A method for preparing a pure aluminum transition armor steel / aluminum alloy laminated composite armor

Abstract

The application discloses a preparation method of a pure aluminum transition armor steel / aluminum alloy layered composite armor, which adopts pure aluminum as a transition layer for hot-pressing diffusion of the armor steel and the armor aluminum alloy, prepares a combination of the armor steel and the pure aluminum first, then carries out hot-pressing diffusion reaction on the prepared combination and the armor aluminum alloy, and finally obtains the pure aluminum transition armor steel / aluminum alloy layered composite armor material. The preparation method can adjust the density of the layered composite armor by selecting armor materials with different layer thicknesses according to the technical requirements of different parts of the armored vehicle, improves the density in the key parts, reduces the density in the secondary parts, and thus achieves the optimal light weight of the armored vehicle. Meanwhile, the pure aluminum as the transition layer can diffuse with the armor steel to generate a high-strength intermetallic compound layer, which can not only serve as a reinforcing phase to improve the anti-bullet performance of the layered composite armor, but also improve the impedance mismatch between the layers of the layered composite armor and improve the impact filtering capacity of the layered composite armor.

Description

Technical Field

[0001] This invention relates to the field of layered composite armor materials technology, specifically a method for preparing pure aluminum transition armor steel / aluminum alloy layered composite armor. Background Technology

[0002] Armored vehicles, as an indispensable component of modern warfare, face a major challenge in their development: balancing defensive and mobility capabilities. Traditional lightweighting solutions, aimed at improving mobility, primarily involve replacing armor steel with aluminum alloys. However, aluminum alloys have limitations in ballistic resistance. Therefore, layered composite armor combining armor steel and aluminum alloys has been proposed. This composite is achieved through bonding or rolling, resulting in a "sandwich" structure (typically two or three layers). While maintaining ballistic resistance, this also achieves lightweighting. However, due to manufacturing limitations, increasing the number of layers is difficult, hindering the effective utilization of the composite material's additive effects (such as bridging, blocking, and discontinuity effects) and impact filtering effects, thus preventing the improvement of ballistic resistance.

[0003] Currently, multilayer composite materials of steel / aluminum mainly use pure aluminum, which is hot-pressed at the semi-solid temperature of pure aluminum (655℃) to solve problems such as instability and weak bonding of dissimilar materials and interlayer cracking in multilayer rolling. Hot-pressing diffusion uses high temperature and high pressure to activate the atoms at the interface of dissimilar metals, causing the interface atoms to interdiffusion, thereby forming an interface diffusion layer and obtaining a densely bonded, defect-free layered composite material. However, the current hot-pressing process of steel and aluminum composites is difficult to prepare multilayer composite armor of armor steel and armor aluminum alloy. The main reasons can be attributed to two points: First, the melting point of aluminum alloys is relatively low, mostly between 500 and 600℃. When hot-pressing at temperatures below the melting point of aluminum alloys, the atoms on the armor steel side at the interface are difficult to activate and diffuse, and the hot-pressing process is extremely time-consuming. Second, due to the low activity of interface atoms and the long hot-pressing diffusion time, the elastic resistance of the armor steel and armor aluminum alloy will decrease to varying degrees under the long-term thermal influence, which defeats the original design purpose of the layered composite material of armor materials.

[0004] To address this significant problem, scholars have primarily focused on using high-melting-point armor aluminum alloys to increase the activity of interfacial atoms and reduce the time of hot-pressing diffusion reactions. However, this has not solved the fundamental problem of preparing multilayered armor steel / aluminum alloy layered composite armor. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing armor steel / aluminum alloy layered composite armor with multiple layers, controllable density, excellent ballistic performance and good impact filtering performance, in contrast to the above-mentioned prior art.

[0006] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: a method for preparing pure aluminum transition armor steel / aluminum alloy layered composite armor, characterized by comprising the following steps:

[0007] S1. Remove the oxide film from the surface of three metal plates: armor steel, armor aluminum alloy, and pure aluminum.

[0008] S2. The armor steel and pure aluminum plates treated in S1 are stacked together and subjected to hot pressing diffusion treatment in a vacuum hot press furnace to obtain two composite materials: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum.

[0009] S3. Perform surface deoxidation treatment on the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum obtained in S2;

[0010] S4. The armor aluminum alloy treated in S1 is placed between the pure aluminum exposed surfaces of the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum treated in S3, and hot-pressing diffusion treatment is carried out in a vacuum hot press furnace to obtain pure aluminum transition armor steel / aluminum alloy layered composite armor.

[0011] Preferably, in step S1, the surface treatment process for the three metal plates—armor steel, armor aluminum alloy, and pure aluminum—is as follows: the surfaces of the three metal plates are sanded, then the armor steel, armor aluminum alloy, and pure aluminum are washed with an alkaline solution under the assistance of ultrasonic vibration, cleaned with anhydrous ethanol after the alkaline washing, dried, and then acid-washed with an acid solution. After the acid washing, they are ultrasonically cleaned with anhydrous ethanol and then quickly placed in a vacuum drying oven for vacuum drying treatment, so that there is no anhydrous ethanol residue on the surface of the metal plates.

