An energetic composite connector based on cemented carbide and tungsten-containing amorphous alloy, a preparation method and application thereof

Abstract

The present application belongs to the technical field of energetic materials and active fragment materials, and more particularly relates to an energetic composite connector based on hard alloy and tungsten-containing amorphous alloy, a preparation method and application thereof. The penetration ability and damage effect of energetic materials are fully considered, and the present application selects hard alloy as the penetration part and tungsten-containing amorphous alloy composite material as the fragment part. The hard alloy has high hardness and high fracture toughness, and can effectively penetrate the shell; the amorphous alloy composite material has high strength, high energy density and good plastic deformation capacity, can deflagrate at a high strain rate and release a large amount of energy, and produce a large amount of fragments to cause damage to the target. The integration of the preparation and connection of the hard alloy penetration part and the amorphous alloy composite material fragment part can be realized by discharge plasma sintering, thereby solving the technical problems that the inert energetic materials in the prior art cause the personnel and weapon equipment to suffer losses due to "hitting but not destroying" the target.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energetic materials and active fragment materials, and more particularly relates to an energetic composite connector based on hard alloy and tungsten-containing amorphous alloy, a preparation method and application thereof. BACKGROUND

[0002] Small-caliber discarding sabot armor-piercing ammunition is usually composed of high specific gravity tungsten alloy, has the advantages of high firing speed, fast reaction, strong mobility and good armor-piercing ability, and can cope with the air attack of targets with strong attack ability such as unmanned aerial vehicles and missiles. However, this inert armor-piercing projectile has a fatal problem. Since the tungsten core armor-piercing projectile is a kinetic energy projectile, it mainly relies on kinetic energy damage mechanism and mechanical penetration damage. The ordinary tungsten core armor-piercing projectile core will have the problem of "hitting but not destroying" for the incoming missile and unmanned aerial vehicle, which will cause the friendly combatants to be injured and the weapons and equipment to be destroyed, and the situation is not favorable. Therefore, it is necessary to improve the damage efficiency of the armor-piercing projectile.

[0003] Energetic fragments refer to a new type of damage material with certain mechanical properties, good stability under normal conditions, but can cause violent chemical reactions between material components or between components and the environment under high strain rate impact load, and release a large amount of energy. The material is usually composed of two or more non-explosive solids, including aluminum thermit, metal / polymer, metastable molecular composite material, metal-based active material, etc. However, although these materials have high energy reaction and damage power, their density and strength are generally low, which easily leads to premature explosion and rupture of the fragments during the penetration process, greatly reducing the damage effect on the internal target.

[0004] At the same time, in order to improve the armor-piercing ability of the fragments, the armor-piercing fragment projectiles are usually connected together by wrapping with a shell or mechanically locking, which has the technical problems of unstable connection, unstable flight and poor damage effect.

[0005] Patent CN108425057A discloses a kind of brittle armor-piercing projectile tungsten alloy and its preparation method, the tungsten alloy material is formed by W powder and Ni powder, Fe powder, Re powder and Al2O3 powder mixed sintering, Al2O3 powder reduces the tensile strength of tungsten alloy and thus improves the fragility of the material, the method still can only produce mechanical penetration damage, cannot produce shock wave overpressure, thermal damage and other damage effects;Patent CN217058527U discloses a kind of high penetration multifunctional bullet with two-body core structure, the front end is hard alloy, effectively penetrates hard armor and large angle oblique armor, the rear end high-density high-entropy alloy improves armor kinetic energy again, and the multifunctional damage effect of the fragments and combustion after penetration, the two are wrapped by aluminum sleeve, the front end and the rear end of this method are still two-body structure, the connection is not firm, which can cause unstable flight trajectory of the bullet, and energy loss occurs in the process of energy transmission of the two ends;At the same time, the density of the front hard alloy is greater than that of the rear tungsten-based high-entropy alloy, which causes the center of gravity of the bullet body to be forward, further causing unstable flight trajectory and reduced effective striking distance of the bullet, and reducing the armor-piercing and damage effects and other technical problems. In summary, the current armor-piercing fragment bullet core material has various problems, and the connection method of the bullet head and the bullet tail has adverse effects on the armor-piercing and damage capacity of the fragment bullet, so it is of great significance to prepare a new type of armor-piercing fragment bullet core material with high strength, high density and high energy reaction, and a connection method suitable for the bullet head and the bullet tail. SUMMARY

[0006] In view of the defects of the prior art, the purpose of the present application is to provide an energetic composite connector based on hard alloy and tungsten-containing amorphous alloy, its preparation method and application, aiming to solve the technical problems of "hitting but not destroying" of inert armor-piercing bullets on unmanned aerial vehicles, missiles and other targets, resulting in loss of personnel and weapons, and the connection of traditional bullet core head and bullet core body using shell wrapping or mechanical locking connection process is not firm, unstable in flight and poor in damage effect.

[0007] To achieve the above purpose, the present application provides an energetic composite connector based on hard alloy and tungsten-containing amorphous alloy, comprising a head penetration part and a tail fragment part, the material of the head penetration part is hard alloy, and the material of the tail fragment part is tungsten-containing amorphous alloy.

[0008] The strength of the hard alloy used in the head penetration part is greater than the strength of the tungsten-containing amorphous alloy used in the tail fragment part, and the hardness of the hard alloy used in the head penetration part is greater than the hardness of the tungsten-containing amorphous alloy used in the tail fragment part.

[0009] The head penetration part and the tail fragment part are integrally connected by discharge plasma sintering.

[0010] Preferably, the length ratio of the head-end penetrating portion to the tail-end fragment portion is 0.5-1.5.

[0011] Preferably, the head-end penetrating portion comprises two regions of a primary head-end primary penetrating portion and a secondary head-end secondary penetrating portion, and the secondary head-end secondary penetrating portion is provided with a gradient cemented carbide material having a gradient density rising in the direction from the head end to the tail end, so that the overall center of gravity of the energetic composite connecting piece moves backward and is close to the centroid of the energetic composite connecting piece, thereby ensuring stable flight of the energetic composite connecting piece.

