Abstract
DD32 single crystal samples, which were prepared by HRS method, were remolten and directionally solidified with electron beam floating zone technology. The microstructures remolten and directionally solidified with difference electron beam scan rate were observed and analyzed deeply. The results show that solid-liquid interface temperature gradient is a function of electron beam scanning rate. When the scanning rate is 0.2 mm/min, solid-liquid interface temperature gradient is ≥ 1000 K/cm. High solute contents of DD32 alloy and relatively high scan rates tend to lead to constitutional overcooling and prevent the formation of single crystals. When electron beam scanning rate is greater than certain value, two fine and wide directional columnar crystals regions can be observed in remolten DD32 directional solidification microstructure. Transformation of remelting zone shape and intense convection are the main reasons why distribution of temperature as well as solute fields is asymmetry.
| Original language | English |
|---|---|
| Pages (from-to) | 37-40 |
| Number of pages | 4 |
| Journal | Jinshu Rechuli/Heat Treatment of Metals |
| Volume | 30 |
| Issue number | 1 |
| State | Published - Jan 2005 |
Keywords
- Directional solidified microstructure
- Electron beam floating zone melting (EBFZM)
- Temperature gradient