Надтверді композиційні матеріали на основі кубічного нітриду бору з активуючими добавками високоентропійних сплавів

• Date: 2026
• Keywords: keywords
• Main Authors: Shcheretskyi, О. А., Shcheretskyi, V. O., Turkevych, V. Z., Stratiichuk, D. A.
• Format: Article
• Published: Physico- Technological Institute of Metals and Alloys of the NAS of Ukraine 2026
• Subjects: високоентропійні сплави; cBN-композити; індукційне плавлення; високотемпературне спікання; реакційна взаємодія
• Online Access: https://momjournal.org.ua/index.php/mom/article/view/2026-2-4
• Journal Title: Metal Science and Treatment of Metals

This study investigates the possibility of using high-entropy alloys (HEAs) as a binder phase in cubic boron nitride (cBN)-based superhard composite materials. A series of Ni–Fe–Cr–Co–Ti–Al system alloys with varying aluminum content was developed and melted, ensuring the formation of single-phase, two-phase, eutectic, and multiphase structures. The relevance of this work is driven by the need to overcome the limitations of traditional metallic and ceramic binders (insufficient wettability, brittleness, high sintering temperatures) for the development of efficient cutting tools. The aim of this work is to establish the influence of the phase composition of HEAs on their reactivity with cBN and to assess the application potential of such alloys as a binder phase for cBN-based superhard composite materials. Five alloys with different aluminum contents were melted. Using methods of synchronous thermal analysis (DSC/TG), ultrasonic spectroscopy, and high-pressure (7.7 GPa) high-temperature sintering, the thermophysical properties of the alloys, their interaction with cBN, as well as the mechanical characteristics of the superhard composite materials (Vickers hardness, Young's modulus, fracture toughness) were investigated. It was found that the phase composition significantly affects the reactivity of the alloys with cBN. It was shown that maximum interaction activity is characteristic of alloys in which titanium is in solid solution, whereas its concentration in ordered phases (of the B2 type) reduces reactivity. Superhard cBN composites were obtained by high-temperature pressing at a pressure of 7.7 GPa and temperatures up to 2200 °C. It was established that the developed materials are characterized by high values of hardness, Young's modulus, and fracture toughness (K₁C = 8–9 MPa·m¹/²), which are comparable to or exceed those of industrial materials. It was shown that the increased fracture toughness is due to the implementation of crack deflection and crack bridging mechanisms facilitated by micron-sized HEA inclusions in the intergranular space of the cBN matrix. The obtained results confirm the promise of using high-entropy alloys as an effective binder for the creation of a new generation of superhard composite materials.