Self accomodation morphology of martensite variants in Zr2.5wt%Nb alloy

Srivastava, D.; Madangopal, K.; Banerjee, S.; Ranganathan, S.

doi:10.1016/0956-7151(93)90224-g

Cited by 61 publications

(27 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The self-accommodation effect has also been proposed in some other Zr-Nb alloys. [22,24,35] The shape strain associated with the martensite crystal nucleation can be minimized by simultaneous nucleation of a group of nonparallel martensite plates or when one plate sympathetically nucleates another, which has been suggested as the motivation for self-accommodation. In this process, the strain fields of individual martensite plates interact with each other in such a way that the total transformation strain energy becomes minimized.…”

Section: A Martensite Formationmentioning

confidence: 99%

“…This observation was found to be consistent with that of Srivastava et al [35] The observation of the {334} C type habit plane of the lath martensite was consistent with the earlier observations made in Zr-Nb alloys and other alloys. [22][23][24][25] The observation of packets in some regions consisting of two-variant and three-variant combinations of the mutually twin-related martensite laths suggested the possibility of self-accommodation. The self-accommodation effect has also been proposed in some other Zr-Nb alloys.…”

Section: A Martensite Formationmentioning

confidence: 99%

“…The phenomenological theory of martensite crystallography (PTMC) has been used successfully to predict the substructure of the martensite crystals. [22][23][24][25][26][27][28][29][30][31] The morphology and substructure of the martensite have been found to be essentially governed by factors such as alloy composition and self-accommodation tendency. [23,25,32] In the present study, the M s value has been roughly estimated for the Zr-1Nb alloy.…”

Section: A Martensite Formationmentioning

confidence: 99%

See 2 more Smart Citations

Microstructural Evolution in Zr-1Nb and Zr-1Nb-1Sn-0.1Fe Alloys

Neogy

Srivastava

Chakravartty

et al. 2007

Metall Mater Trans A

Self Cite

View full text Add to dashboard Cite

This article summarizes the evolution of microstructure in binary Zr-1Nb and quaternary Zr-1Nb-1Sn-0.1Fe alloys after (1) b quenching and tempering and (2) cold working and annealing. The morphologies of constituent phases and precipitates, their shape, size, and nature have been studied in detail using transmission electron microscopy (TEM). The b-quenched alloys, in general, exhibited a lath martensitic microstructure. On tempering, the martensitic microstructure underwent considerable changes with respect to the lath dimensions and precipitation behavior, ultimately leading to an equiaxed recrystallized microstructure. Annealing studies of cold-worked binary alloy showed precipitation of the b phase with varying Nb content depending on the heat-treatment temperature and time. In the quaternary alloy, precipitation of the Zr-Nb-Fe type phase along with the b phase took place on annealing the cold-worked samples. High-resolution electron microscopy (HREM) of the recrystallized microstructures was carried out to study the internal structure and the interface structure of the precipitating phases. In the annealing study, mechanical properties of the annealed samples were also determined. Microstructural observations together with mechanical property data concluded that in both alloys, complete recrystallization of the cold-worked microstructures took place on annealing the samples at 853 K for 1 hour.

show abstract

Section: A Martensite Formationmentioning

confidence: 99%

Section: A Martensite Formationmentioning

confidence: 99%

Section: A Martensite Formationmentioning

confidence: 99%

See 1 more Smart Citation

Microstructural Evolution in Zr-1Nb and Zr-1Nb-1Sn-0.1Fe Alloys

Neogy

Srivastava

Chakravartty

et al. 2007

Metall Mater Trans A

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, martensite plates containing internal twins on {10 1} in Zr-2.5Nb exhibit a 1 {334} ␤ habit plane and a twin thickness ratio of 1:4, [22] as compared to {3, 3.161, 4.1663} ␤ and 1:4.119, respectively. [23] We shall now examine the condition of ILS in the ␤-␣ transformation, which, as will be shown later, governs the crystallography of a number of diffusional transformations. The invariant line of a given transformation can be determined from a knowledge of the transformation strain associated with the lattice distortion and the rigid body rotation.…”

