摘要
利用H3BO3和CO(NH2)2在高温下发生化学反应生成纳米BN,并且形成纳米BN包覆B4C颗粒的B4C/BN纳米复合粉末。利用X射线衍射(XRD),透射电镜(TEM)和选区电子衍射(SAED)对所制备的复合粉末的物相组成和显微结构进行了研究,并且对热压烧结块材的物相组成进行了研究。物相组成和显微结构的研究结果表明,在850℃氮气气氛下热处理6h所得到的复合粉末主要是非晶态纳米BN涂层包覆在B4C颗粒表面所形成的B4C/BN纳米复合粉末,而且非晶态BN包覆层的厚度为300～500nm。此非晶态BN相在1850℃,30MPa,1h的热压烧结工艺条件下完全转变成晶态的h-BN相。
The B4C/BN nanocomposite powders with the microstructure of micro-sized B4C particles coated with nano-sized BN particles were prepared by the chemical reaction of H3BO3 and CO（NH2）2 on the surface of B4C particles at high temperature. The phase composition and microstructure of the B4C/BN nanocomposite powders were investigated by X-ray diffraction analysis （XRD）, transmission electron microscopy （TEM） and selected area electron diffraction （SAED）. The phase composition and microstructure results showed that the coated layer of B4C particles were mainly composed of amorphous nano-sized BN particles after the heat treatment at temperature of 850 ℃ for 6 h, and the thickness of the amorphous BN coated layer was about 300-500 nm, so the B4C/BN nanocomposite powders were prepared by this chemical reaction process. Then the amorphous BN completely transformed into the hexagonal BN （h-BN） after the hot-pressing sintering process of 1850 ℃, 30 MPa and 1 h.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2009年第A01期280-283,共4页
Rare Metal Materials and Engineering
