Formation of Ti2AlN by Solid-Gas Combustion Synthesis with AlN- and TiN-Diluted Samples in Nitrogen

Ti2AlN was prepared by a self-propagating high-temperature synthesis (SHS) in nitrogen at 0.45 and 0.79MPa. TiN and AlN were adopted as diluents in the Ti-Al powder compacts and their contents varied from 8.3 to 25 mol%. Formation of Ti2AlN along with intermediates like TiN, Ti3Al, and TiAl was identified. For the AlN-added samples, the degree of dilution at 11.7 mol% brought about the optimum formation up to 81.8% Ti2AlN in nitrogen of 0.79 MPa. When the sample was diluted with 20 mol% TiN, the SHS process yielded the highest percentage of Ti2AlN reaching 84.3% in nitrogen of 0.45 MPa.