Microstructure and evolution of hafnium carbide whiskers via polymer-derived ceramics: A novel formation mechanism

Polymer-derived ultra-high-temperature ceramic (UHTC) nanocomposites have attracted growing attention due to the increasing demands for advanced thermal structure components in aerospace. Herein, hafnium carbide (HfC) whiskers are successfully fabricated carbon fiber preforms via polymer-derived (PDC) method. A novel nanotube (CNT) template growth mechanism combined with PDC method is proposed this work, which different from conventional vapor–liquid–solid (VLS) that commonly used nanostructured ceramics. The CNTs synthesized and proved be templates fabricating HfC whiskers, generated by released low-molecular-weight gas such as CO, CO2, CH4 during pyrolysis of a Hf-containing precursor. formed products composed inner single crystal measured several tens micrometers length 100–200 nm diameter outer HfC/HfO2 particles. Our work not only proposes new strategy prepare but also puts forward thinking efficient utilization UHTC polymer