JPH11106858A - Aluminum bulletproof material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum bulletproof material excellent in penetrating resistance to high speed flying body by reducing the thickness of a sheet to be required at least by the increase of the strength and toughness of an aluminum alloy and lightening a moving body or the like. SOLUTION: This aluminum bulletproof material is the one in which penetrating resistance to a high speed flying body is improved by imparting a structure in which the average grain size of crystal grains or subcrystal grains is regulated to 0.05 to 1.0 micron thereto. Its producing method includes a stage (A) in which plastic deformation (strain) equivalent to >=220% elongation is imparted to an aluminum alloy to refine its average grain size to 1 micron and a stage (B) in which the obtd. material is subjected to rolling at 25 to 300 deg.C, and in the other manner, a stage in which, after the stage (B), heat treatment is executed at 100 to 300 deg.C for 0.5 to 3 hr as well is included. Suitably, as the stage (A), a side direction extruding stage in which the extruding direction is changed to the side direction of <180 deg. interior angle in the process is adopted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bulletproof material made of an aluminum alloy (hereinafter referred to as an aluminum bulletproof material) and a method for producing the same, and more particularly to a bulletproof vest, a bulletproof helmet, a vehicle, an aircraft, a ship, or the like. The present invention relates to an aluminum bulletproof material used in combination with a plate material such as another metal, a ceramic fiber material, a synthetic resin material, or the like, a composite structure material, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In general, as a bulletproof material, glass fiber, nylon, aramid fiber, steel, titanium alloy, aluminum alloy, ceramics, etc. are used. ,
Alternatively, they have been used in combination. For example, Japanese Patent Application Laid-Open No. 2-208262 discloses that a plate made of a composite material composed of aluminum or an aluminum alloy and at least a part of granular ceramic and a plate made of a metal or an alloy are each one or two sheets. It is constituted by laminating more than one sheet, and the average particle size of the ceramic is 0.01 to 500 μ
m, volume content of ceramics in composite material is 1 to 70%
Discloses a bulletproof material.

[0003]

In the case of the above bulletproof material, it is necessary to increase the thickness in accordance with the assumed bullet speed. For example, since the speed of an armor-piercing ammunition fired from a rifle or a machine gun is 900 m / s, it must be thicker than a bulletproof material that assumes 44 magnum (a bullet speed of 430 m / s). Therefore, for example, when a fiber material such as aramid fiber is used, there is a problem that the volume is enormous. In addition, since it is quite expensive from an economical point of view, it is limited to small parts such as bulletproof vests and helmets. On the other hand, when steel or a titanium alloy is used, its weight increases, which hinders the weight reduction of a moving body such as an armored car or a car. Further, when an aluminum alloy of a light metal is used, since the strength is lower than that of steel or a titanium alloy, the plate thickness becomes large, and as a result, it becomes difficult to reduce the weight. When a composite material composed of an aluminum alloy and ceramics is used, it cannot be used because the toughness is extremely reduced.

Accordingly, an object of the present invention is to reduce the minimum required thickness of the aluminum alloy by increasing the strength and toughness of the aluminum alloy, and to reduce the weight of the moving body and the like.
An object of the present invention is to provide an aluminum bulletproof material having excellent resistance to high-speed flying objects. It is a further object of the present invention to provide a method for producing an aluminum bulletproof material having excellent impact resistance and ballistic resistance at low cost and with good productivity.

[0005]