[0012] Preferably, in step S2, pure aluminum is used as a transition layer between armor steel and armor aluminum alloy. The hot pressing parameters of the vacuum hot press furnace for the two prefabricated composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum are as follows:

[0013] The vacuum hot pressing process is as follows: the vacuum hot pressing equipment is evacuated to a vacuum level of ≤1×10. -1 Pa, heated at a rate of 5-10℃ / min, held at 600-655℃, with a pressure column pressure of 1-10MPa, and held for 10-50 minutes. Then, cooled to 15-50℃ under vacuum at a rate of 10-15℃ / min, with the pressure decreasing to 0MPa synchronously with the temperature change.

[0014] Preferably, in step S2, the hot pressing parameters of the vacuum hot press furnace are: the heating and pressurization in the vacuum hot press equipment are directly raised to the set value, and the cooling and pressurization are also directly reduced to the set value.

[0015] Preferably, in step S3, the surface treatment process of the two composite materials of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum obtained in S2 is as follows: the surface of the two composite materials of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum is polished to remove the graphite paper residue on the surface, and then alkaline washing and acid washing are performed. After acid washing, it is rinsed with anhydrous ethanol. Then, the two composite materials of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum are placed in a vacuum drying oven for vacuum drying treatment so that there is no anhydrous ethanol residue on the surface of the composite material.

[0016] Preferably, in step S4, the hot-pressing diffusion process for preparing the pure aluminum transition armor steel / aluminum alloy layered composite armor is as follows:

[0017] The vacuum hot pressing process is as follows: the vacuum hot pressing equipment is evacuated to a vacuum level of ≤1×10. -1 Pa, heated at a rate of 5-15℃ / min, held at 380-450℃, with a pressure column pressure of 5-15MPa, and held for 30-120 minutes. Then, cooled to 15-50℃ under vacuum at a rate of 5-10℃ / min, with the pressure decreasing to 0MPa synchronously with the temperature change.

[0018] Preferably, in step S4, the hot pressing parameters of the vacuum hot press furnace are: the temperature and pressure are increased directly to the set value or gradually increased to the set value in the vacuum hot press equipment, and the temperature and pressure are also decreased directly or gradually to the set value.

[0019] Compared with existing technologies, the advantages of this invention are as follows: The pure aluminum transition armor steel / aluminum alloy layered composite armor preparation process of this invention uses pure aluminum as the transition layer for hot-pressing diffusion composite of armor steel and armor aluminum alloy. The process first prepares a composite of armor steel and pure aluminum. Through diffusion reaction at the semi-solid temperature (655℃) of pure aluminum, the interface atoms of the armor steel are rapidly activated and diffuse with pure aluminum, resulting in rapid and effective metallurgical bonding between the two dissimilar metals. Then, the pre-prepared composite is hot-pressed and diffused with the armor aluminum alloy at the melting point temperature of the aluminum alloy. Since the diffusion atoms on both sides of the interface are mainly aluminum atoms, diffusion lag caused by large differences in atomic size is less likely to occur, thus quickly achieving effective metallurgical bonding between the pure aluminum and aluminum alloy interfaces.

[0020] Layered composite armor made of armor steel / aluminum alloy through pure aluminum transition and hot-pressing diffusion composite processes allows for the control of the composite armor's density by selecting armor materials of varying thicknesses to meet the technical requirements of different parts of the armored vehicle. This involves increasing density in critical areas and decreasing density in less critical areas, thereby achieving optimal lightweighting of the armored vehicle. Simultaneously, pure aluminum, acting as a transition layer, undergoes a diffusion reaction with the armor steel to generate a high-strength intermetallic compound layer. This layer not only acts as a reinforcing phase to improve the ballistic resistance of the layered composite armor but also increases the impedance matching difference between the layers, enhancing its impact filtering capability.

[0021] In other words, by using pure aluminum transition and hot-press diffusion composite methods to solve the problems of low number of cyclic layers and unstable bonding at dissimilar interfaces in armor steel / aluminum alloy layered composite armor, layered composite armor with controllable density, strong ballistic performance, and excellent impact filtering performance can be obtained.

[0022] In addition, the preparation method of the present invention has low cost, simple process, low noise and air pollution, and good product performance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the stacking method of armor steel / pure aluminum;

[0024] Figure 2 This is a schematic diagram illustrating the stacking of pure aluminum / armor steel / pure aluminum.

[0025] Figure 3 This is an assembly diagram showing the connections between armor steel / pure aluminum, pure aluminum / armor steel / pure aluminum, and graphite molds.

[0026] Figure 4 This is an assembly diagram showing the relationships between armor steel / pure aluminum, pure aluminum / armor steel / pure aluminum, armor aluminum alloy, and graphite molds.

[0027] Figure 5 Macroscopic diagram of the anti-Type 53 7.62mm armor-piercing projectile in a layered composite armor of pure aluminum transition 616 armor steel and 7050 armor aluminum alloy;

[0028] Figure 6 A macroscopic interface diagram showing the combination of pure aluminum transition 616 armor steel and 7050 armor aluminum alloy layered composite armor.

