Abstract: The composite of the present invention comprises a layer of ceramic having completely imbedded therein a metal grid, such composite having been made by coating a metal grid with a viscous ceramic slurry and thereafter firing to form the ceramic to a unitary structure. At the temperature to which the composite is fired to form the unitary structure the metal grid is in an expanded condition because of its high coefficient of thermal expansion, and upon cooling the metal grid is put into tension thereby putting the ceramic in compression. The composite is used as a liner for a metal wall which is cast with the liner in situ and is disclosed as having a hollow shape about which the cast wall extends in a manner having particular utility for insulated components of internal combustion engines.

Abstract: The composite of the present invention comprises a layer of ceramic having completely imbedded therein a metal grid, such composite having been made by coating a metal grid with a viscous ceramic slurry and thereafter firing to form the ceramic to a unitary structure. At the temperature to which the composite is fired to form the unitary structure the metal grid is in an expanded condition because of its high coefficient of thermal expansion, and upon cooling the metal grid is put into tension thereby putting the ceramic in compression. The composite has particular utility as thermal insulation for internal combustion engine exhaust systems.

Abstract: A process is disclosed for making a bent metal tube having a metal-ceramic liner for thermally and acoustically insulating the tube. A generally straight metal tube is first lined with a metal grid before bending the tube to a desired shape. Heating of the grid and a ceramic slurry coated thereon forms the slurry into a monolithic ceramic body with the metal grid embedded therein so that the resultant liner provides a durable thermal and acoustic insulation for the tube. Insulated tubes for internal combustion engine exhaust systems are advantageously made by this process with the liner positioned within the tube to provide heat conservation, lower under-hood temperatures, lower noise, and longer tube life as well as allowing the use of lower grade and lighter gauge metal for the tube. The ceramic slurry is disclosed as being coated on the grid before the grid is inserted into the tube, after the insertion but before the bending, or after the insertion and the bending.