Ambiguous temperature difference in aerodynamic levitation process: Modelling, solving and application

作     者：Xuan Ge Xiaowei Xu Qiaodan Hu Wenquan Lu Liang Yang Sheng Cao Mingxu Xia Jianguo Li 

作者机构：School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Shanghai Key Laboratory of Materials Laser Processing and Modification Shanghai Jiao Tong University Shanghai 200240 China Monash Centre for Additive Manufacturing (MCAM) Monash University Clayton VIC 3800 Australia 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2019年第35卷第8期

页      面：1636-1643页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Key Research and Development Program (2017YFB0305302) the National Natural Science Foundation of China (51374144, 51774201, 51821001) the Shanghai Municipal Natural Science Foundation (13ZR1420600) the Shanghai Rising-Star Program (14QA1402300) 

主　　题：Solidification Levitation Modelling Temperature difference 

摘      要：The aerodynamic levitation provides an efficient technique for the research on thermophysical properties and solidification behavior of refractory materials. However, there is a nonnegligible temperature differences across sample, causing unexpected uncertainty of measurement, such as, thermal expansivity and undercooling limit. We establish thermal filed model with properly simplified boundary condition, and derive quantitative expressions of this ambiguous temperature difference. Here we show that the temperature difference not only related to the average temperature, relative size and thermal conductivity of sample, but significantly influenced by the rotation pattern of sample. A huge temperature differences is almost inevitable when the sample with low thermal conductivity and high melting point is smelted in stationary suspension pattern, however, a drastically reduction of temperature difference can be fulfilled by simply making the sample rotation in up to down pattern. The thermal filed simulation was used to confirm the validity of these theoretical expressions. This work shed light on temperature difference in aerodynamic levitation. Based on this work, one can simply estimate the extent of temperature difference across the sample, and regulated that conveniently if needed, which benefit for novel material preparation and solidification mechanism study based on this technique.