Since layered aluminate coatings such as β"-alumina are being considered for tailoring the interfacial propertiesof oxidation-resistant fiber-reinforced composites, stresses arisingfrom thermal expansion mismatch were calculated for thesubstrate fiber and coating. Both isotropic and anisotropic β"-alumina coatings were analyzed for yttrium aluminum garnet andsingle crystal and polycrystalline alumina fibers. It was possible torank the various fiber-coating combinations in terms of themagnitude of maximum tensile stresses present in the coating.Polycrystalline alumina + isotropic β"-alumina yielded the lowesttensile stresses with radial stress on the order of 10 MPa, whilesingle crystal alumina + anisotropic β"-alumina yielded the highesttensile stresses with tangential stress on the order of >100 MPa.
展开▼