[0029] Figure 7 Microscopic interface diagram of layered composite armor consisting of pure aluminum transition 685 armor steel and 2024 armor aluminum alloy. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0031] A method for preparing a pure aluminum transition armor steel / aluminum alloy layered composite armor includes the following steps:

[0032] S1. Remove the oxide film from the surface of three metal plates: armor steel, armor aluminum alloy, and pure aluminum.

[0033] S2. The armor steel and pure aluminum plates treated in S1 are stacked together and subjected to hot pressing diffusion treatment in a vacuum hot press furnace to obtain two composite materials: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum.

[0034] S3. Perform surface deoxidation treatment on the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum obtained in S2;

[0035] S4. The armor aluminum alloy treated in S1 is placed between the exposed pure aluminum surfaces of the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum treated in S3, and hot-pressing diffusion treatment is carried out in a vacuum hot press furnace to obtain pure aluminum transition armor steel / aluminum alloy layered composite armor material.

[0036] The four steps described above will be explained in detail below:

[0037] S1:

[0038] In step S1, the process for removing the oxide film from the surfaces of armor steel, armor aluminum alloy, and pure aluminum plates is as follows:

[0039] First, the surfaces of three types of metal plates—armor steel (1-10mm thick), armor aluminum alloy (1-10mm thick), and pure aluminum (0.1-0.5mm thick)—are mechanically polished with 100-400 grit sandpaper.

[0040] Then, under the assistance of ultrasonic vibration with an amplitude of 5-15 μm, the three metal plates of armor steel, armor aluminum alloy, and pure aluminum, after their surfaces have been sanded, are alkaline washed with 4-12 mol / L NaOH solution. After alkaline washing, they are ultrasonically cleaned with anhydrous ethanol for 30-60 seconds. Afterward, they are quickly dried with a cold air blower, and then acid-washed with 5-15% HCl solution. After acid washing, they are ultrasonically cleaned with anhydrous ethanol for 30-60 seconds. Afterward, the armor steel and pure aluminum are quickly placed in one vacuum drying oven, and the armor aluminum alloy is placed in another vacuum drying oven for vacuum drying treatment to ensure that there is no anhydrous ethanol residue on the surface of the metal plates.

[0041] S2:

[0042] In step S2, the preparation processes for the two composite materials, armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum, are as follows:

[0043] First, remove the armor steel and pure aluminum sheets from the vacuum drying oven, and then quickly process them in two ways: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum stacking. Figure 1 and Figure 2 The diagrams show two stacking methods: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum. Component 1 is armor steel, and component 2 is pure aluminum.

[0044] The two composite materials, armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum, are then placed between graphite molds in a vacuum hot press furnace. To prevent diffusion reactions between the armor steel and the graphite mold, and between the pure aluminum materials, 0.1mm thick graphite paper is used to separate the upper and lower surfaces of each composite material from the outside. Figure 3 As shown. Figure 3 Component 3 is a graphite pressure column, component 4 is a graphite mold, component 5 is graphite paper, component 6 is an armor steel / pure aluminum composite, and component 7 is a pure aluminum / armor steel / pure aluminum composite.

[0045] The vacuum hot pressing process is as follows: the vacuum hot pressing equipment is evacuated to a vacuum level of ≤1×10. -1 The temperature is increased at a rate of 5–10 °C / min, and the holding temperature is 600–655 °C. The pressure column pressure is set at 1–10 MPa, and the holding time is between 10 and 50 min. Then, the temperature is cooled to between 15 and 50 °C under vacuum at a rate of 10–15 °C / min. The pressure decreases synchronously with the temperature change to 0 MPa. Specifically, the holding temperature can be, for example, but not limited to, any one or any two of 600 °C, 620 °C, 635 °C, and 655 °C. The pressure column pressure can be, for example, but not limited to, any one or any two of 1 MPa, 5 MPa, 7 MPa, and 10 MPa.

[0046] The vacuum hot pressing process for preparing armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites employs a direct heating and holding process. Specifically, the heating rate, holding temperature, and holding time can be set according to the specific type of armor steel and the thickness of the plate. The direct heating process involves directly heating to a certain temperature and holding it for a period of time. For example, it can be, but is not limited to, directly heating to 600℃ at a rate of 5℃ / min and holding for 50 minutes; directly heating to 635℃ at a rate of 7℃ / min and holding for 30 minutes; or directly heating to 655℃ at a rate of 10℃ / min and holding for 10 minutes, etc.

[0047] The vacuum hot pressing process for preparing armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites employs a direct pressure increase and holding process. Specifically, the pressure increase rate and holding time of the pressure column can be set synchronously according to the heating and holding process. The direct pressure increase process involves simultaneously increasing the pressure to a certain level and holding it, for example, but not limited to, directly increasing the pressure to 10 MPa and holding it for 10 minutes; directly increasing the pressure to 5 MPa and holding it for 30 minutes; directly increasing the pressure to 1 MPa and holding it for 50 minutes, etc.

