| 摘要 |
A method for making an equiaxed investment casting. The method utilizes an ultrasonic generator 50 to send an ultrasonic pulse into molten metal in an investment casting mold 32. The investment casting mold 32 is positioned within a working zone 22 of furnace 20 having low output induction coils 24 for generating a convection current in molten metal. The ultrasonic pulse separates dendrites growing from the face of the mold 32 inward into the molten metal. Instead, equiaxed grains can nucleate within the molten metal. In addition, the ultrasonic pulse and the low output induction coils 24 circulate the molten metal as solute is rejected from solidifying equiaxed grains. The mixing reduces the effects of segregation in the solidifying alloy and assists in nucleating equiaxed grains. |
