A novel plasma-sprayed Ti4O7/carbon nanotubes/Al2O3 coating with bifunctional microwave application

Yang Li; Yuchang Qing; Haoyang Yao; Hailong Xu; Hongjing Wu

doi:10.1016/j.jcis.2023.04.145

A novel plasma-sprayed Ti₄O₇/carbon nanotubes/Al₂O₃ coating with bifunctional microwave application

J Colloid Interface Sci. 2023 Sep:645:165-175. doi: 10.1016/j.jcis.2023.04.145. Epub 2023 May 3.

Authors

Yang Li¹, Yuchang Qing², Haoyang Yao¹, Hailong Xu¹, Hongjing Wu³

Affiliations

¹ State Key Laboratory of Solidification Processing, School of Material Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.
² State Key Laboratory of Solidification Processing, School of Material Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China. Electronic address: qingyuchang@nwpu.edu.cn.
³ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China. Electronic address: wuhongjing@nwpu.edu.cn.

PMID: 37148682
DOI: 10.1016/j.jcis.2023.04.145

Abstract

High-performance microwave absorption coatings are critically required in the stealth defense system of military platforms. Regrettably, just optimizing the property but neglecting the application feasibility seriously inhibits its practical application in the field of microwave absorption. To face this challenge, the Ti₄O₇/carbon nanotubes (CNTs)/Al₂O₃ coatings were successfully fabricated by a plasma-sprayed method. For the different oxygen vacancy-induced Ti₄O₇ coatings, the enhanced ε' and ε'' values in the frequency of X-band is due to the synergistic manipulation of conductive path, defects and interfacial polarization. The optimal reflection loss of Ti₄O₇/CNTs/Al₂O₃ sample (0 wt% CNTs) is -55.7 dB (8.9 GHz of 2.41 mm), while the electromagnetic interference shielding effectiveness of Ti₄O₇/CNTs/Al₂O₃ sample (5 wt% CNTs) increases to 20.5 dB as the enhanced electrical conductivity. In special, the flexural strength of Ti₄O₇/CNTs/Al₂O₃ coatings first increases from 48.59 MPa (0 wt% CNTs) to 67.13 MPa (2.5 wt% CNTs) and then decreases to 38.31 MPa (5 wt% CNTs), demonstrating that an appropriate amount of CNTs evenly dispersed in the Ti₄O₇/Al₂O₃ ceramic matrix can effectively play the role of CNTs as the strengthening phase of the coatings. This research will provide a strategy by tailoring synergistic effect of dielectric loss and conduction loss for oxygen vacancy-mediated Ti₄O₇ material to broaden the application of absorbing or shielding ceramic coatings.

Keywords: Coatings; Interfacial polarization; Microwave absorption; Oxygen vacancies; Plasma spraying.