[0048] The vacuum hot pressing process for preparing armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites employs a direct cooling process. Specifically, the cooling rate can be set according to the specific type of armor steel and the thickness of the plate. The direct cooling process involves directly cooling to between 15 and 50°C under vacuum conditions. For example, it can be, but is not limited to, cooling from 600°C to 15°C at a rate of 10°C / min; cooling from 635°C to 30°C at a rate of 12°C / min; and cooling from 655°C to 50°C at a rate of 15°C / min.

[0049] The vacuum hot pressing of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites employs a direct pressure reduction process. Specifically, the pressure reduction rate of the pressure column can be set synchronously with the cooling process. The direct pressure reduction process involves directly reducing the pressure to 0 MPa while simultaneously reducing temperature and pressure.

[0050] S3:

[0051] In step S3, the surface treatment processes for the two composite materials of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum obtained in S2 are as follows;

[0052] First, the surfaces of the armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites are mechanically polished with 100-400 grit sandpaper to remove any residual graphite paper.

[0053] After the surfaces of the armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites are sanded, they are washed with 4-8 mol / L NaOH solution. After washing with alkali, they are rinsed with anhydrous ethanol and then quickly dried with a cold air blower. Next, they are acid washed with 5-10% HCl solution and rinsed with anhydrous ethanol. Then, the armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites are quickly placed in a vacuum drying oven for vacuum drying to ensure that there is no anhydrous ethanol residue on the surface of the composites.

[0054] S4:

[0055] In step S4, the hot-pressing diffusion process for preparing pure aluminum transition armor steel / aluminum alloy layered composite armor is as follows:

[0056] First, the S1-treated armored aluminum alloy is quickly placed between the exposed pure aluminum surfaces of two composites—one treated with S3 (armored steel / pure aluminum) and the other with pure aluminum / armored steel / pure aluminum—to obtain a superimposed composite. Then, the superimposed composite is placed between graphite molds in a vacuum hot press furnace. To prevent diffusion reaction between the armored steel and the graphite molds, 0.1mm thick graphite paper is used to separate the upper and lower surfaces of the superimposed composite from the outside. Figure 4 As shown. Figure 4 Component 8 is made of armored aluminum alloy.

[0057] The vacuum hot pressing process is as follows: the vacuum hot pressing equipment is evacuated to a vacuum level of ≤1×10. -1The temperature is increased at a rate of 5–15 °C / min, and the holding temperature is 380–450 °C. The pressure column pressure is set at 5–15 MPa, and the holding time is between 30 and 120 min. Then, the temperature is cooled to between 15 and 50 °C under vacuum at a rate of 5–10 °C / min. The pressure decreases synchronously with the temperature change to 0 MPa. Specifically, the holding temperature can be, for example, but not limited to, any one or any two of 380 °C, 410 °C, and 450 °C. The pressure column pressure can be, for example, but not limited to, any one or any two of 5 MPa, 10 MPa, and 15 MPa.

[0058] The vacuum hot pressing process for pure aluminum transition armor steel / aluminum alloy layered composite armor can employ either a direct heating and holding process or a staged heating and holding process. Specifically, the heating rate, holding temperature, and holding time can be set according to the specific type and thickness of the armor steel and aluminum alloy. The direct heating process involves directly heating to a certain temperature and holding for a period of time. Examples include, but are not limited to, directly heating to 380℃ at a rate of 5℃ / min and holding for 120 minutes; directly heating to 410℃ at a rate of 10℃ / min and holding for 70 minutes; or directly heating to 450℃ at a rate of 15℃ / min and holding for 30 minutes, etc. Staged heating process: The temperature is raised to a first temperature at a first heating rate, then raised to a second temperature at a second heating rate, and so on, until the temperature is raised to the Nth temperature at the Nth heating rate and held for a certain time. For example, it can be, but is not limited to, raising the temperature to 200℃ at 15℃ / min, then raising it to 300℃ at 10℃ / min, then raising it to 380℃ at 5℃ / min and holding for 120 min; raising the temperature to 300℃ at 15℃ / min, then raising it to 350℃ at 10℃ / min, and finally raising it to 410℃ at 5℃ / min and holding for 70 min; raising the temperature to 300℃ at 15℃ / min, then raising it to 400℃ at 10℃ / min, and finally raising it to 450℃ at 5℃ / min and holding for 30 min.

[0059] The vacuum hot pressing preparation of pure aluminum transition armor steel / aluminum alloy layered composite armor can employ either a direct pressure increase and holding process or a staged pressure increase and holding process. Specifically, the pressure column pressure can be set according to the specific type and thickness of the armor steel and aluminum alloy. The direct pressure increase process involves directly increasing the pressure to a certain level and holding it, with the pressure increase rate and holding time synchronized with the heating and holding times in the direct heating process. For example, it can be, but is not limited to, directly increasing the pressure to 5 MPa and holding it; directly increasing the pressure to 10 MPa and holding it; or directly increasing the pressure to 15 MPa and holding it. Staged pressurization and holding process: The pressure is increased to a first pressure at a first pressurization rate, then increased to a second pressure at a second pressurization rate, and so on, until the pressure is increased to a Nth pressure at an Nth pressurization rate and held for a certain period of time. The pressurization rate and holding time are synchronized with the heating and holding time in the staged heating process. For example, it can be, but is not limited to, first pressurizing to 5MPa, then to 10MPa, and then to 15MPa; first pressurizing to 6MPa, then to 9MPa, and then to 12MPa; first pressurizing to 5MPa, then to 8MPa, and then to 10MPa.

