摘要 |
A turbine engine vane segment, including spaced apart band or platform members and at least one airfoil member carried at metallic bonds between the platform members, is improved by providing at least one, but not necessarily all, of the segment members as an improved member having a directionally oriented Ni base superalloy microstructure with a stress rupture strength greater than the stress rupture strength of the balance of the segment members, which have a conventional generally equiaxed microstructure. For example, the balance of the members are conventionally cast from a Co base alloy. The coefficient of thermal expansion of the improved member is different from that of the balance of the members. A metallic bond including a brazed structure is provided between the improved member and the balance of the members, possessing strength sufficient to carry the stresses caused by differences in coefficients of thermal expansion of the dissimilar materials.
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