Study on self-derived products of nanometer lignin in silicon nitride ceramics during sintering process

Abstract

In this study, the nanometer lignin was mixed with the silicon nitride staring powders, and the mixed powder was pyrolyzed and sintered to obtain a novel composite material. The microstructure and composition of the novel ceramic composite were examined using Raman spectroscopy, electron dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy and field emission scanning electron microscopy. Surprisingly, nitride-doped graphene quantum dots (N-GQDs), derived from nanometer lignin, was found around silicon nitride columnar grains in the form of overlayers. Meanwhile, the test results showed that the formation of N-GQDs overlayer significantly improved the bending strength and fracture toughness of silicon nitride ceramic. This work presents a promising approach for fabricating high-performance ceramic composites by adding nanometer lignin precursors to silicon nitride ceramic matrix.

Keywords

• Biomass material
• Nanometer lignin
• Silicon nitride
• Strength
• Toughness