Method for realizing high-density compression and mixture target

Abstract

The embodiment of the invention discloses a method for achieving high-density compression and a mixture target, the method is applied to the mixture target, the mixture target comprises a container and a mixture contained in the container, and the mixture comprises a low-impedance base material and high-impedance particles; the method comprises the following steps: carrying out single impact loading on a mixture target by using impact waves; wherein in the single impact loading process, the impedance mismatch between the high-impedance particles and the low-impedance matrix material is utilized, so that the low-impedance matrix material is compressed to be higher than the density of the main Rayleigong state in the single impact process, and the density of the low-impedance matrix material is higher than the density of the main Rayleigong state; the effect that the density of the low-impedance material is directly higher than that of the main Rayleigh gong state through a single impact process under the conventional impact loading condition can be achieved.

Description

Technical Field

[0001] This application relates to the field of high-density compression technology of materials, and more specifically, to a method for achieving high-density compression and a mixture target. Background Technology

[0002] In research fields such as shock wave physics, planetary science, and inertial confinement fusion, compressing low-impedance materials (such as hydrogen and water) to extremely high densities is one of the core challenges. While traditional dynamic high-pressure impact loading can generate a high-pressure environment, its path is limited to the material's principal göttingen line, which represents the final state achievable in a single impact. This prevents current technologies from directly compressing low-impedance materials to higher densities through conventional single-impedance loading. For low-impedance materials, even under high impact pressure, their compression ratio and final density remain significantly limited. To overcome this limitation, existing technologies have developed pre-compression methods and ramp loading techniques. Pre-compression methods pre-increase the initial density of the material using a static high-pressure device, but face challenges such as small sample chamber size and difficulties in experimental diagnosis, and require additional pre-processing steps, making it impossible to achieve high-density compression in a single impact. While ramp loading technology can achieve near-isentropic high-density compression, it demands extremely high precision in waveform control of the driving source, making experimental design and analysis exceptionally complex. It typically relies on multiple loadings or complex waveform modulation, making it difficult to achieve direct and efficient compression in a single impact. Furthermore, existing technologies struggle to fully utilize the impedance mismatch effect under conventional impact loading conditions to achieve multiple compression mechanisms in low-impedance materials during a single impact. Therefore, there is an urgent need in this field for a solution that can easily and stably deviate low-impedance materials from their primary density state to a higher density state through a single impact operation in conventional impact loading experiments. Summary of the Invention

[0003] The purpose of this application is to provide a method for achieving high-density compression and a mixture target, which can enable low-resistivity materials to directly reach a density higher than their primary argon state through a single impact process under conventional impact loading conditions.

[0004] In a first aspect, this application provides a method for achieving high-density compression, the technical solution of which is as follows: A method for achieving high-density compression is applied to a mixture target, the mixture target including a container and a mixture contained in the container, the mixture comprising a low-resistivity matrix material and high-resistivity particles; the method includes: subjecting the mixture target to a single impact loading using a shock wave; wherein, during the single impact loading process, the impedance mismatch between the high-resistivity particles and the low-resistivity matrix material is utilized to compress the low-resistivity matrix material to a density higher than its primary density during the single impact process.

[0005] Furthermore, this application also proposes that the method further include a step of determining the post-impact state, comprising:

[0006] The mass fraction, initial specific volume, and initial internal energy of the low-resistivity matrix material and the high-resistivity particles are obtained.

[0007] Based on the mass fraction, the initial specific volume of the mixture is obtained by weighted summation of the initial specific volumes of the low-resistivity matrix material and the high-resistivity particles.

[0008] Based on the mass fraction, the initial internal energy of the low-resistivity matrix material and the high-resistivity particles are weighted and summed to obtain the initial internal energy of the mixture.

[0009] Based on the laws of conservation of mass, momentum, and energy, and combined with the equilibrium condition that the low-resistivity matrix material and the high-resistivity particles have equal pressure after impact, the post-impact state parameters of the mixture are obtained by solving.

[0010] Furthermore, this application also proposes that the solution to obtain the post-impact state parameters includes:

[0011] The impact pressure of the low-resistivity matrix material and the high-resistivity particles is characterized as the sum of their hot-pressing and cold-pressing components, respectively.

[0012] The internal energy of the low-resistivity matrix material and the high-resistivity particles after impact is characterized as the sum of their thermal and cold energy components, respectively.

[0013] Based on the Grüneisen equation of state, the proportional relationship between the thermo-pressure component and the thermal energy component of each component is established;

[0014] By using the aforementioned proportional relationship, the thermal pressure and thermal energy components in the pressure balance condition and energy conservation relationship are substituted to obtain the post-impact pressure.

[0015] Furthermore, this application proposes that the characteristic size range of the high-resistivity particles is from 1 micrometer to 100 micrometers, so that within the timescale of 100 nanoseconds of the single impact loading, the high-resistivity particles and the low-resistivity matrix material simultaneously achieve pressure and temperature equilibrium.

[0016] Furthermore, this application also proposes that, prior to the single impact loading, the method further includes:

[0017] Based on the initial acoustic impedance Zb of the low-impedance matrix material and the acoustic impedance Zp of the high-impedance particles, the impedance matching ratio Zp / Zb is calculated, wherein the impedance matching ratio is greater than 3.

[0018] The volume fraction of the high-resistivity particles in the mixture is determined based on the target compressibility density and the impedance matching ratio, wherein the volume fraction is greater than or equal to 10% and less than or equal to 60%.

[0019] Secondly, this application proposes a mixture target, comprising:

[0020] container;

[0021] A mixture contained within the container, the mixture comprising a low-resistivity matrix material and high-resistivity particles;

[0022] The mixture target is used to implement the method as described in any of the first aspects.

[0023] Furthermore, this application also proposes that the high-resistivity particles are uniformly distributed in the low-resistivity matrix material.

[0024] Furthermore, this application also proposes that the mixture target has a layered structure and further includes a flyer disposed on the impact loading side of the container and / or a window disposed on the back impact side of the container.

[0025] Furthermore, this application also proposes that the mixture is an alloy, a mixed liquid, a solid-liquid mixture, or a solid sample formed by pressing powder.

[0026] Furthermore, this application also proposes that the characteristic size range of the high-resistivity particles is from 1 micrometer to 100 micrometers.

[0027] As can be seen from the above, the method and mixture target for achieving high-density compression provided in this application utilize the impedance mismatch between high-resistivity particles and low-resistivity matrix materials to achieve a density higher than that of the low-resistivity material directly through a single impact process under conventional impact loading conditions. This avoids the shortcomings of traditional methods that require multiple loadings or complex waveform control, and has the advantages of significantly improved compression efficiency, simple operation, and strong experimental controllability.

[0028] Of course, any product implementing this application does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A structural diagram of the mixture target provided in the embodiments of this application;

[0031] Figure 2 A flowchart illustrating the steps of a method for achieving high-density compression provided in this application embodiment;

[0032] Figure 3 In the method for achieving high-density compression provided in the embodiments of this application, the isentropic lines and impact insulation lines of elemental hydrogen and water, as well as the impact insulation lines of their mixture of nickel and tantalum;

[0033] Figure 4 The flowchart of the MOP direct emissivity measurement operation in the method for achieving high-density compression provided in the embodiments of this application is shown. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0035] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0036] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0037] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0038] In existing technologies, dynamic high-pressure impact loading has long faced the challenge of limited compressibility density for low-resistivity materials. Traditional single-impact paths are confined to the material's main parabolic curve, making it difficult to exceed physical limits for the compressibility of low-resistivity materials even under high impact pressure. Pre-compression methods rely on static high-pressure devices to increase initial density, but the miniature sample chambers make experimental observation difficult. While ramp loading technology can achieve quasi-isentropic compression, it demands extremely high precision in controlling the driving source waveform, drastically increasing the complexity of experimental design and analysis. These technological bottlenecks severely restrict research progress in key areas such as planetary interior simulation and fusion fuel compression.

[0039] To address these issues, researchers have noted the interaction characteristics of materials with impedance differences under shock wave action. When a shock wave propagates at an impedance mismatch interface, reflection and transmission phenomena occur, causing the pressure wave to oscillate repeatedly between the materials. This dynamic process may trigger multi-stage compression effects, but existing research has not systematically explored its potential to increase the final density of materials. Through in-depth analysis of the propagation law of shock waves in composite media, it has been found that by rationally designing the impedance matching relationship and microstructure of materials, the low-impedance matrix can accumulate compression effects during multiple pressure oscillations, thereby breaking through the density limit of a single shock.

[0040] In some embodiments, Figure 1 The structural diagram of the mixture target provided in the embodiments of this application includes a flyer, a substrate and a mixture sample arranged sequentially along the impact direction.

