الفهرس 
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Abstract
The effect of Mg addition on structure formation, physical and mechanical properties of a solid solution of Al0.48wt%Ag manufactured by hot rolling route and plane strain compression was reported. The following techniques were employed during the course of investigation: energy dispersive Xray analysis, Xray diffractometer, optical microscope and microhardness tester. To investigate the influence of annealing temperatures on structure variations, electrical resistivity, thermoelectric power and rate of heat flow versus temperatures, the following devices were used: high impedance MicroMillieOhmmeter, differential scanning calorimeter and homemade instrument for measuring the Seebeck coefficient at different temperatures. The EDX analysis showed that the chemical composition of the alloys contains silver 0.48wt%, magnesium ranging from 0.421.1wt % and the balance is aluminum, XRD showed that the lattice parameter of Al0.48wt%Ag solid solution increases by 0.0017Ao upon increasing Mg content by 1wt% and the pole density ratio P220 / P400 decreases exponentially with increasing Mg wt% from 0.42(R*(B1.1. The optical microscope data showed that the shape and the size of grains are influenced by increasing Mgwt%. Elongated grains together with nonequilibrium grain boundaries are transformed into heterogeneous microstructure containing large grains and submicrograins and nearly equilibrium grain boundaries. The microhardness measurements showed that 1wt%Mg dissolved in the alloy is accompanied by an increase of hardness by 91 hardness Vickers number. Annealing temperatures transform the elongated grains and nonequilibrium grain boundaries formed during thermomechanical processing into equiaxed grains and strings of nearly equilibrium grain boundaries. The hardness and/or yield strength versus grain size were found to obey HallPetch relationship. The electrical resisativity dependence on temperature was found to obey the Bloch Gruneisen equation which is modified by Moore et al. Each 1wt%Mg dissolved in the alloy is accompanied by an increase in resiastivity by 138mW. The Seebeck coefficient determination showed a dependence on temperature and Mgwt%. The Fermi level energy decreases with increasing Mg wt%. Four internal friction peaks are observed in DSC curves. The first endothermal peak is near room temperatures (304K) is the result of segregation of Mg atoms to the dislocation cores, and the first exothermal peak (525K) is associated with recovery. The second exothermal peak (710K) is the result of recrystallization and release of stored energy and the last endothermal peak represents the release of Mg atoms from the core of dislocations (730K). The amplitude and position of endothermal and the exothermal peaks are influenced by Mg additions. The activation energy of recovery and recrystallization is 8.5 kJ/mol and 11.764 kJ/mol, respectively.