Ceramic-metal composites

A reinforced composite structure comprising a heat resistant layer of a chemically-bonded ceramic composition mechanically attached to a metallic substrate,

• said structure including a metallic anchoring matrix characterized by a unitary structure formed of a plurality of spatially and cooperably arranged reinforcing elements,
• said matrix being substantially uniformly metallurigcally bonded to said substrate and projecting from the surface thereof with the spatially arranged reinforcing elements of said matrix collectively defining a ceramic-occupiable zone of finite thickness adjacent to and following the surface configuration of said substrate,
• said zone having at least confined therein said heat resistant chemically-bonded ceramic composition in intimate and mechanically-bonded contact with said reinforcing elements,
• said chemically-bonded ceramic composition having been produced by mixing a low-temperature bonding agent with said ceramic composition and heating said mixture to a low temperature below the normal sintering temperature of said ceramic when the low-temperature chemical bonding agent is not present, said chemical bonding temperature being below about 1095.degree. C.,
• wherein said composition of reinforced heat resistant ceramic is strongly mechanically bonded as a layer to said substrate by virtue of said metallic matrix metallurgically bonded to said substrate.

As an article of manufacture, a heat resistant abradable seal for use at elevated temperatures formed of a reinforced composite structure comprising a heat resistant chemically-bonded layer of a ceramic composition mechanically attached to a metallic substrate,

• said structure including a metallic anchoring matrix characterized by a plurality of spatially and cooperably arranged reinforcing elements, said matrix being substantially uniformly attached over the surface of said substrate and projecting from the surface thereof with the spatially arranged reinforcing elements of said matrix collectively defining a ceramic-occupiable zone of finite thickness adjacent to and following the surface configuration of said substrate,
• said zone having at least confined therein said heat resistant chemically-bonded ceramic composition in intimate and mechanically-bonded contact with said reinforcing elements,
• said chemically-bonded ceramic composition having been produced by mixing a low-temperature chemical bonding agent with said ceramic composition and heating said mixed composition to a low temperature below the normal sintering temperature of said ceramic when the low-temperature chemical bonding agent is not present, said chemical bonding temperature being below about 1095.degree. C.,
• whereby said abradable seal is strongly mechanically bonded as a layer to said substrate by virtue of said metallic matrix attached to said substrate.

As an article of manufacture, a heat resistant abradable seal for use at elevated temperatures formed of a reinforced composite structure comprising a heat resistant layer of a chemically-bonded ceramic composition mechanically attached to a metallic substrate,

• said structure including a metallic anchoring matrix characterized by a unitary structure formed of a plurality of spatially and cooperably arranged reinforcing elements,
• said matrix being substantially uniformly metallurgically bonded to said substrate and projecting from the surface thereof with the spatially arranged reinforcing elements of said matrix collectively defining a ceramic-occupiable zone of finite thickness adjacent to and following the surface configuration of said substrate,
• said zones having at least confined therein said heat resistant chemically-bonded ceramic composition in intimate and mechanically-bonded contact with said reinforcing elements,
• said chemically-bonded ceramic composition having been produced by mixing a low-temperature bonding agent with said ceramic composition and heating said mixture to a low temperature below the normal sintering temperature of said ceramic when said low-temperature chemical bonding agent is not present, said chemical bonding temperature being below about 1095.degree. C.,
• whereby said abradable seal is strongly mechanically bonded as a layer to said substrate by virtue of said metallic matrix metallurgically bonded to said substrate.