Preparation and characterization of ZrB2–SiC composite powders from zircon via microwave-assisted boro/carbothermal reduction

Autor: Feng Liang, Shuang Du, Xiangong Deng, Junkai Wang, Zhong Huang, Haijun Zhang, Wanguo Zhao, Shaowei Zhang, Faliang Li
Rok vydání: 2015
Předmět:
Zdroj: Ceramics International. 41:14419-14426
ISSN: 0272-8842
DOI: 10.1016/j.ceramint.2015.07.077
Popis: ZrB 2 –SiC composite powders were successfully synthesized via microwave-assisted boro/carbothermal reduction technique using zircon (ZrSiO 4 ), activated carbon (C) and boron oxide (B 2 O 3 ) as raw materials. They were characterized by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). Thermodynamic analysis on the synthesis process was carried out, and the effects of SiC bedding powder, reaction temperature, soaking time and n(B 2 O 3 ):n(ZrSiO 4 ) molar ratio on the formation of ZrB 2 –SiC composite powders were examined. The results showed that phase pure ZrB 2 –SiC composite powders were successfully synthesized at 1573 K which was 200 K lower than that required by using the conventional boro/carbothermal reduction method. In the final composite powders, fibrous SiC phases with 0.1–0.5 μm in diameter and 1.4–4.2 μm in length were homogeneously distributed among spherical ZrB 2 particles with the average size of 0.1–1 μm.
Databáze: OpenAIRE