What determines the peak-temperature in binary Ni₃Al?

Autor(en)

C. Rentenberger, H. P. Karnthaler

Abstrakt

In Ni₃Al alloys the yield stress increases with increasing temperature up to a maximum stress, reached at the temperature T_p. Below T_p glide occurs on primary octahedral planes whereas above T_p glide on primary cube planes is dominating. Therefore this change of glide planes was considered to determine T_p. TEM investigations were carried out to study the mechanisms that control T_p in Ni₃Al specimens with [001] compression axis. In this case no shear stresses are acting on any of the cube glide systems. The TEM results show a pronounced change of the dislocation structure on the {111} glide planes below and above the peak. The breakdown of the barriers (locked screw dipoles) starts when the diffusion is high enough to facilitate their annihilation. The dynamic recovery of the locked screws occurs by multiple cross-slip via octahedral planes. It is proposed that, in this and other ordered alloys, the value of T_p is diffusion controlled.

Organisation(en)

Physik Nanostrukturierter Materialien

Band

364

Seiten

689-694

Anzahl der Seiten

6

DOI

https://doi.org/10.1557/PROC-364-689

Publikationsdatum

1994

Peer-reviewed

Ja

ÖFOS 2012

103042 Elektronenmikroskopie, 103018 Materialphysik

ASJC Scopus Sachgebiete

Allgemeine Materialwissenschaften, Condensed Matter Physics, Mechanics of Materials, Mechanical Engineering

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/ac0d5684-5afa-46fe-a0b3-55ca1145d01a