Modeling of impact of bullet with core made of hard alloy with high-entropy alloy (HEA) FeNiCrMoW binder into obstacle

A composite powder material based on tungsten carbide with a NiFeCrWMo binder (90 and 10 wt%, respectively) was produced by mechanical alloying and vacuum sintering. The mechanical properties of the material were studied by means of continuous microindentation method. In order to develop a model of material behavior under conditions of intense dynamic loads, a combination of the Johnson-Cook model, which describes the processes of deformation and fracture of material, and the equation of state of stress waves, which characterizes the velocity of particles and the velocity of stress waves during high-speed deformation, the shear modulus and Poisson's ratio, was used. Based to the obtained data, a model of the material was developed, which can be used in other similar calculations to simulate the processes of deformation and fracture of a material. The impact of an armor-piercing bullet into an obstacle was simulated using the "ANSYS 2020 R2 student edition" software for modeling with the finite element method. The models of the bullet and plates of the required thickness were created, and the determined parameters of the materials were used. Models of a 7.62 × 51 mm Bofors Carl Gustaf FFV AP bullet with a tungsten carbide core for the NATO standard M993 armor-piercing cartridge, and 6-, 8-, 10-, 12- and 14-mm thick obstacles made of 4340 steel were created in SolidWorks software. The results of simulation are consistent with experimental data of the fire tests. The model error for an obstacle of a thickness of 14 mm is less than 5%. As a result of the simulation, it is found out that the bullet core made of tungsten carbide and the high-entropy binder is not inferior to the bullet core made of tungsten carbide and cobalt in terms of the strength characteristics, and has similar penetration parameters.