Layered structure of Ni-Al multi-layered metal-intermetallic composites fabricated by in-situ reactions
(1. State Key Laboratory of Metal Matrix Composites, Shanghai Jiaotong University,
Shanghai 200030, China;
2. School of Materials Science and Engineering, Hebei University of Technology,
Tianjin 300132, China;
3. Division of Engineering, Brown University, Providence, USA)
Shanghai 200030, China;
2. School of Materials Science and Engineering, Hebei University of Technology,
Tianjin 300132, China;
3. Division of Engineering, Brown University, Providence, USA)
Abstract: Systematical experiments were done at five temperature levels: 500℃, 630℃, 900℃, 1000℃ and 1100℃ to illuminate the layer structure of the multi-layered metal-intermetallic composites of Ni-Al system that were fabricated by a previously reported simple and cost-effective method. The analysis of back scattering photos and XRD examination of specimens reveal that the look like single compound layer is composed of several different components. The primary phase produced during reaction is Ni2Al3 and there exists a like two-phase field between NiAl3 and Ni2Al3. The high temperature phases like NiAl and Ni3Al are also found at low temperature. The results indicate that the key driving force of in-situ reaction is not temperature, but the atom concentration.
Key words: intermetallic compound; in-situ reaction; layered structure; back scattering photo