Microstructure transition of Al-Cu eutectic alloy during containerless rapid solidification

【摘要】 <正> Abstract Droplets of Al-32. 7% Cu eutectic alloy were rapidly solidified during containerless processing in a 3m drop tube. Themicrostructural evolution of Al-Cu eutectic alloy depends strongly on droplet size. The eutectic growth morphology changes from regularlamellar eutectic to a kind of anomalous eutectic with the decrease in droplet size. This microstructural transition was analyzed within thecurrent theories of eutectic growth. The results indicate that there exists a critical velocity for eutectic growth beyond which anomalous eu-tectic appears. The coupled zone of the Al-Cu eutectic alloy system has been calculated on the basis of the Trivedi-Magnin-Kurz(TMK)eutectic growth and the Lipton- Kurz- Trivedi (LKT) / Boettinger- Coriell- Trivedi (BCT) dendrite growth models, which provides a furtherinterpretation for the morphological transition.更多还原

【Abstract】 Droplets of Al-32.7%Cu eutectic alloy were rapidly solidified during containerless processing in a 3 m drop tube. The microstructural evolution of Al-Cu eutectic alloy depends strongly on droplet size. The eutectic growth morphology changes from regular lamellar eutectic to a kind of anomalous eutectic with the decrease in droplet size. This microstructural transition was analyzed within the current theories of eutectic growth. The results indicate that there exists a critical velocity for eutectic growth beyond which anomalous eutectic appears. The coupled zone of the Al-Cu eutectic alloy system has been calculated on the basts of the Trivedi-Magnin-Kurz(TMK) eutectic growth and the Lipton-Kurz-Trivedi(LKT)/Boettinger-Coriell-Trivedi(BCT) dendrite growth models, which provides a further interpretation for the morphological transition.更多还原