THE CHARACTERISTIC AND CRYSTALLINIC MORPHOLOGY OF A Ti_3Al-BASED POWDER PREPARED BY GAS ATOMIZING

The characteristic and microstructure of rapidly solidified Ti-25Al-10Nb-3V -1Mo (a.%) powder prepared by gas atomizing have been studied in this paper. The powder atomized with gas pressure larger than 8MPa is logarithmic normal function of particle diameter. SEM observation of dendrite on the particle surface shows a obvious characteristic of solidification, which is identical to the micrograph of cross-sectional views. The cooling rate of the powder is 103-105K / s obtained by calculation according to the relationship of cooling rate with secondary dendritic arm space of the powder.