In-situ formed thermal barrier coating for a ceramic component

An apparatus comprising:

• an inner load-bearing portion of a ceramic oxide material exhibiting a first thermal conductivity and a first strength;
• a cooling passage effective to cool the inner load-bearing portion;
• an outer heat-affected thermal barrier portion of the ceramic oxide material integrally connected in graded fashion with the inner load-bearing portion;
• the outer portion exhibiting a graded thermal conductivity range higher than the first thermal conductivity and a graded strength range lower than the first strength resulting from exposure of a surface of the ceramic oxide material to a high temperature while the inner load-bearing portion of the ceramic oxide material is cooled by coolant passing through the cooling passage;
• and
• a thickness of the outer portion effective to provide a desired degree of thermal protection to the cooled inner load-bearing portion during use of the apparatus in a high temperature environment such that a strength of the inner load-bearing portion remains greater than a level of stress applied to the inner load-bearing portion.

An apparatus comprising:

• a structural member comprising an oxide-oxide ceramic matrix composite material;
• an outer heat-affected layer having a thickness of at least 0.25 mm formed in the oxide-oxide ceramic matrix composite material and effective to thermally insulate an underiying structural layer of the oxide-oxide ceramic matrix composite material from an exterior environment;
• and
• reinforcing fibers of the oxide-oxide ceramic matrix composite material extending to interconnect the outer heat-affected layer with the underlying structural layer.

An airfoil comprising:

• a stacked plurality of plates, each plate comprising an oxide-oxide ceramic matrix composite material comprising an outer surface defining an airfoil shape;
• an outer heat-affected portion of each plate collectively defining a thermal barrier layer for the airfoil effective to thermally protect an underlying structural portion of each plate from an exterior environment;
• and
• reinforcing fibers of the oxide-oxide ceramic matrix composite material extending to interconnect the outer heat-affected portion with the underlying structural portion.

An apparatus comprising:

• an inner load-bearing portion of a ceramic oxide material;
• a coolant applied to the inner load-bearing portion;
• an outer heat-affected thermal barrier portion of the ceramic oxide material integrally connected in graded fashion with the inner load-bearing portion, the outer heat-affected thermal barrier portion formed by exposure of a surface of the ceramic oxide material to a high temperature while the inner load-bearing portion of the ceramic oxide material is cooled by the coolant;
• and
• a plurality of cracks extending from the surface into the outer portion and formed as a result of residual stresses generated in the outer portion by the exposure of the surface to the high temperature and subsequent cool down, the plurality of cracks effective to provide stress relief in the outer portion.