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Showing 2 results for Aluminum 6061
Jamal Zamani, Ehsan Etemadi, Morteza Jafarzadeh,
Volume 14, Issue 13 (3-2015)
Abstract
This paper presented a theoretical model to investigate steady plastic shock wave on FCC metals. The method included shear flow stress according to effective parameters and based on microstructure and dynamics of dislocation method. The aim of this paper was to achieve final relation between shear stress and plastic stretch with presenting constitutive equations for shock loading. Then, Shear flow stress to effective plastic strain was plotted with solving final relation between shear flow stress and plastic stretch. Presented constitutive equations were based on loading under one dimensional strain and were validated just for shock loadings. The main innovation of this investigation included using from energy constitutive law with considering entropy generation rate. Entropy generation rate expressed as dislocation generation, dislocation annihilation and dislocation glide. Also, the effect of shock velocity, total stretch and input stress according to plastic stretch were investigated. Furthermore, shock structure was investigated according to different input stresses. Maximum input stress was 25 GPa. Relations and diagrams were verified with published experimental works on Al 6061 alloy. Good agreement was found between presented model and experimental works.
S.a.a. Akbari Mousavi , Gh. Faghani, H.r. Sheivani,
Volume 20, Issue 2 (1-2020)
Abstract
One of the emerging methods of joining various metals is the use of laser beam welding in a variety of industries such as transportation, aerospace, radar, and marine construction, which reduces fuel consumption and thus reduces environmental pollution. In this study, the microstructure and mechanical properties of similar joints of aluminum alloy 6061 with a thickness of 2 millimeters have been investigated by the laser beam welding method with a high power of 5000 watts. Examined items include the effect of laser welding parameters such as power, frequency, and welding speed on microstructural and mechanical properties. Microstructural analysis results using an optical and scanning electron microscope show that in the process, the microstructure of the weld in the base metal to the center of the weld region changed from the dendritic column to the parallel dendritic zone and eventually reached the equiaxed dendritic area, due to the higher input temperature and consequently less cooling rate. Energy-dispersive X-ray spectroscopy (EDS) showed no significant change in the chemical composition. Investigating the mechanical properties using hardness measurement, and the tensile testing showed that the hardness in the fusion zone was lower than other base metal zones, and the optimized sample was failed in the weld zone. The tensile strength of the optimum welding sample is approximately equal to half the tensile strength of the base metal.
