RU130686U1 - Armor-piercing bullet with a lively head of the heart - Google Patents

Abstract

An armor-piercing bullet with an animated head part of the core, containing a shell, a carbide core consisting of a head and a tail part, a lead shirt, a bullet length of (3.52-4.60) d, a bullet core length of (2.36-3.48 ) d, while the core is made of a hard alloy with a tungsten carbide content of 85-96% by mass, having a HRA hardness of at least 85.0 units, a compressive strength of at least 4000 MPa, a bending strength of at least 2000 MPa, solid core alloy has a stress intensity factor K not lower than 8 MPa · m, the head part the core is cone-shaped, the length of which is (0.58-3.70) d, and has a contact pad whose diameter is (0.018-0.25) d, the tail part is in the form of a cylinder or a truncated cone, or interconnected cylinder and a truncated cone, and the smaller diameter of the truncated cone is (0.71-0.86) d, the larger diameter of the truncated cone of the tail is equal to the diameter of the cylinder and the diameter of the head of the core and is (0.72-0.86) d, and the length of the shank cylinder is (0.01-3.58) d, the tail of the core has a chamfer or a radius of curvature of up to 0, 15d, where d is the diameter of the bullet’s caliber, the surface of the core completely or partially has a roughness of not more than Ra 1.6, and the mass of the core is equal to (0.34-0.62) the mass of the bullet, characterized in that the head of the core in the form of a cone is made animated form with a radius animated equal to (0.87-13.28) d.

Description

The utility model relates to ammunition, in particular to automatic and rifle bullets, having a core made of hard alloy with high penetration and barring action.

A solution is known aimed at increasing the breakdown ability of the core by optimizing the geometric dimensions of the core and the properties of the material from which it is made. The core of the bullet is made of carbide material and consists of a tail part and a head part having an animated shape with a top. The carbide material has a compressive strength of more than 4000 MPa, the angle at the top of the head is 90 to 120 °, and the top of the head is rounded with a radius of (0.2-0.6) mm (RU 2254551).

The disadvantage of this technical solution is the lack of penetration of the core of metal armor over 5.0 mm.

Despite the fact that in this solution the compressive strength of the material is not less than 4000 MPa, the main type of core destruction is the cleavage of the shank and the head part. In the case when the core does not penetrate the armor plate, it gets stuck in it and the liner is destroyed, which did not come into contact with the armor plate material. The disadvantage is due to the large angle of the cone at the top of the head.

Known is an armor-piercing bullet containing a shell, a carbide core having a head and a tail, and a lead shirt, the head of the carbide core is pointed, the core length is (2.21-3.48) d, while the core alloy contains tungsten carbide in weight of 85-96%, has a HRA hardness of not less than 85.0 units, a flexural strength of not less than 2000 MPa, the head of the core is cone-shaped, the length of which is (0.58-3.70) d, the tail part has the shape of a cylinder, or truncated cone, or connected x between the cylinder and the truncated cone, and the smaller diameter of the truncated cone is (0.71-0.86) d, the larger diameter of the truncated cone of the shank is equal to the diameter of the cylinder and the diameter of the head of the core and is (0.72-0.86) d , and the length of the shank cylinder is (0.01-3.58) d, where d is the diameter of the bullet’s caliber, the core surface has a roughness in whole or in part not higher than Ra 1.6, and the core mass is 34-62% of the bullet mass. In addition, the hard alloy has a compressive strength of at least 4000 MPa, a stress intensity factor K _{1C of} at least 8 MPa m ^1/2 , the conical shape of the head of the core is formed by a straight line and / or circular arc with a radius equal to (0.31- 10,28) d, which is the conjugation arc between the line forming the cone, and the line forming the cylindrical part of the shank, while the length of the part of the cone formed by the circular arc is (0,01-3,70) d, the conical shape of the head of the core has a radius of curvature of the pointed part not olee 0.3 mm, and the tail portion of the core and / or the head part has a coating formed from one physical or chemical methods of metal deposition. (RU 2438096).

