Showing 3 results for Bakhtiari
M. Safari, H. Mostaan, A. Bakhtiari,
Volume 2, Issue 1 (Journal OF Welding Science and Technology of Iran 2016)
Abstract
In this research, lap joint frictionstir welding of IF sheets with thickness of 0.7 mm is investigated. For this purpose, mechanical properties of joints and also microstructural evolutions are studied. It was found that increase in tool rotational speed and decrease in travel speed results in increase in fracture stress of welded joints. Texture study indicates that no changes can be observed in texture components after friction stir welding. This phenomenon in texture components can be related to high stacking fault energy of IF steel and consequently severe dynamic recrystallization during welding. The results show with increase in the tool rotational speed between 900-1400 Rev/min, ultimate force of fracture of friction stir welded joints is increased. Also, it is concluded from results that with increase in tool travel speed between 50-160 mm/min, ultimate force of fracture of welded joints is decreased. Finally it is proved from results of this paper that in the frictionstir welding of IF sheets with thickness of 0.7 mm, maximum force of fracture of welded joints is achieved in rotational speed of 1400 Rev/min and travel speed of 105 mm/min.
Homan Nikbakht1, Mohammadreza Khanzadeh, Hamid Bakhtiari,
Volume 7, Issue 2 (Journal OF Welding Science and Technology 2022)
Abstract
In the present study, the corrosion behavior and microstructural changes of 5000 series aluminum and copper sheets after the explosive welding process have been investigated. Explosive welding is performed with a fixed stop interval and change of explosive load. Dynamic potential polarization tests and electrochemical impedance spectroscopy, light microscopy, and scanning electron microscopy were used. The results of TOEFL polarization curves show that the lowest corrosion velocity was related to the sample with an explosive load of 1.5 and the highest corrosion velocity was related to the sample with an explosive load of 2.5. The corrosion resistance of a sample with an explosive load of 2.5 is less than that of a sample with an explosive load of 1.5 due to more severe plastic deformation at the joint. The metallographic results show a wave-vortexing of the joint due to the increase in the explosive charge. The results of the impedance test in welded samples showed that the value of n (experimental power parameter) decreased with wave-vortexing of the joint and the sample with 2.5 explosive load had the highest corrosion rate. Based on the results of scanning electron microscopy, it was observed that with an increasing explosive charge, the thickness of the local melting layer gradually increases.
M. Ahmadi, H.r. Ahmadi, M.r. Khanzadeh, H. Bakhtiari,
Volume 9, Issue 1 (Journal OF Welding Science and Technology 2023)
Abstract
In this research, friction stir welding of aluminum 1050 to copper with variable speed was investigated. For friction stir welding, rotational speeds of 900 and 1200 rpm and traverse speeds of 36, 63, and 125 mm/min were used. In order to check the phases and microstructure, scanning electron microscope analysis, X-ray spectrometry, and hardness testing were used. The disturbance zone included Al2Cu3, Al4Cu9, AlCu4, Al2Cu, and AlCu phases. The results showed that the formation of intermetallic phases and severe plastic deformation in the welding area caused an increase in hardness. The highest hardness value in the stirred area was 97.8 Vickers at a rotation speed of 900 rpm and an advance speed of 36 mm/min.
