Physical bases of creation of frame metal-ceramic composites with submicron grain for maintenance of extremely high ballistic characteristics

On the base of the results determined by using modern physical material science methods scientific principles referred to relationships of structure, phase composition, physical and mechanical properties formation of frame metal-ceramic composites based on tungsten carbide with a multicomponent high-entropy alloy (HEA) binder during high-speed electron-beam and induction sintering has been developed for the first time and will play an important role in deepening the understanding of the processes of structure formation in dispersed heterogeneous systems.

The relationship for the effect of HEA binder content, the time of mixing of the initial powder components and processing parameters of sintering on the mechanism of shrinkage, the formation of structure, phase composition, WC grains size, physical and mechanical properties of the framework metal-ceramic composites for ballistic purposes, obtained from WC and HEA powders under conditions of high-speed electron-beam and induction heating, have been established. The regularities of the process of thermodynamic, kinetic, chemical interaction between the materials of the frame (WC) and the matrix phase (HEA) of the volume-reinforced composite and its influence on the structure and properties of frame metal-ceramic composites were determined, and the coefficients of thermal expansion and thermal conductivity of frame metal-ceramic WC–HEA composites has been justified for the first time.

Principles for control of phase composition, structure, shrinkage, and strength characteristics of powdered frame composite WC–HEA hard alloys for ballistic purpose have been justified during optimization of composition and processing parameters of sintering. This would be valuable for development of conceptually new approaches used for creation of high-strength WC-based composites with HEA binder instead Co one. Reasonable conditions for creation high-strength WC-based alloys with HEA binder have been justified and physical principles of strength of the above alloys have been developed. This is thought to be scientific and technical foundation for improvement of conventional technological options as well as for design of novel technical approaches for production of high-quality WC-based hard alloys with HEA binder to replace the traditional cobalt one used under conditions of dynamic shock loads (in particular, bullet penetration), making them competitive all around the world. For the first time in world practice, the possibility of consolidation of WC–HEA alloys under conditions of high-speed heating has been experimentally substantiated.