According to one aspect of the present invention, there is provided an aluminum bulletproof material, the basic aspect of which is that the average grain size of crystal grains or subcrystal grains is reduced. It is characterized by having a 0.05-1.0 micron structure to improve penetration resistance to high-speed flying objects, and has sufficient impact resistance to high-speed flying objects at speeds of 300 m / s or more. ing. In a preferred embodiment, Mg: 2.0 to 6.0% by weight, Mn: 0.0
5 to 0.20% by weight, Cr: 0.05 to 0.20% by weight, other impurities less than 1% by weight in total, and the balance being Al, and the average grain size of crystal grains or subcrystal grains is 0. .
In the range of 0.5-1.0 micron, tensile strength 300M
An aluminum ballistic material characterized by having mechanical properties of Pa or more and elongation of 10% or more is provided. In another preferred embodiment, Mg: 0.3-1.2% by weight, S
i: 0.2 to 0.8% by weight, other impurities total 1% by weight
Having a composition of less than and a balance of Al, the average grain size of crystal grains or sub-crystal grains is in a range of 0.05 to 1.0 micron, and a mechanical property of a tensile strength of 300 MPa or more and an elongation of 10% or more. An aluminum bulletproof material is provided. In any of the above embodiments, Fe and S
It is desirable that the content of i be suppressed to 0.1% by weight or less.

Further, according to the present invention, there is also provided a method of manufacturing the above-mentioned aluminum ballistic material. The basic mode is that (A) an aluminum alloy is subjected to plastic deformation (strain) corresponding to elongation of 220% or more, and the average crystal grain size is set to 1%.
And (B) rolling the obtained material at a temperature of 25 ° C. to 300 ° C. In another embodiment, after the rolling step (B), A step of performing a heat treatment at a temperature of 100 to 300 ° C. for 0.5 to 3 hours, or a step of performing at least one flash annealing (a heat treatment by direct energization) at a temperature of 150 to 400 ° C. for 1 to 30 seconds. And In a preferred embodiment, the step (A) includes the step of changing the extrusion direction of the aluminum alloy to a side having an inner angle of less than 180 ° on the way to give a shear deformation, thereby providing a large elongation corresponding to 220% or more. It consists of a side extrusion process that gives strain and refines the average crystal grain size of the microstructure to 1 micron or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum bulletproof material of the present invention
By giving plastic deformation (strain) equivalent to elongation of 220% or more to the aluminum alloy and reducing the average crystal grain size to 1 micron or less, penetration resistance to high-speed flying objects such as bullets, shells, and fragments thereof. Is improved. By the way, the bulletproof material absorbs the energy of the collision object by its own plastic deformation. However, if the amount of plastic deformation is too large, it interferes with the object to be protected. Therefore, it is necessary to suppress the amount of plastic deformation as much as possible. Therefore, the bulletproof material itself is required to have high strength. However,
Even if the strength is increased, a material that does not have resistance to crack growth will break without plastic deformation when colliding with an object. Therefore, it can be said that a toughened material is the most suitable. In addition, since most of the bulletproof materials are worn or used for a part of a moving body, the lighter the weight, the better.

[0008] In consideration of the above, it can be said that it is best to strengthen an aluminum alloy having a low density and use it as a bulletproof material. Examples of the method of strengthening the metal include work hardening, precipitation strengthening, dispersion strengthening, solid solution strengthening, composite strengthening, and microstructural enhancement. Among them, the one that can be strengthened while suppressing the decrease in elongation and toughness is the strengthening of the microstructure. In addition, it has been found that the impact resistance is improved by making the structure finer. Therefore, by subjecting a conventional material to severe straining by side extrusion or rolling according to the present invention, the crystal grain size can be controlled to 1 micron or less and the dislocation density within the grain can be reduced in a very simple process. It can be controlled, and the toughness and light weight required as a bulletproof material are achieved.

As the aluminum alloy subjected to severe strain processing according to the present invention, various types can be used. For example, in the case of an Al-Mg alloy, when the content of Mg as an additive element of the aluminum alloy increases, the structure becomes fine. However, if it is less than 2% by weight, the strength is low. On the other hand, when the Mg content exceeds 6% by weight, segregation, casting cracks, etc. occur, so that the impact resistance and the ballistic resistance are reduced. Mn and Cr are also effective in refining the structure, but their contents are 0.2% each.
If the content is more than 10% by weight, the compound which is the starting point of the crack is dispersed at a high density, so that the impact resistance and the ballistic resistance are reduced. Al and F
e and Si form an AlFeSi-based compound, which serves as a starting point of a crack, and lowers impact resistance and ballistic resistance.
It is necessary to keep the contents of e and Si low. More preferably, the content of each of Fe and Si is 0.1% by weight.
In the following cases, the impact resistance and the ballistic resistance are dramatically improved.

