Primary cellular/dendritic spacing selection of Al–Zn alloy during unidirectional solidification

{ "0" : "State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, People's Republic of China" , "2" : "68.70.+w" , "3" : "81.30.Fb" , "4" : "Unidirectional solidification" , "5" : "Cellular/dendritic growth" , "6" : "Primary spacing" , "7" : "Al–Zn alloy"}
Journal of Crystal Growth (Impact Factor: 1.69). 02/1999; DOI: 10.1016/S0022-0248(98)00916-6

ABSTRACT Al–4.95 wt% Zn alloy is directionally solidified with Bridgman apparatus to investigate response of cellular/dendritic microstructures and primary spacing to the variation of growth velocity. The results show that, with increasing growth rate, there exist a transition from dendrite to cell and a wide distribution range in primary cellular/dendritic spacing. The maximum, λmax, minimum, λmin, and average primary spacing, , as functions of growth rate, V, can be given by λmax=4578V−0.697, λmin=1315.7V−0.6543, =3084.5V−0.6982, respectively. The experimental results are compared with the Hunt–Lu model, and a reasonable agreement is found.

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