Size dependent phase transformation in atomized TiAl powders.
- Resource Type
- Article
- Authors
- Yang, Dong-Ye; Guo, Shu; Peng, Hua-Xin; Cao, Fu-Yang; Liu, Na; Sun, Jian-Fei
- Source
- Intermetallics. Jun2015, Vol. 61, p72-79. 8p.
- Subject
- *TITANIUM-aluminum alloys
*PHASE transitions
*ATOMIZATION
*POWDER metallurgy
*METAL microstructure
*HARDNESS
- Language
- ISSN
- 0966-9795
The paper focuses on the phase transformation of undercooled Ti–48Al (at.%) droplets atomized by high pressure gas. The microstructural evolution was analyzed using the transient nucleation theory in combination with the microstructural examinations. The primary phase, final phase volume fraction and the hardness are related to the droplets size to provide fundamental understanding. The competitive formation of the primary phases α and β are strongly controlled by the droplets size, and a critical diameter of about 25 μm was identified corresponding to an undercooling of 102 K. The final phase volume fraction of γ increased with the increase of powder size from 12% to 85%. The highest hardness with the value of 652 HV was obtained for powder of 50 μm in diameter. [ABSTRACT FROM AUTHOR]