Self-propagating high temperature synthesis of SiC–Cu and SiC–Al cermets: Role of chemical activation

Ceramic-metal composites (cermets) are widely adopted in the modern technology. These materials with ceramic and metallic phases have properties of both the constituents. In the article the possibility of synthesizing SiC–Cu and SiC–Al cermets under the activated combustion mode was studied. The influence of various parameters such as the composition of initial mixture, amount of chemical activator and metallic phase, etc. on the combustion laws was investigated. It was shown that depending on the amount of metal phase the combustion can proceed in the two different regimes — low temperature (Tc < 1200 °C) and high temperature (Tc > 1600 °C). X-ray diffraction investigations testified that the combustion products, obtained in the optimal conditions, contain silicon carbide and corresponding metal phase (copper or aluminum). According to SEM analyses the obtained products have submicron granular particles and they are characterized by uniform structure.

Research Highlights
► The SiC-Cu and SiC-Al cermets were synthesized under the activated combustion mode utilizing polytetrafluoroethylene (PTFE) as a promoter.
► It was revealed that using PTFE allows to synthesize granular SiC-Cu and SiC-Al cermets having submicron particle sizes.
► Increasing amount of promoter leads to decrease particle size of end-products.
► We revealed that in the Si-C-PTFE-Cu(Al) system combustion proceeds stepwise and leading reaction is Si- PTFE reaction.