Niobium-titanium-zirconium multi-principal-element active material and preparation method thereof, active fragment and preparation method thereof

Abstract

The invention provides a niobium-titanium-zirconium multi-principal-element active material and a preparation method thereof, and an active fragment and a preparation method thereof. Firstly, multi-principal-element active material matrix powder is prepared by adopting a mechanical alloying method, and second-phase particle defects are prefabricated in the matrix material through a high-density hard material; preparing an active material blank by using an ultrasonic pressing forming and vacuum sintering method, and further preparing the active material blank into a multi-principal-element active material with uniform components by using a vacuum melting method; and finally, an active fragment is prepared through electric pulse treatment, machining and laser cladding treatment, interface defects such as cracks and micro holes at the interface of the matrix and the hard particles are repaired, and the mechanical property of the fragment is further improved. Compared with a traditional multi-principal-element metal active material, the strength and the reaction capacity of the active material are improved, and the endpoint damage power of an active fragment to a target is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal active materials, and in particular relates to a niobium-titanium-zirconium series multi-principal active material and a preparation method thereof, and an active fragment and a preparation method thereof. Background Art

[0002] Active materials are a new type of damaging energetic material that possesses both the strength characteristics of metal-like materials and the reaction characteristics of explosive-like materials. These materials exhibit insensitive properties in normal environments, but under impact loads and detonation drive, they are activated and undergo reactions such as combustion, deflagration, and explosion during the process of penetrating the target, releasing a large amount of energy. Therefore, compared to inert metal materials, active materials can not only cause kinetic penetration damage to the target under high-speed collision conditions, but also release energy to enhance the damage efficiency, and produce ignition, detonation, and implosion effects on the target, achieving kinetic-chemical energy coupled damage, and providing a new technical approach to significantly increase the damage power of ammunition warheads. Based on the above characteristics of active materials and the demand for efficient damage technology on future battlefields, this material has become a key research direction in the field of warhead damage elements, and has good application prospects for use as materials such as fragments, liners, and penetration cores.

[0003] Currently, active materials can be primarily categorized into metal / metal hydride / polymer composites, thermite, and intermetallic compounds. Research and application of active materials primarily focuses on polytetrafluoroethylene / aluminum / metal and metal oxide additives, and nickel / aluminum / metal additives. For fragmentation damage elements, polytetrafluoroethylene / aluminum / metal and metal oxide additives have low density and strength, resulting in insufficient target penetration and weak anti-detonation driving capability. Nickel / aluminum / metal additives have poor plasticity, low energy release rates, and high reaction thresholds, resulting in insufficient target damage. Therefore, driven by the practical demand for high-density, high-strength, and high-energy-release damage elements, multi-principal metal active materials have gradually attracted the attention of researchers.

[0004] Multi-principal-element metal active materials (MPAMs) are typically composed of multiple metallic elements mixed in specific atomic ratios. Compared to polytetrafluoroethylene / aluminum / metal and metal oxide additives (or metal / metal hydride / polymer composites), these materials possess greater density and strength, and can undergo energy-releasing reactions under impact loads. Existing research primarily focuses on MAMs based on cobalt-chromium-nickel (iron), a system with low energy content and low target damage effectiveness. To ensure a uniform mixing of the MAMs to form a solid solution, these materials are typically prepared using spark plasma sintering, ultrahigh-temperature sintering, or vacuum melting, allowing the various components to fuse fully to form a single-phase or multiphase solid solution structure. Among them, multi-principal metal active materials prepared by spark plasma sintering or ultra-high temperature sintering typically have uneven distribution of metal components and poor ability to form the expected phase structure. Vacuum melting methods require more than seven repeated melting cycles to ensure the formation of the expected phase structure. In cases involving high-melting-point metals, repeated melting may be required more than ten times, resulting in increased costs. At the same time, the melting points of the metal elements in multi-principal metal active materials vary greatly. Repeated melting can cause the low-melting-point metal to volatilize, resulting in changes in the composition of the material product, further affecting the material performance. In addition, traditional multi-principal metal active materials exhibit weak reactivity under impact loads, with a high threshold velocity required for the reaction (usually exceeding 1000m / s) and low reaction energy release, which seriously hinders their application as fragment damage elements. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides a niobium-titanium-zirconium series multi-principal element active material and a preparation method thereof, an active fragment and a preparation method thereof, so that the multi-principal element metal active material has the performance advantages of high density, high strength, low reaction threshold, high reaction energy release, etc. The prepared active fragments have good penetration ability and anti-detonation driving ability, and have good explosive damage capability.

[0006] The present invention provides a niobium-titanium-zirconium series multi-principal active material, wherein the active material raw materials include matrix material powder and high-density hard material powder; By mass, the matrix material powder / the high-density hard material powder=1.2~9; The matrix material powder comprises a mixture of niobium powder, titanium powder and zirconium powder, and has a particle size of 80 to 150 μm; The high-density hard material powder is any one of tungsten powder, tantalum powder, tungsten carbide powder, tantalum carbide powder, tungsten nitride powder, tantalum nitride powder, ditungsten boride powder, and tantalum boride powder, and has a particle size of 13 to 58 μm.

[0007] Furthermore, the matrix material powder further comprises, by mass percentage, 0-20% aluminum powder, 0-10% magnesium powder, and 0-20% vanadium powder; In terms of mass percentage, the contents of niobium powder, titanium powder and zirconium powder in the matrix material powder are 24-40%, 12-20% and 24-40% respectively; the mass percentage of niobium powder, titanium powder and zirconium powder is 2:1:2.