The method for manufacturing an aluminum bulletproof material according to the present invention is characterized in that an aluminum alloy material is stretched to about 220% or more by plastic working such as extrusion, rolling, and forging at a relatively low temperature, preferably at a temperature lower than the recrystallization temperature. By giving the corresponding plastic deformation, the average crystal grain size is reduced to 1 micron or less, ductility at high temperature (formability) is improved, and large elongation is exhibited in a temperature range where the mechanical properties of the material are not significantly reduced. A material having deformability (crystal grain refinement step) is then rolled at a temperature of about 25 to 300 ° C. (rolling step) to produce a bulletproof material having a desired shape.

In the crystal grain refinement step (A), the aluminum alloy is subjected to plastic deformation with a strain amount corresponding to elongation of 220% or more to give a structure refined to a crystal grain size of 1 micron or less. in molding conditions at about 10 ^-5 ~10 ⁰ s ^-1 is shown about 150% or more of elongation. Further, when the material is formed under the above conditions, the material is deformed due to deformation due to grain boundary sliding and intragranular (plastic) deformation, that is, superplastic deformation occurs. Therefore, in the present invention, the material that has undergone the grain refinement step as described above is preferably in a region where superplastic processing is possible (conditions for imparting ductility without lowering the mechanical properties of the material). And rolling.

Hereinafter, the method of the present invention will be described in detail. First, as the crystal grain refining step (A), a side extrusion method, a rolling method, a forging method, etc. can be applied. Most preferred in this regard is the side extrusion method. As shown in FIG. 1, the side extrusion method according to the present invention comprises two extrusion containers having the same cross-sectional area on the inner surface, or a container 1 and a die 2 having an appropriate angle (2 °) of less than 180 °.
ψ), the aluminum alloy S is inserted into one container 1 and the next container or die 2 is
This is a method in which lateral shearing is applied to the material by extruding the material, and this step is performed a plurality of times as necessary. By applying this method to an aluminum alloy, the crystal grains can be refined to 1 micron or less in a very simple process without reducing the cross-sectional area, and can be strengthened more than the conventional strength by work hardening. At the same time, the toughness can be greatly improved. Also, the process is
Cast structure, macro and micro segregation fracture of alloy components,
It also has an effect on homogenization, and high-temperature and long-time homogenization heat treatment generally performed for aluminum alloys can be omitted. Further, even if the cross section of the die 2 is reduced, the effect is not changed.

The amount of shear deformation applied to the aluminum alloy in the side extrusion method of the present invention depends on the joining angle of the two containers or the container and the die. Generally, the amount of strain Δε _i per extrusion by such shearing deformation is given by the following equation (1).

(Equation 1) That is, when the inner angle of the joint between the two containers or the container and the die is a right angle (90 °), the amount of strain is 1.15 (equivalent elongation: 220%) in one side extrusion, and when 120 °, the amount of strain is Is given by 0.67 (equivalent elongation: 95%). By extruding at right angles to the side while keeping the same cross-sectional area, a process equivalent to a rolling reduction (cross-sectional reduction) of 69% by rolling can be added.

By repeating the above process, infinite strain can be applied to the material. The accumulated strain amount ε _t given to the material by the repetition is given by the following equation (5).

(Equation 2) The number of repetitions (N) is theoretically better as it is larger, but in practice, the effect is saturated at a certain number of times depending on the alloy. In a general wrought aluminum alloy, the number of repetitions is four (when the joining angle is a right angle, the integrated strain amount is 4.
6, equivalent elongation: 10,000%), a sufficient effect can be obtained. Infinite strains can also be accumulated by rolling, in which case the cross-sectional area becomes infinitely small, in contrast to the lateral extrusion method. The lateral extrusion according to the present invention can be extruded not only in one lateral direction but also in multiple directions or in all directions, and can be extruded into a lateral cavity of any shape such as a flat plate.