[0012] Further preferably, the gradient is a structural gradient and / or a composition gradient; the secondary head-end secondary penetrating portion cemented carbide material having a gradient density rising in the direction from the head end to the tail end is obtained by adjusting the content of raw materials used in the preparation of the gradient cemented carbide or adjusting the temperature field distribution in the sintering process.

[0013] According to another aspect of the present application, a preparation method of the energetic composite connecting piece is provided, comprising the following steps:

[0014] (1) performing roughening treatment on the surface of the head-end penetrating portion of the cemented carbide block to be connected, to obtain a roughened head-end penetrating portion cemented carbide block surface to be connected;

[0015] (2) uniformly mixing amorphous alloy powder and tungsten reinforcing phase powder used in the tail-end fragment portion to obtain tungsten / amorphous alloy composite powder used in the tail-end fragment portion;

[0016] (3) directly performing spark plasma sintering connection of the tungsten / amorphous alloy composite powder in step (2) and the roughened surface to be connected of the cemented carbide block in step (1) by spark plasma sintering, to obtain the energetic composite connecting piece; or,

[0017] firstly preparing an amorphous alloy composite material block from the tungsten / amorphous alloy composite powder in step (2) by spark plasma sintering, then performing roughening treatment on the surface to be connected of the amorphous alloy composite material block used in the tail-end fragment portion to obtain a roughened amorphous alloy composite material block surface to be connected used in the tail-end fragment portion; then welding the roughened amorphous alloy composite material block surface to be connected used in the tail-end fragment portion and the roughened surface to be connected of the head-end penetrating portion cemented carbide block in step (1) together, to obtain the energetic composite connecting piece.

[0018] According to another aspect of the present application, a penetrator fragment projectile is provided, the core material of which comprises the energetic composite connecting piece as described.

[0019] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages:

[0020] (1) The present application provides an energetic composite connector based on hard alloy and tungsten-containing amorphous alloy, which fully takes into account the penetration ability and damage effect of energetic materials. The present application selects hard alloy as the penetration part and tungsten-containing amorphous alloy composite material as the fragment part. Hard alloy has high hardness and high fracture toughness, which can effectively penetrate the shell; amorphous alloy composite material has high strength, high energy density and good plastic deformation ability, which can detonate at high strain rate and release a large amount of energy to produce a large number of fragments to damage the target. The integration of the hard alloy penetration part and the amorphous alloy composite material fragment part can be achieved by spark plasma sintering, thereby solving the technical problems of the prior art using inert energetic materials to cause "hit but not destroy" to the target, resulting in loss of personnel and weapons and equipment.

[0021] (2) The present application provides a preparation method of an energetic composite connector based on hard alloy and tungsten-containing amorphous alloy. The tungsten / amorphous alloy composite powder used in the tail fragment part is directly sintered and connected with the surface of the hard alloy block used in the head penetration part after roughening treatment by spark plasma sintering, to obtain the energetic composite connector of the present application; or, first, the tail fragment part is prepared into an amorphous alloy composite material block by spark plasma sintering with tungsten / amorphous alloy composite powder, and then the surface of the roughened tail fragment part with amorphous alloy composite material block is welded together with the surface of the roughened head penetration part with hard alloy block, to obtain an energetic composite connector for armor-piercing fragment projectiles. The common preparation process of armor-piercing fragment projectiles is mold-sintering forming method, explosive forming method, etc., but these methods have defects in different aspects, such as uneven density of the material obtained by mold-sintering method, and problems of explosion safety, noise pollution and difficult control of product manufacturing tolerance in explosive forming method, which have certain influence on the strength, density and other properties of the energetic fragment. The present application first selects appropriate amorphous alloy composition and second phase reinforcing phase composition for the tail (i.e. tail fragment part), then mixes them uniformly, and then sinter connects the amorphous alloy composite material block and the hard alloy block by spark plasma sintering process, or directly sinter connects the amorphous alloy composite material powder and the hard alloy block by spark plasma sintering process. Spark plasma sintering is a rapid sintering technology that densifies powder or block materials by applying pulse current and under pressure assistance, which has the characteristics of fast sintering speed, low sintering temperature and small required pressure, and can obtain fragment materials with high density and excellent mechanical properties.

[0022] (3) The energetic composite connector provided by this invention fully considers both the penetration performance and the damage performance of the fragments, and selects an amorphous alloy composite material as the fragment material. Compared with crystalline materials, amorphous materials do not have defects such as dislocations and grain boundaries, so amorphous materials generally have excellent mechanical properties such as ultra-high mechanical strength and high elastic modulus. At the same time, considering that amorphous alloys lack plasticity, the plasticity of amorphous alloys can be effectively improved by adding tungsten particles to amorphous alloys to prepare amorphous alloy composite materials, thereby enhancing the penetration ability of fragments. At the same time, the introduction of tungsten particle reinforcing phase increases the number of interfaces inside the amorphous alloy composite material, so that the material can generate more fragments along the interfaces during explosion.

[0023] (4) When the energetic composite connector provided by this invention is used as the core material of an armor-piercing fragmentation projectile, the amorphous alloy composition of the material used in the tail fragment part can be amorphous alloys with high energy storage, such as zirconium-based, zirconium-titanium-based, and zirconium-niobium-based alloys. The energy storage in the glassy state can reach 40% to 50% of the heat of melting. Under high stress, it breaks into a high-temperature fragment cloud, which increases the contact area with oxygen, deflagrates and releases a large amount of energy. Although there is only a small amount of gas or even no gas in the reaction products, it still has the potential to achieve "gas-free explosion", which can produce combined damage effects such as shock wave overpressure and thermal damage, greatly improving the destructive power of the armor-piercing fragmentation projectile.

[0024] (5) In traditional armor-piercing fragmentation projectiles, the projectile and fragments are usually connected by a shell or mechanical locking, which can lead to technical problems such as weak connection, unstable flight, and poor damage effect. SPS welding, developed based on spark plasma sintering technology, is a rapidly developing low-temperature, low-deformation, and fast vacuum welding method in recent years. It achieves the connection of dissimilar materials with or without an intermediate layer under electric heating and pressure. Compared with traditional diffusion welding, SPS diffusion welding often has significant advantages such as low connection temperature, short welding time, rapid interface mass transfer, fast healing, and high welding precision. This invention uses SPS welding technology to directly connect the amorphous alloy composite material projectile tail to the hard alloy projectile head, obtaining a joint with excellent mechanical properties. Furthermore, the integrated projectile core has a more stable flight trajectory and stronger penetration capability compared to a split projectile core.

