Abstract
Abstract Nanocrystalline powder of hafnium-rich-HfC has been successfully synthesised by the electro-deoxidation of HfO2–carbon precursors in molten chloride. The progress of the solid state reduction was monitored ex situ by analysing partially reduced samples using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It has been shown that the reduction started by converting HfO2 to CaHfO3 and an oxycarbide phase of the form HfCxO2(1−x). The CaHfO3 phase then also reduced to give HfCxO2(1−x), which subsequently reduced to HfC by ionising oxygen. The morphological analysis indicated almost no growth in the grain size occurred during the course of the electro-deoxidation. This investigation showed some loss of carbon during the electro-deoxidation resulted in metallic rich HfC. The synthesised powder exhibited better sinterability than the commercial HfC powder. Using the synthesised powder, fully dense monolithic HfC ceramics were produced by pressureless sintering at 1973 K with average grain size of about 3 μm.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