[0060] The vacuum hot pressing process for preparing pure aluminum transition armor steel / aluminum alloy layered composite armor can employ a direct cooling process. Specifically, the cooling rate can be set according to the specific type of armor steel and the thickness of the plate. The direct cooling process involves directly cooling to between 15 and 50°C under vacuum conditions. For example, it can be, but is not limited to, cooling from 380°C to 15°C at a rate of 5°C / min; cooling from 410°C to 35°C at a rate of 7°C / min; and cooling from 450°C to 50°C at a rate of 10°C / min.

[0061] The vacuum hot pressing of pure aluminum transition armor steel / aluminum alloy layered composite armor can be carried out using a direct depressurization process. Specifically, the depressurization rate of the pressure column can be set synchronously with the cooling process. The direct depressurization process is to directly reduce the pressure to 0 MPa while simultaneously reducing temperature and pressure.

[0062] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0063] Example 1

[0064] The pure aluminum transition armor steel / aluminum alloy layered composite armor manufacturing process in this embodiment includes the following steps:

[0065] S1. Remove the oxide film from the surface of three metal plates: armor steel, armor aluminum alloy, and pure aluminum.

[0066] Specifically as follows:

[0067] Depending on the surface hardness, the surface of 603 armor steel (1mm thick) was first mechanically polished with 100-grit sandpaper, the surface of 7075 armor aluminum alloy (1mm thick) was mechanically polished with 280-grit sandpaper, and the surface of 1060 industrial pure aluminum (0.1mm thick) was mechanically polished with 400-grit sandpaper.

[0068] Then, with the assistance of ultrasonic vibration at an amplitude of 15μm, the three metal plates of armor steel, armor aluminum alloy, and pure aluminum, whose surfaces have been sanded, were alkaline washed with 4mol / L NaOH solution. After alkaline washing, they were ultrasonically cleaned with anhydrous ethanol for 30s, and then quickly dried with a cold air blower. Next, they were acid washed with 5% HCl solution. After acid washing, they were ultrasonically cleaned with anhydrous ethanol for 30s. Then, the armor steel and pure aluminum were quickly placed in one vacuum drying oven, and the armor aluminum alloy was placed in another vacuum drying oven for vacuum drying treatment to ensure that there was no anhydrous ethanol residue on the surface of the metal plates.

[0069] S2. The armor steel and pure aluminum plates treated in S1 are stacked together and subjected to hot pressing diffusion treatment in a vacuum hot press furnace to obtain two composite materials: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum.

[0070] Specifically as follows:

[0071] First, remove the armor steel and pure aluminum sheets from the vacuum drying oven, and then quickly process them into two stacking methods: armor steel / pure aluminum composite and pure aluminum / armor steel / pure aluminum composite.

[0072] The two composites, armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum, are then placed in the graphite molds inside a vacuum hot press furnace. To prevent diffusion reaction between the armor steel and the graphite molds, and between the pure aluminum and pure aluminum, 0.1 mm thick graphite paper is used to separate the upper and lower surfaces of each composite from the outside.

[0073] The vacuum hot pressing process is set as follows: vacuum degree ≤ 1×10 -1 Pa was heated to 655℃ at a rate of 10℃ / min, and the pressure column pressure rose to 1MPa simultaneously with the temperature. The temperature and pressure were maintained for 10min, and then cooled to 50℃ under vacuum at a rate of 15℃ / min. The pressure dropped to 0MPa simultaneously with the temperature change.

[0074] S3. Surface treatment is performed on the two composite materials obtained in S2: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum.

[0075] Specifically as follows:

[0076] First, the armor steel surface of the two composite materials obtained by S2, namely armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum, is mechanically polished with 100-grit sandpaper, and the pure aluminum surface is mechanically polished with 400-grit sandpaper to remove the residual graphite paper on the surface.

[0077] After the surfaces of the armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites were sanded, they were washed with an 8 mol / L NaOH solution. After washing with an alkali, they were rinsed with anhydrous ethanol and then quickly dried with a cold air blower. They were then acid washed with a 10% HCl solution and rinsed with anhydrous ethanol. After that, the armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites were quickly placed in a vacuum drying oven for vacuum drying to ensure that there was no anhydrous ethanol residue on the surface of the composites.

[0078] S4. The armor aluminum alloy treated in S1 is placed between the exposed pure aluminum surfaces of the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum treated in S3, and hot-pressing diffusion treatment is carried out in a vacuum hot press furnace to obtain pure aluminum transition armor steel / aluminum alloy layered composite armor material.

