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Principles of Using Liquidus Projections for Equilibrium and Non-Equilibrium Solidification in Metallic and Ceramic Systems
Published in D. R. F. West, N. Saunders, Ternary Phase Diagrams in Materials Science, 2017
The latter equation, often called the Scheil equation, has been used quite extensively to describe solidification under non-equilibrium cooling conditions. However, eqns. (i–iv) cannot be derived by the same mathematical procedure if k varies with temperature and/or composition, which is the more usual case in practice. Furthermore, while the Scheil equation can be applied to dendritic solidification, it cannot be applied to subsequent eutectic formation. The Calphad procedure enables these limitations to be overcome, and also allows multi-component systems to be dealt with ( see Chapter 8).
Principles of Using Liquidus Projections for Equilibrium and Non-Equilibrium Solidification in Metallic and Ceramic Systems
Published in D. R. F. West, N. Saunders, Ternary Phase Diagrams in Materials Science, 2020
The latter equation, often called the Scheil equation, has been used quite extensively to describe solidification under non-equilibrium cooling conditions. However, eqns. (i-iv) cannot be derived by the same mathematical procedure if k varies with temperature and/or composition, which is the more usual case in practice. Furthermore, while the Scheil equation can be applied to dendritic solidification, it cannot be applied to subsequent eutectic formation. The CALPHAD procedure enables these limitations to be overcome, and also allows multi-component systems to be dealt with (see Chapter 8).
Effect of the nozzle diameter and melt velocity at the tundish outlet on solidification along microstructural and mechanical properties of the cooling slope casted AZ91 Mg alloy
Published in Canadian Metallurgical Quarterly, 2022
For investigating the impact of melt velocity for solidification and microstructural and mechanical properties, thorough experiments were performed for the molten AZ91 Mg alloy for five diverse melt velocities (0.1, 0.2, 0.3, 0.4, and 0.5 m/s) and a constant nozzle diameter of 8 mm. Bigger melt velocity involves smaller residence/solidification moment owing to the faster-molten alloy stream over the cooling slope. As a result, slurry temperature beside the sloped exit increases along alloy velocity. Eventually, a smaller solid fraction results from a bigger melt velocity. Table 2 encapsulates temperature and solid fraction (by Scheil equation [22,23,32]) details of AZ91 Mg alloy slurry released from the sloped exit for five diverse melt velocities. Solidification intensity declines with the enhancement of melt velocity owing to the faster-molten alloy flow caused by smaller residence/solidification time.