By the side extrusion method as described above, for example,
Mg: 0.3-1.
In the case of having a composition of 2% by weight, Si: 0.2 to 0.8% by weight, other impurities less than 1% by weight in total, and the balance of Al, the average grain size of crystal grains or sub-crystal grains is about 0.05 to
In the range of 1.0 μm, tensile strength of 300 MPa or more,
A tough aluminum alloy material having mechanical properties of elongation of 10% or more can be obtained. The obtained aluminum alloy material has a fibrous structure in which crystal grain boundaries are elongated, and the inside of the crystal grains is composed of a subcrystal of about 0.05 to 1.0 μm.

In the case of an aluminum alloy containing 1 to 9% by weight of Mg, the average grain size of crystal grains or subcrystal grains is in the range of about 0.05 to 1.0 μm, and about 1 × 10 ^-4 to 2
A tough aluminum alloy material in which the strain rate dependence of strength is suppressed in a strain rate region of × 10 ³ s ⁻¹ can be obtained. For example, when the material alloy is an A5056 series alloy, Mg: 2.0
~ 6.0% by weight, Mn: 0.05 ~ 0.20% by weight, C
r: 0.05 to 0.20% by weight, when the total content of other impurities is less than 1% by weight, and the balance is Al, the average grain size of the crystal grains or subcrystal grains is about 0.05 to 1.0 μm.
, Tensile strength 300 MPa or more, elongation 10%
A tough aluminum alloy material having the above mechanical properties can be obtained. The obtained aluminum alloy material has a fibrous structure in which crystal grain boundaries are similarly elongated, and the inside of the crystal grains is composed of a subcrystal of about 0.05 to 1.0 μm.

Al-Mg based alloys have an appropriate strength by solid solution hardening and work hardening and have excellent ductility (forming workability). Has a wide range of uses. However, when the concentration of Mg, which is a solute atom, increases, a stripe pattern called a stretcher strain mark is formed when a load is applied at a room temperature or higher at a yield point or higher. On the other hand, discontinuous yielding repeatedly occurs on the stress-strain curve, which appears as serrations having a saw-tooth shape, and is expressed by Portevin-LeChate.
It is also called the lier effect (PL effect). When such serrations occur, negative strain rate sensitivity, that is, the tendency of the strength to decrease when the strain rate increases, is likely to be exhibited, so that localization of deformation occurs and the formability of the material is deteriorated. Becomes In addition, the impact strength and the dynamic fracture toughness decrease the reliability of the alloy itself, which hinders thinning and weight reduction of the product. On the other hand, by subjecting a conventional material to severe straining by a lateral extrusion method according to the present invention, by controlling the crystal grain size and the solid solution state of Mg in the crystal grains in a very simple process. Serration can be suppressed. Moreover, the material after processing has a large elongation and drawing, is excellent in formability, has high strength, and has high impact absorption and dynamic fracture toughness, so that its reliability as a material is high.

It is considered that the serration is caused by the dislocation fixation by the solute atmosphere and the release from the fixation by the load stress.
It is considered that a method of reducing the concentration of, or a method of distributing grain boundaries serving as barriers at a high density immediately after dislocations are released from fixation is considered to be effective. The former method introduces dislocations and accumulates Mg solute atoms near sub-grain boundaries formed by cell walls and sub-grains formed by recovery to reduce apparent Mg concentration in crystal grains. I just need. The latter method can be achieved by making the crystal grains fine. As the former method, cold working by rolling can be considered, but problems such as a decrease in ductility, anisotropy, and stress corrosion cracking may occur as the working ratio increases. On the other hand, according to the present invention, it is possible to refine the crystal grains and control the Mg concentration in the crystal grains by strong working by the side extrusion process, suppress serration, and achieve toughening of the aluminum alloy. it can.

