Dynamics of metal/ceramic interface formation.

McCarty, Kevin F.

Sandia National Laboratories

关键词: 36 Materials Science;    Crystal Structure;    Nickel Oxides;    Interfaces;    Nickel Alloys;   

DOI  :  10.2172/918253
RP-ID  :  SAND2003-8730
RP-ID  :  AC04-94AL85000
RP-ID  :  918253

美国|英语

来源: UNT Digital Library

【 摘 要 】

We summarize the work of the Laboratory Directed Research and Development (LDRD) project 'Dynamics of Metal/Ceramic Interface Formation.' Low-energy electron microscopy (LEEM) was used to monitor in real time how the metal/ceramic interface between the alloy NiAl and its oxide formed. The interfaces were synthesized by exposing the clean alloy to oxygen at either low or high temperature. During low-temperature exposure, an initially amorphous oxide formed. With annealing, this oxide crystallizes into one type of alumina that has two orientational domains. While the oxide is relatively uniform, it contained pinholes, which coarsened with annealing. In marked contrast, high-temperature exposure directly produced rod-shaped islands of crystalline oxide. These rods were all aligned along the substrate's [001] direction and could be many microns in length. Real-time observations showed that the rods can both grow and shrink by addition and subtraction, respectively, at their ends.