Nucleation and growth of the <script type="math/tex">Ni_{5}Al_{3}</script> phase in Ni-Al austenite and martensite

Schryvers, D.; Toth, L.; Ma, Y.; Tanner, L.

doi:10.1051/JP4:1995246

Title

Nucleation and growth of the $Ni_{5}Al_{3}$ phase in Ni-Al austenite and martensite

Author

Schryvers, D.

Toth, L.

Ma, Y.

Tanner, L.

Abstract

The nucleation and growth mechanisms of Ni5Al3 precipitates and microtwinned plates in B2 austenite and 2M (3R) martensite phases are described on the basis of conventional and high resolution electron microscopy. In the Ni62.5Al37.5 B2 austenite matrix short annealings at 550 degrees C introduce three-pointed star shaped precipitates consisting of twin related parts of different variants of the Ni5Al3 structure. Longer annealings result in plates growing separately from these wings and developing microtwinning in order to accommodate stress built-up at the interfaces with the surrounding matrix. Annealing of Ni65Al35 2M martensite plates induces simple reordering into the Ni5Al3 phase, increasing the fct c/a ratio by about 1%. As a result stracking faults are introduced in the smallest twin variants.

Language

English

Source (journal)

Journal de physique: 4. - Les Ulis, 1991 - 2006

Source (book)

IIIrd European Symposium on Martensitic Transformations (ESOMAT 94), SEP 14-16, 1994, BARCELONA, SPAIN

Publication

Les Ulis : 1995

ISSN

1155-4339

DOI

10.1051/JP4:1995246