The lateral extrusion according to the invention is preferably carried out at as low a temperature as possible. However, the deformation resistance of the alloy tends to be higher at lower temperatures, and the deformability tends to be lower at lower temperatures. In order to obtain the relationship between the strength of the extrusion tool and the sound extruded material, it is usually carried out at an appropriate temperature depending on the alloy. Generally, it is carried out at a temperature of about 300 ° C. or less, preferably at or below the recrystallization temperature of the alloy, and more preferably at or below the recovery temperature. However, the recrystallization temperature and the recovery temperature vary depending on the degree of processing applied to the material. The extrusion temperature is
When ψ = 45 ° (90 ° lateral extrusion), room temperature to 150 ° C for Al-Mg-Si-based A6063 alloy and room temperature to 200 ° C for Al-Mg-based A5056 alloy, which are typical of aluminum alloys for spreading. , Al-Zn-Mg-Cu-based A707
A typical temperature is 50 to 200 ° C. for the five alloys. The extrusion temperature depends on the extrusion angle, and the larger the angle, the lower the temperature. This is because the pushing force (energy required for shearing deformation) is reduced, and the constraint due to the deformability of the material is relaxed.

When the structure of the laterally extruded material is observed with an optical microscope and a transmission electron microscope, it is 200-200 before processing.
The crystal grains of 500 microns or more are remarkably refined to about 0.1 microns by extrusion three to four times (dislocation cell structure,
(Including subcrystal and recrystallized structures). When a metal material is processed, most of its plastic deformation energy is converted into heat, but a part of the energy is accumulated in the material as point defects, dislocations, stacking faults or internal stress. The accumulation of these lattice defects causes hardening (strengthening). When the crystal grains are further processed, the crystal grains are elongated and the dislocation density is increased, so that a three-dimensional network structure (cell structure) of dislocations is formed as a lower structure in the elongated crystal grains. This cell becomes finer as processing increases. Cell walls with a high dislocation density are inherently thick, and are understood to have a smaller cell structure microscopically. Is hardly observed and is not a characteristic structure obtained by the side extrusion method.

In general, the cell structure is assumed to be transformed into subcrystals by recovery accompanied by rearrangement of defects (early stage of release of stored energy; without structural change), and the rearrangement of these defects has a melting point (absolute temperature). It is said to occur when heated to a temperature of about 1/3 to 1/2. Lateral extrusion has been performed at lower temperatures, but with a considerable elongation of 1,000.
%, The dislocation density cannot be increased due to remarkable hard working exceeding 100%, and the transition temperature to sub-crystals has decreased and transition to sub-crystals has occurred. It is presumed that the crystals were mainly used. Conventionally, a thermomechanical treatment method is known as a method for refining a crystal of an aluminum alloy, but is not suitable for industrial crystal refining of 1 micron or less. For the first time, a material comprising crystals of 1 micron or less can be industrially obtained by the method of the present invention, in which a strong working is forcibly performed at a low temperature. Moreover, since each crystal does not have a high dislocation density characteristic of a processed structure, these structures are stable in a temperature range of industrial application.

Fine crystal grains (or sub-crystal grains) of 1 micron or less (preferably 0.5 micron or less) as described above.
Is characteristic of the aluminum alloy material obtained in step (A) of the method of the present invention, which characterizes the mechanical properties of the material. Generally, there are methods of strengthening materials, such as work strengthening, solid solution strengthening, precipitation strengthening, and dispersion strengthening.
Indices of material flexibility, such as the Charpy impact value, decrease, and of course, the fracture toughness value also decreases. As a method of strengthening a material without losing its flexibility, there is a method of making a crystal finer. The strength of the material increases with the refinement of the crystal.
Also known as Petch's law. As described above, the material structure obtained in the crystal grain refining step (A) of the present invention is a very fine crystal grain and does not have a high dislocation density. High Charpy impact value and excellent secondary workability.

After the crystal grain refining step (A), rolling is performed at a temperature of about 25 to 300 ° C. At this time, if the temperature exceeds 300 ° C., the crystal grains grow and coarsen, and as a result, the strength decreases, which is not preferable. In this rolling step, the rolling reduction is not limited to a specific reduction rate, as long as the structure refined in the step (A) can be maintained. Further, when rolling is performed at around room temperature, work hardening occurs and a large amount of strain remains in crystal grains. In this state, elongation and toughness decrease, so it is desirable to remove residual strain by heat treatment. However, if the heat treatment temperature exceeds 300 ° C., the crystal grains grow and coarsen, and as a result, the strength decreases, which is not preferable. Therefore, the heat treatment conditions are as follows.
0 to 300 ° C., treatment time about 0.5 to 3 hr, or at a higher temperature (about 150 to 400 ° C.) for a short time (about 1 to 30 seconds) at least once (several times if necessary) Heat treatment (flash annealing) is appropriate.