[0079] Specifically as follows:

[0080] First, the S1-treated armored aluminum alloy is quickly placed between the exposed pure aluminum surfaces of two composites, namely armored steel / pure aluminum and pure aluminum / armored steel / pure aluminum, after S3 treatment, to obtain a superimposed composite. Then, the superimposed composite is placed between graphite molds in a vacuum hot press furnace. To prevent diffusion reaction bonding between the armored steel surface and the graphite mold, 0.1mm thick graphite paper is used to separate the upper and lower surfaces of the superimposed composite from the outside.

[0081] The vacuum hot pressing process is set as follows: vacuum degree ≤ 1×10 -1 Pa was heated to 380°C at a rate of 5°C / min, and the pressure column pressure rose to 15MPa simultaneously with the temperature. The pressure was maintained at this temperature for 120min, and then cooled to 25°C under vacuum at a rate of 5°C / min. The pressure dropped to 0MPa simultaneously with the temperature change.

[0082] Macroscopic diagram of the resistance to Type 53 7.62mm armor-piercing projectiles in layered composite armor made of pure aluminum transition 616 armor steel and 7050 armor aluminum alloy, as shown below. Figure 5 As shown. From Figure 5 As can be seen, the surface of the projectile exhibits multi-layered petal-shaped cracks, with localized peeling of the surface layer. This peeling phenomenon is caused by the accumulation of metal in the material as the bullet penetrates each layer, and it also plays a certain role in dissipating energy for the layered composite material in resisting ballistic energy absorption.

[0083] Example 2

[0084] The pure aluminum transition armor steel / aluminum alloy layered composite armor manufacturing process in this embodiment includes the following steps:

[0085] S1. Remove the oxide film from the surface of three metal plates: armor steel, armor aluminum alloy, and pure aluminum.

[0086] Specifically as follows:

[0087] Depending on the surface hardness, the surface of 616 armor steel (10mm thick) was first mechanically polished with 100 grit sandpaper, the surface of 7050 armor aluminum alloy (10mm thick) was mechanically polished with 280 grit sandpaper, and the surface of 1060 industrial pure aluminum (0.5mm thick) was mechanically polished with 400 grit sandpaper.

[0088] Then, with the assistance of ultrasonic vibration at an amplitude of 10μm, the three metal plates of armor steel, armor aluminum alloy, and pure aluminum, whose surfaces have been sanded, were alkaline washed with 8mol / L NaOH solution. After alkaline washing, they were ultrasonically cleaned with anhydrous ethanol for 45s, and then quickly dried with a cold air blower. Next, they were acid washed with 10% HCl solution. After acid washing, they were ultrasonically cleaned with anhydrous ethanol for 45s. Then, the armor steel and pure aluminum were quickly placed in one vacuum drying oven, and the armor aluminum alloy was placed in another vacuum drying oven for vacuum drying treatment to ensure that there was no anhydrous ethanol residue on the surface of the metal plates.

[0089] S2. The armor steel and pure aluminum plates treated in S1 are stacked together and subjected to hot pressing diffusion treatment in a vacuum hot press furnace to obtain two composite materials: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum.

[0090] Specifically as follows:

[0091] First, remove the armor steel and pure aluminum sheets from the vacuum drying oven, and then quickly process them into two stacking methods: armor steel / pure aluminum composite and pure aluminum / armor steel / pure aluminum composite.

[0092] The two composites, armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum, are then placed in the graphite molds inside a vacuum hot press furnace. To prevent diffusion reaction between the armor steel and the graphite molds, and between the pure aluminum and pure aluminum, 0.1 mm thick graphite paper is used to separate the upper and lower surfaces of each composite from the outside.

[0093] The vacuum hot pressing process is set as follows: vacuum degree ≤ 1×10 -1 Pa was heated to 635°C at a rate of 8°C / min, and the pressure column pressure rose to 6MPa simultaneously with the temperature. The pressure was maintained at this temperature for 30 minutes, and then cooled to 40°C under vacuum at a rate of 13°C / min. The pressure dropped to 0MPa simultaneously with the temperature change.

[0094] S3. Surface treatment is performed on the two composite materials obtained in S2: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum.

[0095] Specifically as follows:

[0096] First, the armor steel surface of the two composite materials obtained by S2, namely armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum, is mechanically polished with 100-grit sandpaper, and the pure aluminum surface is mechanically polished with 400-grit sandpaper to remove the residual graphite paper on the surface.

[0097] After the surfaces of the armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites were sanded, they were washed with 6 mol / L NaOH solution. After washing with alkali, they were rinsed with anhydrous ethanol and then quickly dried with a cold air blower. Then they were acid washed with 8% HCl solution and rinsed with anhydrous ethanol. After that, the armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites were quickly placed in a vacuum drying oven for vacuum drying to ensure that there was no anhydrous ethanol residue on the surface of the composites.

[0098] S4. The armor aluminum alloy treated in S1 is placed between the exposed pure aluminum surfaces of the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum treated in S3, and hot-pressing diffusion treatment is carried out in a vacuum hot press furnace to obtain pure aluminum transition armor steel / aluminum alloy layered composite armor material.

[0099] Specifically as follows:

[0100] First, the S1-treated armored aluminum alloy is quickly placed between the exposed pure aluminum surfaces of two composites, namely armored steel / pure aluminum and pure aluminum / armored steel / pure aluminum, after S3 treatment, to obtain a superimposed composite. Then, the superimposed composite is placed between graphite molds in a vacuum hot press furnace. To prevent diffusion reaction bonding between the armored steel surface and the graphite mold, 0.1mm thick graphite paper is used to separate the upper and lower surfaces of the superimposed composite from the outside.

[0101] The vacuum hot pressing process is set as follows: vacuum degree ≤ 1×10 -1 Pa was subjected to a staged heating process, with the temperature increased to 300℃ at 15℃ / min and the pressure increased to 6MPa simultaneously. Then, the temperature was increased to 350℃ at 10℃ / min and the pressure increased to 9MPa simultaneously. Finally, the temperature was increased to 410℃ at 5℃ / min and the pressure increased to 12MPa simultaneously. The temperature and pressure were held for 70min. After that, the temperature was cooled to 15℃ under vacuum at a rate of 7℃ / min, and the pressure decreased to 0MPa simultaneously with the temperature change.

[0102] A macroscopic interface diagram of the layered composite armor made of pure aluminum transition 616 armor steel and 7050 armor aluminum alloy, as shown below. Figure 6 As shown. From Figure 6 As can be seen, the armor steel, armor aluminum alloy and pure aluminum are tightly bonded at the edge of the sample, but there are a few gaps. This is mainly due to the fact that the edges of different metal plates cannot be tightly bonded and diffused. Subsequent processing requires the removal of 1 mm of the sample edge.

[0103] Example 3

[0104] The pure aluminum transition armor steel / aluminum alloy layered composite armor manufacturing process in this embodiment includes the following steps:

[0105] S1. Remove the oxide film from the surface of three metal plates: armor steel, armor aluminum alloy, and pure aluminum.

[0106] Specifically as follows:

[0107] Depending on the surface hardness, the surface of 685 armor steel (5mm thick) was first mechanically polished with 100 grit sandpaper, the surface of 2024 armor aluminum alloy (5mm thick) was mechanically polished with 280 grit sandpaper, and the surface of 1060 industrial pure aluminum (0.3mm thick) was mechanically polished with 400 grit sandpaper.

[0108] Then, with the assistance of ultrasonic vibration at an amplitude of 5μm, the three metal plates of armor steel, armor aluminum alloy, and pure aluminum, whose surfaces have been sanded, were alkaline washed with 12mol / L NaOH solution. After alkaline washing, they were ultrasonically cleaned with anhydrous ethanol for 60s, and then quickly dried with a cold air blower. Next, they were acid washed with 15% HCl solution. After acid washing, they were ultrasonically cleaned with anhydrous ethanol for 60s. Then, the armor steel and pure aluminum were quickly placed in one vacuum drying oven, and the armor aluminum alloy was placed in another vacuum drying oven for vacuum drying treatment to ensure that there was no anhydrous ethanol residue on the surface of the metal plates.

[0109] S2. The armor steel and pure aluminum plates treated in S1 are stacked together and subjected to hot pressing diffusion treatment in a vacuum hot press furnace to obtain two composite materials: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum.

[0110] Specifically as follows:

[0111] First, remove the armor steel and pure aluminum sheets from the vacuum drying oven, and then quickly process them into two stacking methods: armor steel / pure aluminum composite and pure aluminum / armor steel / pure aluminum composite.

[0112] The two composites, armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum, are then placed in the graphite molds inside a vacuum hot press furnace. To prevent diffusion reaction between the armor steel and the graphite molds, and between the pure aluminum and pure aluminum, 0.1 mm thick graphite paper is used to separate the upper and lower surfaces of each composite from the outside.

[0113] The vacuum hot pressing process is set as follows: vacuum degree ≤ 1×10 -1 Pa, heated to 600℃ at a rate of 5℃ / min, the pressure column pressure rises to 10MPa simultaneously with the temperature, held at the temperature and pressure for 50min, and then cooled to 30℃ under vacuum at a rate of 10℃ / min, the pressure drops to 0MPa simultaneously with the temperature change.

[0114] S3. Surface treatment is performed on the two composite materials obtained in S2: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum.

[0115] Specifically as follows:

[0116] First, the armor steel surface of the two composite materials obtained by S2, namely armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum, is mechanically polished with 100-grit sandpaper, and the pure aluminum surface is mechanically polished with 400-grit sandpaper to remove the residual graphite paper on the surface.

[0117] After the surfaces of the armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum composites were sanded, they were washed with 4 mol / L NaOH solution, rinsed with anhydrous ethanol, and then quickly dried with a cold air blower. They were then acid-washed with 5% HCl solution, rinsed with anhydrous ethanol, and then quickly placed in a vacuum drying oven for vacuum drying to ensure that there was no anhydrous ethanol residue on the surface of the composites.

[0118] S4. The armor aluminum alloy treated in S1 is placed between the exposed pure aluminum surfaces of the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum treated in S3, and hot-pressing diffusion treatment is carried out in a vacuum hot press furnace to obtain pure aluminum transition armor steel / aluminum alloy layered composite armor material.

