【摘要】 采用新研制的超高梯度定向凝固装置，研究了不同凝固速率下定向凝固高温合金ＤＺ２２的枝晶臂间距和枝晶偏析．结果表明，冷却速率增大，枝晶臂间距显著细化，枝晶偏析被强烈抑制，当冷却速率为５２．４Ｋ·ｓ^－１时，一次、二次枝晶臂间距λ１和λ２分别为２８．８和８．４μｍ，Ｎｂ，Ｔｉ，Ａｌ，Ｃｒ，Ｃｏ，Ｗ等元素的偏析比均趋近于１．更多还原

【Abstract】 The dendritic arm spacings and microsegregations of directionally solidified superalloy DZ22 at various solidification rates have been studied with the help of a ZMLMC directional solidification equipment.which has superhigh temperature gradient.The results show that the dendritic arm spacings have been refined highly and the microsegregation has been suppressed seriously with increasing the cooling rate.The primary and secondary dendritic arm spacings.λ1 and λ2.are equal to 28.8 and 8.4 μm respectively.and the microsegregation ratios of elements Na.Ti.Al.Cr.Co and W tend to unity when the solidification rate is equal to 54.2 K·s(-1).更多还原