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Copper die-casting is still a relatively new casting process and the numerical formulation of this process is still in its developmental stages. A casting simulation software - ADSTEFAN was used to numerically determine the porosity in edge-gated copper rotor die-casting. The results obtained from simulation were then compared to the real die-cast copper rotors that were produced. Shot profiles are shown to be very instrumental in controlling porosity. Profiles designed to pre-fill a portion of the gate end ring at the slow shot speed prior to accelerating to the fast velocity to fill the conductor bars and ejector end ring are shown to be very effective in minimizing and controlling porosity. Since the electrical conductivity of copper is nearly 60% higher than that of aluminum, substituting copper for aluminum in the rotor would markedly increase the electrical efficiency of the motor.

High-pressure die casting is a highly productive process that yields near net-shape castings at a relatively low cost. One disadvantage of die casting, however, is residual porosity that is inherently present in the castings. Semi-solid die casting is a method that is superior to die casting as it relates to porosity but has historically been a more expensive process. This is due to the higher cost of the billet feed material and the inability to easily recycle billets and runners. Slurry-on-Demand is a new semi-solid casting process that develops the semi-solid slurry directly from the liquid, thereby eliminating the cost penalties intrinsic to the billet semi-solid process. This paper will describe the Slurry-on-Demand process in detail and present case studies comparing the casting of large components using both Slurry-on Demand and conventional high-pressure die casting. It will also provide examples of quality improvements achievable by the Slurry-on-Demand process.