[0008] Furthermore, in the matrix material powder, the ratio of aluminum to the sum of niobium, titanium, and zirconium is 0 to 0.286 by mass; The ratio of magnesium to the sum of niobium, titanium and zirconium in the matrix material powder is 0 to 0.135 by mass; The ratio of vanadium to the sum of niobium, titanium and zirconium in the matrix material powder is 0 to 0.375 by mass.

[0009] The present invention provides a method for preparing a niobium-titanium-zirconium series multi-principal active material, which specifically comprises the following steps: Step S1: taking the required types of matrix material powders, mixing them in proportion, and grinding them in an inert atmosphere grinding jar; after grinding, passing them through a 100-180 mesh sieve to obtain matrix material powders with a particle size of 80-150 μm; Take the required type of high-density hard material powder, pass it through a 250-1000 mesh sieve, and obtain a high-density hard material powder with a particle size of 13-58 μm; Step S2: The base material powder obtained in step S1 is mixed with the high-density hard material powder in proportion to obtain a mixed powder; In terms of mass percentage, base material powder / hard material powder = 1.2~9; Step S3: taking the mixed powder obtained in step S2, placing it in an ultrasonic vibration mold for stamping to obtain an active material embryo; Step S4: placing the active material embryo body obtained in step S3 in a sintering furnace protected by an inert atmosphere for sintering, heating to a sintering temperature at room temperature, maintaining the sintering time, and then stopping heating, and cooling the embryo body to room temperature in the furnace to obtain a sintered active material embryo body; Step S5: The sintered active material embryo is ultrasonically cleaned and dried with anhydrous ethanol, loaded into a furnace and evacuated, and smelted in a vacuum melting furnace with inert gas for protection. After the active material embryo is completely melted, it is cooled with the furnace. The smelting is repeated 2 to 7 times. The material is cast into a crucible for the final time and cooled to form to obtain the active material.

[0010] Furthermore, in step S1, the ball milling speed of the grinding jar is 200-350 rpm, the ball milling time is 12-144 h; the ball milling temperature is not higher than 25° C.; and the mass ratio of the matrix material powder to the grinding balls is (5-15):1.

[0011] Furthermore, in step S3, the ultrasonic vibration mold applies an ultrasonic frequency of 20-30 kHz, an applied pressure of 100-350 MPa, and a holding time of 2-5 min.

[0012] Furthermore, in step S4, the sintering temperature in the sintering furnace is 1200-1950° C., the heating rate is 5-15° C. / min, and the sintering temperature is maintained for 2-6 hours.

[0013] Furthermore, in step S5, the power of the vacuum melting furnace is adjusted to 100 kW to 200 kW, and the melting time is 10 to 20 minutes.

[0014] The present invention provides a method for preparing an active fragment, comprising the following steps: SP1: The active material is subjected to electric pulse treatment with a pulse current density of 80~200A / mm 2 , the pulse duration is 100~600ms, and the active material after electric pulse treatment is obtained; SP2: Mechanically process the active material after electric pulse treatment to obtain active fragment embryos of preset shape and size; SP3: The outer surface of the active fragment embryo is laser clad to a thickness of 0.05-0.10 mm to obtain active fragments; The active material is the above-mentioned active material or an active material prepared by the above-mentioned active material preparation method.

[0015] The present invention provides an active fragment prepared by the above-mentioned method for preparing the active fragment.

[0016] The beneficial effects of the present invention are: (1) The active material obtained by the present invention has higher density and strength than traditional active materials, and its compressive strength is not less than 1200 MPa; (2) The present invention achieves the dual purpose of improving the mechanical properties and reaction performance of the material by adding high-density hard material to the niobium-titanium-zirconium matrix. On the one hand, the high-density hard material particles play a role of second-phase particle strengthening and dispersion strengthening in the matrix material, which can improve the density and strength of the material; on the other hand, under the action of impact load, the high-density hard material has higher strength and hardness than the matrix material. During the deformation of the material, defects are more likely to accumulate at the location of the hard particles, thereby generating a high-temperature and high-stress area at this location, forming a hot spot that induces chemical reactions in the matrix, and improving the reactivity of the material, so that its reaction speed threshold is no higher than 700m / s; (3) The present invention reasonably controls the particle size and proportion of hard material powder so that the hot spot area formed is large enough and the heating rate is fast enough, which is conducive to the occurrence of chemical reactions of the material. It prevents the particle size from being too small, resulting in insufficient energy in the hot spot area to enhance the reaction, or the particle size from being too large, resulting in a decrease in material strength and plasticity, and further resulting in a decrease in anti-detonation driving ability. (4) The present invention adopts a reasonable ultrasonic pressing-vacuum sintering-vacuum melting process technology route, so that during the preparation process of the material, the matrix components are fully mixed and uniformly distributed, the second phase particles are evenly distributed in the matrix, and there are no obvious cracks at the interface between the matrix and the second phase particles, so that the material obtains a good matching relationship between strength and reaction threshold; (5) The present invention prepares active fragments. After the active material is subjected to electric pulse treatment and mechanical processing, high-density hard second-phase particles are laser-clad on its outer surface, so that the high-density hard second-phase particles form a gradient distribution in the sample, further improving the strength and anti-detonation driving ability of the sample; (6) The active fragments prepared by the present invention can undergo chemical reactions under impact loads and release a large amount of energy, and have good penetration ability, anti-detonation driving ability and explosive damage ability. When the collision speed is not less than 1200m / s, the aftereffect damage area of ​​the fragments on the 4mm steel target and the 1.5mm aluminum target is not less than 10 times the cross-sectional area of ​​785mm. 2 , the overpressure peak generated in the 27L closed pressure vessel is not less than 0.1MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the multi-principal active material structure with prefabricated defects in the present invention.

[0018] Figure 2 Schematic diagram of the internal temperature rise of the active material and the "hot spot" effect of prefabricated defects after the active material is subjected to impact load in the present invention.

