JPH01296098A - Protective board - Google Patents

Abstract

PURPOSE:To obtain a light protective board never permitting the penetration of the projectiles of small arm, by a method wherein light alloy sheets, containing hard particles bindable to metallic matrix, are laminated and thin steel sheets, applied with hard surface treatment, are laminated between respective laminated layers and on the surface of the laminates to bond them with rubber or resin. CONSTITUTION:A metallic sheet, in which super-hard particles such as silicon carbide, boron carbide, 2-vinyl fluoride or the like are bound to a light alloy and having the thickness of 1-20mm, and steel sheets having the thickness of 0.3-0.8mm are laminated. Three sheets of super-hard SiC particle containing aluminum alloy sheet 1 having the thickness of 5mm, for example, are laminated and 0.4mm thick cold-rolled steel sheets 2 applied with hard chrome plating are bonded between respective alloy sheets 1 and to the surface side and rear side of the sheets 1 by epoxy resin 3 while the peripheral rim of the laminates is sealed by the same epoxy resin 4.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention has the strength to protect not only pistol bullets, but also rifle bullets and missile armor-piercing bullets M16, and is lighter than conventional products. This relates to a protective plate that can be used to

[Conventional technology]

Previously, bulletproof flickers were used to protect 380-diameter and 450-diameter pistol bullets, and a type in which more than a dozen aramid fibers were laminated and crimped onto resin such as polyester as a protective plate to protect organs directly related to life in the body. A type of composite plate made of a fiber-based plate and an alumina-based ceramic plate was used. In short, these protection plates provided protection against 9MM pistol bullets.

However, the need for protection against high-speed, powerful weapons such as rifles and armor-piercing M16 missiles has increased recently, but it is difficult to provide technical solutions. For this reason, the role of conventional devices had come to an end, but to date there has been no product that satisfies its performance, and development in specialized fields has been urgently needed.

For this reason, ceramics were considered, including laminated layers of inexpensive alumina plates, laminated aramid fiber fabrics, zirconia ceramics with improved fracture resistance, and boron carbide and boron nitride. A lot of research has been done, but not only is it unable to withstand something as powerful as the M16, but it has also become extremely expensive. This meant that the material properties had not been sufficiently investigated for the essential penetration of the bullet.

However, this does not mean that ceramic materials are completely unsuitable for this purpose. Low-energy bullets can also play a role.

On the other hand, the so-called armor impenetrability concept of laminating hard steel plates whose strength exceeds the specific energy of the bullet has been shown to be quite effective, but the current method is too heavy as a protective plate. However, it is completely unsuitable and has not been put to practical use.

[Problem to be solved by the invention]

The object of the present invention is to provide a lightweight protective plate that is effective in protecting not only pistol bullets but also rifle bullets and armor-piercing missile bullets.

[Means for solving the problem] (Basic idea of the present invention) As is well known, the penetrating power of a bullet is MV'' (where M is mass,
The power increases in proportion to the impact velocity), and its power is the value obtained by dividing the energy of this bullet by its cross-sectional area S (MV"/S)
In other words, the larger the specific energy of the bullet, the more powerful it becomes.

In addition, at the moment the bullet collides with the protective plate, the energy of the bullet is concentrated at the apex of the tip cone of the bullet, and penetration begins from this point, but the hardness and strength of the protective plate are correlated, They begin to fracture each other, and if the protective plate is relatively hard and strong, the bullet will fracture from its tip and be prevented from penetrating. In reality, it is extremely difficult to achieve the goal with this mechanism alone and rely solely on the material. Therefore, the protective plate of the present invention was obtained by investigating and confirming the penetration mechanism through tests, and by incorporating the special characteristics of the trajectory, improving the material, and combining it with various steel plates. .

Its special characteristics are the following points.

1) It is known that a bullet fired by a rifle collides with the bullet while rotating in a spiral pattern, but it always tries to enter in a direction that is at a certain angle to the incident angle, and it is known that the direction of the bullet's energy also coincides with that direction. There is. This varies depending on the distance after firing and the layer passing through the middle, and if there is a particularly dense and hard layer, the -layer angle will become thicker.

Therefore, the larger the angle at the point of incidence, the lower the bullet specific energy.

