High-temperature synthesis of composite materials based on (Cr, Mn, V)–Al–C MAX phases

Abstract

Composite materials based on (Cr, Mn, V)–Al–C MAX phases were obtained by self-propagating high-temperature synthesis (SHS). Regularities of synthesis of composite materials from mixtures containing chromium (III) oxide, manganese (IV) oxide, vanadium (V) oxide, calcium (IV) oxide, aluminum, and carbon powders were studied. The synthesis of 30-g blend was carried out in an SHS reactor with a volume of 3 l under Ar pressure (5 MPa). Variation in the amount of the starting reagents markedly affected the process parameters, phase composition, and microstructure of combustion products. The combustion products were characterized by XRD, SEM, and EDS analysis. For Cr–Al–C system, MAX Cr2AlC phase in addition to chromium aluminide Cr5Al8 and chromium carbides (Cr7C3, Cr3C2) was detected. SEM studies showed that Cr2AlC has a laminated structure with layer thickness varying from 3 to 20 nm. XRD pattern of Mn–Cr–Al–C composite material were found to have signals belonging (CrxMn1–x)2AlC solid solution, Mn3AlC, and Cr2Al. It was shown that V–Al–C composite material contains nano-layered MAX V2AlC phase and particles VCх, VAl3.