A disadvantage of the known solution is the insufficient over-penetration ability of the bullet core when it penetrates metal armor with increasing caliber.

The closest in technical essence and the achieved result to the proposed pool is an armor-piercing bullet containing a shell, a carbide core having a head and a tail, and a lead shirt, the core length is (2.21-3.48) d, while the core alloy is hard contains tungsten carbide by weight 85-96%, has a hardness of HRA of at least 85.0 units, a flexural strength of at least 2000 MPa, the head of the core is cone-shaped, the length of which is (0.58-3.70) d, the tail portion has the shape of a cylinder, or truncated cone, or between a cylinder and a truncated cone, and the smaller diameter of the truncated cone is (0.71-0.86) d, the larger diameter of the truncated cone of the shank is equal to the diameter of the cylinder and the diameter of the head of the core and is (0.72-0, 86) d, and the length of the shank cylinder is (0.01-3.58) d, where d is the diameter of the bullet’s caliber, the surface of the core completely or partially has a roughness not higher than Ra 1.6, and the mass of the core is 34-62% of the mass the bullet in this case, the head of the core has a contact pad, the diameter of which is (0.018-0.250d. In addition, the hard alloy has a compressive strength of at least 4000 MPa, a stress intensity factor K _{1C of} at least 8 MPa m1 / 2, the tail of the core has a chamfer or a radius of curvature of 0.15 d, and the tail of the core and / or head has coating made by one of the physical or chemical methods of metal deposition. (The decision to grant a patent for a utility model on the application 2012147315 from 11.28.2012)

A disadvantage of the known solution is the inadequate damaging ability of a bullet to penetrate metal armor.

The objective of this technical solution to increase the defeat of manpower, sheltered in lightly armored military equipment and openly located in body armor.

In the process of solving this problem, a technical result is achieved, which consists in increasing the forbidden speed of the carbide core when breaking through metal armor and increasing the damaging effect from fragmented armor fragments formed by the core when leaving the armor.

The specified technical result is achieved by the claimed bullet armor-piercing with a lively head part of the core containing the shell, a carbide core consisting of a head and a tail part, a lead shirt, the length of the bullet is (3.52-4.60) d, the length of the core of the bullet is (2, 36-3.48) d, wherein the core is made of a hard alloy with a tungsten carbide content of 85-96% by mass, having an HRA hardness of at least 85.0 units, and a compressive strength of at least 4000 MPa. the bending strength is not less than 2000 MPa, the hard alloy of the core has a stress intensity factor K _{1C of} at least 8 MPa m ^1/2 , the head of the core is cone-shaped, the length of which is (0.58-3.70) d and has a contact a pad whose diameter is (0.018-0.25) d, the tail portion is in the form of a cylinder, or a truncated cone, or interconnected cylinder and a truncated cone, and the smaller diameter of the truncated cone is (0.71-0.86) d, the larger diameter of the truncated cone of the tail is equal to the diameter of the cylinder and the diameter of the goal of the outer part of the core and is equal to (0.72-0.86) d, and the length of the cylinder of the shank is (0.01-3.58) d, the tail of the core has a chamfer or radius of curvature up to 0.15d, where d is the diameter of the caliber bullets, the surface of the core, in whole or in part, has a roughness of not more than Ra 1.6, and the mass of the core is equal to (0.34-0.62) the mass of the bullet, while the head of the core in the form of a cone is made in the shape of a cone with a radius animated equal to (0, 87-13.28) d.

When breaking through metal armor at the point of contact, for a short period of time, a significant increase in temperature and pressure occurs. The authors of this technical solution experimentally established that at the contact point are formed areas with highly localized plastic deformation, called adiabatic shear planes (PAS), in the vicinity of which heat is concentrated. Instantaneous deformation of the metal leads to localized heating of the contact and the catastrophic destruction of the armor in the form of melting. Having a contact pad on the head cone-shaped part of the core, whose diameter is (0.018-0.25) d, a penetration mechanism is realized, which can conditionally be divided into two stages. The first stage - the formation of PAS concentrating heat deformation, leading to melting of the metal, the second stage - brittle (spallation) destruction of the back side of the armor plate. When implementing such a mechanism of penetration, brittle destruction of the core does not occur, it retains its shape. It should be noted that the first stage of the mechanism of penetration of the armor plate is much higher in energy costs, at this stage most of the kinetic energy of the bullet is spent.

