Solidification microstructure of super- alpha sub 2 alloy prepared by gas atomization

• Published in: Journal of materials science Vol. 32; no. 14; pp. 3821 - 3827
• Main Authors: Xu, R, Cui, Y Y, Li, D, Xu, D M, Li, Q C, Hu, Z Q
• Format: Journal Article
• Language: English
• Published: 15.07.1997
• ISSN: 0022-2461

Ti-25Al-10Nb-3V-1Mo alloy has been prepared by gas atomization with atomizing pressure > 8 MPa. The cooling rate of 5x10 exp 3 approx3x10 exp 5 K s exp -1 was obtained according to secondary dendritic arm spacing, as the particle size is 30-300 mu m. It is known that in the big particles two dendrite morphologies can be found, cellular dendrite and well-developed dendrite, and in small particles there exists only well-developed dendrite. The surface of particles is characteristic of solidification that is identical to the observation on the cross-sectional views. The micrographs of cross-sectional views show that the big particles, whether of cellular dendrite or well-developed dendrite, solidify by multiple nucleation events while the small particles of well-developed dendrite solidify from a single nucleation event. The microstructure of the alloy consists of single beta sub 0 phase.