Authors: J B Ferguson Meysam TabandehKhorshid John C Mantas Pradeep K Rohatgi Kyu Cho ChangSoo Kim
Publish Date: 2014/03/11
Volume: 45, Issue: 4, Pages: 1407-1417
Abstract
In the present work we developed an analytical model to describe the effect of pouring temperature on the crystallite density remelting growth kinetics and the resultant final grain size for aluminum Albased alloys synthesized using gravity casting The model predicts that there are three regimes of pouring temperature/grain sizerelated behavior i at low superheats grain size is small and relatively constant ii at intermediate levels of superheat there appears to be a transitional behavior where grain size increases in a rapid nonlinear fashion and iii at high superheats grain size increases linearly with increasing temperature This general pattern is expected to be shifted upward as distance from the bottom of the casting increases which is likely a result of the slower cooling rates and/or longer solidification times with increasing distance from the bottom of the casting To validate the model a set of experiments has been conducted using AlCu and AlSi alloys ie Al30 wt pct Cu Al45 wt pct Cu and AlA3562 alloys and the experimental measurements showed consistent results with theoretical predictions
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