镍基单晶高温合金定向凝固初期温度场演化过程  

Evolution of Temperature Field of Ni-Based Single Crystal Superalloy at Early Stage of Directional Solidification

作　　者：杨振宇 陈昊 胡松松 杨功 张剑[1] 骆宇时[1] YANG Zhen-yu;CHEN Hao;HU Song-song;YANG Gong;ZHANG Jian;LUO Yu-shi(National Key Laboratory of Advanced High Temperature Structural Materials,Beijing Institute of Aeronautical Materials,Bejjing 100095,China;No.6 Military Representative Office of Equipment Department of Air Force in Beijing,Beijing 101300,China;School of Materials Science and Engineering,Xiangtan University,Xiangtan 411105,Hunan,China)

机构地区：[1]北京航空材料研究院,先进高温结构材料重点实验室,北京100095 [2]空军装备部驻北京地区第六军事代表室,北京101300 [3]湘潭大学材料科学与工程学院,湖南湘潭411105

出　　处：《铸造》2020年第11期1180-1184,共5页Foundry

摘　　要：镍基单晶高温合金制备过程中凝固缺陷的形成与温度场演化密切相关。采用ProCAST数值模拟的方法研究了籽晶法制备镍基单晶高温合金时定向凝固初期温度场的演化过程。结果表明,定向凝固初期温度场演化开始前存在一定时间的孕育期,之后凝固界面迁移速率从0逐渐增加到抽拉速度附近,孕育期随着抽拉速率的增加而减少。最后,讨论了定向凝固初期温度场演化对杂晶形核和长大的影响。The formation of solidification defects in Ni-based single crystal superalloys is closely related to the temperature field. In this paper, the numerical simulation is carried out by using the ProCAST software to study the evolution of the temperature field at the initial withdrawal stage of seed region during the preparation of Ni-based single crystal superalloys. The results show that there is an incubation stage for temperature field at the initial withdrawal stage during directional solidification. Then, the Liquid/Solid(L/S) interface migration speed gradually increases from 0 to near the withdrawal rate. And the incubation time decreases with increasing the withdrawal rate. Finally, the nucleation and growth of stray grains around of seed surface is discussed based on the temperature field evolution at the initial withdrawal stage.

关 键 词：镍基单晶高温合金 定向凝固 籽晶法 温度场 抽拉速率 

分 类 号：TG132[一般工业技术—材料科学与工程]