Cooling rate evaluation during solidification in the suction casting process

Abstract

In this work, axial cooling rates during solidification in the Fe-25Ni (wt.%) suction-cast alloy were evaluated based on cellular spacing measurements. Good agreement of the experimental results with the 20/{d(cm)}2 relationship was observed for the standard water-cooling system temperature of 17 ± 1 °C. The importance of this casting parameter is reported for the first time. A linear decrease in the cooling rate with increasing water-cooling system temperature is demonstrated and at least 20% lower values are expected for a temperature increase by 10 °C compared to standard conditions. Furthermore, the cooling rate exponentially decreases with increasing rod diameter for all water-cooling system temperatures. A new expression for cooling rates during solidification, taking into account the casting parameter (WCST expressed in K), i.e. CR=10-0.0059⋅WCST+4.9746{d(mm)}0.0195⋅WCST-3.6351 , is proposed. The reliability and benefits of this formula have been demonstrated by casting the Zr50Cu40Al10 glass-forming alloy at various water-cooling system temperatures.

Keywords

• Solidification
• Suction casting
• Cooling rate
• Critical diameter
• Constitutional supercooling