Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7882164 | Acta Materialia | 2014 | 12 Pages |
Abstract
An in situ technique for studying the effect of a pulsed electromagnetic field on dendrite fragmentation behavior based on synchrotron X-ray imaging has been developed, involving the passage of an oscillating current through a foil specimen placed in a static magnetic field. In all cases, the application of a pulsed electromagnetic field to an array of Al-15Â wt.%Cu dendrites led to an increase in dendrite fragmentation rate. The induced movement of inter-dendritic liquid between the primary and secondary dendrite arms even at high solid fraction led to instabilities in the local temperature-concentration-curvature equilibrium and the rapid remelting of the most vulnerable microregions. The new in situ methodology provides a basis for the optimization of pulsed electromagnetic field parameters to enhance grain refining performance for specific alloys and casting conditions.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
E. Liotti, A. Lui, R. Vincent, S. Kumar, Z. Guo, T. Connolley, I.P. Dolbnya, M. Hart, L. Arnberg, R.H. Mathiesen, P.S. Grant,