Elsevier

Journal of Crystal Growth

Volume 18, Issue 2, February 1973, Pages 151-158
Journal of Crystal Growth

Unidirectional solidification of monovariant CuNiMg eutectic alloys II. Microstructures and properties

https://doi.org/10.1016/0022-0248(73)90193-0Get rights and content

Abstract

Examination of solidification microstructures showed that the lamellar morphology of the CuCu2Mg binary eutectic is maintained over much of the composition range studied when solidification proceeds with a planar solid/liquid interface. The thermal stability of lamellar monovariant alloys was shown by annealing tests to be unaffected by the presence of nickel. The growth characteristics of the alloys were observed to undergo a gradual transition with added nickel, becoming faceted/nonfaceted in alloys containing 20 at%Ni. Microstructural variations as a function of composition and solidification conditions were determined and are discussed in relation to the tendency toward a faceted/non-faceted growth morphology. Results of room temperature compression tests on lamellar samples containing up to 4 at% Ni showed that, with the exception of fracture strength, no significant variation in the composite properties occurs over this range of composition. The fracture strength of monovariant alloys containing as little as 0.5 at% Ni was significantly greater than that of the binary alloy.

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    Present address: Fuel Materials Branch, Atomic Energy of Canada Ltd., Chalk River, Ontario, Canada.

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