Effect of cerium addition on casting/chill interfacial heat flux and casting surface profile during solidification of Al-14%Si alloy

4th International Conference on Advances in Solidification Processes

材料科学;物理学

Vijeesh, V.^1 ; Prabhu, K.N.^1

Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka Surathkal, Mangalore

575025, India^1

关键词: Arithmetical mean;    Casting/chill interfaces;    Heat transfer coefficient (HTC);    Interfacial heat flux;    Inverse modelling;    Radial direction;    Surface profiles;    Surface profilometers;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/117/1/012034/pdf
DOI  :  10.1088/1757-899X/117/1/012034

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In the present investigation, Al-14 wt. % Si alloy was solidified against copper, brass and cast iron chills, to study the effect of Ce melt treatment on casting/chill interfacial heat flux transients and casting surface profile. The heat flux across the casting/chill interface was estimated using inverse modelling technique. On addition of 1.5% Ce, the peak heat flux increased by about 38%, 42% and 43% for copper, brass and cast iron chills respectively. The effect of Ce addition on casting surface texture was analyzed using a surface profilometer. The surface profile of the casting and the chill surfaces clearly indicated the formation of an air gap at the periphery of the casting. The arithmetic average value of the profile departure from the mean line (Ra) and arithmetical mean of the absolute departures of the waviness profile from the centre line (Wa) were found to decrease on Ce addition. The interfacial gap width formed for the unmodified and Ce treated casting surfaces at the periphery were found to be about 35μm and 13μm respectively. The enhancement in heat transfer on addition of Ce addition was attributed to the lowering of the surface tension of the liquid melt. The gap width at the interface was used to determine the variation of heat transfer coefficient (HTC) across the chill surface after the formation of stable solid shell. It was found that the HTC decreased along the radial direction for copper and brass chills and increased along radial direction for cast iron chills.