DISCONTINUOUS IN THE NI-CO-AL PRECIPITATION ALLOY SYSTEM

The synthesis of nanoplates of 0 by use of discontinuous precipitation was investigated in the Ni-Co-Al alloy system. A series of experiments, such as heat treatment, cold rolling, and electrolytic etching, have been performed to develop the desired microstructure. Nanostructured materials have great potential in a number of applications, such as catalysis, light weight structural materials, thermal management and pollution reduction. Kinetic information of the Ni-Co-Al alloy was obtained through measuring the optical micrographs of samples aged at di erent temperatures. The morphology of the nanostructure of the Ni-Co-Al alloy was investigated using scanning electron microscopy (SEM). The mechanical property (hardness) of the Ni-Co-Al alloy was obtained in di erent conditions as well. The Ni-Co-Al alloys were recrystallized in di erent ways. The texture of the alloys were determined using electron backscattered di raction (EBSD). After analyzing those experimental results, we nd that the discontinuous precipitation goes to completion in the Ni-Co-Al alloy. The discontinuous precipitates present a lamellar structure. The size of plates is similar with the spacing between plates and achieves a nanoscale architecture. The TTT curve of the Ni-Co-Al alloy with a composition of 43 at.% Ni, 48 at.% Co and 9 at.% Al provides abundant kinetic information. Further work is needed to produce a strong cube texture ((100) planes parallel to the foil surface).M.S. in Materials Engineering, May 201