[0025] (6) The energetic composite connector provided by the present invention can be used as the core material of armor-piercing fragmentation projectiles. By using spark plasma sintering to prepare the armor-piercing fragmentation projectile core from amorphous alloy composite powder and hard alloy block, the preparation and connection can be integrated, simplifying the production process and reducing production costs. At the same time, the method has great controllability and can flexibly change the material type, size, shape and gradient structure to produce different strike effects and deal with different strike targets.

[0026] (7) When the object is composed of the same homogeneous material, the center of gravity of the object coincides with the centroid, and the object can keep balance during flight. However, when the energy-containing composite connector is used as the core material of the armor-piercing fragment projectile, the density of the hard alloy projectile part (>15 g / cm 3 ) is greater than that of the amorphous alloy composite material projectile tail (7~12 g / cm 3 ), the center of gravity of the projectile body moves forward, and the bullet will drop during flight, resulting in a decrease in the effective striking distance of the bullet, and a decrease in the armor-piercing and damage effect. In the preferred embodiment of the present application, the projectile head is divided into a head-end main armor-piercing part and a secondary head-end secondary armor-piercing part. The main armor-piercing part of the hard alloy projectile is uniform and has a larger density, which ensures the armor-piercing ability of the projectile head. At the same time, by changing the raw material composition such as the content of the matrix material and / or the binder phase or the temperature field distribution in the sintering process when preparing the secondary armor-piercing part of the hard alloy projectile head, the density of the prepared secondary armor-piercing part of the hard alloy projectile head increases along the gradient from the head to the tail, so that the center of gravity of the whole projectile core material moves backward and approaches the centroid. This method of setting the density gradient takes into account the armor-piercing and damage ability of the armor-piercing fragment projectile, and considers the problems of unstable flight trajectory, decrease in effective striking distance of the bullet, etc. caused by the uneven mass distribution of the two-body projectile, adjusts the center of gravity to approach or coincide with the centroid of the projectile body, thereby greatly improving the stability of the projectile body during flight. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic diagram of the core structure and material of an armor-piercing projectile according to an embodiment of the present application.

[0028] Figure 2 is a schematic diagram of the flight trajectory of an armor-piercing fragment projectile according to the present application, Figure 2 1 represents the flight trajectory when the center of gravity keeps balance, and 2 represents the flight trajectory when the center of gravity is forward.

[0029] Figure 3 is a schematic diagram of a gradient hard alloy according to an embodiment of the present application, Figure 3 1 is a hard alloy head-end main armor-piercing part, and 2 is a hard alloy secondary head-end secondary armor-piercing part.

[0030] Figure 4 is a flowchart of the preparation and connection method of the core material of the armor-piercing fragment projectile of the present application.

[0031] Figure 5 is a schematic diagram of the preparation and connection of the core of the armor-piercing projectile of embodiment 1 of the present application and a discharge plasma sintering mold. Wherein: 1-upper punch, 2-amorphous alloy / tungsten composite powder, 3-lower punch, 4-upper electrode, 5-concave die, 6-lower electrode, 7-amorphous alloy composite material, 8-hard alloy material.

[0032] Figure 6 is a schematic diagram of preparation and connection of the armor-piercing core of embodiment 2 of the present application and the discharge plasma sintering mold. Wherein: 2-amorphous alloy / tungsten composite powder, 8-cemented carbide material.

[0033] Figure 7 is a schematic diagram of setting the component gradient of the cemented carbide of embodiment 3 of the present application.

[0034] Figure 8 is a schematic diagram of the center of gravity and main dimensions of each part in a cross-sectional view of the armor-piercing core of embodiment 3 of the present application, wherein c1, c2, c3 are the center of gravity of the main armor-piercing part at the head end of the cemented carbide, the secondary armor-piercing part at the secondary head end of the cemented carbide, and the fragment tail of the amorphous alloy composite, respectively, X c1 , X c2 , X c3 is the horizontal distance of c1, c2, c3 from the head end of the armor-piercing core, d1, d2, d3 are the total length of the main armor-piercing part at the head end of the cemented carbide and the secondary armor-piercing part at the secondary head end of the cemented carbide, the length of the secondary armor-piercing part at the secondary head end of the cemented carbide, and the length of the fragment tail of the amorphous alloy composite, respectively, , is the diameter of the cross section of the main armor-piercing part at the head end of the cemented carbide, the diameter of the cross section of the secondary armor-piercing part at the secondary head end of the cemented carbide, or the diameter of the cross section of the fragment tail of the amorphous alloy composite, respectively.

[0035] Figure 9 is a schematic diagram of the gradient structure of the secondary armor-piercing part of the cemented carbide of embodiment 3 of the present application. represents density, x1, x2…x n represents horizontal length, and h represents height. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. It should be understood by those skilled in the art that the embodiments are only used to help understand the present application and should not be regarded as a specific limitation on the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] The embodiments of the present application are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and processes are given, but the protection scope of the present application is not limited to the following embodiments. The process parameters not specified in the following embodiments are usually according to conventional conditions.

[0038] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0039] In this invention, unless otherwise specified and / or stated, all values ​​relating to component amounts are in parts by weight throughout. Process parameters in the following examples that do not specify particular conditions are generally performed under conventional conditions.

[0040] This invention provides an energetic composite connector based on cemented carbide and tungsten-containing amorphous alloy, comprising a head-end penetrating portion and a tail-end fragment portion. The head-end penetrating portion is made of cemented carbide, and the tail-end fragment portion is made of tungsten-containing amorphous alloy. The cemented carbide used in the head-end penetrating portion has a greater strength and a greater hardness than the tungsten-containing amorphous alloy used in the tail-end fragment portion. The head-end penetrating portion and the tail-end fragment portion are integrally connected by spark plasma sintering.

