Showing 3 results for Karimzadeh
V. Zohoori-Shoar, F. Karimzadeh, A. Eslami,
Volume 3, Issue 1 (Journal OF Welding Science and Technology of Iran 2017)
Abstract
In this study, The Al 6061 alloy sheets were produced by Cryorolling process and then were welded by resistance spot welding method. In this regard, the solution treated Al 6061 alloy cryorolled subsequently up to 90% reduction in thickness to produce nanostructure alloy. The cryorolled sheets were then subjected to aging treatment (130˚C-30h) in order to obtain simultaneous strength and ductility. Tensile strength of 370 MPa, hardness of 135 HV, and ductility of 11 % was obtained for the nanostructured Aluminum sheets. The Cryorolled samples were then resistance spot welded with different welding parameters, including welding current 50 to 100 kA, electrode force of 2.8 kN, and welding time of 0.1 s. The most tensile shear peak load of weld spot of nanostructured samples was 5580 N. The results for different welded samples showed that the nanostructured ones, have higher weld strength when compared with 6061-T6 Aluminum alloy samples with common grain size.
En Payam Gheysari, Dr Fathallah Karimzadeh, Dr Ahmad Rezaeian, En Amin Shahsavari,
Volume 3, Issue 2 (Journal OF Welding Science and Technology of Iran 2018)
Abstract
In this research in order to improve the mechanical properties of Aluminium alloy 2024, nanostructure Aluminum sheets were first produced by Cryorolling process and then was welded by resistance spot welding method. For this purpose, the samples solution treated at 495˚C for 55 minute and subsequently cryorolled up to 85% reduction in thickness. For obtaining simultaneous strength and ductility, the cryorolled sheets were then subjected to aged. In this regard the produced samples were then resistance spot welded with different welding parameters, including welding current 60 to 105 KA, electrode force of 3 KN, and welding time of 0.1 s. The highest tensile shear peak load was obtained through welding with 95 KA current.
S. Ghaderi, F. Karimzadeh, A. Ashrafi,
Volume 5, Issue 2 ((Journal OF Welding Science and Technology) 2020)
Abstract
In the present study, the effect of time and base metal microstructure on the Transient Liquid Phase (TLP) bonding of 304L stainless steel was studied. TLP was performed at 1050 0C for 5 and 60 minutes on the coarse grain austenitic and martensitic microstructure using BNi-2 interlayer. To prepare martensitic microstructure, as-received 304L was rolled at -15 0C up to 80% rolling reduction. TEM analysis was proved that the microstructure of 80% rolled samples consisted of two different morphologies of martensite namely as lath-type and dislocation cell type martensite. It was observed that the structure of bonded zone after 5 min has consisted of isothermally solidified zone (ISZ) containing γ solid solution and athermally solidified zone (ASZ) containing complex boride phases. Meanwhile, after 60 min of heating, the structure of bonded zone completely solidifies isothermally. The obtained results also showed that the martensitic microstructure considerably effect on the width of diffusion affected zone (DAZ) which was related to the reversion of martensite to ultrafine grain austenite during heating.
