Understanding the Evolution of the Microstructure in Melt-Conditioned Direct-Chill Cast Al Alloys
Present work focuses on understanding the solidification mechanism responsible for the grain-refinement in melt-conditioned direct chill (MC-DC) cast Al-alloy. It has been found that the melt-conditioning performed by stirring the liquid above the solidification front using a rotor–stator type melt-...
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| Format: | Article |
| Language: | English |
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Taylor & Francis
2014
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| Online Access: | http://umpir.ump.edu.my/id/eprint/6249/ http://umpir.ump.edu.my/id/eprint/6249/ http://umpir.ump.edu.my/id/eprint/6249/ http://umpir.ump.edu.my/id/eprint/6249/1/fkp-2014-Prasada-Understanding_the_Evolution_abs_only.pdf |
| Summary: | Present work focuses on understanding the solidification mechanism responsible for the grain-refinement in melt-conditioned direct chill (MC-DC) cast Al-alloy. It has been found that the melt-conditioning performed by stirring the liquid above the solidification front using a rotor–stator type melt-conditioning device, results in substantial fragmentation of dendrites due to forced convection and thermo-solutal distribution across the billet sump. Results also indicate that an isothermal region is created in the MC-DC regime of the billet sump, which further enhances the nucleation and restricts growth of the α-Al phase. The forced convection together with the solute transport lead to catastrophic dendrite fragmentation. |
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