Experimental and theoretical investigation of some physical properties of Al-Sc and Al-Sc-Mg alloys depending on the temperature

Al-Sc and Al-Sc-Mg Alloys in industry; It is preferred especially in the automotive and aviation sectors for its lightness, ductility and strength. We examined these alloys as Al-1.1Sc, Al-1.9Sc, Al-6Mg-1.1Sc and Al-6Mg-1.9Sc experimentally and theoretically. Experimentally, firstly, XRD, TG-DSC, TMA and Vickers hardness analyzes of the alloys were performed. In XRD analysis, measurements were made between 30º and 120º and at temperatures of 100ºC, 200ºC, 300ºC, 400ºC, 500ºC and 600ºC, starting from 30ºC to the powdered samples using x-ray powder diffraction method. By analyzing the XRD patterns using the Bragg law, the lattice parameters of the alloys were obtained for different temperatures. The temperature-dependent changes of the grain sizes of the alloys were determined by using the Debye - Scherrer method by XRD pattern analysis. TG-DSC analyzes data were taken from 30℃ to 600℃. He determined the change in mass with temperature increase in TG measurements, recrystallization temperatures of alloys, enthalpy, entropy, Gibbs energy and activation energy were calculated with DSC measurements. The thermal expansion coefficients of the alloys and their variation with temperature were obtained using TMA measurements. In the theoretical part of the study, by using the crystal structure and lattice parameters and crystal symmetries of this structure, we obtained from the results of the experimental studies based on x-ray analysis; The second order elastic constants, which are the basic mechanical parameters of the alloys, and the Bulk Modulus, Shear Modulus, Young Modulus, Poisson Ratio and Anisotropy Parameters were calculated. In addition, changes in the elastic constants of the alloys with respect to temperature were also investigated. Keywords: Al-Sc, Al-Sc-Mg, Anisotropy Parameter, DSC, DTA, Elastic Constant, Young's Modulus, Bulk Modulus, Poisson's Ratio, XRD