[0019] Figure 3 Schematic diagram of the temperature curves of the matrix material and defective particles at different positions in the present invention.

[0020] Figure 4 This is a scanning electron microscope image of a typical multi-principal active material structure in Example 1 of the present invention (black represents the matrix and white represents the second phase particles).

[0021] Figure 5 This is the mechanical property curve of the active fragment in Example 1 of the present invention.

[0022] Figure 6 This is the mechanical property curve of the active fragment in Example 2 of the present invention.

[0023] Figure 7This is the mechanical property curve of the active fragment of experimental group 3-1 in Example 3 of the present invention.

[0024] Figure 8 This is the mechanical property curve of the active fragment of experimental group 3-2 in Example 3 of the present invention.

[0025] Figure 9 This is the mechanical property curve of the active fragment of experimental group 3-3 in Example 3 of the present invention. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical features of this solution, this solution is described below through specific implementation methods.

[0027] The present invention first uses mechanical alloying to prepare a multi-principal active material matrix powder. Second-phase particle defects are preformed within the matrix using a high-density hard material. Ultrasonic pressing and vacuum sintering are then used to prepare an active material embryo. Vacuum melting is then used to transform the active material embryo into a uniformly composed multi-principal active material. Finally, active fragments are prepared through electric pulse processing, mechanical machining, and laser cladding. Interfacial defects such as cracks and micropores at the interface between the matrix and the hard particles are repaired, further enhancing the mechanical properties of the fragments. Compared to traditional multi-principal metal active materials, this approach improves the active material's strength and reactivity, and enhances the terminal destructive power of the active fragments against the target.

[0028] A method for preparing a niobium-titanium-zirconium multi-principal active material, comprising the following steps: Step S1: taking the required types of matrix material powders, mixing them in proportion, and grinding them in an inert atmosphere grinding jar; after grinding, passing them through a 100-180 mesh sieve to obtain matrix material powders with a particle size of 80-150 μm; The matrix material powder is selected from at least niobium powder, titanium powder, and zirconium powder, and aluminum powder, magnesium powder, and vanadium powder can also be added; In terms of mass percentage, the matrix material powder comprises 24-40% niobium powder, 12-20% titanium powder, and 24-40% zirconium powder, respectively. The matrix material powder may also contain 0-20% aluminum powder, 0-10% magnesium powder, and 0-20% vanadium powder. The mass ratio of niobium powder, titanium powder, and zirconium powder is 2:1:2. The milling speed is 200-350 rpm for 12-144 hours. The milling temperature is no higher than 25°C. The mass ratio of matrix material powder to grinding balls is (5-15):1. The inert atmosphere can be any inert gas known in the art.

[0029] Take the required type of high-density hard material powder, pass it through a 250-1000 mesh sieve, and obtain a high-density hard material powder with a particle size of 13-58 μm; The high-density hard material powder is a mixture of any one or more of tungsten powder, tantalum powder, tungsten carbide powder, tantalum carbide powder, tungsten nitride powder, tantalum nitride powder, ditungsten boride powder, and tantalum boride powder.

[0030] The purpose of adding a high-density hard material is to select a material with high density, high hardness, and high strength as a reinforcing particle in a composite material. In this solution, this particle primarily serves as a "prefabricated defect" to increase the reactivity of the multi-principal material, while also contributing to a certain increase in overall material density and strength. While its impact on reactivity is limited, it is not significant. In practical applications, only one high-density hard material is typically added.

[0031] The particle sizes of matrix material powder and high-density hard material powder, as well as their matching relationship, influence the performance and preparation process of multi-principal active materials. To increase the density of multi-principal active materials, the matrix material powder and high-density hard material powder must meet a certain matching relationship. Excessively large or small particle size ratios will increase the porosity within the multi-principal active material, thereby reducing the material's density. A suitable ratio of high-density hard material powder to matrix material powder size is 0.2-0.4. Larger powder particle sizes increase the grain size of the resulting multi-principal active material, which in turn reduces the material's mechanical properties. Smaller powder particle sizes increase the susceptibility of the more active metal powder to oxidation during the preparation process, altering the material's phase structure and reducing its mechanical properties, reactivity, and energy content. Furthermore, excessively small high-density hard material powder particle sizes result in insufficient energy in "hot spots" to induce reactions. Experimental verification indicates that suitable particle sizes for matrix material powders range from 80-150 μm and for high-density hard material powders range from 13-58 μm. At the same time, when the mass percentage of niobium powder, titanium powder and zirconium powder is 2:1:2, a NbTiZr single-phase solid solution with an equiatomic ratio can be formed, which has a good strength-plasticity match.

[0032] Step S2: The base material powder obtained in step S1 is fully mixed with the high-density hard material powder in proportion to obtain a mixed powder; in terms of mass percentage, the base material powder / hard material powder = 1.2-9; In this step, the mixture can still be added to an inert atmosphere grinding jar for mixing and grinding to obtain a mixed powder; the grinding jar ball milling speed is 50-100 rpm, the ball milling time is 0.5-3 min, and the ball milling temperature is not higher than 25°C; The content of high-density hard material powder affects the performance of multi-principal active materials. Excessive high-density hard material content reduces the material's theoretical energy content, potentially making molding difficult and degrading mechanical properties. Excessive high-density hard material powder content reduces the number and density of "hot spots" within the material, diminishing their ability to enhance the material's reactivity and reducing its reactivity. Experimental verification indicates that the optimal mass ratio of matrix material powder to high-density hard material powder in this multi-principal active material scheme is between 1.2 and 9.

[0033] Step S3: Take the mixed powder obtained in step S2 and place it in an ultrasonic vibration mold for stamping. The ultrasonic frequency applied by the upper and lower punches is 20-30 kHz, the applied pressure is 100-350 MPa, and the holding time is 2-5 minutes to obtain an active material embryo.

