Oxidation-induced cavity formation in binary β-NiAl alloys

被引：0

作者：

Zimmermann, D. ^{[1
]}

Bobeth, M. ^{[2
]}

Rühle, M. ^{[1
]}

Clarke, D.R. ^{[3
]}

机构：

[1] Max-Planck-Institut für Metallforschung, Stuttgart, Germany

[2] Technical University of Dresden, Dresden, Germany

[3] Materials Department, University of California, Santa Barbara,CA, United States

来源：

International Journal of Materials Research | 2004年 / 95卷 / 02期

关键词：

Alpha alumina - Cavity form - Cavity formation - Flux divergences - Interdiffusion - Inward diffusion - NiAl alloy - Outward diffusion - Phases transformation - β-NiAl;

D O I：

10.3139/ijmr-2004-0020

中图分类号：

学科分类号：

摘要：

Previously, it has been established that oxidation-induced cavitation of binary NiAl alloys occurs primarily when Nirich compositions are oxidized. In this work it is shown that at 1100 °C cavities form principally during the very early stages of oxidation for these compositions. During this time, the growing oxide is a transient, theta-alumina whereas on the Al-rich compositions the growing oxide rapidly transforms to alpha alumina. It is concluded that cavity formation is associated with tensile stresses generated by the flux divergence created by the outward diffusion of Al during the growth of theta-alumina and the inward diffusion of nickel. Once the transient oxide transforms to alpha alumina, the outward flux of aluminum is decreased and with it the flux divergence. Values for the inter-diffusion coefficients for the alloys investigated, derived from the diffusion profiles, are also reported. © 2004 Carl Hanser Verlag, München.

引用

页码：84 / 90