Synthesis and electromagnetic wave absorption performances of a novel (Mo0.25Cr0.25Ti0.25V0.25)3AlC2 high-entropy MAX phase. (20th February 2023)

• Record Type: Journal Article
• Authors: Qiao, Linjing; Bi, Jianqiang; Liang, Guandong; Liu, Chen; Yin, Zhuangzhuang; Yang, Yao; Wang, Hongyi; Wang, Shaoyin; Shang, Mengmeng; Wang, Weili
• Is Part Of: Journal of materials science & technology. Volume 137(2023)
• Page Start: 112
• Page End: 122
• Publication Date: 2023-02-20
• Subjects: (Mo0.25Cr0.25Ti0.25V0.25)3AlC2 -- High-entropy MAX phase -- Two-step synthesis -- Oxidation -- Electromagnetic wave absorption; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2022.07.039
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: A new two-step solid state reaction process was proposed to synthesize single-phase high-entropy MAX phases. A novel (Mo0.25 Cr0.25 Ti0.25 V0.25 )3 AlC2 high-entropy MAX phase was successfully prepared. Investigations on electromagnetic (EM) wave absorption properties and effects of oxidation on EM wave absorption performances of (Mo0.25 Cr0.25 Ti0.25 V0.25 )3 AlC2 were conducted for the first time. (Mo0.25 Cr0.25 Ti0.25 V0.25 )3 AlC2 powders exhibit excellent EM wave absorption properties, whose minimum reflection loss value can reach -45.80 dB (at 1.7 mm thickness) and maximum effective absorption bandwidth is 3.60 GHz (at 1.5 mm thickness). After oxidation at 400–800 °C, (Mo0.25 Cr0.25 Ti0.25 V0.25 )3 AlC2 can retain good EM wave absorption properties in a certain frequency range. Abstract: Herein, a novel kind of high-entropy MAX phases, (Mo0.25 Cr0.25 Ti0.25 V0.25 )3 AlC2 powders were successfully synthesized by a newly proposed two-step solid state reaction process. The oxidation experiments demonstrate that the oxidation products of Al2 Mo3 O12 and rutile TiO2 are formed at about 600 and 800 °C, respectively. Besides, the dielectric and electromagnetic (EM) wave absorption properties of (Mo0.25 Cr0.25 Ti0.25 V0.25 )3 AlC2 powders and those after oxidation at different temperatures were also examined. The results show that the as-synthesized (Mo0.25 Cr0.25 Ti0.25 V0.25 )3 AlC2 powders possess excellent EM wave absorption performances with the minimum reflection loss ( RL ) of -45.80 dB (at 1.7 mm thickness) and the maximum effective absorption bandwidth ( E AB ) of 3.6 GHz (at 1.5 mm thickness). After oxidation at 400–800 °C, due to the coupling of conductivity loss and polarization loss, (Mo0.25 Cr0.25 Ti0.25 V0.25 )3 AlC2 powders can retain good EM wave absorption properties in a certain frequency range. In this paper, the effects of oxidation on EM wave absorption properties of high-entropy MAX phases were systematically investigated for the first time. This work manifests that high-entropy MAX phases are promising EM wave absorbing candidates and can maintain good EM wave absorption performances after oxidation.