MICROSTRUCTURAL EVOLUTION DURING THE α_2→α_2 + O TRANSFROMATION IN Ti-AL-NA ALLOYS: PHASE-FIELD SIMULATION AND EXPERIMENTAL VALIDATION

摘要

The microstructural development during precipitation of a coherent orthorhombic phase(O-phase) from the α_2 matrix(DO_19) in a Ti-Al-Nb system is investigated through computer simulations using the phase-field approach and through experimental observations using transmission electron microscopy(TEM). Two compositions were considered in the simulations in order to examine the influence of volume fraction Of the O-phase on the microstructure.