Layered structure of Ni-Al multi-layered metal-intermetallic composites fabricated by in-situ reactions

摘要

Systematical experiments were done at five temperature levels: 500 deg C , 630 deg C , 900 deg C , 1 000 deg C and 1 100 deg C 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 Ni_2 Al_3 and there exists a like two-phase field between NiAl3 and Ni2 A13. The high temperature phases like NiAl and Ni_3 Al 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.