Formation of HfCxNy by carbothermal reduction nitridation and their laser ablation behavior

Abstract

Hafnium carbonitride (HfCxNy) powders have been successfully prepared by heating a mixture of fine-grained HfO2 and nano-carbon powders during 1873 K-2273 K in nitrogen. The carbothermal reduction nitrdation (CTRN) process is composed of two steps: (1) the formation of microporous HfC and (2) catalytic nitridation of microporous HfC. The results demonstrate that the as-prepared HfCxNy powder consists of a single phase and various nitrogen content through different sintering parameters. The mechanism consists of three stages: (1) Formation of cubic mixed crystal HfCxOy, (2) Transformation into microporous hafnium carbide, and (3) Crucially, microporous hafnium carbide catalyzes the activation and dissociation of nitrogen molecules, leading to the formation of HfCxNy. Additionally, we introduce a laser etching method to confirm the ultra-high-temperature melting behavior of HfCxNy. This study enhances our understanding of HfCxNy powders synthesis and their laser ablation performance, offering valuable insights for future material applications.