| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon nitride sintered compact especially excellent in corrosion resistance in hot acid and alkaline solutions, having high strength and capable of easily be compacted, and to provide a method for producing the same compact. SOLUTION: This silicon nitride sintered compact contains 0.1-2 wt.% magnesium in terms of MgO, 0.1-2 wt.% aluminum in terms of Al2O3, 0.5-2 wt.% tantalum in terms of Ta2O5 and 1-5 wt.% zirconium in terms of ZrO2. The total content of Mg, Al and Ta is preferably <=4 wt.% in terms of their oxides. The sintered compact is easily produced at a low cost by the gas power burning of silicon nitride powder with a preferred sintering additive powder in a nitrogen atmosphere especially at 10-100 kg/cm2 pressure. In addition, burning in a reducing atmosphere leads to the formation of a sintered compact containing TaC as tantalum, which has the high value of commodity suppressed in uneven coloring. |
