Effect of melt convection on primary dendrite arm spacing in directionally solidified Pb-26%Bi hypo-peritectic alloys
| Autor: | Lin Liu, Heng-zhi Fu, Si-feng Gao, Xiao-wu Hu, Shuang-ming Li |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
High concentration
Materials science Metallurgy Metals and Alloys Geotechnical Engineering and Engineering Geology Condensed Matter Physics Growth velocity Dendrite (crystal) Materials Chemistry Melt convection Composite material Concentration gradient Mass fraction Dissolution Directional solidification |
| Zdroj: | Transactions of Nonferrous Metals Society of China. 21:65-71 |
| ISSN: | 1003-6326 |
| Popis: | Primary dendrite arm spacing (PDAS) of α phase in directionally solidified Pb-26%Bi (mass fraction) hypo-peritectic alloys was measured by considering the effect of melt convection in cylindrical samples with different diameters. The experimental results show the measured PDAS increases with increasing diameter of the sample. At the growth velocity of 5 μm/s, its value changes from 161.5 μm for the sample with 1.8 mm in diameter to 240.4 μm for the sample with 7 mm in diameter. The strong melt convection in large diameter samples causes a high bulk alloy composition and a high concentration gradient in peritectic β phase, resulting in a larger PDAS. Simultaneously, the high concentration gradient could effectively promote the peritectic transformation, enhancing the dissolution of the thin a dendrite. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect