LAUSR

Preparation of TiB 2 -Al 2 O 3 and CrB 2 -Al 2 O 3 composites with a broad range of phase composition was conducted by self-propagating high-temperature synthesis (SHS) involving reaction of different types. The formation of fibrous crystals of aluminum oxide with length of about 10-25 microns and with diameter of 200-500 nm at self-propagating high-temperature synthesis in the system 2B 2 O 3 -Cr 2 O 3 -6A1 was established. Thermite mixtures of Al-TiO 2 and Al-TiO 2 -B 2 O 3 were incorporated with the Ti-B combustion system to produce the composites of TiB 2 -Al 2 O 3 , within which the increase of the thermite mixture for a higher content of Al 2 O 3 decreased the reaction temperature and combustion wave velocity. This implies that the thermite reaction of Al with TiO 2 reduces the exothermicity of the overall SHS process. It was found that adoption of B 2 O 3 as one of the thermite reagents improved the product formation effectively. For investigate the combustion wave in 0.75TiO 2 -0.25Ti-2B-Al system the «quenching» method was used. The XRD analysis shows that the final products containing diborides and aluminium oxide.