Coating reinforcing fibre - with oxide barrier coating, used in ceramic matrix composite material

摘要

An oxidic barrier coating of preselected microstructure and thickness is applied to a reinforcing fibre of predetermined dia. by applying a layer of metal salt and then thermally decomposing the salt to a metal oxide which does not deleteriously chemically react with the fibre at the intended service temps. The metal salt concn. in the layer is selected to obtain the preselected coating microstructure and the layer thickness is selected to result in a metal oxide coating thickness of 0.05 to less than 7% of the fibre dia. - Also claimed are: (i) a reinforcing fibre of preselected dia., which can be exposed to an oxidising atmos. at more than 1000 deg.C without deleterious change in mechanical properties and which has a barrier coating of ZrO2 and/or HfO2 with a thickness of 0.05 to less than 7% of the fibre dia.; etc.