Porous sintered reaction-bonded silicon nitride body and manufacturing methods for the same

摘要

PURPOSE: A porous sintered reaction-bonded silicon nitride body and a method for manufacturing the same are provided to increase the ventilating characteristic and the trapping efficiency by controlling the sizes of pore channels. CONSTITUTION: A raw material containing silicon and a sintering agent is granulized. The granulized raw material is pre-sintered at inert atmosphere. The pre-sintered granulized raw material is pressure-molded to obtain a molded body. The molded body is pre-sintered at hydrogen/nitrogen mixed gas atmosphere. The molded body is post-sintered at nitrogen atmosphere at temperature between 1700 and 1900 degrees Celsius. The sintering agent includes yttria and alumina. At least one alkaline earth metal oxide is further included in the sintering agent.