Etude et caractérisation de certains alliages de magnésium

Abstract

Magnesium is the lightest metal element used for the structural alloys. Magnesium alloys are characterized by low density and acceptable mechanical properties. Primarily for these reasons, the magnesium alloys have a wide application in the automobile and aircraft industries. This thesis aims to investigate and characterize three magnesium alloys to better understand their behavior concerning the artificial aging effect on the mechanical properties of these alloys. For the characterization of these samples we used various experimental techniques such as optical microscopy, X-ray diffraction, microhardness measurements and the differential scanning calorimetry (DSC). Structural characterization by X-ray diffraction revealed the presence of a phase in addition to the α-magnesium matrix. The technique did not provide proof of the presence of other phases, if one phase exists; its volume fraction is low to be detected. The microhardness measurements show showed the evolution of the mechanical properties of the alloys studied as a function of temperature or as a function of time. Differential scanning calorimetric study shows the reactions of phases transformation of the precipitation sequence in the studied alloys.