[0119] Specifically as follows:

[0120] First, the S1-treated armored aluminum alloy is quickly placed between the exposed pure aluminum surfaces of two composites, namely armored steel / pure aluminum and pure aluminum / armored steel / pure aluminum, after S3 treatment, to obtain a superimposed composite. Then, the superimposed composite is placed between graphite molds in a vacuum hot press furnace. To prevent diffusion reaction bonding between the armored steel surface and the graphite mold, 0.1mm thick graphite paper is used to separate the upper and lower surfaces of the superimposed composite from the outside.

[0121] The vacuum hot pressing process is set as follows: vacuum degree ≤ 1×10 -1 Pa was heated to 450℃ at a rate of 15℃ / min, and the pressure column pressure rose to 5MPa simultaneously with the temperature. The pressure was maintained at this temperature for 30min, and then cooled to 15℃ at a rate of 10℃ / min under vacuum. The pressure dropped to 0MPa simultaneously with the temperature change.

[0122] Microscopic interface diagram of layered composite armor made of pure aluminum transition 685 armor steel and 2024 armor aluminum alloy, as shown in the figure. Figure 7 As shown. From Figure 7 As can be seen, the armor steel, pure aluminum, and armor aluminum alloy are tightly bonded together, with no obvious defects at the microscopic interface. Pure aluminum plays a good connecting role in this process. Moreover, due to the short reaction time and low reaction temperature, the diffusion reaction at the interface between armor steel and pure aluminum did not exhibit the common "tongue-shaped morphology".

Claims

1. A method for preparing pure aluminum transition armor steel / aluminum alloy layered composite armor, characterized in that, Includes the following steps: S1. Remove the oxide film from the surface of three metal plates: armor steel, armor aluminum alloy, and pure aluminum. S2. The armor steel and pure aluminum plates treated in S1 are stacked together and subjected to hot pressing diffusion treatment in a vacuum hot press furnace to obtain two composite materials: armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum. S3. Perform surface deoxidation treatment on the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum obtained in S2; S4. The armor aluminum alloy treated in S1 is placed between the pure aluminum exposed surfaces of the two composites of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum treated in S3, and hot-pressing diffusion treatment is carried out in a vacuum hot press furnace to obtain pure aluminum transition armor steel / aluminum alloy layered composite armor.

2. The preparation method according to claim 1, characterized in that: In step S1, the surface treatment process for the three metal plates—armor steel, armor aluminum alloy, and pure aluminum—is as follows: the surfaces of the three metal plates are sanded, then the armor steel, armor aluminum alloy, and pure aluminum are washed with an alkaline solution under the assistance of ultrasonic vibration, cleaned with anhydrous ethanol after the alkaline washing, dried, and then acid-washed with an acid solution. After the acid washing, they are ultrasonically cleaned with anhydrous ethanol and then quickly placed in a vacuum drying oven for vacuum drying treatment, so that there is no anhydrous ethanol residue on the surface of the metal plates.

3. The preparation method according to claim 1, characterized in that: In step S2, the vacuum hot pressing parameters are: the vacuum hot pressing equipment is evacuated to ≤1×10 -1 Pa, heated at a rate of 5-10℃ / min, held at 600-655℃, with a pressure column pressure of 1-10MPa, and held for 10-50 minutes. Then, cooled to 15-50℃ under vacuum at a rate of 10-15℃ / min, with the pressure decreasing to 0MPa synchronously with the temperature change.

4. The preparation method according to claim 3, characterized in that: In step S2, the hot pressing parameters of the vacuum hot press furnace are as follows: the heating and pressurization of the vacuum hot press equipment are directly raised to the set value, and the cooling and pressurization are also directly reduced to the set value.

5. The preparation method according to claim 1, characterized in that: In step S3, the surface treatment process of the two composite materials of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum obtained in S2 is as follows: the surface of the two composite materials of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum is polished to remove the graphite paper residue on the surface, and then alkaline washing and acid washing are performed. After acid washing, it is rinsed with anhydrous ethanol. Then, the two composite materials of armor steel / pure aluminum and pure aluminum / armor steel / pure aluminum are placed in a vacuum drying oven for vacuum drying treatment to ensure that there is no anhydrous ethanol residue on the surface of the composite material.

6. The preparation method according to claim 1, characterized in that: In step S4, the vacuum hot pressing process for pure aluminum transition armor steel / aluminum alloy layered composite armor is as follows: the vacuum hot pressing equipment is evacuated to ≤1×10 -1 Pa, heated at a rate of 5-15℃ / min, held at 380-450℃, with a pressure column pressure of 5-15MPa, and held for 30-120 minutes. Then, cooled to 15-50℃ under vacuum at a rate of 5-10℃ / min, with the pressure decreasing to 0MPa synchronously with the temperature change.

7. The preparation method according to claim 6, characterized in that: In step S4, the hot pressing parameters of the vacuum hot press furnace are as follows: the temperature and pressure in the vacuum hot press equipment are increased directly to the set value or increased in stages to the set value, and the temperature and pressure are also decreased directly or decreased in stages to the set value.

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