中國有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 24 No. 7 July 2014 |
（1. Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education,
School of Materials Science and Engineering, Beihang University, Beijing 100191, China;
2. Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan;
3. Center for Advanced Die Engineering and Technology, Gifu University,
1-1 Yanagido, Gifu City, Gifu 501-1193, Japan;
4. Hebei Sitong New Metal Material Co., Ltd., Baoding 071105, China）
Abstract:Al-1.0%Sc-1.0%Zr (mass fraction) master alloy was prepared at different cooling rates. The morphology and thermodynamics data of the primary particles of the master alloy were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). It shows that the primary particles are dendrite-shaped particles comprised of several attached small cubic, cusped-cubic or crucifershape particles at slow cooling rate. However, the primary particles are separated with crucifer shape at intermediate cooling rate, and they are cubic with cusped-cubic shape at high cooling rate. Meanwhile, the separated and attached particles present Al3Sc/Al3Zr1-xScx core-shell structure. The formation mechanism of the structure was systematically investigated by a mathematical model.
Key words: Al-Sc-Zr master alloy; morphology; core-shell structure; cooling rate; formation mechanism