[0041] In some embodiments, the above-described energetic composite connector of the present invention is used as the core material of an armor-piercing fragmentation projectile, such as... Figure 1 As shown, the fragmentation core material includes a projectile head and a projectile tail. The projectile head is the penetrating portion at the front end, and the projectile tail is the fragmentation portion at the rear end. The projectile head is made of cemented carbide, and the projectile tail is made of tungsten-containing amorphous alloy. The strength of the cemented carbide used for the projectile head is greater than the strength of the tungsten-containing amorphous alloy used for the projectile tail, and the hardness of the cemented carbide used for the projectile head is greater than the hardness of the tungsten-containing amorphous alloy used for the projectile tail.

[0042] In some embodiments, the head-end penetrating portion, i.e. Figure 1 The hard alloy used for medium-thrust warheads has a Vickers hardness greater than or equal to 15 GPa and a density greater than or equal to 15 g / cm³. 3 Flexural strength greater than or equal to 1500 MPa, fracture toughness greater than or equal to 10 MPa•m 1 / 2; the selection criteria of the component of the hard alloy used for the bullet head is that the hard alloy is tungsten-cobalt type, tungsten-nickel type, tungsten-nickel-cobalt type hard alloy, including but not limited to WC-Co, WC-Ti-Co, WC-Ni, WC-Ni-Co; the selection criteria of the component of the tungsten-containing amorphous alloy used for the tail fragment part, i.e. the bullet tail, is that the amorphous alloy matrix component is zirconium-based, zirconium-titanium-based, zirconium-niobium-based amorphous alloy, including but not limited to ZrCuAl, ZrCuNiAl, ZrCuNiAlTi, ZrTiCuNiBe; the energy density per unit mass of the amorphous alloy is greater than or equal to 5 KJ·g -1 , the density is 7~12 g / cm 3 , and the critical forming size of the amorphous alloy component is greater than or equal to 0.1 mm, the temperature range of the supercooled liquid phase is greater than 40 K; the reinforcing phase component in the amorphous alloy is tungsten particles.

[0043] In some embodiments, the length ratio of the head penetration part to the tail fragment part is 0.5~1.5, more preferably 0.8-1.2. Controlling within this range ensures excellent armor-piercing fragment capability of the connecting piece. The length of the head penetration part and the tail fragment part mentioned here refers to the length in the armor-piercing flight direction of the connecting piece as an armor-piercing fragment bullet core material. The size of the bullet core material perpendicular to the armor-piercing flight direction is selected as needed.

[0044] When an object is composed of the same homogeneous material, the center of gravity of the object coincides with the centroid, and the object can maintain a balanced state during flight. However, when the energy-containing composite connecting piece of the present application is used as the bullet core material of an armor-piercing fragment bullet, the density of the hard alloy bullet head part, i.e. the head penetration part, of the armor-piercing fragment bullet (>15 g / cm 3 ) is greater than the density of the amorphous alloy composite bullet tail, i.e. the tail fragment part, (7~12 g / cm 3 ), the center of gravity of the bullet body moves forward, and the bullet will produce a serious drop during flight, as shown in Figure 2 , causing the effective striking distance of the bullet to decrease, and reducing the armor-piercing and damage effects. Figure 2 1 represents the flight trajectory when the center of gravity is balanced, and 2 represents the flight trajectory when the center of gravity is forward. To solve this problem, in the preferred embodiment of the present application, as shown in Figure 3 , the hard alloy used for the bullet head is divided into a head main armor-piercing part 1 (i.e. the most head main penetration part) and a secondary head secondary armor-piercing part 2 (i.e. the secondary head secondary penetration part), and the secondary head secondary armor-piercing part is set to be a gradient hard alloy material, which makes the density of the hard alloy of the secondary head secondary armor-piercing part increase in the direction from the head to the tail, so that the overall center of gravity of the bullet core material moves backward and is close to the centroid of the bullet core material, thereby ensuring stable flight of the bullet core material.

[0045] Specifically, the gradient is a structure gradient and / or a composition gradient; the density of the sub-nose sub-penetration portion of the hard alloy material increases in the direction from the head to the tail by adjusting the content of raw materials such as carbide matrix and / or binder used in the preparation of the hard alloy or designing the temperature field distribution in the sintering process when the hard alloy is prepared.

[0046] For example, in some embodiments, the hard alloy is a powder metallurgy product prepared by using micron-sized powder of carbide of high-hardness refractory metal (WC, TiC) as the main component, and cobalt (Co), nickel (Ni) or molybdenum (Mo) as the binder, and sintering in a vacuum furnace or a hydrogen reduction furnace; by adjusting the content of carbide and / or binder, the sub-nose sub-penetration portion of the hard alloy with the density increasing in the direction from the head to the tail in the range of 5-16 g / cm 3 is prepared, so that the center of gravity moves backward and is closer to the centroid of the object.

[0047] In other embodiments, the gradient hard alloy can be a structure gradient. By designing and adjusting the temperature field distribution in the sintering process of the hard alloy, the sub-nose sub-penetration portion of the hard alloy with the density increasing in the direction from the head to the tail in the range of 5-16 g / cm 3 is prepared, so that the center of gravity moves backward and is closer to the centroid of the object.

[0048] The application also provides a preparation method of the energetic composite connector, comprising the following steps:

[0049] (1) performing roughening treatment on the surface of the hard alloy block to be connected in the head penetration portion, to obtain a roughened surface of the hard alloy block to be connected in the head penetration portion;

[0050] (2) uniformly mixing amorphous alloy powder and tungsten reinforcing phase powder used in the tail fragment portion to obtain tungsten / amorphous alloy composite powder used in the tail fragment portion;

[0051] (3) directly performing spark plasma sintering connection of the tungsten / amorphous alloy composite powder in step (2) and the roughened surface of the hard alloy block to be connected in step (1) by spark plasma sintering, to obtain the energetic composite connector; or,

[0052] The tungsten / amorphous alloy composite powder in step (2) is first prepared into an amorphous alloy composite material block by spark plasma sintering, and then the surface to be connected of the amorphous alloy composite material block is subjected to roughening treatment to obtain a roughened tail-end fragment portion of the amorphous alloy composite material block to be connected; then the roughened tail-end fragment portion of the amorphous alloy composite material block to be connected is welded with the roughened head-end penetration portion of the cemented carbide block to be connected in step (1) to obtain the energetic composite connector.