[0034] Step S4: The active material embryo obtained in step S3 is placed in a sintering furnace protected by an inert atmosphere for sintering. The temperature is raised to a sintering temperature of 1200-1950°C at room temperature, with a heating rate of 5-15°C / min. The sintering temperature is maintained for 2-6 hours, and then heating is stopped. The embryo is cooled to room temperature in the furnace to obtain a sintered active material embryo.

[0035] The sintering temperature and sintering holding time affect the performance of the active material embryo. Excessively high sintering temperatures and long holding times will lead to excessively large grains within the active material embryo, reducing the mechanical properties of the active material embryo. Excessively low sintering temperatures and insufficient holding times will result in insufficient fusion of the metal components in the matrix material, altering the expected phase structure. This also results in insufficient fusion between the matrix material and the high-density hard material, reducing the density of the active material embryo. Experimental verification indicates that the optimal sintering temperature for the multi-component active material in this scheme is 1200-1950°C, with an optimal sintering holding time of 2-6 hours.

[0036] Step S5: The sintered active material embryo is ultrasonically cleaned and dried with anhydrous ethanol, loaded into a furnace and evacuated, and then smelted in a vacuum melting furnace with inert gas for protection. The power of the vacuum melting furnace is adjusted to 100kW~200kW, and the smelting time is 10~20min. After the active material embryo is completely melted, it is cooled with the furnace and the smelting is repeated 2~7 times. The material is cast into a crucible for the final time and cooled to form to obtain the active material.

[0037] Ultrasonic cleaning and drying are best carried out in a vacuum environment to avoid oxidation of highly active metal powders such as aluminum, titanium, magnesium, and zirconium. Usually, when multi-principal alloys, especially those containing high-melting-point metals, are smelted in the form of metal blocks or metal particles, in order to ensure uniform melting of each component, it is necessary to repeat the melting 7 to 11 times. For example, WNbTiZr is usually melted 10 to 11 times. In this scheme, metal powder is used for melting, and "pre-homogenization" such as mechanical alloying and ultrasonic vibration pressing are carried out before melting, so that the number of repeated melting times in step S5 is reduced. The specific number of melting times is more appropriate and reasonable, and is usually set according to actual conditions. In this scheme, the above process is adopted and repeated melting 2 to 7 times can achieve good test results, which greatly reduces the number of repeated melting times and its workload.

[0038] A method for preparing active fragments, the specific steps are as follows: Step SP1: The obtained active material is subjected to electric pulse treatment with a pulse current density of 80~200A / mm 2 , the pulse duration is 100~600ms, and the active material after electric pulse treatment is obtained.

[0039] The active material prepared by the present invention is essentially a particle-reinforced composite material, in which the particles serve as a reinforcing phase and can also act as "hot spots" to promote reactions during the material impact reaction. However, there is an interface between the particle phase and the matrix, and even cracks and other defects are generated at the interface during the preparation process, resulting in a decrease in the overall strength of the material. Therefore, this solution uses electric pulses as a heat treatment method for crack repair, and uses electric pulse methods to treat solids to close possible cracks and other defects, improve the strength properties of the material, and reduce the impact of crack defects inside the material during the preparation process on the performance. The larger the pulse current and the longer the pulse duration, the larger the grain size inside the active material and the lower the mechanical properties of the material. If the pulse current is too small and the pulse duration is insufficient, the defect closure effect will not be significant. Experimental verification shows that the pulse current is 80~200A / mm 2 For optimal use, the pulse duration should be 100~600ms.

[0040] Step SP2: Mechanically process the active material after the electric pulse treatment to obtain an active fragment embryo with a preset shape and size.

[0041] The shape and size of the active fragments can be processed according to actual needs, such as cylindrical, square, trapezoidal, and spherical. It should be noted that the machining size should take into account the size difference reserved for the subsequent laser cladding layer.

[0042] Step SP3: The outer surface of the active fragment embryo is subjected to laser cladding treatment, and the thickness of the laser cladding is 0.05-0.10 mm to obtain active fragments.

[0043] Laser cladding materials can be selected from the corresponding high-density hard materials and compounds mentioned above.

[0044] During use, active materials must possess sufficiently high strength or a strong-to-plastic match to resist detonation loading. After penetrating the target's protective structure, a chemical reaction occurs internally, causing kinetic-chemical energy coupled explosive damage to the internal structure, resulting in large-scale structural damage or functional destruction. At the same time, excessive strength is undesirable, resulting in direct penetration of the target without a reaction. Therefore, the laser cladding layer should be controlled at 0.05-0.10mm. The laser cladding layer can serve as a "shell," simultaneously improving the active fragment's resistance to detonation loading and increasing its strength and penetration capability. Multiple tests have shown that, under the same conditions, after electric pulse + laser cladding treatment, the strength increased by 3.3-5.8%, the explosive damage area increased by 1.2-2.3%, and the quasi-static overpressure increased by 1.6-2.3%.

[0045] The chemical reaction mechanism of the metal active material is that the material undergoes an oxidation reaction with oxygen in the air to release energy. Since this type of material will undergo severe fragmentation under the action of high-speed impact loads, the reaction degree is faster than the combustion of metal under static conditions, and the reaction rate is faster, exhibiting a detonation-like phenomenon, thereby generating quasi-static overpressure in a closed pressure vessel.

[0046] Typically, a spacer target plate consisting of a 2-6 mm 2A12 aluminum or steel protective structure equivalent target and a 1-3 mm aluminum equivalent effect target is used to simulate targets such as radars or aircraft. Therefore, in this embodiment, a spacer target plate consisting of a 4 mm steel target and a 1.5 mm aluminum target is provided to measure the terminal damage power of active fragments on the target.

