| Abstract Scope |
Ultra-high temperature ceramics (UHTCs) are of significant interest for aerospace, manufacturing, and energy applications due to their melting temperatures exceeding 3000 °C. Among the limited number of UHTC compounds, there exists a subset with the potential to exhibit much higher fracture toughness than traditional ceramics, including substoichiometric phases of TaC and HfN. To explore the impact of composition, bonding, and processing on these compounds, substoichiometric TaC1-x, HfN1-x, and their solid solutions were synthesized via spark plasma sintering.
The study aimed to examine the effect of composition on the mechanical properties, specifically Vickers hardness and fracture toughness, of samples with varying ratios of Ta:Hf, C:N, and Hf/Ta:C/N. Furthermore, the influence of spark plasma sintering processing parameters such as time, temperature, and pressure on the mechanical properties was investigated. Characterization techniques, including scanning electron microscopy, energy dispersive spectroscopy, and atom probe tomography, were employed to assist in the interpretation of the results. |