[0053] In some embodiments, the energetic composite connector is used as a penetrator-fragment projectile core material, such as Figure 4 The preparation method thereof comprises the following steps:

[0054] (1) the surface to be connected of the penetrator-fragment projectile head is subjected to roughening treatment to obtain a roughened head-end of the cemented carbide block to be connected;

[0055] (2) the tail-end of the penetrator-fragment projectile is mixed with amorphous alloy powder and tungsten reinforcing phase powder to obtain a tungsten / amorphous alloy composite powder for the tail-end of the projectile;

[0056] (3) the tungsten / amorphous alloy composite powder for the tail-end of the projectile in step (2) is directly connected with the roughened head-end of the cemented carbide block to be connected in step (1) by spark plasma sintering to obtain a penetrator-fragment projectile core material; or,

[0057] The tungsten / amorphous alloy composite powder in step (2) is first prepared into an amorphous alloy composite material block by spark plasma sintering, and then the surface to be connected of the amorphous alloy composite material block is subjected to roughening treatment to obtain a roughened tail-end fragment portion of the amorphous alloy composite material block to be connected; then the roughened tail-end fragment portion of the amorphous alloy composite material block to be connected is welded with the roughened head-end penetration portion of the cemented carbide block to be connected in step (1) to obtain the energetic composite connector.

[0058] In some embodiments, the roughening treatment in step (1) and step (3) is independently one or more of sandpaper polishing and laser roughening; the roughened head-end of the cemented carbide block to be connected has a roughness of less than 2.5 μm; and the roughened tail-end of the amorphous alloy composite material block to be connected has a roughness of less than 2.5 μm.

[0059] In some embodiments, the roughening treatment in step (1) and step (3) is first sandpaper polishing, and then laser roughening, and the laser roughening has a hole spacing of 50-150 μm, a laser pulse energy of 1.0 mJ-2.0 mJ, a pulse width of 150-300 ns, and a pulse frequency of 10-100 kHz.

[0060] In some embodiments, the volume fraction of tungsten reinforcing phase powder in the tungsten / amorphous alloy composite powder is within 20% to 60%, and the tungsten reinforcing phase powder has a spherical, ellipsoidal, sheet, or other shape.

[0061] In some embodiments, the amorphous alloy powder and the tungsten reinforcing phase powder are independently prepared by an atomization method, a water atomization method, a mechanical ball milling method, a plasma ball milling method, or a plasma rotating electrode method.

[0062] In some embodiments, the amorphous alloy powder has a particle size within 1 μm to 50 μm, and the tungsten reinforcing phase powder has a particle size within 1 μm to 100 μm.

[0063] In some embodiments, the amorphous alloy powder and the tungsten reinforcing phase powder are uniformly mixed by a ball milling process, and the ball milling process has the following parameters: the ball milling material is a hard alloy, stainless steel, or agate, the rotation speed is 100 to 800 r / min, the ball-to-material ratio is 30:1 to 3:1, and the ball milling time is 10 min to 24 h.

[0064] In some embodiments, the tungsten / amorphous alloy composite powder for the tail of the projectile in step (2) is directly connected to the surface of the hard alloy block for the head of the projectile in step (1) by spark plasma sintering, the sintering temperature is set within the undercooled liquid phase region of the amorphous alloy, the sintering pressure is 50 to 150 MPa, the sintering time is 5 to 30 min, and the temperature rising and falling rate is 10 to 100 K / min.

[0065] In some embodiments, the tungsten / amorphous alloy composite powder for the tail of the projectile in step (2) is prepared into an amorphous alloy composite material block by spark plasma sintering, the sintering temperature is set within the undercooled liquid phase region of the amorphous alloy, the sintering pressure is 100 to 600 MPa, the sintering time is 5 to 30 min, and the temperature rising and falling rate is 20 to 200 K / min.

[0066] In some embodiments, the amorphous alloy composite material block for the tail of the projectile after the texturing treatment is welded to the surface of the hard alloy block for the head of the projectile after the texturing treatment in step (1), the welding temperature is set to be 10 to 100 K below the glass transition end temperature Tx of the amorphous alloy, the welding pressure is 10 to 150 MPa, the welding time is 1 to 10 min, and the temperature rising and falling rate is 10 to 100 K / min.

[0067] In the preferred embodiment, the hard alloy used in the bullet head of step (1) comprises a head-end main penetration portion and a tail-end secondary penetration portion, and the tail-end secondary penetration portion is made of a gradient hard alloy with a density gradient rising from the head to the tail; the preparation method of the gradient hard alloy comprises the following steps: by adjusting the content of the raw material composition used in the preparation of the gradient hard alloy or adjusting the temperature field distribution in the sintering process of the preparation of the gradient hard alloy, a tail-end secondary penetration portion hard alloy material with a density gradient rising from the head to the tail is obtained.

[0068] The present application belongs to the technical field of energetic materials and active fragment materials, and more particularly relates to an energetic composite connector based on hard alloy and tungsten-containing amorphous alloy, a preparation method and application thereof. The connector can be used as a penetrator fragment bullet core material, fully considering the penetration ability and damage effect of the penetrator fragment bullet, and selecting hard alloy as the penetrator bullet head and tungsten-containing amorphous alloy composite material as the fragment bullet tail. The amorphous alloy composite material has high strength, high energy density and good plastic deformation capacity, can detonate at a high strain rate and release a large amount of energy, and produces a large number of fragments to cause damage to the target in the armor. The integration of the preparation and connection of the hard alloy bullet head and the amorphous alloy composite material bullet tail can be realized by discharge plasma sintering, thereby solving the technical problems of the prior art, such as the loss of personnel and weapons and equipment caused by the "strike but not destroy" of inert penetrator bullets, and the connection being not firm, flight being unstable and damage effect being poor caused by the connection process of the traditional bullet core head and bullet core body using an outer shell wrapping or mechanical locking.

