Solute redistribution and Rayleigh number in the mushy zone during directional solidification of Inconel 718  

作　　者：Wang Ling Dong Jianxin Liu Lin Zhang Lei 

机构地区：[1]College of Math and Physics,Nanjing University of Information Science and Technology,Nanjing 210044,China High Temperature Materials Research Laboratories,University of Science and Technology Beijing,Beijing 100083,China National Key Laboratory of Solidification Technology,Northwestern Polytechnical University,Xi''an 710072,China College of Math and Physics,Nanjing University of Information Science and Technology,Nanjing 210044,China

出　　处：《China Foundry》2009年第3期208-213,共6页中国铸造（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 50371006);the school fund of Nanjing University of Information Science and Technology

摘　　要：The interdendritic segregation along the mushy zone of directionally solidified superalloy Inconel 718 has been measured by scanning electron microscope (SEM) and energy dispersion analysis spectrometry (EDAX) techniques and the corresponding liquid composition profile was presented. The liquid density and Rayleigh number (Ra) profiles along the mushy zone were calculated as well. It was found that the liquid density difference increased from top to bottom in the mushy zone and there was no density inversion due to the segregation of Nb and Mo. However carbide formation in the freezing range and the preferred angle of the orientated dendrite array could prompt the fluid flow in the mushy zone although there was no liquid density inversion. The largest relative Rayleigh number appeared at 1,326 degrees C for Inconel 718 where the fluid flow most easily occurred.The interdendritic segregation along the mushy zone of directionally solidified superalloy Inconel 718 has been measured by scanning electron microscope (SEM) and energy dispersion analysis spectrometry (EDAX) techniques and the corresponding liquid composition profile was presented. The liquid density and Rayleigh number (Ra) pro files along the mushy zone were calculated as well. It was found that the liquid density difference increased from top to bottom in the mushy zone and there was no density inversion due to the segregation of Nb and Mo. However carbide formation in the freezing range and the preferred angle of the orientated dendrite array could prompt the fluid flow in the mushy zone although there was no liquid density inversion. The largest relative Rayleigh number appeared at 1,326 °C for Inconel 718 where the fluid flow most easily occurred.

关 键 词：superalloy  directional solidification SEGREGATION fluid flow 

分 类 号：TG132.3+2[一般工业技术—材料科学与工程]