Method of fabricating a metal/ceramic composite structure

A method of producing a metal/ceramic composite structure comprising:

• (a) loading unconsolidated metal or metal alloy powder into a sealable glass mold comprising a hollow ceramic sleeve and a sealable outer glass envelope surrounding the ceramic sleeve and forming with the outer wall of the ceramic sleeve a sealable chamber for the metal or metal alloy powder, wherein the glass is of a type that becomes plastic when heated;
• (b) evacuating the atmosphere from the metal or metal alloy powder filled chamber in the mold;
• (c) sealing the chamber;
• (d) placing the mold in an open top refractory container and packing with free flowing refractory powder selected to freely flow at all the temperatures in the process;
• (e) heating the mold and the metal or metal alloy contents of the mold at a temperature at which sintering of the metal or metal alloy powder takes place and holding at this temperature for a time sufficient to cause substantially complete densification of the powered metal or metal alloy, during which step the mold is supported by the free flowing refractory powder as the glass sleeve and the glass envelope become plastic and the mold shrinks in volume as its metal or metal contents densify and are compressed against the hollow ceramic sleeve;
• (f) cooling and removing the glass portion of the mold to leave a composite article comprising the consolidated metal or metal alloy layer surrounding and placing the hollow ceramic sleeve under both axial and radial compression.