[0047] The critical value of shock wave overpressure causing serious injury or most deaths to the human body is 0.1MPa, which is used to describe the killing criterion of shock wave overpressure to human targets.

[0048] Figure 1 The structure of the active material of the present invention is shown in FIG. Figure 1 The black dots are large and densely marked, mainly for ease of viewing and understanding. The mass percentage of the defect is approximately 10% to 45% of the entire material, and the volume percentage is 4% to 23% (this is an example of a certain ratio, which does not represent all ratios in the description). However, in the actual scanning electron microscope image, the volume percentage of the defect that can be observed is not completely consistent with the structural schematic. Figure 1 Medium defect particles can represent all kinds of high-density hard material particles in the specification.

[0049] Figure 2 It shows the internal temperature rise of the material and the "hot spot" effect of the prefabricated defects after the active material of the present invention is subjected to impact load.

[0050] Figure 3 Shown are the temperature curves of the matrix material and defective particles of the present invention at different positions.

[0051] It should be noted that Figure 1-Figure 3 This is only a schematic diagram and is applicable to all subsequent embodiments. Example 1

[0052] A method for preparing a niobium-titanium-zirconium multi-principal active material, comprising the following steps: Step S1: 144 g, 72 g, and 144 g of niobium, titanium, and zirconium metal powders, respectively, were mixed and added to a grinding jar. Three 10 g tungsten carbide grinding balls were used, the milling speed was 250 rpm, and the milling time was 72 h. Argon was used in the grinding jar for protection, and circulating cooling water was used to ensure that the milling temperature was not higher than 25° C. After grinding, the powder was passed through a 100 mesh sieve to obtain a niobium, titanium, and zirconium matrix powder with a particle size of 150 μm. Take metal tungsten powder and pass it through a 250-mesh sieve to obtain 120 g of metal tungsten powder with a particle size of 58 μm.

[0053] Step S2: 180 g of the niobium-titanium-zirconium matrix powder obtained in S1 and 120 g of the metal tungsten powder are added to a grinding jar, mixed and evenly ground to obtain a mixed powder; the ball milling speed is 100 rpm, the ball milling time is 1 min, argon gas is used for protection in the grinding jar, and circulating cooling water is used to ensure that the ball milling temperature is not higher than 25°C.

[0054] Step S3: Take 200 g of the mixed powder obtained in S2 and place it in an ultrasonic vibration mold with a diameter of 40 mm for stamping. The ultrasonic frequency applied by the upper and lower punches is 20 kHz, the applied pressure is 200 MPa, and the holding time is 2 min to obtain an active material embryo.

[0055] Step S4: The active material embryo obtained in step S3 is placed in a sintering furnace protected by an argon atmosphere for sintering. The temperature is raised to a sintering temperature of 1450°C at room temperature with a heating rate of 10°C / min. The sintering temperature is maintained for 2.5 hours and then heating is stopped. The active material embryo is cooled to room temperature in the furnace to obtain a sintered active material embryo.

[0056] Step S5: The sintered active material embryo is ultrasonically cleaned and dried with anhydrous ethanol, placed in a furnace and evacuated, and then melted in a vacuum melting furnace with argon gas for protection. The power of the vacuum melting furnace is adjusted to 150 kW, and the melting is carried out for 15 minutes. After the active material embryo is completely melted, it is cooled with the furnace, and the melting is repeated three times. The material is cast into a crucible for the final time and cooled to form, thereby obtaining the active material.

[0057] Figure 4Shown is a scanning electron microscope image of the structure of the active material of Example 1. Figure 4 In the figure, the black area is the matrix phase, and the white area is the hard particle phase. During the preparation process, the hard particle material will aggregate and grow, making a few hard particles larger in size.

[0058] A method for preparing active fragments, the specific steps are as follows: Step SP1: The obtained active material is subjected to electric pulse treatment with a pulse current density of 120A / mm 2 , the pulse duration is 400ms, and the active material after electric pulse treatment is obtained.

[0059] Step SP2: The active material after the electric pulse treatment is mechanically processed into a cylinder with a diameter of 10 mm and a height of 10 mm.

[0060] Step SP3: laser cladding treatment is performed on the outer surface of the cylinder, the thickness of the laser cladding is 0.05 mm, and active fragments are obtained; the laser cladding treatment material is a mixed powder of tungsten carbide and tungsten nitride, and the mass ratio is 1:1.

[0061] Figure 5 Shown is the mechanical property curve of the active fragment of Example 1.

[0062] The density of the active material prepared in this Example 1 is 8.9 g / cm 3 The strength is 1270MPa. When the active fragments prepared by it collide with a 4mm steel target at a speed of 1200m / s, the explosion damage area of ​​the 1.5mm aluminum target at a distance of 200mm from the steel target is 1280mm. 2 , the quasi-static overpressure generated in the 27L closed pressure vessel is 0.10MPa. Example 2

[0063] A method for preparing a niobium-titanium-zirconium multi-principal active material, which differs from Example 1 in that: 144g, 72g, 144g, 40g, and 60g of niobium, titanium, zirconium, aluminum, and vanadium metal powders, respectively, were mixed and ground to obtain a niobium-titanium-zirconium-aluminum-vanadium matrix powder, which was passed through a 100-mesh sieve to obtain 180g of a matrix powder with a particle size of 150μm. Tantalum metal powder was passed through a 250-mesh sieve to obtain 120g of a tantalum metal powder with a particle size of 58μm. The aluminum-niobium-titanium-zirconium-vanadium powder and the tantalum powder were thoroughly mixed to obtain a mixed powder. 200g of the obtained mixed powder was subjected to subsequent treatment to obtain active materials and active fragments. Figure 6 Shown is the mechanical property curve of the active fragment in Example 2.

