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Friction stir welding is a novel, economical and high quality technique among aluminum welding and joining methods. In this present paper, by introducing the friction stir welding the affecting parameters on thermal, micro structural and mechanical properties of 7000 series aluminum aerospace alloys joining using Friction Stir Welding is investigated. Results show that the sizes of nugget grains are between 5 through 12 micrometer and the least grain size constructed in nugget zone which the thermal effect is responsible for. By using thermal analysis and experimental results, the amount of loosed energy during FSW process can be drawn. Furthermore the effect of process parameters on loosed energy can be investigated. In this work and in the beginning and during welding, the appropriate temperature near to the tool shoulder is 330 degrees centigrade which can be used as a norm for quality control of weld ability. Cylindrical tool with plain pine surface made a welding joint with strength up to 80 percent of base metal. Welding quality is strongly affected by defects in joining zone which came from selecting non proper welding parameters.

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Sever plastic deformation process in one of the important methods to produce nanostructures materials that is highly regarded in two past decades. Accumulative press bonding (APB) is a novel variant of severe plastic deformation processes (SPD), which is devised to produce materials with ultra-fine grain (UFG). In the present work, effect of APB technique on mechanical properties and microstructural of AA1100 alloy, were investigated. The study of the microstructure of AA1100 alloy was performed via optical microscopy. This article revealed that the grain size of the produced samples decreased to 950 nm, after six passes of APB process. The yield strength of AA1100 alloy after six passes of the process increased up to 264 MPa, which is three times higher than that of the as-cast material (89 MPa). After six passes, microhardness values of AA1100 alloy increased from 38 to 61 HV. Furthermore, the results showed that the behavior of variations in mechanical properties are in accordance with the microstructural changes and it can be justified by using the Hall-Patch equation. Moreover, the rise in the yield strength can be attributed to the reduction of the grain size and strain hardening phenomenon.

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Accumulative press bonding (APB) process is one of the newest approaches of SPD processes in which the applying of strain in materials lead to the substantial plastic deformation and microscopic changes. In this study, APB method was used to production of Al/Cu composite and AA1100 and pure commercial Copper sheets used as matrix and reinforcement respectively. Microstructure evolutions samples proceeding by APB process were studied by Scan Electron Microscopy (SEM) and Optical Microscopy (OM). Mechanical characteristics were accomplished by conducting standard tensile and microhardness tests. The microscopic analysis indicates that as the number of APB passes increased, the reinforcement phase (Cu) dispersion be improved and result in Cu continues layers discrete in to shorter layers. As well, by increasing the number of APB passes up to 3 the ultimate strength, microhardness and elongation had been increased so that, the ultimate strength is raised to 375Mpa, it about 3.1 and 2.7 times is more than as Al and Cu respectively. Under the 3 cycles of APB, the hardness of Al and Cu were reached to 62 and 152.6 HV respectively which are 1.6 and 2.6 times greater than those of corresponding pure materials. Furthermore, SEM observations demonstrated the failure mode in Al/Cu composite proceeding by APB process is shear ductile rupture.