抽拉速率对DD5单晶高温合金定向凝固组织及偏析的影响  

Effect of Withdrawal Rate on Microstructures and Segregation of Directionally Solidified DD5 Single Crystal Superalloy

作　　者：齐永顺 李丰文 玄伟东[1,2,3] 王江 任忠鸣[1,2,3] 李传军 QI Yongshun;LI Fengwen;XUAN Weidong;WANG Jiang;REN Zhongming;LI Chuanjun(State Key Laboratory of Advanced Special Steel,Shanghai University,Shanghai 200444,China;Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai 200444,China;School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [2]上海市钢铁冶金新技术开发应用重点实验室,上海200444 [3]上海大学材料科学与工程学院,上海200444

出　　处：《上海金属》2022年第3期65-71,共7页Shanghai Metals

基　　金：航空发动机及燃气轮机重大专项基础研究项目(2017-Ⅶ-0008-0102)。

摘　　要：研究了高速凝固条件下抽拉速率对DD5单晶高温合金定向凝固组织的影响。结果表明:随着抽拉速率的增大,DD5合金枝晶组织逐渐细化,一次枝晶间距减小;偏析程度加重;γ′相尺寸减小且趋于规则的立方状,枝晶干γ′相的尺寸小于枝晶间;γ/γ′共晶含量、碳化物含量和显微疏松随抽拉速率增大而增加,而γ/γ′共晶和碳化物的尺寸减小。Effect of withdrawal rate on the microstructures of DD5 single crystal superalloy highspeed solidified directionally was investigated.The results showed that the dendritic structures became finer gradually,and the primary dendrite arm spacing decreased with the increase in withdrawal rate;the degree of segregation was aggravated;theγ′precipitates decreased in size and turned to regular cubic shape,the average size ofγ′phase in the dendrite trunk smaller than that in the interdendritic region.With the increase in withdrawal rate,the volume fraction ofγ/γ′eutectic,carbides content and porosity all increased,while the size ofγ/γ′eutectic and carbides decreased.

关 键 词：高温合金 定向凝固 抽拉速率 微观组织 偏析 

分 类 号：TG132.3[一般工业技术—材料科学与工程]