Décomposition de la phase β-métastable de l'alliage de titane β-Cez au cours du chauffage et du recuit

Abstract
This work carries out the study of the precipitation during continuous heating up to 830°C and ageing at this same temperature from β meta + w aniso or β meta + α. The heating rates varied between 0.25 and 5°C/s. The transfomations were followed by electric resistivity and hardness measurements. Different samples were quenched from different temperatures during the heating range and were then studied by X-ray and TEM. The beginning temperatures of precipitations of the w and α phases were established, as the continuous heating transformation diagrams. Near 700°C, X-ray quantitative analysis and EAM studies revealed ( for quenching and 4.5°C/s cooling rate) that the structure consisted of a maximum content of the α phase, surrounded by β zones enriched in Fe, Cr. For temperatures greater than 700°C, the content of the α phase diminished and the β phase composition was homogenized.