[0069] The following is an example:

[0070] Example 1

[0071] The energetic composite connector based on hard alloy and tungsten-containing amorphous alloy provided in this embodiment is used as a penetrator fragment bullet core material, the head-end penetration portion, i.e. the bullet head, is made of WC-3%Co hard alloy (Hv>22GPa, bending strength >2200MPa, density 15.7 g / cm 3 , fracture toughness >12 MPa•m 1 / 2 ), and the tail-end fragment portion, i.e. the bullet tail, is made of amorphous alloy, the base component of which is selected from Zr 55 Cu 30 Al5Ni 10 (Tg=411℃, Tx=484℃, density 7 g / cm 3 , energy density per unit mass 10.981 KJ•g -1 , σ=1900MPa), and the critical forming size of the amorphous alloy is not less than 0.1 mm. WC-3%Co hard alloy is used as the penetrator bullet head material, and Zr55 Cu 30 Al5Ni 10 Amorphous alloys and W particles were combined to form Zr as the tail material for fragmented projectiles. Zr was first prepared by spark plasma sintering. 55 Cu 30 Al5Ni 10 / W amorphous alloy composite material bulk, and then WC-Co and Zr are bonded together by SPS diffusion welding. 55 Cu 30 Al5Ni 10 / W are welded together. The specific preparation method is as follows:

[0072] Weigh out high-purity metal raw materials according to their nominal composition, and obtain Zr by arc melting the high-purity elements six times in an argon atmosphere using Ti getter. 55 Cu 30 Al5Ni 10 The mother alloy ingot of W was used to prepare amorphous alloy and tungsten powder by high nitrogen atomization. The high-purity nitrogen atomization pressure was 20 MPa and the diameter of the guide hole was 2 mm. Zirconium-based amorphous alloy powder with a particle size of 1 μm to 50 μm and tungsten powder with a particle size of 1 μm to 100 μm were screened out.

[0073] Amorphous alloy composite powder was obtained by uniformly mixing zirconium-based amorphous alloy powder and tungsten powder through ball milling, wherein the volume fraction of tungsten reinforcing phase powder was 40%. The grinding balls were made of cemented carbide, the rotation speed was 600 r / min, the ball-to-powder ratio was 10:1, and the ball milling time was 7 hours. Figure 5 The schematic diagram of the spark plasma sintering mold shown (1-upper pressure head, 2-amorphous alloy composite powder, 3-lower pressure head, 4-upper electrode, 5-dip mold, 6-lower electrode, 7-amorphous alloy composite material, 8-hard alloy material) illustrates the preparation of Zr using spark plasma sintering technology. 55 Cu 30 Al5Ni 10 The process parameters for the / W composite material bulk material, which is subjected to spark plasma sintering, are as follows: sintering temperature of 723 K, sintering pressure of 300 MPa, sintering time of 5 min, and heating / cooling rate of 50 K / min.

[0074] WC-3%Co cemented carbide is processed into the following form: Figure 1The WC-3%Co cemented carbide (length of 19 mm) and Zr 55 Cu 30 Al5Ni 10 / W composite bulk (length of 20 mm) were welded by the spark plasma sintering technology. The process parameters for the spark plasma sintering welding were as follows: welding temperature of 623 K, welding pressure of 100 MPa, welding time of 2 min, and temperature rising and falling rate of 50 K / min.

[0075] Example 2

[0076] The energy-containing composite connecting piece based on the cemented carbide and the tungsten-containing amorphous alloy provided in the embodiment is used as the core material of the armor-piercing fragment projectile, the head end penetrating part, i.e., the projectile head, uses the WC-10%Ni cemented carbide (Hv>15 GPa, bending strength >2100 MPa, density of 15.2 g / cm 3 , fracture toughness >12 MPa•m1 / 2), and the tail end fragment part, i.e., the projectile tail, uses the amorphous alloy, the base component of which uses the Zr 55 Cu 30 Al5Ni 10 (Tg=411℃, Tx=484℃, density of 7 g / cm 3 , energy density per unit mass of 10.981 KJ•g -1 , σ=1900 MPa), and the critical forming size of the amorphous alloy is not less than 0.1 mm. The WC-10%Ni cemented carbide is used as the armor-piercing projectile head material, the Zr 55 Cu 30 Al5Ni 10 amorphous alloy and W particles are compounded as the fragment projectile tail material, and the powder-like Zr 55 Cu 30 Al5Ni 10 / W and the bulk WC-10%Ni are welded together by the spark plasma sintering welding technology. The specific preparation method is as follows:

[0077] The high-purity metal raw materials are weighed according to the nominal composition, the high-purity elements are obtained by arc melting six times in an argon atmosphere by using a Ti getter, and the Zr 55 Cu30 Al5Ni 10 The mother alloy ingot of W was used to prepare amorphous alloy and tungsten powder by high nitrogen atomization. The high-purity nitrogen atomization pressure was 20 MPa and the diameter of the guide hole was 2 mm. Zirconium-based amorphous alloy powder with a particle size of 1 μm to 50 μm and tungsten powder with a particle size of 1 μm to 100 μm were screened out.

[0078] Amorphous alloy composite powder was obtained by uniformly mixing zirconium-based amorphous alloy powder and tungsten powder through ball milling, wherein the volume fraction of tungsten reinforcing phase powder was 40%. The grinding balls were made of cemented carbide, the rotation speed was 600 r / min, the ball-to-powder ratio was 10:1, and the milling time was 7 h. The WC-10%Ni cemented carbide was then processed into the following... Figure 1 The shape of the carbide projectile is shown. The surfaces to be joined with the carbide are then sequentially polished using sandpaper of different grits: 400 grit, 800 grit, 1200 grit, and 2000 grit, each polishing continuing until no obvious scratches remain. The polished surfaces are then subjected to laser surface roughening treatment with a hole spacing of 100 μm, a laser pulse energy of 1.8 mJ, a pulse width of 240 ns, and a pulse frequency of 30 kHz. [The text abruptly ends here.] Figure 6 In the schematic diagram of the spark plasma sintering mold shown (2-amorphous alloy composite powder, 8-hard alloy material), WC-10%Ni hard alloy and Zr are prepared by spark plasma sintering welding technology. 55 Cu 30 Al5Ni 10 The process parameters for the / W amorphous alloy composite powder welded parts, using spark plasma sintering, are: sintering temperature 723 K, sintering pressure 100 MPa, sintering time 10 min, and heating / cooling rate 50 K / min. After sintering, the length of the cemented carbide in the resulting core material is 19 mm, and the length of the amorphous alloy is 20 mm.

