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利用超高梯度快速定向凝固装置，对ＤＺ２２合金在快速定向凝固下的枝晶组织和显微偏析进行了研究。实验结果表明：快速定向凝固的一次枝晶间距和二次枝晶间距及冷却速率随凝固速率变化有一极值。在凝固速率８１５μｍ／ｓ时，枝晶间距（λ１，λ２）为最小，而冷却速率为最大。各元素显微偏析程度随冷却速率增大而减小。除Ｈｆ元素外，在最大冷却速率５４℃／ｓ（Ｒ＝８１５μｍ／ｓ）时，其余元素的偏析比均趋于１
Dendritic microstructure and microsegregation of DZ22 alloy under rapid directional solidification were investigated by means of ultra-high gradient rapid solidification equipment. The experimental results show that the primary dendrite spacing, the secondary dendrite spacing and the cooling rate in the rapid solidification have an extreme value with the variation of the solidification rate. At the solidification rate of 815μm / s, the dendrite spacing (λ1, λ2) is the minimum and the cooling rate is the maximum. The degree of micro segregation decreases with the increase of cooling rate. In addition to the Hf element, the segregation ratios of the remaining elements all tend to 1 at the maximum cooling rate of 54 ° C / s (R = 815 μm / s)