PRODUCTION OF TRANSPARENT COMPOUND SINTERED MATERIAL OF ALUMINUM OXYNITRIDE

摘要

PURPOSE:To obtain the subject sintered material having excellent transparency in a short time at a low temperature compared with conventional process by mixing a specific amount of a Y compound to a mixture of Al2O3 powder and AIN powder at a specific ratio and pressing and sintering the mixture under specific condition. CONSTITUTION:A mixture composed of 86.5-93.4wt.% of Al2O3 powder, 6.6-13.5wt.% of AIN powder and =10wt.% of a Y compound (based on the above powders in terms or Y2O3) is sintered at 1750-1900 deg.C for 1-10hr under a pressure of =100kgf/cm2 to obtain a compound sintered material at least containing Al23O27N5 phase and Al11O15N phase as constituent matrices. The sintering can be promoted and performed at a lower temperature because the Y compound and the Al11O15N phase form liquid phase at a low temperature compared with Al23O275N. Al11O15N phase is formed in the sintered material when the ratio of Al2O3 to AIN is within the above range. When the sintering temperature is lower than the lower limit, the transparency of the product is deteriorated and when it exceeds the upper limit, sufficiently sintered material cannot be obtained. The transparency becomes poor when the sintering time is shorter than the lower limit and there is no formation of Al11O15N phase when the time is longer than the upper limit.