不同模组结构高效制备单晶叶片定向凝固过程的温度场及组织模拟  

Temperature Field and Microstructure Simulation of Directional Solidification Process of Single Crystal Blade Prepared Efficiently with Different Module Structures

作　　者：杨文超[1] 撒世鹏 郝文硕 秦嘉润 张军[1] 刘林[1] Yang Wenchao;Sa Shipeng;HaoWenshuo;Qin Jiarun;Zhang Jun;Liu Lin(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2023年第11期3847-3856,共10页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52071263);陕西省自然科学基础研究计划(2021JC-13);陕西省重点研发计划(2020ZDLGY13-02)。

摘　　要：针对18个单晶高温合金叶片高效制备过程中温度场不均匀而导致的杂晶缺陷问题,设计了3种不同的单晶叶片模组结构,采用ProCast软件和CAFE模块对第2代单晶高温合金DD6不同模组结构在高速凝固工艺下的温度场和晶粒组织进行模拟研究,分析了不同模组结构下叶片的温度场演化和抽拉速率对杂晶的影响。结果表明,单层模组由于中柱的保温作用较小,导致叶片近中柱侧的散热效率高于近炉壁侧,凝固过程固液界面弯曲严重,凝固过冷大,杂晶形成倾向大;通过对单层模组添加套筒,以加强保温作用,可有效改善温度场,减小固液界面弯曲程度,避免杂晶形核;而双层叠加模组温度场分布均匀,凝固过冷小,杂晶形成倾向小。套筒模组和双层叠加模组在抽拉速率小于100μm/s时均无杂晶形成,但双层叠加模组将模组直径缩小为其余2种模组结构的一半,降低了对炉体型腔尺寸的要求,有望实现单晶叶片的高效制备。For the stray grain problem of 18 single crystal blades in high efficiency preparation due to the non-uniform temperature field,three different module structures with the same production capacity were designed.The high rate solidification of DD6 Ni-based superalloy under different module structures was simulated by ProCast software and CAFE model,and the influence of the temperature field evolution and the withdrawal rate on stray grains was analyzed.The results show that the solid-liquid interface of the single-layer module becomes curved seriously because the cooling efficiency of side close to the center pillar is higher than that of the side close to the furnace body due to weak heat preservation effect of center pillar,and it has a large undercooling and tendency to form stray grains.By adding a sleeve to the single-layer module to increase the heat preservation effect,the temperature field can be changed effectively,and the degree of bending is reduced to avoid the nucleation of stray grain.The double-layer superimposed module has a uniform temperature field and a low undercooling,which can decrease the tendency of stray grain effectively.Both the double-layer superimposed module and the sleeve module can form a complete single crystal when the withdrawal rate is below 100μm/s,while the diameter of the double-layer superimposed module reduces to a half of the diameter of the other two modules,which can reduce the requirement for size of furnace body,achieving efficient preparation of single crystal blades.

关 键 词：模组结构 单晶叶片 定向凝固 数值模拟 

分 类 号：TG146.15[一般工业技术—材料科学与工程]