[0064] The density of the active material sample prepared in Example 2 is 10.1 g / cm 3The strength is 1354MPa. When the active fragments prepared by the fragments collide with a 4mm steel target at a speed of 1200m / s, the explosion damage area of ​​the 1.5mm aluminum target at a distance of 200mm from the steel target is 1382mm. 2 , the quasi-static overpressure generated in the 27L closed pressure vessel is 0.12MPa. Example 3

[0065] On the basis of the above-mentioned Example 1 and Example 2, and taking Example 1 and Example 2 as a control group, the following multiple groups of experiments were designed when the ratio of aluminum to the sum of niobium, titanium, and zirconium was 0.06-0.286, the ratio of magnesium to the sum of niobium, titanium, and zirconium was 0.025-0.135, and the ratio of vanadium to the sum of niobium, titanium, and zirconium was 0.03-0.375, based on the calculation of the base material powder as a whole: Experimental group 3-1: the contents of niobium, titanium, zirconium, aluminum, magnesium, and vanadium were 32%, 16%, 32%, 5%, 5%, and 10%, respectively; Experimental group 3-2: the contents of niobium, titanium, zirconium, aluminum, magnesium, and vanadium were 32%, 16%, 32%, 10%, 5%, and 5%, respectively; Experimental group 3-3: the contents of niobium, titanium, zirconium, aluminum, magnesium, and vanadium were 32%, 16%, 32%, 15%, 2%, and 3%, respectively; The hard material is tungsten, and the base material powder / hard material powder = 1.5.

[0066] The final active fragment performance table is shown in Table 1: Table 1 Comparison of each experimental group in Example 3 with Example 1 and Example 2 <![CDATA[Sample density g / cm 3 > Compressive strength MPa <![CDATA[Burst damage area mm 2 > Quasi-static overpressure MPa Example 1 8.9 1270 1280 0.10 Example 2 10.1 1354 1382 0.12 Experimental group 3-1 11.0 1317 1356 0.11 Experimental group 3-2 10.8 1421 1533 0.13 Experimental group 3-3 10.8 1513 1427 0.15 As shown in Table 1, by comparing the experimental group 3-1 with the control group, it can be seen that adding elements such as aluminum, magnesium, and vanadium to the matrix can effectively improve the material's strength, quasi-static overpressure, and the burst damage area of ​​the target plate behind the spacer target; Comparing Experimental Group 3-1 with Example 2 shows that when the hard material changes from tungsten to tantalum, the material's strength decreases. Experimental Group 3-1 has a higher proportion of high-energy elements such as magnesium and aluminum, but the quasi-static overpressure is lower than that of Example 2. Further comparison and analysis of the mechanical property curves of Experimental Group 3-1 and Example 2 show that Experimental Group 3-1 has better plasticity, which may reduce the degree of material fragmentation during penetration of the front target, thereby reducing the degree of reaction and reducing the quasi-static overpressure. Comparing Experimental Group 3-1 with Experimental Group 3-2 shows that increasing the aluminum content and reducing the vanadium content can improve the material's strength, quasi-static overpressure, and the explosive damage area to the rear target. Comparing the mechanical property curves of Experimental Group 3-1 with Experimental Group 3-2 shows that the material's plasticity is significantly reduced and its brittleness is increased, which is likely to lead to a decrease in the material's ability to resist detonation loading. Comparing Experimental Groups 3-1 and 3-3, we can see that as the aluminum content increases, the magnesium and vanadium contents decrease, and the material's strength and quasi-static overpressure further increase, but the increase in the explosive damage area of ​​the rear target is relatively small. Comparing the mechanical property curves of Experimental Groups 3-1 and 3-3, we can see that the material's plasticity decreases, its brittleness increases, and its ability to resist detonation loading decreases. The material may be damaged during the driving process, which reduces the material's explosive damage power. Comparing experimental group 3-2 with experimental group 3-3, it can be seen that the increase in the total content of high-energy elements such as aluminum and magnesium can increase the quasi-static overpressure of the material, but the explosive damage area of ​​experimental group 3-2 to the rear target is higher. Further comparison of the mechanical property curves of experimental group 3-2 and experimental group 3-3 shows that the plasticity of experimental group 3-3 is worse and the brittleness is higher, resulting in a decrease in the material's ability to resist impact loading and a decrease in the explosive damage power.

[0067] Figure 7-Figure 9 They are respectively the mechanical property curves of the active fragments of the experimental groups 1-3 in Example 3 of the present invention. Example 4

[0068] On the basis of the above-mentioned Examples 1 and 2, and with Examples 1 and 2 as control groups, the following multiple tests were designed, with the base material powder as the whole being calculated, and the ratio of the sum of aluminum and vanadium to the sum of niobium, titanium, and zirconium being 0.125-0.4 by mass: Experimental group 4-1: niobium, titanium, zirconium, aluminum, magnesium, and vanadium contents were 30%, 15%, 30%, 10%, 5%, and 10%, respectively; Experimental group 4-2: the contents of niobium, titanium, zirconium, aluminum, magnesium, and vanadium were 28%, 14%, 28%, 15%, 5%, and 10%, respectively; Experimental group 4-3: the contents of niobium, titanium, zirconium, aluminum, magnesium, and vanadium were 28%, 14%, 28%, 10%, 5%, and 15%, respectively; The hard material is tungsten, and the base material powder / hard material powder = 1.5.

