Key Words:Nitrogen compounds;Aluminum nitride - Chemical analysis - Electromagnetic waves - Electron irradiation - Fibers - Mechanical properties - Nitridation - Polysilanes - Silicon carbide - Silicon nitride - X ray photoelectron spectroscopy
Abstract:In this work, we report a novel kind of Si<inf>3</inf>N<inf>4</inf>/SiC composite fibers, which exhibit a controlled gradient Si<inf>3</inf>N<inf>4</inf>(shell)/SiC(core) structure. These composite fibers are fabricated through a controlled nitridation and pyrolysis process on electron irradiation-cured polycarbosilane fibers. Structural and chemical analysis based on Elemental Analyzer, FT-IR, Raman spectroscopy, electron probe micro-analyzer, X-ray photoelectron spectroscopy, and X-ray diffraction confirm the gradient structure of obtained fibers, which consist a shell with high Si<inf>3</inf>N<inf>4</inf> content and a SiC core. The as-fabricated fibers exhibit dense and smooth surfaces, and no microscopic holes or defects were observed. The effects of nitridation temperature on mechanical properties and electrical resistivity were also investigated. Combined with high mechanical properties and lightweight, the present gradient Si<inf>3</inf>N<inf>4</inf>/SiC fibers open a new strategy to fabricate multifunctional and electromagnetic wave absorbing materials.<br/> © 2019 Elsevier Ltd
Volume:39
Issue:13
Translation or Not:no