Abstract
The characteristics of rapid solidification and microstructure formation of Fe-50wt%Sn hypermonotectic alloy have been investigated. The rapid solidification microstructure is composed of regular arrays of fiber-like (3-Sn phase, a-Fe phase distributed in fiber interspacing, and a small amount of metallic compounds. The angle between the fiber array and ribbon surface is within the range of 0°-15°. According to the heat transfer equation and Navier-Stokes equation under melt-spinning condition, the solidification behaviors and microstructure formation processes are analyzed theoretically. It is revealed that the liquid phase flow has a remarkable effect on the phase separation of hypermonotectic alloy. This separation behavior occurs in the bottom of the melt puddle, which is about 200μm from roller surface, where the shapes of separated L2 droplets are deformed by shear stress. The collision/stretch of the separated L2 droplets finally leads to the formation of fiber-like microstructures. Due to the high cooling rate, the peritectic transformation at elevated temperatures is suppressed, thus resulting in the existence of some metastable phase at room temperature.
| Original language | English |
|---|---|
| Pages (from-to) | 1909-1915 |
| Number of pages | 7 |
| Journal | Wuli Xuebao/Acta Physica Sinica |
| Volume | 53 |
| Issue number | 6 |
| State | Published - Jun 2004 |
Keywords
- Crystal growth
- Fluid flow
- Liquid state
- Phase separation
- Rapid solidification