Abstract: To explore the effect of TiO₂ crystal forms (anatase and rutile) on the microwave heating prepared TiB₂ powder,TiB₂ powder was rapidly prepared using anatase or rutile TiO₂ as the titanium source,B₄C as the boron source,and carbon black as the carbon source by the boro/carbothermal reduction method under the microwave heating condition.Effects of TiO₂ crystal forms on the phase composition,microstructure,and C and O impurity contents of the TiB₂ powder were investigated.The results show that by microwave heating,pure phase TiB₂ powder can be prepared from both forms of crystalline TiO₂ after reaction at 1 450 ℃ for 20 min.Among them,the TiB₂ powder prepared from rutile TiO₂ exhibits a regular hexagonal flake structure with perfect grain development.However,TiB₂ prepared from anatase TiO₂ has a nearly spherical structure.In comparison,rutile TiO₂ as boron source is more conducive to preparing TiB₂ powder with high purity and complete crystal form.

Key words: boro/carbothermal reduction method, anatase, rutile, TiB₂ powder, TiO₂ crystal

摘要： 为探究TiO₂晶型(锐钛矿型和金红石型)对微波加热制备TiB₂粉体的影响,分别以锐钛矿型和金红石型TiO₂为钛源,B₄C为硼源,炭黑为碳源,在微波加热的条件下通过硼热/碳热还原法快速制备了TiB₂粉体,探讨了TiO₂晶型对微波加热制备TiB₂粉体的物相组成、显微结构以及C和O杂质含量的影响。结果表明:在微波加热条件下,2种晶型TiO₂原料在1 450 ℃反应20 min后均可制备纯相TiB₂粉体,其中金红石型TiO₂制备的TiB₂粉体呈规则的六方片状结构,晶粒发育较为完善。而锐钛矿型TiO₂制备的TiB₂则为近似球状结构。相比较,金红石型TiO₂作为硼源更有利于制备高纯度、晶型完整的TiB₂粉体。

关键词: 硼热/碳热还原法, 锐钛矿, 金红石型, TiB₂粉体, TiO₂晶型