In Situ Growth Behavior of SiC Whiskers with High Aspect Ratio in the Synthesis of ZrB2-SiC Composite Powders
School of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
*
Author to whom correspondence should be addressed.
Materials 2020, 13(16), 3502; https://doi.org/10.3390/ma13163502
Received: 6 July 2020
/
Revised: 25 July 2020
/
Accepted: 29 July 2020
/
Published: 8 August 2020
(This article belongs to the Section Advanced Composites)
Aiming to provide key materials in order to improve the fracture toughness of ZrB2 ceramics, ZrB2-SiC composite powders with in situ grown SiC whiskers were successfully synthesized via a simple molten-salt-assisted ferrous-catalyzed carbothermal reduction method. Thermodynamic calculations on the ZrO2-SiO2-B2O3-C-Fe system were carried out. The effects of heating temperature and ferrous catalyst amount on the growth behavior of SiC whiskers in ZrB2-SiC composite powders were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The results showed that the aspect ratio of SiC whiskers and the relative content of ZrB2 particles increased with increasing heating temperature (1523–1723 K) and a molar ratio of Fe to ZrSiO4 from 0:1 to 0.2:1. Phase-pure ZrB2-SiC composite powders were obtained at 1723 K when the molar ratio of raw materials was 0.2:0.5:1:1.5:8.4 (Fe:NaCl:ZrSiO4:B2O3:C). Single crystalline β-SiC whiskers with a mean diameter of 0.15 μm and an aspect ratio of 70–120 were homogeneously distributed in the final composite powders. A molten-salt-assisted iron-catalyzed vapor–solid mechanism was promoted for the growth mechanism of in situ grown SiC whiskers.
View Full-Text
Keywords:
in situ synthesis; whisker; SiC; ZrB2
▼
Show Figures
Figure 1
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
MDPI and ACS Style
Lian, X.; Hua, X.; Wang, X.; Deng, L. In Situ Growth Behavior of SiC Whiskers with High Aspect Ratio in the Synthesis of ZrB2-SiC Composite Powders. Materials 2020, 13, 3502. https://doi.org/10.3390/ma13163502
AMA Style
Lian X, Hua X, Wang X, Deng L. In Situ Growth Behavior of SiC Whiskers with High Aspect Ratio in the Synthesis of ZrB2-SiC Composite Powders. Materials. 2020; 13(16):3502. https://doi.org/10.3390/ma13163502
Chicago/Turabian StyleLian, Xiaoqing, Xiaohu Hua, Xiaogang Wang, and Lirong Deng. 2020. "In Situ Growth Behavior of SiC Whiskers with High Aspect Ratio in the Synthesis of ZrB2-SiC Composite Powders" Materials 13, no. 16: 3502. https://doi.org/10.3390/ma13163502
Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
