Structure of molten Al and eutectic Al-Si alloy studied by neutron diffraction
- University of Rouen
- Ames Laboratory
- Oak Ridge National Laboratory
The structure of molten eutectic Al87.8Si12.2 alloy has been studied by neutron diffraction during a temperature cycle. For comparison measurements were performed on pure molten Al. The measurements show that the alloy after heating above the liquidus contains particles of two kinds, aluminum-rich and silicon-rich. The silicon-rich particles are partly dissolved after a further heating. Earlier published data obtained by the γ-ray absorption technique of the density of the molten eutectic Al–Si alloy had demonstrated the existence of two temperatures above the liquidus temperature: A dissolution temperature Td, at which the microstructure of the melt inherited from the ingot starts to dissolve and a branching temperature, Tb, at which the melt reaches a fully mixed state. The highest temperature that was possible to reach during the neutron experiments lies between Td and Tb. The obtained results support these conclusions that molten alloys after melting are inhomogeneous up to a temperature well above the liquidus. Moreover, the difference in shape between the static structure factors measured by neutron and X-ray diffraction on molten aluminum is observed and is found to be more accentuated and to extend to larger wavevectors than in earlier works.
- Research Organization:
- Ames Lab., Ames, IA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC02-07CH11358
- OSTI ID:
- 1082464
- Report Number(s):
- IS-J 7947
- Journal Information:
- Journal of Non-Crystalline Solids, Vol. 361, Issue 1 February 2013
- Country of Publication:
- United States
- Language:
- English
Similar Records
The {beta}-Ti(Al,Si) + Ti{sub 5}(Si,Al){sub 3} eutectic reaction in the Ti-Al-Si ternary system
Effect of Mn on eutectic phase equilibria in Al-rich Al-Ce-Ni alloys