【摘要】 TiB₂是一种超高温陶瓷材料,通常采用碳热、硼热法在1000℃以上的高温制备,其纳米晶体的制备一直是个难题。在本研究工作中,采用TiO₂、LiBH₄和Mg在600～800℃成功制备并分离提纯出了10～20nm的TiB₂纳米晶体。在反应中,LiBH₄既作为硼源,又作为还原剂,而Mg则作为助还原剂。该反应使TiO₂在600℃全部转化为TiB₂纳米晶,并通过800℃的保温使纳米晶体得到适度长大。最终获得粒度均匀、形貌规整、结晶度好的圆盘状TiB₂纳米晶。更多还原

【Abstract】 TiB₂ is an ultra-high temperature ceramic（UHTC） material.It is usually synthesized at high temperatures through carbothermal or borothermal reactions,making it difficult to obtain nanosized crystals in a controllable way.In this work,we successfully synthesized and purified TiB₂ nanocrystals of around 10-20 nm through a solid state reaction route using TiO₂,LiBH₄ and Mg.During the reaction,LiBH₄ and Mg collaboratively reduced TiO₂ and transformed it completely into TiB₂ below 600 ℃．The growth of TiB₂ nanocrystallites was fulfilled at a higher temperature of 800 ℃,resulting in TiB₂ nanocrystals with a homogeneous size distribution.The present synthesis method ensured not only desirable nanosizes,but also well-crystallized structure for TiB₂ nanoparticles in a facile and controllable way.更多还原