| 摘要 |
A method of bonding an insulation layer (26) to a CMC layer (22) by applying a compliant joining layer (24) between them in a series of steps (52-70) effective to bond the layers (22, 24, 26) with reduced differential shrinkage stresses during firing and reduced residual stresses. The CMC layer (22) and the compliant layer (24) may each be fired to an intermediate stage prior to applying the next layer (24 and 26 respectively), such that the compliant layer (24) has a remaining amount of curing shrinkage between that of the CMC layer (22) and the insulating layer (26) during a final firing stage. The insulation layer (26) may be a friable graded insulation (26F) cast as a composite of hollow ceramic spheres (26S) in a ceramic matrix (26M). The compliant layer (24) may form a checkerboard of cracks (72) oriented generally perpendicular to the layer surface that function to relax stress. The cracks define columns (74) of material that form a bond at opposed ends to the CMC layer and to the insulation respectively.
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