不同硼含量的硼掺杂各向同性热解炭制备及微观结构研究

以CH4、H2和BCl3为原料,利用化学气相沉积方法制备了硼掺杂各向同性热解炭材料。研究了制备工艺及硼元素掺杂对热解炭微观结构和抗氧化性能的影响。结果表明,硼元素能够均匀地掺入热解炭中,其含量随着BCl3流量的增大而增加;硼掺杂并未改变热解炭的各向同性性质,但随着BCl3流量的增加,硼掺杂各向同性热解炭的结构由球形颗粒状结构逐渐向卷曲片层状结构转变,硼在热解炭中的存在形式则由单一形式(取代)逐渐过渡到混合形式(取代硼和碳化硼);硼元素的掺杂能有效抑制热解炭的氧化,大幅提高材料的起始氧化温度,显著降低氧化损失。

Preparation and microstructure of boron-doped isotropic pyrolytic carbons with different boron contents

Boron-doped isotropic pyrolytic carbons were prepared by chemical vapor deposition(CVD) with CH4、H2 and BCl3 as gaseous precursors.The effects of boron on the microstructure and oxidation properties of pyrolytic carbons were investigated.The results show that boron can be doped into pyrolytic carbon,and the concentration increases with the flow rate of BCl3.Boron doping does not change the isotropy of pyrolytic carbons,but remarkably changes the microstructure of pyrolytic carbons.Increasing the flow rate of BCl3,the microstructure of pyrolytic carbon changes gradually from spherical carbon structures to fine wrinkled graphitic sheet structures,while boron changes from substitutional boron into boron carbide.The results from oxidation show that boron can effectively inhibit the oxidation of pyrolytic carbon.