[0069] The final active fragment performance table is shown in Table 2: Table 2 Comparison of each experimental group in Example 4 with Example 1 and Example 2 <![CDATA[Sample density g / cm 3 > Compressive strength MPa <![CDATA[Fragmentation damage area mm 2 > Quasi-static overpressure MPa Example 1 8.9 1270 1280 0.10 Example 2 10.1 1354 1382 0.12 Experimental group 4-1 10.8 1433 1843 0.14 Experimental group 4-2 10.6 1537 1671 0.16 Experimental group 4-3 10.8 1470 1821 0.14 As shown in Table 2, by comparing experimental groups 4-1 and 4-2, increasing the aluminum content and reducing the niobium, titanium, and zirconium contents can improve the material's strength and quasi-static overpressure, but reduce the burst damage area. According to the analysis in Example 3, aluminum reduces the material's plasticity, resulting in a decrease in its ability to resist impact loading. Comparing experimental group 4-1 with experimental group 4-3, it can be seen that increasing the vanadium content and reducing the niobium, titanium, and zirconium contents can slightly increase the strength of the material, but have almost no effect on the quasi-static overpressure; Comparing experimental group 4-2 with experimental group 4-3, it can be seen that reducing the aluminum content and increasing the vanadium content will reduce the strength of the material, which shows that the effect of aluminum on improving the strength of the material is greater than that of vanadium. Example 5

[0070] On the basis of the above-mentioned Example 1 and Example 2, and taking Example 1 and Example 2 as a control group, the matrix material powder is calculated as a whole, and the ratio of the sum of the mass of magnesium and vanadium to the sum of niobium, titanium and zirconium is 0.0625~0.357.

[0071] On the basis of the above-mentioned Examples 1 and 2, and with Examples 1 and 2 as control groups, the following multiple tests were designed, with the base material powder as a whole and the ratio of the sum of aluminum and vanadium to the sum of niobium, titanium, and zirconium being 0.125-0.16 by mass: Experimental group 5-1: the contents of niobium, titanium, zirconium, aluminum, magnesium, and vanadium were 30%, 15%, 30%, 5%, 10%, and 10%, respectively; Experimental group 5-2: the contents of niobium, titanium, zirconium, aluminum, magnesium, and vanadium were 32.8%, 16.4%, 32.8%, 5%, 3%, and 10%, respectively; Experimental group 5-3: the contents of niobium, titanium, zirconium, aluminum, magnesium, and vanadium were 32%, 16%, 32%, 5%, 10%, and 5%, respectively; The hard material is tungsten, and the base material powder / hard material powder = 1.5.

[0072] The final active fragment performance table is shown in Table 3: Table 3 Comparison of each experimental group in Example 5 with Example 1 and Example 2 <![CDATA[Sample density g / cm 3 > Compressive strength MPa <![CDATA[Burst damage area mm 2 > Quasi-static overpressure MPa Example 1 8.9 1270 1280 0.10 Example 2 10.1 1354 1382 0.12 Experimental group 5-1 10.6 1369 1621 0.15 Experimental group 5-2 11.1 1299 1327 0.11 Experimental group 5-3 10.7 1320 1644 0.15 As shown in Table 3, by comparing experimental group 5-1 with experimental group 5-2, increasing the magnesium content and reducing the niobium, titanium, and zirconium contents can improve the material strength and significantly increase the quasi-static overpressure of the material, which results in a larger explosion damage area in experimental group 1. Comparing experimental groups 5-1 and 5-3, it can be seen that increasing the vanadium content and reducing the niobium, titanium, and zirconium contents can slightly increase the strength of the material, but has almost no effect on the quasi-static overpressure, and the explosion damage area is also similar; Comparing experimental group 5-2 with experimental group 5-3, it can be seen that the strength of the material increases when the magnesium content is increased while the vanadium, niobium, titanium and zirconium contents are reduced, indicating that the magnesium element has a higher gain in improving the strength. The quasi-static overpressure of experimental group 5-3 is also greater than that of experimental group 5-2, but the explosive damage area is smaller, which indicates that the magnesium element will significantly reduce the material's ability to resist impact loading.

[0073] Finally, from the data in Examples 3 to 5, it can be seen that the active material prepared in this solution achieves the combined properties of high density, high strength, low reaction threshold, and high reaction energy release.

[0074] It should be noted that in Examples 1 to 5, the value of the matrix material powder / high-density hard material powder is set to 1.5. This is mainly to facilitate the comparison of the test results in each example, and to explore the influence of changes in the aluminum, magnesium, and vanadium components in the niobium-titanium-zirconium system on the overall performance of the active material test; the value of the matrix material powder / high-density hard material powder can also be set to 1.2, 3, 5, and 9, respectively. After a large number of experimental verifications, it was found that except for the different mechanical properties of the active samples, the performance change trend is basically consistent with that in the above examples, which will not be described in detail here.

[0075] Based on the comprehensive analysis of the results in Examples 1 to 5, in general, aluminum and magnesium can increase the energy content of the material, while other elements have no significant effect. Aluminum, magnesium, and vanadium can increase the strength of the material, and the strength enhancement effect is aluminum > magnesium > vanadium. Increased aluminum and magnesium content will lead to a decrease in the material's plasticity and increase its brittleness, with magnesium causing a more significant deterioration in the material's plasticity than aluminum. Tantalum, as a high-density hard material, can increase the material's plasticity compared to tungsten, but the material's strength will be reduced to a certain extent. It is worth noting that as plasticity decreases, the material's ability to resist impact loading decreases, the degree of material fragmentation increases during penetration, and the reaction energy release capacity increases. Therefore, as plasticity decreases, the area of ​​​​blast damage to the rear target by the material first increases and then decreases.

