M.m. Jafari, A. Afsari, S.a. Behgozin, Sh. Heidari,
Volume 8, Issue 2 (Journal OF Welding Science and Technology 2023)
Abstract
In this study, the mechanical and tribological properties of 4 different types of welding filler metals were examined on a 1.6959 steel (DIN35NiCrMoV12-5) by the Gas Tungsten Arc Welding process. The fillers used in this study include ER70S-6, ER80S-G, ER80S-Ni1, ER80S-B2. The main reasons for choosing these fillers in this study are their availability and close chemical composition to the base metal. To evaluate the weld and quality of weld joints, tensile, impact, hardness and abrasion tests performed on the samples and related microstructures was investigated by optical microscope. The results indicated that the presence of molybdenum and chromium alloying elements in ER80S-B2 filler and related microstructure at HAZ has led to an increase in weld strength up to 38 percent. The best and worst wear resistance obtained from the filler ER 80S-Ni1 and ER 70S-6 respectively. The best weld quality and mechanical properties were acquired in welding using ER 80S-B2 welding filler metal.
M. Niazi, A. Afsari, Seyed A. Behgozin, M. R. Nazemosadat,
Volume 9, Issue 1 (Journal OF Welding Science and Technology 2023)
Abstract
Optimization of Stir Friction Welding parameters such as linear and rotational speed of the tool can be effective to a large extent in improving welding properties. In this research, welding of two sheets of Aluminum of Al-7075 and Al-6061 were validated based on theoretical relations and numerical simulation. The simulation of the contact characteristics of the workpieces with the tool was done using the contact algorithms available in the Ansys software. From the FEM, rotational and linear speed and diameter of the tool were selected as design variables, and multi object optimization was carried out with genetic algorithm and RSM to reach the lowest tool temperature and residual stress.The parametric analysis of FSW of the threaded and non-threaded tool pins showed that the generated heat has proportional and inverse relation with rotation and linear speed of tool respectively. Tool with a diameter of 20 mm showed minimum residual stress in the workpiece. By increasing welding speed, the temperature curves become more compact and the effect of thread on heat generation was more evident in all cases at lower heat input.
