Phase Stability and Mechanical Properties of N-Metallic Carbides

The phase stability and mechanical properties of N-metallic carbides are assessed using entropy forming ability (EFA), mixing enthalpy, and Mazhnik-Oganov ab initio model of mechanical properties. EFA quantifies configurational disorder of solid solutions and is currently used to predict the phase stability and assess the hardness of high-entropy carbides with 5 transitional metals on the metallic sublattice. In this work, we use the concept of EFA for the 13 N-metallic carbides (N=2-5), four of which are investigated for the first time. Additionally, we propose a semi-empiric version of the Mazhnik-Oganov model and perform micro-indentation testing of the investigated compositions to verify the model’s capabilities. The proposed approach allows for a fast modeling and nanoindentation-based screening of the most promising carbide solid solutions for more detailed characterization.