凝固速率对定向凝固合金DZ22枝晶臂间距和枝晶偏析的影响  

DENDRITIC ARM SPACING AND MICROSEGREGATION OF DIRECTIONALLY SOLIDIFIED SUPERALLOY DZ22 AT V ARIOUS SOLIDIFICATION RATES

作　　者：刘忠元[1] 李建国[1] 傅恒志[1] 

机构地区：[1]西北工业大学

出　　处：《金属学报》1995年第7期A329-A332,共4页Acta Metallurgica Sinica

基　　金：国家自然科学基金;航空科学基金

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．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).

关 键 词：定向凝固 凝固速率 枝晶偏析 耐热合金 

分 类 号：TG132.33[一般工业技术—材料科学与工程]