Showing 4 results for Finite Element
M. E. Kazemian, F. Mohsenifar, R. Ghanbarzadeh,
Volume 3, Issue 1 (8-2017)
Abstract
In this paper, laser beam welding of a rectangular piece of steel was simulated using Fluent software. Physical properties of analytical field was constant and its changes with temperature was ignored. In the present work, effect of tool speed and laser power on temperature distribution of workpiece surface and different deeps in the plane of symmetry and also maximum of temperature and depth of penetration were investigated. Using a macro code, geometry generation and meshing of the analytical field by helping required geometric parameters were provided for software. Moreover, laser radiation power was exerted by writing an UDF in the fluent software. In this case, it was assumed that the workpiece is stationary and gaussian thermal source model defined in UDF moves with the intended speed. Results show that at a constant power, maximum temperature of the workpiece decreases with increasing heat source speed, moreover, in this case, gradient of temperature in front of the workpiece and behind of it, increases and decreases respectively. It is found that the temperature in the depth of the workpiece increases with increasing the power.
B. Sadeghian, A. Taherizadeh, M. Atapour, T Salehi, M Nosouhian,
Volume 3, Issue 1 (8-2017)
Abstract
Aluminum to stainless steel joints are broadly used in industries in order to reduce fuel consumption. While fusion welding is not a suitable method to join these metals. solid state welding, like friction welding (FW), is an effective way to this process. However, risk of intermetallic compounds (IMCs) formation is probable in these welds. In previews investigations formation of FeAl3, Fe2Al5 and Fe4Al13 is reported. In this study, effect of different parameters on generated heat and temperature distribution that lead to formation of these compounds in a FW of aluminum alloy to stainless steel is investigated using Finite Element Method (FEM). Additionally, a mathematical modeling of the parameters is performed using Artificial Neural Network (ANN) and the optimum level of the parameters has been found.
N. Marchin, A.r. Soltanipoor, K. Farmanesh,
Volume 5, Issue 2 (1-2020)
Abstract
In this study, the effect of tool's advance velocity on the mechanical behavior of the Al-7075 alloy during friction stir welding was simulated. In this simulation, the Lagrangian method with rigid-Visco-plastic material was used. The results of the process temperature obtained by the simulation method were verified by the experimental welding test. Using the characteristic stress, strain and temperature relationships in the Al-7075 alloy, the changes and the relationship between the material strength during the welding process by simulation was studied. The generated simulation defects was verified by experimental test.
E. Ranjbarnodeh, P. Raissi , A. Kolagar , M. Cheraghzadeh,
Volume 10, Issue 2 (12-2024)
Abstract
Nickel base superalloy IN738LC is widely used in power plant industry and gas turbine blade manufacturing. The main strengthening mechanism of this alloy is the precipitation hardness caused by γ′ precipitates. These precipitates play an important role in determining the mechanical properties of this alloy and their amount and morphology changes under heat treatment. In this research, in order to investigate the evolution of γ' precipitates during heat treatment, a number of solution annealed samples were subjected to arc heat treatment. In this heat treatment, by applying heat caused by a static arc, a temperature ranges from the ambient temperature to above the melting point is created in the sample. Using this process, samples with 100 amp currents were heat treated for 1, 2 and 15 minutes. Electron microscope, image processing and transient heat transfer model with axial symmetry were used for experimental and mathematical investigations. In the following, using the experimental and numerical results simultaneously, a mathematical model for the dissolution kinetics of γ' precipitates in the heat-affected zone of these welds was presented. The results of electron microscopy showed that the dissolution rate and shape of γ′ precipitates are strongly influenced by the distance from the heat source. The activation energy of dissolution of γ′ precipitates increased with increasing time and its value was between 40 and
80 kJ/mol.