Section: Lattice Correspondence and Orientation Relationsmentioning

confidence: 99%

“…[12,22,23,27,28] In a recent article, self-accommodating morphologies of martensite variants in the Zr-2.5Nb alloy were described and discussed. [23] The martensite morphologies in these alloys can be classified into the following categories.…”

Section: Martensite Productsmentioning

confidence: 99%

Plate-shaped transformation products in zirconium-base alloys

Banerjee

Dey

Srivastava

et al. 1997

Metall Mater Trans A

Self Cite

View full text Add to dashboard Cite

Plate-shaped products resulting from martensitic, diffusional, and mixed mode transformations in zirconium-base alloys are compared in the present study. These alloys are particularly suitable for the comparison in view of the fact that the lattice correspondence between the parent ␤ (bcc) and the product ␣ (hcp) or ␥-hydride (fct) phases are remarkably similar for different types of transformations. Crystallographic features such as orientation relations, habit planes, and interface structures associated with these transformations have been compared, with a view toward examining whether the transformation mechanisms have characteristic imprints on these experimental observables. Martensites exhibiting dislocated lath, internally twinned plate, and self-accommodating three-plate cluster morphologies have been encountered in Zr-2.5Nb alloy. Habit planes corresponding to all these morphologies have been found to be consistent with the predictions based on the invariant plane strain (IPS) criterion. Different morphologies have been found to reflect the manner in which the neighboring martensite variants are assembled. Lattice-invariant shears (LISs) for all these cases have been identified to be either {10 1} ␣ ͗ 123͘ ␣ slip or twinning on {10 1} ␣ planes. Widmanstätten ␣ 1 1 1 precipitates, forming in a step-quenching treatment, have been shown to have a lath morphology, the ␣/␤ interface being decorated with a periodic array of ͗c ϩ a͘ dislocations at a spacing of 8 to 10 nm. The line vectors of these dislocations are nearly parallel to the invariant lines. The ␣ precipitates, forming in the retained ␤ phase on aging, exhibit an internally twinned structure with a zigzag habit plane. Average habit planes for the morphologies have been found to lie near the {103} ␤ Ϫ {113} ␤ poles, which are close to the specific variant of the {112} ␤ plane, which transforms into a prismatic plane of the type {1 00} ␣ . The crystallography of the formation of the ␥-hydride phase (fct) 1 from both the ␣ and ␤ phases is seen to match the IPS predictions. While the ␤-␥ transformation can be treated approximately as a simple shear on the basal plane involving a change in the stacking sequence, the ␣-␥ transformation can be conceptually broken into a ␣ → ␤ transformation following the Burgers correspondence and the simple ␤-␥ shear process. The active eutectoid decomposition in the Zr-Cu system, ␤ → ␣ ϩ ␤', has been described in terms of cooperative growth of the ␣ phase from the ␤ phase through the Burgers correspondence and of the partially ordered ␤' (structurally similar to the equilibrium Zr 2 Cu phase) through an ordering process. Similarities and differences in crystallographic features of these transformations have been discussed, and the importance of the invariant line vector in deciding the geometry of the corresponding habit planes has been pointed out.

show abstract

Martensitic Transformations

2012

Crystallography and Crystal Defects

View full text Add to dashboard Cite

Self accomodation morphology of martensite variants in Zr2.5wt%Nb alloy

Cited by 61 publications

References 14 publications

Microstructural Evolution in Zr-1Nb and Zr-1Nb-1Sn-0.1Fe Alloys

Microstructural Evolution in Zr-1Nb and Zr-1Nb-1Sn-0.1Fe Alloys

Plate-shaped transformation products in zirconium-base alloys

Martensitic Transformations

Contact Info

Product

Resources

About