Synthesis and Properties of the Composite Material Based on a (V,Cr)AlC Solid Solution.

A material based on a (VCr)₂AlC solid solution has been obtained for the first time by self-propagating high-temperature synthesis from a powder reaction mixture of vanadium(V) and chromium(III) oxides with aluminum and carbon (graphite). The synthesized material has been studied by X-ray diffraction and microstructural analyses. It has been shown that the product also contains vanadium and chromium carbides and intermetallics. The presence of these phases seems to be associated with the nonequilibrium character of the synthesis process due to a short "lifetime" of melt and its fast cooling and crystallization. The synthesized material is an electrical conductor, which demonstrates a metallic character of conductivity throughout the entire measured temperature range of 300–1300 K. The room-temperature specific resistance of the composite material based on a (Cr,V)₂AlC solid solution is 1.14 µΩ m, which is higher than the specific resistance of the materials based on the Cr₂AlC and V₂AlC MAX phases. The microhardness of the synthesized material is 6.9 GPa. [ABSTRACT FROM AUTHOR]