2) The energy possessed by the bullet is simply thermal shock energy, which is applied to the warhead and absorbed by the plate.

Naturally, the board must be made of a material that is both thermally conductive and resistant to thermal shock.

3) In order to provide penetration strength, it is impossible to penetrate the energy of MV"/S through a single material alone, so avoid receiving large impact energy through a single material and diffuse the absorption throughout the material. This problem can be solved by stacking several layers of thin steel sheets and light alloy sheets with added carbide particles.Moreover, in order to increase the material strength, the structure of the light alloy sheets with added cemented carbide particles is made up of particles or fibers. It would be even more effective if it had a network structure of ultra-strength material.

4) Even in steel plates, when the quenched structure is not only a single structure, but also has an austenite solid solution group m (stainless steel), it has strength and ability to absorb bullet energy, so a correlative yield strength is expected.

5) Ceramics still have extremely low fracture toughness compared to metals, but adhesive materials such as rubber will definitely improve their performance.

Therefore, great effects can be expected by changing the experimental example of ceramics to metals with high fracture toughness.

6) When investigating the state in which a bullet enters a protective plate inserted between an m-plate and ceramic plates laminated at regular intervals, the exit area after penetration is 10 times the entrance area, and the same It was found that a large amount of energy was absorbed compared to the case where the output area was the same as the incident area in the case of only a thick ceramic plate.

From this, a synergistic effect is observed when coexisting with an iron plate, and this is also applied in the present invention.

7) Since it is desirable that the protective plate be lightweight and inexpensive, a light alloy is used.

(Configuration of the present invention) The present invention is configured as follows based on the above basic idea.

That is, in the present invention, hard particles that are bonded to a metal matrix are added to a light alloy, cast, and then pressed into a plate.
The plates with a thickness of 1 m/++ to 20-/- are laminated, and a thin steel plate of 0.3 m/m-0.8 m/+w is sandwiched between each plate, and the front and back surfaces of the laminated plates are The thin steel plates described above are stacked, the thin steel plates are subjected to hard surface treatment, and each of the plates is bonded with rubber or resin.

The main material of the protective plate according to the present invention is hard particles bonded to the metal matrix, such as ultra-hard particles such as silicon carbide, boron nitride, and titanium difluoride, or particles of a hard alloy, and particles of a light alloy, such as 1 Metal plate bonded to alloy, hardness HMV
176 or more, and has a tensile strength of 65 kg/ya" or more, and has extremely excellent wear resistance, so its performance against 4) is compared to ceramic materials used in conventional protective plates such as zirconia and boron nitride. It has extraordinary performance.

In addition, the fact that a steel plate is inserted between the laminated metal plates and bonded with rubber, resin, etc. is not only a strong protective plate, but also
For example, in the case of 8E alloy, the specific gravity was 3, which is effective in improving the property 5) and is optimal for reducing weight.

Furthermore, in order to reduce the weight of the negative layer, it is also possible to use an Mg alloy. However, in general, Mg alloys are a metal in which the metallic bonds of the ultra-hard particles are easily oxidized, which poses a problem, but by adding 0.1% or less beryllium, hot forging and melting treatment are possible. Therefore, it is possible to produce high-performance protective plates in the future. It has a specific gravity of 1.6
Therefore, it is possible to create an excellent product that is extremely strong, lightweight, and has excellent corrosion resistance. The thickness of the steel plate is 0.3 tg/
The range of 0.8 s/m from - to 0.8 m/s was decided because the manufacturing range of cold rolled steel sheets is 0.3 mars or less, which is a special order.
This is because the weight increases if the value is more than +.

In addition, it is difficult to manufacture particle-reinforced light alloys below 1-/-, and when above 20 m/m, protective plates generally have a thickness of 20 III/l.
This is because it is less than l.

The reason why the steel plate on the surface of the protective plate was subjected to hard surface treatment, such as hard chrome plating, was in anticipation of the effect described in 1) above. That is, the purpose is to change the incident angle to a large value by providing layers with different hardnesses, and the effect of 4) above is taken into account by laminating thin steel plates, for example, austenitic stainless steel plates.

〔Example〕

Fig. 1 is a perspective view of an embodiment of the present invention, and Fig. 2 is an A-A thereof.
In the enlarged cross-sectional view, Aj! containing ultra-hard SiC particles with a plate thickness of 5 m+/m! Three alloy plates 1 are laminated, and cold-rolled steel plates 2 of 0.4 m/m thickness with hard chrome plating between each plate and on the front and back surfaces are adhered with epoxy resin 3, and the periphery is also sealed with epoxy resin 4. be.

Note that the SiC particle reinforced A! used in the examples of the present invention! The properties of the alloy are as follows.

■Material A sample was produced by hot forging after casting the material added to 5iC33%A2 alloy.

■ Mechanical properties Tensile strength kg/am” 75 Elongation 2.4 ■ Physical properties Specific gravity 3, hardness Lung V 176 or more ■ Abrasion resistance test conditions Testing machine Ogoshi type circular disk 5KHz (H*C60) Friction distance 100m, final load 12.6kg Wear rate 4 /sec Specific wear amount 8 XIO"'IIta" 7kg or less 5OS
It has excellent properties, with the amount of wear being less than 1/7 of that of 304.

The dimensions of this example are length a=12 inches, width b-1
0 inch, thickness C-2cm, radius of curvature R=50c+s
It is bent and molded and weighs 3.85 kg.

In order to compare the performance with the present example, the following Comparative Examples 1 to 5 were prepared.

Three silicon nitride-based ceramic plates with a thickness of 4 ml are laminated, and the front and back sides are plated with hard chrome of 0.4 ml. Cold-rolled steel plate and stainless steel plate YUS304N are used.
At the same time, the plated steel plates were placed on top of the ceramic plates, each bonded with an epoxy resin, and the periphery was sealed. The size is the same as the above embodiment of the present invention, and the weight is 3.5 kg.

Comparison 1 Three alumina-based ceramic lattice plates lined with natural rubber with a thickness of 1 m/s + thickness were laminated, and as in Comparative Example 2,
Comparative Example 2 was prepared by inserting a hard plated steel plate between the front and back surfaces and the ceramic grid plate, adhering it with epoxy resin, and sealing the periphery.

The size and shape are the same as in the previous embodiment.

Kitakari Main Kevlar cloth 18 layers laminated and polyester resin bonded 9m/m x300 +*/+s x300 mlm
Comparative Example 3 was obtained by stacking two plates having the size of . The size and shape of this comparative example are also the same as those of the above example.

Comparative Example 4 Comparative Example 4 was prepared by adhering 15 sheets of Kevlar cloth to the back surface of a boron carbide ceramic plate with a thickness of 8 ml using polyester resin. The size and shape of this comparative example are also the same as those of the above example.

Comparison 1 Kevlar cloth 1 on the back of a titanium plate with a thickness of 2 m/+m
Comparative Example 5 was obtained by bonding 0 sheets with polyester resin. The size and shape of this comparative example are also the same as those of the above example.

The Example and Comparative Example were placed in the storage pocket of a bulletproof vest, and a live firing test was conducted with an M16 rifle (range 25 m) and a 9MM pistol. The results are shown in Table 1 (long-lasting test results) and Table 2 (short gun test results).

Table 1 Table 2 [Effects of the invention] As is clear from the actual firing test results, the present invention
The MM protective plate has a satisfactory performance as a protective plate against short guns (pistols) and 16M long guns, and there is a large technical gap between it and conventional protective plates.
It is excellent.

4. Brief description of the drawings FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is an enlarged sectional view thereof.

1...-Ann complete set Plate...Steel plate Figure 1 1...A2 alloy plate 2... Steel plate 3 and 4...Epoxy resin Figure 2

Claims (1)

[Claims] (1) Hard particles that bond with the metal matrix are added to a light alloy, cast, and then pressed into a plate with a thickness of 1 m.
/m ~ 20m/m plates are stacked, and between each plate 0.3
In addition to sandwiching thin steel plates of m/m to 0.8 m/m, the above-mentioned thin steel plates are also stacked on the front and back sides of the laminated plate, and the thin steel plates are subjected to a hard surface treatment, and each plate is coated with rubber or A protective plate that is bonded with resin.