Synthesis and characterization of nano-crystalized HfC based on an aqueous solution-derived precursor

Youlin Jiang; Dewei Ni; Qi Ding; Bowen Chen; Xiaowu Chen; Yanmei Kan; Shaoming Dong

doi:10.1039/c8ra08123a

Synthesis and characterization of nano-crystalized HfC based on an aqueous solution-derived precursor

RSC Adv. 2018 Nov 26;8(69):39284-39290. doi: 10.1039/c8ra08123a. eCollection 2018 Nov 23.

Authors

Youlin Jiang^{1

2

3}, Dewei Ni^{1

2}, Qi Ding^{1

2

3

4}, Bowen Chen^{1

2

3}, Xiaowu Chen^{1

2}, Yanmei Kan^{1

2}, Shaoming Dong^{1

2}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences Shanghai 200050 China [email protected].
² Structural Ceramics and Composites Engineering Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences Shanghai 200050 China [email protected].
³ University of Chinese Academy of Sciences Beijing 100049 China.
⁴ ShanghaiTech University Shanghai 201210 China.

Abstract

Nano-crystalized HfC was successfully synthesized based on an aqueous solution-derived precursor using hafnium tetrachloride and sucrose as raw materials. The precursor can be converted to pure phase HfC after pyrolysis at ∼600 °C and subsequent carbothermal reduction reaction at ∼1600 °C, with a ceramic yield of around 46.3%. Reaction mechanisms of the synthesis process are revealed based on FT-IR, TG-DSC, TEM analysis and thermodynamic calculations, etc. The obtained HfC nanoparticles possess an equiaxial shape with an average particle size of ∼73 nm. Oxygen content of the as-synthesized HfC powders is as low as 0.64 wt%, which exists in the form of an amorphous Hf-O-C thin layer covering the surface of the HfC particles. This feasible and promising method for HfC particle synthesis is believed to be suitable for the fabrication of continuous fibers reinforced HfC ceramic matrix composites.