (UFSW) is a solid-state joining technique which uses a non-consumable tool to weld metals. The objective of this investigation is to evaluate the mechanical properties of the AA5052 Aluminium alloy joints prepared by UFSW. The effect of different type of welding tools and welding parameters on the weld joint properties are studied. Square, tapered cylindrical and taper threaded cylindrical type of welding tools have been used to produce the joints with the tool rotational speed varying from 500 rpm to 2000 rpm while the welding speed varying from 50 mm/min to 150 mm/min. Tensile strength, micro-hardness distribution, fracture features, micro-and macrostructure of the fabricated weld joints have been evaluated. The effect of welding process parameters that influences the mechanical properties and fracture characterization of the joints are explained in detail. A maximum Ultimate Tensile Strength (UTS) value of 222.07 MPa is attained with a gauge elongation of 14.78%. Microstructural evaluation revealed that most of the fracture are found on the thermal mechanically affected zone (TMAZ)adjacent to the weld nugget zone (WNZ) due to bigger grain sizes. It is found that most of the joints exhibit ductile characteristics in failure. Fractography analysis has been used to find the behavior of weld joints in failure.


2020 ◽  
Vol 22 (4) ◽  
pp. 110-123
Author(s):  
Alexey Ivanov ◽  
◽  
Valery Rubtsov ◽  
Evgeny Kolubaev ◽  
Vladimir Bakshaev ◽  
...  

Introduction. Friction stir welding conditions determines character of thermomechanical impact on welded material, so a critical alteration of even one of condition parameters can result in formation of defects and strength decrease of welded joint. Also an important factor is an orientation of welded material relative to a welding direction since it determines kinetics of material deformation and consequently its final structure and properties. Research efforts of friction stir welding properties generally consist in analysis of final properties of obtained weld joints and its correlation with parameters of welding condition. But to solve a problem of obtaining of weld joints with strength and quality, it’s also important to estimate a welded material resistance to deformation from welding tool impact which could be achieved by monitoring a number of parameters directly in process of welding. The purpose of the work is to research an impact of welding condition parameters and an orientation of welded material’s structure on friction stir welding process behavior and also on structure and strength of weld joints of 2024 aluminum alloy. Results and discussion. By monitoring the torque and welding force, it is shown that as the tool penetration force increases, the material's resistance to deformation increases. When welding is longitudinal to the direction of base metal rolling a torque and a welding force parameters decreases in value of 5-20%. An increase of welding speed provides a growing of material resistance to welding tool movement, at that, a direction of welding doesn’t have a significant impact. With an increase of welding tool rotational speed, a material resistance to deformation decreases, a welding temperature grows and it results in growing of material’s plasticization degree and in improvement of its mass transfer conditions. It is also shown that the welding conditions, which allows welding the 2024 alloy at a temperature of 450 – 500 ºС, provides the degree of plasticization of the material, at which welded joints with a high-quality structure and high mechanical properties are obtained. In this conditions a direction of welding in relation to the direction of base metal rolling has an impact: when welding is longitudinal to the direction of rolling the tensile strength of weld joints reaches a value of 92%, and when welding is transverse - 95% of base material tensile strength.


2014 ◽  
Vol 984-985 ◽  
pp. 604-607 ◽  
Author(s):  
V. Jaiganesh ◽  
P. Sevvel

In the Present paper, the effects of axial force, rotational speed of the FSW tool, welding speed and shoulder penetration on various mechanical properties of Aluminium alloy 6063 butt joint produced by Friction Stir Welding have been analyzed. The mechanical properties like tensile strength, Yield strength and % Elongation have been tested using 6 mm thickness plate. The tool used for conducting the experiment was Hot Die Steel (HDS). The welding quality can be improved by enhancing the mechanical properties and minimizing the defects. Hence, analysing & examining the mechanical or physical properties and other relevant significant factors would help to enhance the weld reliability. Tensile Strength (TS), Percentage of Elongation & Yield Strength (YS) of FSW Al 6063 alloy has been carried out under different processing condition using Taguchi’s experimental design. An optimum result has been obtained using main effects plot using S/N ratio values. The rotation speed of the FSW tool has been found dominant factor for TS followed by feed and shoulder penetration. Shoulder diameter shows the least effect on TS compared to parameters like Percentage of Elongation & Yield Strength (YS).


Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh

At present, magnesium alloys are extensively used in numerous applications due to their light weight and better characteristics. Welding of magnesium alloys is regarded as one of the most complex phenomena in various industries. The friction stir welding of magnesium alloys has encouraged abundant scientific and industrial interest as it has the potency to form a good quality joint. Post welding heat treatment is an appropriate process to further improve the properties or performance of FSW joints. Therefore, the present work aims to join AZ31 Mg alloy plates by friction stir welding, and microstructural and mechanical properties of the joint have been examined. Furthermore, the consequence of post welding heat treatment on the microstructure and mechanical properties of FSW joint has been evaluated. Tensile strength and elongation of FSW joint were about 145.4 ± 4.9 MPa and 9.5 ± 0.9%, respectively. It was found that post welding heat treatment was beneficial in homogenizing grains and to enhance mechanical properties. Tensile strength and elongation of the joint were improved by 4.74% and 15.78% respectively after PWHT. The highest microhardness of stir zone decreased about 6.84% (73 Hv to 68 Hv) after heat treatment and hardness pattern of weld became relatively smooth. Toughness of PWHT joint was 4.5 ± 0.17 Joules. The mode of tensile failure of as-welded and PWHT joint was ductile.


2021 ◽  
Vol 23 (4) ◽  
pp. 140-154
Author(s):  
Tatiana Kalashnikova ◽  
◽  
Vladimir Beloborodov ◽  
Kseniya Osipovich ◽  
Andrey Vorontsov ◽  
...  

Introduction. Friction stir welding and processing are almost identical processes of severe plastic deformation at elevated temperatures. These technologies differ mainly in the purpose of its use: the formation of a hardened surface layer or producing a welded joint. However, it is known that both during welding and during processing of heavy gauge workpieces temperature gradients occur. As a result, the conditions of adhesive interaction, material plastic flow, and the formation of the stir zone change as compared to thin-sheet workpieces with fundamentally different heat dissipation rates. In this connection, the purpose of the work is to determine the regularities of the structure formation and stability of the mechanical properties in different directions in the material of 35-mm-thick aluminum-magnesium alloy samples produced by friction stir welding/processing. Research Methodology. The technique and modes of friction stir welding and processing of AA5056 alloy workpieces with a thickness of 35 mm are described. Data on the equipment used for mechanical tests and structural research are given. Results and discussion. The data obtained show the excess mechanical properties of the processing zone material over the base metal ones in all studied directions. Material structure heterogeneities after friction stir welding/processing of heavy gauge workpieces have no determining effect on the stir zone properties. At the same time, there is no clear correlation between the tensile strength values and the load application direction, nor is there any significant difference in mechanical properties depending on the location of the samples inside the stir zone. The average ultimate tensile strength values in the vertical, transverse, and longitudinal directions are 302, 295 and 303 MPa, respectively, with the yield strength values of 155, 153 and 152 MPa, and the relative elongation of 27.2, 27.5, 28.7 %.


Author(s):  
R Palanivel ◽  
RF Laubscher ◽  
S Vigneshwaran ◽  
I Dinaharan

Friction stir welding is a solid-state welding technique for joining metals such as aluminum alloys quickly and reliably. This article presents a design of experiments approach (central composite face–centered factorial design) for predicting and optimizing the process parameters of dissimilar friction stir welded AA6351–AA5083. Three weld parameters that influence weld quality were considered, namely, tool shoulder profile (flat grooved, partial impeller and full impeller), rotational speed and welding speed. Experimental results detailing the variation of the ultimate tensile strength as a function of the friction stir welding process parameters are presented and analyzed. An empirical model that relates the friction stir welding process parameters and the ultimate tensile strength was obtained by utilizing a design of experiments technique. The models developed were validated by an analysis of variance. In general, the full impeller shoulder profile displayed the best mechanical properties when compared to the other profiles. Electron backscatter diffraction maps were used to correlate the metallurgical properties of the dissimilar joints with the joint mechanical properties as obtained experimentally and subsequently modeled. The optimal friction stir welding process parameters, to maximize ultimate tensile strength, are identified and reported.


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