DOI: 10.3724/SP.J.1077.2014.13564

Journal of Inorganic Materials (无机材料学报) 2014/29:7 PP.717-721

Effects of Gel Aging on Synthesis of ZrB2 Powders

ZrB2 particles were synthesized by a Sol-Gel method using zirconium n-propoxide, boric acid, acetic acid and D-fructose. D-Fructose acts as both a modifier and a carbon source for carbothermal reduction reaction. For comparison, both nascent state gel and aged gel were used to clarify the aging-time-dependent mechanism for ZrB2 synthesis. As a result, a single phase ZrB2 powder with a uniform size and shape distribution can be obtained from the aged gel with a boron and carbon to zirconium molar ratio of 3.5–4 and 7, respectively, after reduced at 1550 ℃ for 2 h. Besides, the synthesized ZrB2 particles exhibit prism-like morphology with average particle size of ca. 4–7 μm in length, 1 μm in diameter of excircle of the cross-section and 4–7 in aspect ratio, when initial raw materials ratio n(B)/n(Zr) is 3.5-4 and n(C)/n(Zr) is 7. The median diameter D50 is 6.46 μm and specific surface area is about 2.53 m2/g. Furthermore, a complete carbothermal reduction of ZrO2 can be achieved using the aged gel.

Key words:aging,Sol-Gel,synthesis,ZrB2

ReleaseDate:2016-07-11 11:25:02

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