In-situ fabrication of ZrB2-ZrC-SiCnws hybrid nanopowders with tuneable morphology SiCnws

Abstract

SiC nanowires (SiCnws) having different morphologies can be applied to reinforce ceramic materials. However, the in-situ synthesis of SiCnws in ceramic powders, which is critical to ensure satisfactory reinforcement effects, is challenging. To facilitate the reinforcement of ZrB 2 –ZrC composites, this study proposes a simple method for in-situ fabrication of SiCnws with various morphologies in nanosized ZrB 2 –ZrC powders by pyrolyzing ZrB 2 –ZrC–SiC gel precursors. The prepared ZrB 2 –ZrC ceramic powders had a mean diameter of approximately 100 nm, with uniformly distributed SiCnws having nanocylider, bead-like, bamboo-shape with tuneable nodes, chain-like, and hexagonal prism morphologies prepared by optimizing the preparation process. Moreover, the SiCnws had diameters ranging from 100 to 400 nm, and the length was controlled from tens to hundreds of microns. The generation of ZrB 2 /ZrC influences the formation of SiCnws with specific morphologies through the production of CO gas, which influences the local supersaturation of the SiO and CO vapours. The findings can provide a basis for fabricating SiCnw-reinforced ceramic materials with an enhanced strengthening effect while ensuring a reasonable fabrication process.