The studies showed that in the presence of a contact pad, the diameter of which is (0.018-0.25) d, the inner surface of the bullet hole has zones of brittle fracture of different sizes, depending on the design of the head of the core. The maximum zone of brittle fracture is observed on bullets with a core, the head of which is made in the form of a cone in an animated shape with a radius animated equal to (0.87–13.28) d.

When the core is introduced into the armor, the contact area in front of itself forms annular cracks with the formation of the so-called Hertz cones (G. Karkashadze. Mechanical rock destruction: Textbook for universities. - M.: Moscow State Mining University Publishing House. 2004. - p. 136-137). The load inside the Hertz cone increases and a leading compaction core is formed under the core area - the zone of comprehensive compression. In the compression core, the armor material experiences stresses many times, one or two orders of magnitude higher than the basic strength characteristic - ultimate strength under uniaxial compression. The compaction core accumulates potential strain energy. At the moment concentric cracks exit to the surface, an output crater forms, the potential energy of the deformations passes into the kinetic energy of the armor fragments, causing them to detach, fragment, and expand at a high speed, up to 100 m / s. After completion of the act of freeing the exit zone from fragments of destruction, the core continues to move beyond the armor barrier at high speed. On bullets with a core, the head of which is made in the form of a cone in an animated shape with a radius animated equal to (0.87-13.28) d. in addition to compressing the armor material under the site, there is a more intense deformation of the side walls of the bullet hole. The potential energy of wall deformation, together with the compression core of the armor material, leads to an earlier and larger separation of the rear side of the armored plate. The optimal parameters of the radius enlivened the cones of the living form, providing the maximum zone of brittle fracture, were determined experimentally.

Evaluation of the material according to the microstructure allows optimization of the material for the core of the bullet armor-piercing, which has maximum penetration. The implementation of the core of a hard alloy with a tungsten carbide content by weight of 85-96%, having a hardness of HRA of at least 85.0 units, a flexural strength of at least 2000 MPa, a compressive strength of at least 4000 MPa and a stress intensity factor of K _1C not below 8 MPa m ^1/2 , allows in contact with the barrier to withstand high contact loads at the time of impact. In addition, an important role in the mechanisms of destruction is played by surface defects that appear during the core manufacturing process. Elimination of the defective core layer, bringing its surface to a roughness of Ra 1.6 and lower, will significantly increase its breakdown ability by eliminating the nucleation and development of surface microcracks. Additional machining will increase the accuracy of core manufacturing, reduce its weight spread, optimize geometric parameters, which ultimately improves accuracy and increases the range of damage in general.

The manufacture of a core in the form of a body of revolution, interconnected by a cone-shaped head part, the length of which is (0.58-3.70) d, a tail part in the form of a cylinder, or a truncated cone, or interconnected cylinder and a truncated cone, with a smaller diameter the truncated cone is (0.71-0.86) d, the larger diameter of the truncated cone of the tail is equal to the diameter of the cylinder and the diameter of the head of the core and is (0.72-0.86) d, and the length of the cylinder of the shank is (0.01 -3.58) d, the tail of the core has a chamfer or radius of curvature up to 0.15d, pos olyaet lower cores brittle fracture at a penetration of armor.

