| 摘要 |
PURPOSE:To manufacture a target free from cavities by unidirectionally solidifying molten metal in a mold when the molten metal of rare earth transition metal alloy is cast into a sputtering target. CONSTITUTION:A matrix 1 manufactured of cast iron having a high frequency heating coil 6 on the outside fitted so that it can move vertically is put on a copper cooling plate 4 having a water cooling pipe 5. The molten metal 3 of rare earth transition metal alloy is cast from a melting crucible 2 into this mold 1. Since the mold is heated by the high frequency heating coil 6, the molten metal 3 is kept at a fixed temperature such as about 1350 deg.C and solidified by the cooling plate 4 from the bottom to the top in the mold 1. In this case, the high frequency heating coil 6 is lifted with the solidification of the molten metal 3 and the molten metal in the circumference flows, with the solidification and shrinkage, into the cavity in the central part which is not yet solidified and is solidified upward in one direction. Accordingly, the target free from cavities in the central part based on solidification and shrinkage can be manufactured stably by the casting method. |
