Structural and mechanical properties of nitrogen-deficient cubic Cr–Mo–N and Cr–W–N systems

Our computational and experimental results reveal the inherent driving force of cubic Cr–TM–N (TM = Mo, W) solid solutions for nitrogen deficiency, expressed chemically as Cr1-xTMxN1–0.5x. Their computationally predicted large positive mixing enthalpies indicate a high driving force for isostructural decomposition into B1-structured CrN and γ-TM2N. The calculations further predict an improved ductility with increasing TM-content and significant anisotropy of elastic constants and Young's modulus in the entire compositional range. The experimentally measured lattice parameters, nitrogen content in Cr-Mo-N, and elastic properties of Cr1-xTMxN1–0.5x corroborated our theoretical predictions. Our combined theoretical and experimental study provides new understanding and insights into these complex material systems.