| 摘要 |
1501224 Ni based superalloy OFFICE NATIONAL D'ETUDES ET DE RECHERCHES AEROSPATIALES 12 Sept 1975 [13 Sept 1974] 37608/75 Heading C7A A refractory metal composite material obtained by directional solidification comprises a nickelbased superalloy containing: Co 20-30 Cr 6-15 W 7-10 Al 3-6 Nb 4-6 C 0À4-0À65 and Ni balance, and has a matrix in which the Al is present as N 1 3 Al precipitate and a reinforcing phase orientated mono-crystalline NbC fibres formed in situ during uni-directional solidification. Since the difference in coefficient of expansion of the matrix and the fibres is minimized, the material is suitable for aeronautical gas turbine blades where repeated variations in temperature cause rupture of current materials. The composition is adjusted by the addition of Co to ensure that 6% by volume of the reinforcing fibres is present, and the density of the material is maintained about 8À5. |
