燃焼合成法による微細TiB₂粒子生成過程の観察と微細化手法の検討

抄録

Titanium boride (TiB₂) particles were synthesized in aluminum matrix by a combustion reaction of Ti–B–Al preform, aiming at synthesizing nano-scale fine particles. The formation behavior of TiB₂ particle was observed by Combustion Front Quenching Method (CFQM) , in which self-propagating combustion wave was terminated by heat absorption of metallic mold. At the earliest stage of the reaction, the reaction between aluminum and titanium took place, and boron was not involved in the reaction. The nucleation site of TiB₂ was a peripheral area of boron particles. TiB₂ particles synthesized at the early stage of the reaction was very fine (~200 nm) , and the growth of particles occurred during a high-temperature stage of the combustion reaction. The effect of powder blending ratio on the size of TiB₂ particle was examined. The combustion temperature was reduced by increasing aluminum fraction in the preform. The synthesized TiB₂ particle was effectively refined by increasing the blending ratio of aluminum. By using finer boron particles or by increasing boron fraction in the preform, TiB₂ particle was also refined effectively.