摘要
Stealth materials with high dependability at elevated temperatures and outstanding mechanical properties are urgently needed for practical applications.As one-dimensional ultrahigh temperature ceramic(UHTC)materials,zirconium carbide whiskers(ZrCw)have attracted a great deal of attention due to their desirable mechanical and ablation resistance performance in high-temperature environments.We have successfully synthesized ZrCw using a carbothermal reduction technique without the introduction of metal catalytic in this paper.ZrCw shows a typically prismatic structure with the diameter of 1e2 mm and the aspect ratio of up to 250.The growth of ZrCw is controlled by a solid-liquid-solid(SLS)and vaporsolid(VS)compound mechanism in conjunction with the auxiliary action of mesophase Na3ZrF7.The ZrCw/paraffin hybrids achieve the minimum reflection loss(RL(min))of25.77 dB at 13.28 GHz under the thickness of 1.25 mm,and reach an effective absorption bandwidth(EAB)of 3.04 GHz(14.96 e18.00 GHz)with a thickness of only 1.0 mm.This work presents a promising approach for large-scale producing high-purity whiskers,and verifies that ZrCw has extensive application prospects in the field of stealth materials.
基金
supported by the National Natural Science Foundation of China(Grant Nos.51872234,51872232 and 52231004)
the Joint Funds of the National Natural Science Foundation of China(Grant No.U21B2067)
the Key R&D Program of Shaanxi Province(Grant Nos.2019ZDLGY04-02 and 2021ZDLGY14-04)and Natural Science Basic Research Plan in Shaanxi(2022JC-25).