铌硅基高温合金定向凝固铸造温度场模拟计算  

Simulation of temperature field in directional solidification casting of Nb–Si based alloys

作　　者：秦蓉 付华栋 康永旺[2] 周晓舟 张志豪 谢建新 QIN Rong;FU Hua-dong;KANG Yong-wang;ZHOU Xiao-zhou;ZHANG Zhi-hao;XIE Jian-xin(Key Laboratory for Advanced Materials Processing of Ministry of Education,Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;Science and Technology on Advanced High Temperature Structural Materials Laboratory,Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]北京科技大学新材料技术研究院材料先进制备技术教育部重点实验室,北京100083 [2]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

出　　处：《工程科学学报》2020年第9期1165-1173,共9页Chinese Journal of Engineering

基　　金：国家重点研发计划资助项目(2017YFB0702904)。

摘　　要：以铌硅基高温合金定向凝固铸造过程为对象,通过实验测试和反求法确定了铌硅基高温合金和型壳的热物性参数,以及凝固过程各界面换热系数等边界条件;利用ProCAST软件对不同抽拉速率下铌硅基高温合金凝固过程温度场进行了模拟.结果表明,随着抽拉速率由5 mm·min-1增加到10 mm·min-1,固/液界面离液态金属锡表面的距离由12.1 mm下降到8.2 mm;平均糊状区宽度逐渐变窄,由11.5 mm减小到10.4 mm.针对抽拉速率为5 mm·min-1的实验结果表明,数值模拟结果与实际定向凝固实验获得的一次枝晶间距差异在6%以内,从一个方面验证了温度场模拟结果的正确性,相关结果可为铌硅基高温合金叶片定向凝固铸造参数的确定提供参考.With the increasing demand for improvements in the temperature capability of aero-engines,there is an urgent need to develop new-generation turbine blade materials.Compared with Ni-based superalloys that have a lower melting point(~1300℃),the higher melting point(>1750℃),lower mass density(6.6–7.2 g·cm–3),and high-temperature strength of the Nb–Si based alloys make them one of the most promising of the new-generation high-temperature structural materials.A directional solidification process can further enhance the performance of Nb–Si based alloys and lay a foundation for replacing the Ni-based single-crystal superalloys in service at higher temperatures.Accurately determining the thermal property parameters of Nb–Si based alloys and their interfacial heat transfer behavior during solidification is the key to their numerical simulation,which could accelerate the development of Nb–Si based alloys.As yet,however,there has been no research reported in relation to this issue.In this study,we used the directional solidification process of Nb–Si based alloys as the research object and the experimental testing and reverse methods to determine the thermal properties of Nb–Si based alloys and their shells as well as the boundary conditions of the heat transfer coefficient at the interface during the solidification process.To simulate the temperature field of the solidification process of Nb–Si based alloys at different drawing rates,we used ProCAST software.The results reveal that as the withdrawal rate increased from 5 to 10 mm·min-1,the distance between the solid/liquid interface and the surface of the liquid metal tin decreased from 12.1 to 8.2 mm,and the average width of the mushy zone gradually narrowed from 11.5 mm to 10.4 mm.The discrepancy in the spacing of the primary dendrites between the numerical simulation and the actual experimental results at a withdrawal rate of 5 mm·min-1 was within 6%,which verifies the correctness of the temperature-field simulation results.These results provide

关 键 词：PROCAST 数值模拟 定向凝固 液态金属冷却 抽拉速率 

分 类 号：TG27[金属学及工艺—铸造]