Ceramic coated abrasion resistant member and process for making

Abstract

A ceramic coated abrasion resistant member and method of making are described in which a plurality of thin plates of polycrystalline ceramic material of small size, for example, a square plate measuring 1.0 inch by 1.0 inch having a thickness less than 0.200 inch are bonded to a thicker substrate base member with a uniform layer of organic adhesive bonding material. The bonding material includes a thermosetting organic plastic adhesive and a coupling agent which forms covalent chemical bonds with the ceramic plates, base member and plastic adhesive. An organosilane, such as .gamma.-aminopropyl trimethoxy silane, may be used as the coupling agent. The ceramic material may be selected from the group consisting of aluminum oxide, zirconium oxide, silicon carbide, silicon nitride, and spinel ceramic materials. The substrate member is preferably metal, such as steel and the plastic adhesive may be an epoxy resin. The ceramic coated abrasion resistant member may be an impeller blade such as the blades of a high speed fan for conveying coal dust or other abrasive particulate material through a conduit, or the blades of a pump impeller for pumping abrasive liquid. In the process for making the abrasion resistant member, the substrate base member and the ceramic plates are coated on the surfaces to be bonded with a thin layer of coupling agent of about one molecule thickness before they are bonded together with the thermosetting organic plastic adhesive.