POROUS SILICON NITRIDE ARTICLE AND METHOD FOR PRODUCTION THEREOF

摘要

A porous silicon nitride article which is prepared by nitriding a formed article containing metallic silicon as a primary component and subjecting the nitrided article to a heating treatment at a temperature higher than that for the above nitriding reaction, characterized in that the silicon nitride article has a porous structure having an average pore diameter of 3 m or more and comprises at least one element selected from the group consisting of the Group 2A, the Group 3A, the Group 3B including lanthanoids and the Group 4B. The porous silicon nitride article has a porous structure having a large average pore diameter and a specimen from the article exhibits a high thermal conductivity and a low thermal expansion coefficient, and thus the article can be suitably used for parts of a gas and/or solution clarification device such as a ceramic filter.