The Influence of Interlamellar Spacing on the Strength of the Ni3Al-Ni3Cb Eutectic.
UNITED AIRCRAFT RESEARCH LABS EAST HARTFORD CONN
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The temperature dependence of the tensile properties was determined for the eutectic after directional solidification at rates between 0.5 and 10.6 cmhr. The cubic gamma in the eutectic grows in the 110 and the orthorhombic delta in the 100. The preferred slip plane of the delta phase is parallel to the growth direction and, in response to a longitudinal stress, deformation in the delta occurred initially by twinning. The lamellar spacing which decreased with increased solidification rate was found to affect the tensile strength of the eutectic according to a Hall-Petch correlation. By decreasing the spacing by a factor of 4.7, the room temperature strength was increased by 35 percent and the strength at 2000F by 100 percent. The eutectic grown at 10.6 cmhr possessed the phenomenal strength of 130,000 psi at 2000F. Author
- Properties of Metals and Alloys