Effect of growth conditions on the structure of directionally solidified. gamma. /. gamma. '-delta eutectic

Journal Article · Sat Sep 01 04:00:00 EDT 1979 · Metall. Trans., B; (United States)

DOI:https://doi.org/10.1007/BF02652509· OSTI ID:5796924

Farag, M M ^[1]; Matera, R; Flemings, M C

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1. American Univ., Cairo, Egypt

..gamma../..gamma..'-delta eutectic alloy containing 21.5 wt pct Nb, 2.5 wt pct Al, balance Ni was directionally solidified under a thermal gradient (G) of 500 K/cm and different schedules of growth rate (R). Under steady state growth rate conditions, the critical (G/R) for plane front solidification is 25 K h/cm/sup 2/. At progressively lower (G/R) the structure becomes richer in ..gamma..-phase, i.e. hypoeutectic. Sudden increase in growth speed causes the structure to change from lamellar to cellular and gradual increase in growth speed results in interlamellar spacings that are larger than the extremum values. Sudden decrease in growth speed causes little disturbance in the structure but causes the eutectic grain size to increase.

• OSTI ID: 5796924
• Journal Information: Metall. Trans., B; (United States), Journal Name: Metall. Trans., B; (United States) Vol. 10B:3; ISSN MTTBC
• Country of Publication: United States
• Language: English

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