In engineering, in order to predict materials behaviors in similar conditions, mathematical modelling are developed. These models have to be validated and revised by designing and conducting experiments at various conditions. In general, plastic deformation results in increasing dislocation density which in turn leads in greater stored energy in material. In this work, the stored energy was determined using different laboratory methods. Different strains (plastic deformation) was applied on commercially pure aluminum specimen using standard, single-axis tensile test. Then, X-ray diffraction (XRD), Ultrasonic Velocity test (UV), and differential scanning calorimetry (DSC) were employed in order to determine the above-mentioned energy. Each method had its own parameters, therefore the effect of the same on dislocations behavior and density as well as the stored energy was evaluated. In addition, by substitution of the calculated dislocation density in the Tylor's equation, stress-strain curve of the Aluminum was generated and compared with the ones achieved by the tensile test. Comparing these two sets of data, friction stress in Tylor's equation was defined. Small deviations exhibited the relatively high accuracy (and validity) of the calculations. Then, the fractions of mobile and immobile dislocations were calculated using XRD and UV results. Finally, the stored energy was estimated using dislocation density values and the results were compared with the ones obtained from DSC. It was showed (as expected) that the tensile test led in increased dislocation density in the aluminum specimen, of which, a big share was attributed to immobile dislocatio whereas the amount of mobile dislocations remained almost constant during the deformation test. Key words: Stored Energy, Dislocation density, X-Ray Diffraction, Ultrasonic Velocity, Differential Scanning Calorimetry.
