Thermal stability of cerium-based bulk metallic glasses. Influence of iron addition
Résumé
Cerium-based bulk metallic glasses are attractive due to their low glass transition temperature, comparable to that of polymers. Their mechanical properties, especially their elastic and viscoelastic ones are reported in a large temperature range. Like in other bulk metallic glasses, the shear modulus, close to 11.5 GPa at room temperature, decreases drastically in the glass temperature range (at about 373 K), while the viscoelastic component becomes very important. Heating to high temperature induces crystallization. As shown by X-ray diffraction experiments performed in situ, the increase of elastic modulus due to the formation of crystalline particles is strongly connected to the volume fraction of these particles. Addition of iron shifts the phenomena towards higher temperatures and affects the crystallization process. (C)