J. Feng
,
W.D. Huang
,
X. Lin
,
T. Li
,
Y.F. Xue and Y.H. Zhou(State Key Lab. of Solidilication Processing
,
Northwestern Polytechnical University
,
Xi'an 710072
,
China)
金属学报(英文版)
In order to investigate the response of cellular spacing to the variation of growth velocity under near-rapid directional solidification condition, Al-0.53wt%Zn alloy is directionally solidified with Bridgman apparatus. The results show that at the given temperature gradient the obtained microstrvctures are all cells and there exists a wide distribution range of cellular spacing. The maximum, λmax, minimum, λmin, and average cellular spacing, λ, as functions of growth rate, V, can be given by λmax=948.51V-0.4961, λmin= 661.16V-0.5015 and λ=412.41V-0.5049, respectively. The experimental results are compared with that predicted by KGT model, and a good agreement is found. Moreover,it is found that the average cellular spacing is also remarkably history-dependent.
关键词:
Al-Zn alloy
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