Estimation of Heat Transfer Coefficient in Squeeze Casting of Wrought Aluminum Alloy 7075 by the Polynomial Curve Fitting Method

Numerical simulation is used to improve the productivity and optimize casting process in today’s foundry. The accurate estimation of heat transfer coefficients (HTC) at the metal-mold interface is essential to simulate casting solidification processes. In this work, a 5-step casting mold was employed with section thicknesses of 2, 4, 8, 12, 20 mm. Wrought aluminum alloy 7075 was squeeze cast under an applied pressure of 60MPa in a hydraulic press. By placing the type-K thermocouples at different locations of each step in the mold, the casting-die interfacial IHTC in the 5-step casting were evaluated from the measured temperatures by applying the polynomial curve fitting method. The results from the estimation indicated that the wall thickness of squeeze cast wrought aluminum 7075 significantly influenced the value of IHTC. The peak IHTC value increased as the step thickness increased.