Bulk high-entropy nitrides and carbonitrides

Traditional ceramics often face limitations in mechanical performance and thermal stability. Prior research has shown that introducing configurational entropy can alter material behavior. However, the specific effects of high configurational entropy on nitride and carbonitride ceramics remain unclear. This uncertainty motivated the exploration of high-entropy nitrides and carbonitrides. No prior work had resolved the extent to which entropy influences hardness and modulus in these systems. The gap motivated this study to test the synthesis and properties of bulk high-entropy nitrides and carbonitrides. Existing knowledge suggested that entropy could enhance stability, but the exact mechanisms remained unproven. This paper's contribution is to experimentally validate the role of entropy in improving mechanical properties. The study addresses a key question in materials science about entropy-driven property enhancements.

The aim of this work is to investigate the mechanical properties of high-entropy nitrides and carbonitrides. The specific problem is to determine whether high configurational entropy can enhance hardness and elastic modulus in these materials. The motivation stems from the need for ceramics with superior mechanical performance at high temperatures. The authors propose that increasing entropy may improve material properties. The study also seeks to identify parameters that can be used to tune these properties. The research addresses a gap in understanding how entropy affects ceramic behavior. The authors suggest that electron concentration and entropy are key variables. This work provides a framework for designing high-entropy ceramics with desired properties.

The researchers prepared 11 samples of high-entropy nitrides and carbonitrides. They focused on synthesizing five bulk nitrides and four bulk carbonitrides as single-phase materials. The synthesis process involved controlled conditions to form stable phases. Mechanical properties were measured using standard hardness and modulus tests. The rule-of-mixtures average was calculated for comparison. The study compared experimental results with theoretical predictions. The authors used electron concentration as a parameter to assess valence effects. The approach combined materials synthesis with mechanical characterization.

The hardness of high-entropy nitrides increased by an average of 22% over monocarbide precursors. High-entropy carbonitrides showed a 39% increase in hardness compared to mononitride precursors. Elastic modulus values rose by 17% in nitrides and 31% in carbonitrides over rule-of-mixtures averages. The study found that higher configurational entropy correlated with improved mechanical properties. A decrease in valence electron concentration also contributed to property enhancements. The results suggest that entropy and electron concentration are tunable parameters. Five bulk HENs and four HECNs formed single-phase materials among the 11 samples. The findings support the hypothesis that entropy enhances ceramic performance.

The authors propose that increased configurational entropy enhances mechanical properties in high-entropy ceramics. A decrease in valence electron concentration also contributes to property improvements. The study shows that entropy and electron concentration are key parameters for tuning behavior. The results support the idea that high-entropy ceramics offer advantages over traditional materials. The findings suggest a framework for designing ceramics with desired properties. The authors suggest that these parameters can be used to guide future material development. The study does not claim that entropy is essential but proposes it as a significant factor. The conclusions are based on observed correlations between entropy and mechanical performance.