[0076] At the same time, the relationship between mechanical properties, energy content, quasi-static overpressure, and explosive damage area. Materials with better comprehensive mechanical properties of strength and plasticity have stronger resistance to explosive loading and are less likely to suffer internal damage during the loading process. Under the premise of ensuring that the material is not prematurely activated and serious structural damage is not caused, the higher the energy content and the stronger the reaction energy release ability of the material, the greater the quasi-static overpressure released and the greater the explosive damage to the target. However, it is worth noting that when the threshold is too low or the brittleness is too large, the material may react prematurely or completely shatter during the ballistic gun drive or explosive loading process, which will also lead to a decrease in damage power. At the same time, the destructive power of active fragments is closely related to the matching of the active fragment performance and the target structure. The requirements for the active fragment performance are different for targets of different types and structures. Therefore, this plan does not involve the optimal ratio of active materials, but only discusses the factors affecting material properties.

[0077] All experiments in the embodiment of this scheme are experimental data obtained from ballistic gun experiments. The impact load on the material during the loading process is smaller than the explosive detonation loading.

[0078] Technical features not described in the present invention can be achieved through or by adopting existing technologies and will not be described in detail here. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A niobium-titanium-zirconium multi-principal active material, characterized in that: The active material raw materials include base material powder and high-density hard material powder; By mass, the matrix material powder / the high-density hard material powder=1.2~9; The matrix material powder comprises a mixture of niobium powder, titanium powder and zirconium powder, and has a particle size of 80 to 150 μm; The high-density hard material powder is any one of tungsten powder, tantalum powder, tungsten carbide powder, tantalum carbide powder, tungsten nitride powder, tantalum nitride powder, ditungsten boride powder, and tantalum boride powder, and has a particle size of 13 to 58 μm.

2. The niobium-titanium-zirconium multi-principal active material according to claim 1, characterized in that: In terms of mass percentage, the matrix material powder further comprises 0-20% aluminum powder, 0-10% magnesium powder, and 0-20% vanadium powder; In terms of mass percentage, the contents of niobium powder, titanium powder and zirconium powder in the matrix material powder are 24-40%, 12-20% and 24-40% respectively; the mass percentage of niobium powder, titanium powder and zirconium powder is 2:1:

2.

3. The niobium-titanium-zirconium multi-principal active material according to claim 2, characterized in that: In terms of mass, the ratio of aluminum to the sum of niobium, titanium, and zirconium in the matrix material powder is 0 to 0.286; The ratio of magnesium to the sum of niobium, titanium and zirconium in the matrix material powder is 0 to 0.135 by mass; The ratio of vanadium to the sum of niobium, titanium and zirconium in the matrix material powder is 0 to 0.375 by mass.

4. A method for preparing a niobium-titanium-zirconium multi-principal active material, characterized in that: The specific steps include: Step S1: taking the required types of matrix material powders, mixing them in proportion, and grinding them in an inert atmosphere grinding jar; after grinding, passing them through a 100-180 mesh sieve to obtain matrix material powders with a particle size of 80-150 μm; Take the required type of high-density hard material powder, pass it through a 250-1000 mesh sieve, and obtain a high-density hard material powder with a particle size of 13-58 μm; Step S2: The base material powder obtained in step S1 is mixed with the high-density hard material powder in proportion to obtain a mixed powder; In terms of mass percentage, base material powder / hard material powder = 1.2~9; Step S3: taking the mixed powder obtained in step S2, placing it in an ultrasonic vibration mold for stamping to obtain an active material embryo; Step S4: placing the active material embryo body obtained in step S3 in a sintering furnace protected by an inert atmosphere for sintering, heating to a sintering temperature at room temperature, maintaining the sintering time, and then stopping heating, and cooling the embryo body to room temperature in the furnace to obtain a sintered active material embryo body; Step S5: The sintered active material embryo is ultrasonically cleaned and dried with anhydrous ethanol, loaded into a furnace and evacuated, and smelted in a vacuum melting furnace with inert gas for protection. After the active material embryo is completely melted, it is cooled with the furnace. The smelting is repeated 2 to 7 times. The material is cast into a crucible for the final time and cooled to form to obtain the active material.

5. The method for preparing a niobium-titanium-zirconium multi-principal active material according to claim 4, characterized in that: In step S1, the ball milling speed of the grinding jar is 200-350 rpm, the ball milling time is 12-144 h; the ball milling temperature is not higher than 25° C.; and the mass ratio of the base material powder to the grinding balls is (5-15):

1.

6. The method for preparing a niobium-titanium-zirconium multi-principal active material according to claim 4, characterized in that: In step S3, the ultrasonic vibration mold applies an ultrasonic frequency of 20-30 kHz, an applied pressure of 100-350 MPa, and a holding time of 2-5 minutes.

7. The method for preparing a niobium-titanium-zirconium multi-principal active material according to claim 4, characterized in that: In step S4, the sintering temperature in the sintering furnace is 1200-1950° C., the heating rate is 5-15° C. / min, and the sintering temperature is maintained for 2-6 hours.

8. The method for preparing a niobium-titanium-zirconium multi-principal active material according to claim 4, characterized in that: In step S5, the power of the vacuum melting furnace is adjusted to 100 kW to 200 kW, and the melting time is 10 to 20 minutes.

9. A method for preparing active fragments, characterized in that: The following steps are involved: SP1: The active material is subjected to electric pulse treatment with a pulse current density of 80~200A / mm 2 , the pulse duration is 100~600ms, and the active material after electric pulse treatment is obtained; SP2: Mechanically process the active material after electric pulse treatment to obtain active fragment embryos of preset shape and size; SP3: The outer surface of the active fragment embryo is laser clad to a thickness of 0.05-0.10 mm to obtain active fragments; The active material is the active material according to any one of claims 1 to 3 or the active material prepared by the preparation method according to any one of claims 4 to 8.

10. An active fragment, characterized in that: The active fragment is prepared according to the preparation method of claim 9.

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