Impact of the air gap at the casting/water-cooled-mold interface on casting microstructure

International Conference on Mechanical Engineering and Applied Composite Materials

机械制造;材料科学

Zeng, Y.D.^1 ; Li, X.F.^1 ; Liu, Y.^1

College of Materials Science and Engineering, Inner Mongolia University of Technology, Huhehaote

010051, China^1

关键词: Casting/mold interfaces;    Equiaxial grains;    Experimental modeling;    Gravity casting;    Interfacial heat transfer coefficients;    Non-linear estimation;    Solidification process;    Temperature profiles;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/307/1/012083/pdf
DOI  :  10.1088/1757-899X/307/1/012083

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In this paper, we report the results of experiments on gravity castings based on the experimental model of the controllable air gap. On basis of the temperature profiles at different locations of casting and mold were first measured, Beck's non-linear estimation procedure was applied to obtain the interfacial heat-transfer coefficient (IHTC) at the casting/mold interface. Using this as the boundary condition, the microstructures of the casting were simulated under different air-gap widths and formation time, which were compared to the microstructures of the measured casting. Furthermore, the impacts of the width of the air gap and the formation time of the air gap on the microstructure were analyzed. The results indicate that the air gap at the interface reduces the IHTC at the casting/mold interface, alters the solidification process of the casting, and has a great influence on the casting microstructure. Further, when the width of the air gap increases, the zone of the columnar grain of the casting decreases, the zone of the equiaxial grain is enlarged, and the columnar grains and equiaxial grains become coarser. When the formation time of the air gap increases, the zone of columnar grains of the casting is enlarged, the zone of the equiaxial grain is reduced, and the columnar grains and the equiaxial grains become finer.