熔体超温处理对DD3镍基单晶高温合金凝固组织的影响  

INFLUENCE OF THE MELT SUPERHEATING TREATMENT ON SOLIDIFICATION MICROSTRUCTURE OF DD3 Ni BASE SINGLE CRYSTAL SUPERALLOY

作　　者：邹敏明[1] 张军[1] 刘林[1] 傅恒志[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《金属学报》2008年第1期59-63,共5页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展计划资助项目2006CB605202~~

摘　　要：在保持固/液界面温度梯度不变的条件下,研究了不同熔体超温处理温度对DD3单晶高温合金凝固组织的影响,并利用DTA研究了合金熔体结构的变化.结果表明:合金熔体在1380—1650℃发生一系列的结构变化;当抽拉速率为50μm/s时,随熔体超温处理温度由1500℃升至1640和1780℃,合金一次枝晶间距由177μm分别减至150和125μm,枝干与枝间γ′相的尺寸减小,且枝间γ′相形貌变得规整.The solidification microstructure of DD3 Ni base single crystal superalloy is studied under different melt superheated temperatures and constant solid/liquid interface temperature gradient. The DTA results show that there are a series of melt structure changes between 1380 ℃ and 1650℃. At withdrawn rate of 50 μm/s, the primary dendrite arm spacing is decreased from 177 μm to 150 μm and 125 μm when the superheating temperature is increased from 1500 ℃ to 1640 ℃and 1780 respectively, the γ′are refined in both dendrite core and interdendrite area, and the morphology of the latter trends to be uniform.

关 键 词：DD3单晶高温合金 熔体超温处理 凝固组织 一次枝晶间距 γ′相 

分 类 号：TG132.32[一般工业技术—材料科学与工程]