[0079] Example 3

[0080] This embodiment provides an energetic composite connector based on cemented carbide and tungsten-containing amorphous alloy, used as the core material of an armor-piercing fragmentation projectile. WC-x%TiC-10%Ni (x=0,30,60,90) cemented carbide is selected as the material for the penetrating part of the projectile, i.e., the armor-piercing projectile head, where the density of WC is 15.9 g / cm³. 3 The density of TiC is 4.9 g / cm³. 3 The density of Ni is 8.9 g / cm³. 3 Zr 55 Cu 30 Al5Ni 10Amorphous alloy and W particles are combined as the tail fragment material, i.e., the fragment tail material, and powdered Zr is bonded together using spark plasma sintering welding technology. 55 Cu 30 Al5Ni 10 / W is welded together with bulk WC-x%TiC-10%Ni (x=0,30,60,90). The specific preparation method is as follows:

[0081] Weigh out high-purity metal raw materials according to their nominal composition, and obtain Zr by arc melting the high-purity elements six times in an argon atmosphere using Ti getter. 55 Cu 30 Al5Ni 10 Amorphous alloy and tungsten powders were prepared from the mother alloy ingot of W using a high-nitrogen atomization method. The high-purity nitrogen atomization pressure was 20 MPa, and the diameter of the guide hole was 2 mm. Zirconium-based amorphous alloy powder with a particle size of 1 μm to 50 μm and tungsten powder with a particle size of 1 μm to 100 μm were screened out. The zirconium-based amorphous alloy powder and tungsten powder were then uniformly mixed by ball milling to obtain an amorphous alloy composite powder, in which the volume fraction of tungsten reinforcing phase powder was 40%. The grinding balls were made of cemented carbide, the rotation speed was 600 r / min, the ball-to-powder ratio was 10:1, and the ball milling time was 7 h.

[0082] Cemented carbide powders with different carbide contents were placed into... Figure 5 Sintering was carried out in the mold shown, at a sintering temperature of 1250℃, a holding time of 1 hour, a heating rate of 100℃ / min, and a sintering pressure of 50MPa. (Main armor-piercing part) Figure 3 (Subject No. 1) is 90% WC-0% TiC-10% Ni, with a height of 7mm, and the secondary armor-piercing portion ( Figure 3 (Subject No. 2) comprises four layers, each 3 mm high. The first layer is 0% WC-90% TiC-10% Ni. The TiC content decreases by 30% with each subsequent layer, while the WC content increases by 30% with each subsequent layer. See [link to details] for specific distribution. Figure 7 And Table 1:

[0083] Table 1

[0084]

[0085] The sintered WC-Ni gradient cemented carbide is processed as follows: Figure 3 As shown in the diagram, the surfaces of the carbide alloy to be joined are first polished sequentially using sandpaper of different grits: 400 grit, 800 grit, 1200 grit, and 2000 grit, each time until the surface is free of obvious scratches. Then, the polished surface is subjected to laser surface roughening treatment with a hole spacing of 100 μm, a laser pulse energy of 1.8 mJ, a pulse width of 240 ns, and a pulse frequency of 30 kHz. (The last sentence appears to be incomplete and possibly refers to a different process.) Figure 6In the schematic diagram of the spark plasma sintering mold shown (2-amorphous alloy composite powder, 8-hard alloy material), WC-TiC-Ni gradient hard alloy and Zr are prepared by spark plasma sintering welding technology. 55 Cu 30 Al5Ni 10 The process parameters for the / W amorphous alloy composite powder welded parts, using spark plasma sintering, are as follows: sintering temperature of 723 K, sintering pressure of 100 MPa, sintering time of 10 min, and heating / cooling rate of 50 K / min.

[0086] The following calculation compares the impact of whether or not a gradient hard alloy projectile is used on the center of gravity of the overall projectile core material.

[0087] The center of gravity of an armor-piercing fragmentation projectile can be calculated in the following ways. For example... Figure 8 As shown, for the position c of the center of gravity of an armor-piercing fragmentation projectile, considering that the projectile is axially symmetric and its center of gravity lies on the axis, we only need to consider the horizontal coordinate X of the center of gravity on the axis. c The center of gravity referred to below is the horizontal axis position of the center of gravity. An armor-piercing fragmentation projectile can be divided into three parts: the first part is the main armor-piercing part 1 of the armor-piercing projectile, the second part is the secondary armor-piercing part 2 of the armor-piercing projectile, and the third part is the fragmentation tail part 3, which correspond to the centers of gravity c1, c2, and c3 respectively.

[0088] Let the x-coordinate of the centroid on the axis be... , and According to the centroid formula, we can obtain:

[0089]

[0090]

[0091]

[0092] set up , , For the quality of each part, Density of cemented carbide Given the density of the amorphous alloy composite material, the mass of each part is:

[0093]

[0094]

[0095]

[0096] For the system of objects with different mass, the center of gravity coordinates of each figure is taken to calculate the total center of gravity coordinates, so the center of gravity position of the whole armor-piercing fragment projectile is:

[0097]

[0098] For the system of objects with density gradient, the center of gravity coordinates of each part is also taken to calculate the total center of gravity coordinates, as shown in Figure 9 The center of gravity of the second part is:

[0099]

[0100]

[0101] The center of gravity of the object with gradient is:

[0102]

[0103] Assuming that the density of the armor-piercing fragment projectile is uniform, the center of gravity of the armor-piercing fragment projectile body is located at 19.3 mm to the right of the front end of the hard alloy armor-piercing projectile head according to the above calculation formula. In the present embodiment, d1=19 mm, d2=12 mm, d3=20 mm, =15.2 g / cm 3 , =10 g / cm 3 , =6 mm, =8.6 mm. The parameters are brought into the above formula, and the center of gravity of the armor-piercing fragment projectile without using gradient hard alloy projectile head is located at =18.2 mm, and the center of gravity of the armor-piercing fragment projectile after using gradient hard alloy projectile head is located at =19.1 mm.

