Phase transformations in an in situ Nb-reinforced Nb3Al intermetallic composite

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)23-29
Journal / PublicationIntermetallics
Volume4
Issue number1
Publication statusPublished - 1996
Externally publishedYes

Abstract

The development of two-phase Nb/Nb3Al in situ composite microstructures by thermal treatment in a Nb-6wt.%Al alloy, processed through powder-metallurgy techniques, is examined in detail using transmission and scanning electron microscopy. Observations reveal that the precipitation of Nb3Al in a heavily dislocated Nb solid solution matrix initiates at grain boundaries and progresses along the <110> and <211> directions in the matrix and Nb3A1 precipitate, respectively; the precipitates eventually fuse into small, elongated grains with 1-10 μm dimensions. The evolution of the in situ composite microstructure from the hot-pressed equiaxed structure proceeds by a diffusion-controlled nucleation and growth transformation and not by a massive transformation. The lamellar microstructure of the alloy displays a five-fold increase in toughness over unreinforced Nb3Al primarily due to crack bridging and plastic deformation associated with the ductile Nb phase.

Research Area(s)

  • Fracture toughness, In situ composites, Nb3Al

Citation Format(s)

Phase transformations in an in situ Nb-reinforced Nb3Al intermetallic composite. / Bencher, C. D.; Murugesh, L.; Rao, K. T. V.; Ritchie, R. O.

In: Intermetallics, Vol. 4, No. 1, 1996, p. 23-29.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review