The precipitation of second phases in Incoloy 909 has been studied using optical microscopy, scanning electron microscopy, and transmission electron microscopy. The compositions and crystal structures of several second phases were determined by analytlcal electron microscopy. A time–temperature–transformation diagram was constructed. The Si addition was found to promote the precipitation of an Fe2Nb type Laves phase during casting and thermal processing, and the formation of Si rich orthorhombic phase at high aging temperatures. Both types of precipitate are considered to enhance the rupture properties of the alloy.
MST/1748
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References
1.
MUZYKAD. R., WHITNEYC. R., and SCHLOSSERD. K.:J. Met., July 1975, 11-15.
2.
CARPENTERH. W.: Met. Prog., Aug. 1976, 25-29.
3.
SMITHD. F. and CLATWORTHYE. F.: Met. Prog., March 1988, 32-35.
4.
SMITHD. E and SMITHJ. S.: in ‘Superalloys 1984’, (ed. M. Gell et al.), 591-600; 1984, Warrendale, PA, The Metallurgical Society of AIME.
5.
BRICKNELLR. H. and WOODFORDD. A.: Metall. Trans., 1981, 12A, 1673-1680.
6.
CIESLAKM. J., HEADLEYT. J., KNOROVSKYG. A., A. D. ROMIG, Jr, and T. KOLLIE: Metall. Trans.,1990, 21A, 479–488.
7.
CHENZ.: Scr. Metall.,1992, 26, 1077–1082.
8.
SPIEGELF. X., BARDOSD., and BECKP. A.: Trans. Metall. Soc. AIME, 1963, 227, 575-579.
9.
HECKK. A., SMITHD. H., SMITHJ. S., WELLSD. A., and HOLDERBYM. A.: in Superalloys 1988’, (ed. S. Reichman et al.), 151-160; 1988, Warrendale, PA, The Metallurgical Society of AIME.
10.
WANNERE. A., DeANTONIOD. A., and MAHIDHARAR. K.: in ‘Superalloys 1988’, (ed. S. Reichman et al.), 161-170; 1988, Warrendale, PA, The Metallurgical Society of AIME.
11.
SMITHD. F. and SMITHJ. S.: in ‘Physical metallurgy of controlled expansion Invar-type alloys’, (ed. RussellK. C. and SmithD. F.), 253-271; 1990, Warrendale, PA, TMS.
