Tuning the mechanical and thermal properties of (MgNiCoCuZn)O by intelligent control of cooling rates

• Published in: Journal of the European Ceramic Society Vol. 43; no. 10; pp. 4517 - 4529
• Main Authors: Nallathambi, Varatharaja, Bhaskar, Lalith Kumar, Wang, Di, Naberezhnov, Aleksandr A., Sumnikov, Sergey V., Ionescu, Emanuel, Kumar, Ravi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2023
• Subjects: CuO nucleation; Entropy stabilized oxides; Heat-treatment; Phase stability; Entropy stabilized oxides; Phase stability; CuO nucleation; Heat-treatment
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2023.03.016

The possibility of altering the phase equilibria of multicomponent oxide systems through precise control of configurational entropy has opened a platform with unlimited possibilities to fine-tune material properties. The current work is aimed at tailoring the mechanical and thermal properties of (MgNiCoCuZn)O by an intelligent design of constituent phase structure resulting from controlled cooling from the stabilization temperature. Based on the cooling rates, the amount of CuO nucleation was found to vary between 5.4 and 12.3 wt%, along with a corresponding decrease in Cu2+ content in the matrix. It was observed that with the decrease in Cu2+ ion concentration in the matrix, the Young’s modulus and hardness increased by 33% and 26%, respectively, along with a corresponding decrease in the coefficient of thermal expansion by 15%. Similarly, an increased nucleation of CuO precipitates led to the improvement of fracture toughness of the material by 15%, while its thermal conductivity remained unaltered. [Display omitted]