Boron Nitride - Polymer Binder Systems for Protection of Reaction Sensitive Ceramics During Sintering

Abstract

A boron nitride (BN)-polymer barrier that isolates and protects boron suboxide (nominally, B6O) and other carbon sensitive ceramic powders during the densification and sintering process is described. The BN-polymer barriers (or “systems”) may include formulations such as free-standing films, appliques (e.g., paints, sprays, coatings, etc.), and solution formulations. Such formulations may be able to be applied to elements such as a graphite mold, die, crucible, and/or graphite paper interlayer. The BN-polymer barrier systems provide superb protection for B6O ceramic powder from reaction with the carbon originating from graphite molds utilized during sintering, thus reducing the need to machine out and grind large portions of sintered ceramic parts where exposure to carbon transforms B6O ceramic into undesirable boron carbide (nominally, B4C). In addition, the polymer binder systems described herein will facilitate the future development of novel ceramic materials previously unavailable due to incompatibility with graphite mold material.

Dependencies are inferred from the claim text.