A study of metal/die interfacial heat transfer behavior of vacuum die cast pure copper

Abstract

High pressure die casting copper is used to produce rotors for induction motors to improve efficiency. Experiments were carried out for a special “step-shape” casting with different step thicknesses. Based on the measured temperature inside the die, the interfacial heat transfer coefficient (IHTC) at the metal/die interface during vacuum die casting was evaluated by solving the inverse problem. The IHTC peak value was 4.5×103- 11×103 W·m-2·K-1 under the basic operation condition. The influences of casting pressure, fast shot speed, pouring temperature and initial die surface temperature on the IHTC peak values were investigated. Results show that a greater casting pressure and faster shot speed could only increase the IHTC peak values at the location close to the ingate. An increase of pouring temperature and/or initial die surface temperature significantly increases the IHTC peak values.

Keywords

• vacuum die casting; interfacial heat transfer behavior; inverse method; copper; metal/die interface