The aluminum alloy produced by the above-described method is used for a vehicle body, a bumper, a door beam,
It can be applied as various protective materials and bulletproof materials such as safety shoes and helmets, bodies of airplanes and helicopters, tanks, armored vehicles and missile bodies, bulletproof doors, bulletproof windows (sashes), bulletproof vests and bulletproof helmets.

The method of the present invention can be applied to any aluminum alloy.
S A5056, A5083, A6063, A606
1, A7039, 7N01 alloy and the like. As typical examples, A6063 alloy and A50 specified in JIS
Table 1 shows the composition range of the 56 alloys. Further, the method of the present invention can be applied not only to aluminum alloys produced by intermediate processing such as homogenization heat treatment and hot extrusion at room temperature or in a heating region or other methods, but also to aluminum alloys after casting.

[Table 1]

[0026]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples, but it goes without saying that the present invention is not limited to the following Examples.

Example 1 A drawn material (diameter: 50 mm) of an A5056 alloy having a composition shown in Table 1 was used as an applicable alloy.
After heat treatment for an hour, the sample was quenched in water to obtain a test material. The prepared test material is inserted into one of two containers (both having an inner diameter of 50 mm) connected at a right angle (ψ = 45 °), and is laterally extruded four times at 100 ° C. to obtain a treated material having a diameter of 50 mm. Obtained.
As a result, according to the above equation (5), the integrated distortion amount (ε
_t ) An aluminum alloy material processed to 4.6 (equivalent elongation of 10,000%) was obtained. From the laterally extruded material thus produced, anti-elastic test pieces having a diameter of 50 mm and a thickness of 15 mm, 20 mm, 25 mm and 40 mm, respectively, were cut out. The test piece 10 was simply fixed to a stainless steel tube 11 shown in FIG. 2 using a steel ring 12 and a vinyl tape 13 for simple fixing, and this was set at a predetermined position in a vacuum chamber 20, and about 16 g of lead 15 was removed. Bullet 1 attached
4 (total weight 28 g) were collided in a vacuum at a speed of 770 m / s. The bullet 14 was provided with a speed calculating magnet 16 by a resin 17. Also, in order to grasp the anti-elasticity of the whole aluminum alloy, an annealing material of A1050,
A7075 T6 material, A5056 annealed material (crystal grain size 50 microns) to investigate the effect of grain refinement
Was also performed.

The annealed material of A1050 has the lowest strength among aluminum alloys, and the T6 treated material of A7075 is the highest strength material. However, for the same thickness of 40 mm, A1050
The annealed material of No. 7 was deformed to a depth of 20 mm to stop the bullet, but the T6 treated material of A7075 was cracked and cracked. Therefore, it is understood that not only the strength but also the toughness is required. When the thickness of the annealed material of A5056 was changed, the bullet penetrated at a thickness of 20 mm, but at a thickness of 40 mm, it was shallower than the annealed material of A1050 (15 m from the surface).
m). The minimum required thickness is 25mm
It turned out to be. In the case of the laterally extruded material of A5056, the bullet penetrated at a thickness of 15 mm, but stopped at a position of about 12 mm or less from the surface at a thickness of 20 mm or more. From the results, it was found that the minimum required thickness was 20 mm. From the above results, it was found that an aluminum alloy whose crystal grain size was reduced to 1 micron or less exhibited the best ballistic resistance. Further, when the aluminum alloy which has been miniaturized is made into a multi-layer (two or more sheets), as shown in Table 2, when the thickness is 15 mm or more, the penetration of bullets is prevented, so it can be said that the ballistic resistance is further improved.

