PURPOSE: To obtain the subject spinel-type sintered material colored with a yellow-based color, excellent in transparency and useful as a decorative member for a watch case, etc., by adding MnO to a spinel-type powder having a specified purity and specific surface area, pressure-molding the resultant mixture and subsequently sintering it under normal pressure.
CONSTITUTION: To (A) a spinel-type powder (purity: ≥99.9wt.%, BET specific surface are: ≥5m2/g), (B) a colorant component MnO or an inorganic salt or an alkoxide capable of forming MnO by heating is added in an amount of 10-5000ppm, based on MnO. After pressure-molding the resultant mixture powder, pressureless sintering is carried out at 1500-1800°C and HIP treatment is furthermore carried out at ≥500kg/cm2 and 1500-1800°C as necessary, thus obtaining the objective transparent spinel-type sintered material colored with a yellow- based color.
Next Patent: COLORED TRANSPARENT SPINEL-TYPE SINTERED MATERIAL AND ITS PRODUCTION