The growing frontage microstructure of the quenched PMP samples and research of liquid phase ingredient

摘要

The frontage microstructure of the peritectic reaction was investigated by SEM and a planar growth was found. As the elevation speed ranged from 1mm/h to 4mm/h, the sample can grow in planar form. The slower the elevation speed is, the more tidily the reaction frontage grows, the larger the 211 phase particles are at the same time. Along the c-axis direction, the interface between 123 phase and liquid phase is not as tidy as in ab-plane. Near the 123 base in liquid phase, a "temporary" phase was found. The frontage stage growing was found for the first time and it is very thin about 2 approx 3 mu m. It was found that the original concentration of Y in the liquid phase in PMP sample is very low. As the melting time extends, the concentration increases considerably. The diffusion distance is about 1 mu m and the 123 phase may nucleate within this distance.