[Table 2] After the lateral extrusion, the same result was obtained also in the case where rolling was performed to give a shape and the structure was adjusted to the same structure as the laterally extruded material by annealing.

[0029]

As described above, according to the present invention, a conventional aluminum alloy is subjected to plastic working such as extrusion, rolling, and forging at a relatively low temperature, preferably at a temperature not higher than the recrystallization temperature, particularly side extrusion. By giving plastic deformation corresponding to elongation of 220% or more, the average crystal grain size can be relatively easily reduced to 1 micron or less in a small number of steps, thereby improving impact resistance and ballistic resistance. An aluminum bulletproof material having excellent resistance to high-speed flying objects can be manufactured. As a result, it is possible to significantly reduce the weight of the bulletproof material as compared with conventional steel, titanium alloy and the like. Further, a bulletproof material having such excellent characteristics can be manufactured at low cost and with high productivity.

[Brief description of the drawings]

FIG. 1 is a schematic partial cross-sectional view for explaining the concept of a side extrusion method of an aluminum alloy used in the present invention.

FIG. 2 is a schematic configuration diagram of an anti-ballistic test performed in Examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Die 3 Ram S Aluminum alloy material 10 Test piece 14 Bullet 15 Lead 16 Magnet for speed calculation

Continuation of the front page (51) Int.Cl. ⁶ identification symbol FI // C22F 1/00 601 C22F 1/00 601 604 604 672 672 682 685 685Z 686 686B 694 694A 694B

Claims (12)

[Claims] 1. The method according to claim 1, wherein the average grain size of the crystal grains or subcrystal grains is 0.0
An aluminum bulletproof material characterized by having a texture of 5 to 1.0 microns to improve penetration resistance to high-speed flying objects. 2. The aluminum bulletproof material according to claim 1, which has impact resistance to a high-speed flying object having a speed of 300 m / s or more. 3. Mg: 2.0-6.0% by weight, Mn:
0.05 to 0.20% by weight, Cr: 0.05 to 0.20
Wt%, total less than 1 wt% of other impurities, and the balance Al
Having an average grain size of crystal grains or subcrystal grains in the range of 0.05 to 1.0 micron and a tensile strength of 30
An aluminum bulletproof material having mechanical properties of 0 MPa or more and elongation of 10% or more. 4. The aluminum bulletproof material according to claim 3, wherein Fe is 0.1% by weight or less and Si is 0.1% by weight or less. 5. Mg: 0.3-1.2% by weight, Si:
It has a composition of 0.2-0.8% by weight, other impurities less than 1% by weight in total, and the balance being Al, and the average grain size of crystal grains or sub-crystal grains is in the range of 0.05-1.0 micron. An aluminum bulletproof material having mechanical properties of tensile strength of 300 MPa or more and elongation of 10% or more. 6. The method according to claim 5, wherein Fe is 0.1% by weight or less.
The aluminum bulletproof material according to 1. 7. (A) a step of giving a plastic deformation (strain) corresponding to elongation of 220% or more to an aluminum alloy to reduce the average crystal grain size to 1 micron or less; and (B) a material obtained. A step of rolling at a temperature of 25 to 300 ° C. 8. After the rolling step (B), the temperature is further increased to 10 ° C.
The method according to claim 7, comprising a step of performing a heat treatment at 0 to 300 ° C for 0.5 to 3 hours. 9. After the rolling step (B), the temperature is further increased to 15 ° C.
The method according to claim 7, comprising a step of performing at least one heat treatment at 0 to 400C for 1 to 30 seconds. 10. The method according to claim 1, wherein in the step (A), the extruding direction of the aluminum alloy is changed to a side angle of less than 180 ° on the way to give a shear deformation, whereby a large strain corresponding to elongation of 220% or more is obtained. The method according to claim 7 or 8, comprising a side extrusion step of providing a microstructure with an average crystal grain size of 1 micron or less. 11. The method according to claim 7, wherein the aluminum alloy is an Al—Mg alloy. 12. An aluminum alloy comprising Al-Mg-Si.
The method according to any one of claims 7 to 9, which is a system alloy.