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Effect of pin penetration depth on double-sided friction stir welded joints of AA6061-T913 alloy

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Transactions of Nonferrous Metals Society of China 2016年第3期26卷 676-683页

作者： Iman HEJAZI seyyed ehsan mirsalehi Department of Mining and Metallurgical Engineering Amirkabir University of Technology (Tehran Polytechnic)424 Hafez AveP.O.Box 15875-4413TehranIran

Friction stir welding (FSW) of aluminum alloys is currently utilized in several modern industries. The joints must have sufficient elastic?plastic response and formability levels similar to that of the base metal. In this work, double-sided FSW of AA6061 sheet was compared with its conventional single-sided one. An adjustable tool with different pin lengths (50%?95% of the sheet thickness) was used to perform the double-sided welds. Macro- and micro-structures, strength, and hardness of the joints were investigated to determine the optimum pin penetration depth. The best results were obtained for a double-sided joint made by a pin length equal to 65% of the sheet thickness, which showed an increase of 41% in the ultimate tensile strength compared with the single-sided joint.

关键词： AA6061 aluminium alloy friction stir welding double-sided joint pin length mechanical properties microstructure

Mechanical and metallurgical characterization of AA6061 friction stir welded joints using microhardness map

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Transactions of Nonferrous Metals Society of China 2016年第9期26卷 2313-2319页

作者： Iman HEJAZI seyyed ehsan mirsalehi Department of Mining and Metallurgical Engineering Amirkabir University of Technology (Tehran Polytechnic)

The relationships between microhardness and microstructure, macrostructure and mechanical properties of friction stir welded joints AA6061-T913 were studied. Three equations were suggested to predict the grain size, ultimate tensile strength and yield strength from the hardness throughout the weld. Two-dimensional contour of grain size and three-dimensional maps of ultimate tensile and yield strengths were plotted according to the proposed equations. Also, the location of macroscopic zones was estimated based on hardness distribution. The modeling results were compared with the results obtained from microscopy and tensile tests. The modeling results show good agreement with the experimental findings, and the average differences between them for the ultimate tensile strength and yield strength were about 8% and 3%, respectively.

关键词： AA6061 alloy friction stir welding microhardness macrostructure microstructure mechanical properties

Preparation of bimetallic nano-composite by dissimilar friction stir welding of copper to aluminum alloy

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Transactions of Nonferrous Metals Society of China 2021年第5期31卷 1363-1380页

作者： Farhad BAKHTIARI ARGESI Ali SHAMSIPUR seyyed ehsan mirsalehi Department of Mining and Metallurgical Engineering Amirkabir University of TechnologyTehranIran

Butt friction stir welding between pure copper and AA5754 alloy was carried *** SiC nanoparticles were utilized in friction stir welded(FSW)joints to decline the harmful effects of intermetallic *** tests,micro-hardness experiments,scanning electron microscopy and X-ray diffraction analysis were applied to studying the properties of welded *** joints with a travel speed of 50 mm/min and a rotation speed of 1000 r/min showed the best *** presence of nano-sized SiC particles reduced the grain size of aluminum and copper in the stir zone(SZ)from 38.3 and 12.4μm to 12.9 and 5.1μm,*** tensile strength of the joint in the presence of reinforcing SiC nano-particles was~240 MPa,which is~90%of that for the aluminum ***,the highest microhardness of the weld zone was significantly increased from HV 160 to HV 320 upon the addition of SiC *** results also showed that raising the heat generation in FSW joints increased the amount of Al_(4)Cu_(9) and Al_(2)Cu intermetallic compounds.

关键词： friction stir welding dissimilar Al/Cu joint SiC nano-particles intermetallic compounds microstructural characteristics mechanical properties

Effect of second-phase particle size and presence of vibration on AZ91/SiC surface composite layer produced by FSP

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Transactions of Nonferrous Metals Society of China 2020年第4期30卷 905-916页

作者： Behrouz BAGHERI Mahmoud ABBASI Amin ABDOLLAHZADEH seyyed ehsan mirsalehi Department of Mining and Metallurgy Amirkabir University of TechnologyTehranIran Faculty of Engineering University of KashanKashanIran Department of Materials Science and Engineering Sharif University of TechnologyTehranIran Institute of Materials Engineering and Advanced Processes Department of Mining and MetallurgyAmirkabir University of TechnologyTehranIran

An improved method of friction stir processing(FSP)was introduced for the processing of AZ91 magnesium alloy *** novel process was called“friction stir vibration processing(FSVP)”.FSP and FSVP were utilized to develop surface composites on the studied alloy while SiC nanoparticles were applied as second-phase *** effect of reinforcing SiC particles with different sizes(30 and 300 nm)on different characteristics of the composite surface was *** results indicated that the microstructure was refined and mechanical properties such as hardness,ductility,and strength were enhanced as FSVP was ***,it was concluded that the effect of reinforcing particles with a size of 30 nm on the microstructure and mechanical properties of the surface composite was more obvious than that of particles with a size of 300 *** was also found that mechanical properties and microstructure of FSV-processed specimens were improved as vibration frequency *** hardness value in the stir zone was about 157 MPa for the FSV-processed specimen at a vibration frequency of 50 Hz,while this value was around 116 MPa for the FSV-processed specimen at a vibration frequency of 25 Hz.

关键词： friction stir processing vibration SiC nano-particles particle size mechanical properties microstructure residual stress