[0104] From the above calculation, it can be seen that when the sub-penetration part of the projectile head is made of gradient hard alloy, the center of gravity of the whole projectile core material can be moved backward to 19.1 mm, which is only 0.2 mm away from the center of gravity, and the center of gravity and the center of gravity are close to coincide, so the projectile core material is expected to fly more stably.

[0105] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An energetic composite connector based on cemented carbide and tungsten-containing amorphous alloy, characterized in that, It includes a head-end penetrating section and a tail-end fragment section. The head-end penetrating section is made of cemented carbide, and the tail-end fragment section is made of tungsten-containing amorphous alloy. The hard alloy used in the head-end penetrating part has a greater strength than the tungsten-containing amorphous alloy used in the tail-end fragment part, and the hardness of the hard alloy used in the head-end penetrating part is greater than the hardness of the tungsten-containing amorphous alloy used in the tail-end fragment part. The head-end penetrating portion and the tail-end fragment portion are integrated and connected by spark plasma sintering.

2. The energetic composite connector as described in claim 1, characterized in that, The hard alloy used for the penetrating portion at the tip has a Vickers hardness greater than or equal to 15 GPa, a bending strength greater than or equal to 1500 MPa, and a fracture toughness greater than or equal to 10 MPa•m. 1 / 2 ; and / or, The cemented carbide is composed of tungsten-cobalt, tungsten-nickel, or tungsten-nickel-cobalt cemented carbide; and / or, The matrix composition of the amorphous alloy is a zirconium-based, zirconium-titanium-based, or zirconium-niobium-based amorphous alloy, and the energy density per unit mass is greater than or equal to 5 kJ•g. -1 Its density is 7~12 g / cm³ 3 Furthermore, the critical forming size of the matrix composition of the amorphous alloy is greater than or equal to 0.1 mm, and the temperature difference between the upper and lower limits of the supercooled liquid phase region is greater than 40 K; the reinforcing phase composition in the tungsten-containing amorphous alloy is tungsten particles.

3. The energetic composite connector as described in claim 1, characterized in that, The length ratio of the penetrating portion at the head end to the fragmented portion at the tail end is 0.5 to 1.

5.

4. The energetic composite connector as described in claim 1, characterized in that, The head-end penetrating portion includes two regions: the main head-end penetrating portion and the secondary head-end penetrating portion. The secondary head-end penetrating portion is made of gradient hard alloy material, and the density of the gradient hard alloy material increases in a gradient direction from the head to the tail. This causes the overall center of gravity of the energetic composite connector to move backward and closer to the centroid of the energetic composite connector, thereby ensuring the stable flight of the energetic composite connector.

5. The energetic composite connector as described in claim 4, characterized in that, The gradient is a structural gradient and / or a compositional gradient; by controlling the content of the raw material components used in preparing the gradient cemented carbide or controlling the temperature field distribution during the sintering process in preparing the gradient cemented carbide, a secondary head-end penetrating portion cemented carbide material with a density gradient increasing in the direction from head to tail is obtained.

6. The method for preparing the energetic composite connector according to any one of claims 1 to 5, characterized in that, Includes the following steps: (1) The surface to be connected on the cemented carbide block used for the head-end penetration part is roughened to obtain the roughened surface of the cemented carbide block to be connected in the head-end penetration part. (2) Mix the amorphous alloy powder and tungsten reinforced phase powder used in the tail fragment part evenly to obtain the tungsten / amorphous alloy composite powder used in the tail fragment part; (3) The tungsten / amorphous alloy composite powder described in step (2) and the roughened hard alloy block surface to be joined are directly joined by spark plasma sintering to obtain the energetic composite connector; or, First, the tungsten / amorphous alloy composite powder described in step (2) is prepared into an amorphous alloy composite material block by spark plasma sintering. Then, the surface to be joined is roughened to obtain the amorphous alloy composite material block to be joined for the roughened tail fragment part. Then, the amorphous alloy composite material block to be joined for the roughened tail fragment part is welded together with the hard alloy block to be joined for the roughened head penetration part described in step (1) to obtain the energetic composite connector.

7. The preparation method according to claim 6, characterized in that, The texturing processes described in steps (1) and (3) are each independently one or more of sandpaper polishing and laser texturing; and / or, The roughness of the surface of the cemented carbide block to be joined in the head end penetrating part of the texturing treatment is less than 2.5 μm; the roughness of the surface of the amorphous alloy composite material block to be joined in the tail end fragment part of the texturing treatment is less than 2.5 μm.

8. The preparation method according to claim 6, characterized in that, The volume fraction of tungsten reinforcing phase powder in the tungsten / amorphous alloy composite powder is between 20% and 60%.

9. The preparation method according to claim 6, characterized in that, Step (3) involves directly connecting the tungsten / amorphous alloy composite powder used in the tail fragment portion described in step (2) to the hard alloy block used in the roughened head penetration portion described in step (1) via spark plasma sintering. The sintering temperature is set within the supercooled liquid phase region of the amorphous alloy, the sintering pressure is 50~150 MPa, the sintering time is 5~30 min, and the heating / cooling rate is 10~100 K / min; and / or, Step (3) involves preparing an amorphous alloy composite material block from the tungsten / amorphous alloy composite powder used in the tail fragment portion described in step (2) by spark plasma sintering. The sintering temperature is set within the supercooled liquid phase region of the amorphous alloy, the sintering pressure is 100~600 MPa, the sintering time is 5~30 min, and the heating / cooling rate is 20~200 K / min; and / or, Step (3) Weld the amorphous alloy composite material block used in the tail fragment part of the texturing treatment to the hard alloy block used in the head penetration part of the texturing treatment in step (1) together. The welding temperature is set 10~100 K below the glass transition end temperature Tx of the amorphous alloy, the welding pressure is 10~150 MPa, the welding time is 1~10 min, and the heating and cooling rate is 10~100 K / min.

10. An armor-piercing fragmentation projectile, characterized in that, Its core material includes the energetic composite connector as described in any one of claims 1 to 5.

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