The figure 1 presents the design of the inventive bullet armor-piercing with the lively head of the core. Bullet 1, consisting of a bimetallic shell 2, a lead shirt 3, and a carbide core 4. The core 4 consists of a head part 4.1 and a tail part 4.2. The head part 8.1 is made in the form of a cone with an animating shape with a radius animating equal to R ₁ = (0.87-13.28) d. The tail part 8.2 consists of either a cylinder 8.2.1, or a truncated cone 8.2.2, or a cylinder 8.2.1 and a truncated cone 8.2.2 connected to each other, has a chamfer or a radius of curvature of 8.2.3 to 0.15d., the length of the shank cylinder is (0.01-3.58) d. The ratio of the design parameters of the cartridge is determined depending on the caliber of the cartridge. The length l _{0 of} core 4 is l ₀ = (2.36-3.48) d, the length of the head part l _{1 of} core 4.1 is l ₁ = (0.52-2.41) d, The larger diameter D _{1 of the} truncated shank cone is the diameter of the cylinder and the diameter of the head of the core and is equal to D ₁ = (0.72-0.86) d, the smaller diameter D _{2 of the} truncated cone is D ₂ = (0.71-0.86) d. The head part of the cone-shaped core has a contact pad, the diameter of D _{3 of} which is equal to D ₃ = (0.018-0.25) d. The core surfaces in whole or in part (either the head part or the tail part) are additionally ground to a roughness not higher than Ra 1.6.

To confirm the high barrage damaging effect of the proposed armor-piercing bullet with the lively head of the core, comparative firing was conducted with 7.62 caliber cartridges with a carbide core made according to the prototype. As punched material used armor plate brand 2P with a thickness of 10 mm at a distance of 250, 280 and 300 meters. The number of penetrations was estimated at 10 credits. Shooting was carried out from the Pecheneg machine gun with an optical sight.

The table provides the results of comparative tests.

Table. Core type The number of penetrations of the armor plate with 10 hits 250 m 280 m 300 m Prototype. one hundred% 8 5 Bullet with a conical head core

The proposed technical solution. one hundred% 8 7 A bullet with a core with a conical warhead in the form of a lively cone with a radius animated equal to (0.87-13.28) d.

As can be seen from the results of comparative tests, the proposed cartridge has a higher breakdown ability (number of penetrations per 300 m) compared to the prototype.

Thus, the totality of all the ratios of the design parameters of the cartridge specified in the formula ensures the creation of a bullet that has higher characteristics in terms of punching action. These ratios and the obtained data on the mechanism of destruction of metal armor can be used to create bullets of various calibers.

The carried out optimization of the mass of the core, the geometric parameters of the core depending on the caliber of the bullet and the physico-mechanical properties of the core material, taking into account the studies of the mechanism of core destruction, analysis of existing theories of barrier destruction when objects are introduced at high speed, made it possible to create an armor-piercing bullet with an animated warhead core, exceeding analogues and prototype in terms of penetration of armor-piercing plate.

Claims (1)

An armor-piercing bullet with an animated head part of the core, containing a shell, a carbide core consisting of a head and tail parts, a lead shirt, a bullet length of (3.52-4.60) d, a bullet core length of (2.36-3.48 ) d, while the core is made of a hard alloy with a tungsten carbide content of 85-96% by mass, having a HRA hardness of at least 85.0 units, a compressive strength of at least 4000 MPa, a bending strength of at least 2000 MPa, solid core alloy has a stress intensity factor K _{1C of} at least 8 MPa · m ^1/2 , the head the core part is cone-shaped, the length of which is (0.58-3.70) d, and has a contact pad whose diameter is (0.018-0.25) d, the tail part is in the form of a cylinder or a truncated cone, or interconnected cylinder and a truncated cone, and the smaller diameter of the truncated cone is (0.71-0.86) d, the larger diameter of the truncated cone of the tail is equal to the diameter of the cylinder and the diameter of the head of the core and is (0.72-0.86) d, and the length of the shank cylinder is (0.01-3.58) d, the tail of the core has a chamfer or radius of curvature up to 0.15d, where d is the diameter of the bullet’s caliber, the surface of the core completely or partially has a roughness of not more than Ra 1.6, and the mass of the core is equal to (0.34-0.62) the mass of the bullet, characterized in that the head of the core in the shape of the cone is made in an animated form with an animated radius equal to (0.87–13.28) d.

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