Micropyretic synthesis studies of Ni-, Al-, Ti-, and Nb-containing alloys

A series of new micropyretically synthesized complex intermetallics and intermetallic composites containing Ni, Al, Ti, and Nb have been studied. At the extremities of this series were the two alloys with the B(2) structure, namely, the NiAl and Nb(45)Al(15)Ti(40) intermetallic compounds, the former being brittle and the latter ductile. The alloys in the series were made by adding Ti and Nb to NiAl and processing them by micropyretic methods. In addition to the matrix B(2) phase, the synthesized alloys were found to contain other phases. Some of the alloys in the series were noted to possess high fracture toughness and oxidation resistance. A detailed microstructural characterization of the synthesized alloys was carried out. The mechanism of synthesis in the alloys has been established by microstructural examination of the partially reacted specimens by arresting the combustion process during the synthesis process.