| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a mold which can manufacture the mold showing different thermal conductivities between its center and peripheral parts through a simple step in a short time, and the mold for an optical element obtained through the same. <P>SOLUTION: A powder material 16 for the peripheral part is prepared by mixing a tungsten carbide powder with a particle size of ≤0.3 μm and a tungsten carbide powder with a particle size of ≤0.8 μm so as to achieve a ratio of carbon to tungsten after sintering of 1:1. The powder material 16 is filled into a vessel formed from an outer mold frame 17 and a lower punch 20. A DC pulse voltage applied by a power supply unit 15 generates discharge plasma to sinter powder material 16 by its self-heating, thus giving a sintered compact 24 which corresponds to the peripheral region of the mold for an optical element with a recessed part formed at the center by a convex part 21a. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
