原位反应合成B_(4)C@TiB_(2)粉体及其介电吸波性能  

In-situ formation of B_(4)C@TiB_(2) powder and its dielectric andelectromagnetic absorbing properties

作　　者：邹鑫 陈平安[1] 朱颖丽 李享成[1] ZOU Xin;CHEN Pingan;ZHU Yingli;LI Xiangcheng(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,武汉430081

出　　处：《功能材料》2023年第7期7200-7206,共7页Journal of Functional Materials

基　　金：国家自然科学基金项目(51972242,51774218);湖北省重点研发计划项目(2020BAA028);湖北省自然科学基金创新群体项目(2020CFA038)。

摘　　要：以钛酸四正丁酯和B_(4)C粉体为原料,采用化学包覆结合热处理在B_(4)C表面原位生成TiB_(2),制备了具有核壳结构的B_(4)C@TiB_(2)复合粉体。结果表明,利用原位反应构建了B_(4)C-TiB_(2)核壳界面,使碳化硼由计量比B_(4)C转变为富硼相B_(13)C_(2),使碳化硼产生晶格畸变。因此,当TiB_(2)含量由0%(质量分数)增加至20%(质量分数)时,复合粉体的最低反射损耗值(RL min)由-9.76 dB增至-19.94 dB。这是由于原位生成的TiB_(2)改善了B_(4)C粉体的阻抗匹配性;B_(4)C的晶格畸变增强了偶极子极化,核壳结构增强了界面极化,二者协同作用提高了复合粉体的介电损耗能力,使B_(4)C粉体的电磁波吸收性能得到明显提高。The B_(4)C@TiB_(2) composite powders with core-shell structure were fabricated by in-situ formation of TiB_(2) on the surface of B_(4)C by chemical coating combined with heat treatment,which the tetrabutyl titanate and B_(4)C powders were used as raw materials.The results showed that the B_(4)C-TiB_(2) core-shell interface was constructed,which transformed boron carbide from stoichiometric B_(4)C to boron-rich phase B_(13)C_(2) and caused severe lattice distortion.When the TiB_(2) content increased from 0 wt%to 20 wt%,the minimum reflection loss value(RL min)of B_(4)C@TiB_(2) composite powder increased from-9.76 dB to-19.94 dB.It can be attributed to the improvement of impedance matching of B_(4)C powders.Furthermore,the lattice distortion and core-shell structure enhanced the dipole polarization and the interface polarization,respectively.The synergistic effects improved the dielectric loss capability,which significantly improved the electromagnetic wave absorption performance of B_(4)C powders.

关 键 词：B_(4)C@TiB_(2) 原位反应 晶格畸变 电磁波吸收 

分 类 号：TB34[一般工业技术—材料科学与工程]