[0041] In some embodiments, based on Figure 1 Regarding the mixed target in this application, this application proposes a method for loading the mixed target using shock waves, such as... Figure 2 As shown, Figure 2 This application provides a flowchart of a method for achieving high-density compression, applied to a mixture target. The mixture target includes a container and a mixture contained within the container. The mixture comprises a low-resistivity matrix material and high-resistivity particles. The method includes at least the following steps:

[0042] Step 201: Load the mixture target with a shock wave; wherein, during a single impact loading process, the impedance mismatch between the high-resistivity particles and the low-resistivity matrix material is utilized to compress the low-resistivity matrix material to a density higher than its primary argon state during a single impact.

[0043] Low-impedance matrix materials refer to materials with significantly lower acoustic impedance than high-impedance particles. These can be achieved using substances such as hydrogen, liquid water, or polymers. However, these materials are difficult to compress under conventional impact loading. High-impedance particles are solid particles with an acoustic impedance at least three times that of the matrix material. These can be achieved using metals such as tungsten, copper, or alumina, as well as ceramic materials. Their impedance difference is a key factor in generating pressure oscillations. Shock wave loading refers to high-pressure pulses generated through high-speed collisions, laser-driven processes, or explosions. This can be achieved using gas cannon loading devices or high-energy lasers. This loading method can generate sufficiently strong pressure waves to excite interactions between materials.

[0044] Understandably, when a shock wave propagates to the interface between the matrix material and the high-impedance particles, the difference in acoustic impedance generates reflected and transmitted waves. The reflected wave forms a reverse pressure gradient within the matrix material, while the transmitted wave propagates rapidly within the particles. Because the particle size is much smaller than the propagation distance corresponding to the shock wave's duration, the pressure wave quickly reaches equilibrium within the particles and is reflected back to the matrix material. This repeated energy exchange process causes the matrix material to undergo multiple pressure loadings, with each reflection generating a new compression phase. Ultimately, when the pressure gradient between the particles and the matrix is ​​eliminated, the system reaches an equilibrium state, at which point the accumulated compressibility density of the matrix material has exceeded the maximum compressibility density corresponding to a single impact.

[0045] As can be seen from the above, the method and mixture target for achieving high-density compression provided in this application utilize the impedance mismatch between high-resistivity particles and low-resistivity matrix materials to achieve a density higher than that of the low-resistivity material in a single impact loading process under conventional impact loading conditions. This avoids the shortcomings of traditional methods that require multiple loadings or complex waveform control, and has the advantages of significantly improved compression efficiency, simple operation, and strong experimental controllability.

[0046] It is understood that, in the specific embodiments of this application, the method for achieving high-density compression can achieve high-density compression through a single impact loading. Specifically, during the single impact loading process, the significant impedance mismatch (impedance matching ratio greater than 3) between the high-impedance particles and the low-impedance matrix material causes the shock wave to be reflected multiple times at the interface between the particles and the matrix material. This multiple reflection effect is not a simple superposition, but rather, through dynamic energy accumulation, the low-impedance matrix material undergoes multi-stage compression: each reflection generates a new pressure gradient, gradually increasing the material density until the pressure between the particles and the matrix material reaches equilibrium. The reason why the method can directly achieve a density higher than the main Gonne state in a single impact is that the coupling effect of impedance mismatch and interface reflection breaks through the path limitation of traditional single impacts, avoiding energy dissipation, and instead efficiently converting the shock wave energy into compression work. In addition, based on the laws of conservation of mass, momentum, and energy, and combined with the Grünesen equation of state to characterize the proportional relationship between the thermo-pressure component and the thermal energy component, it is ensured that the compression process achieves pressure and temperature equilibrium simultaneously within a hundred nanosecond timescale, thereby ensuring the stability and repeatability of the compression effect.

[0047] The aforementioned "deviation" refers to a density higher than that predicted by its main rain line.

[0048] It is worth noting that this application relates to the field of high-density compression technology. Existing technologies for achieving high-density compression mainly include two types: static high pressure and dynamic high pressure. Static high pressure technology uses slow static compression to achieve an isothermal process, but its pressure limit is limited by the strength of the anvil material and sealing technology, making it difficult to exceed 200 GPa. Dynamic high pressure technology generates adiabatic compression through transient impact, achieving pressures in the TPa range, but accompanied by significant temperature rise and limited by the energy of the driving source, material response characteristics, and waveform control accuracy. Existing improvement methods such as pre-compression and ramp loading can increase compression density, but they suffer from problems such as limited sample cavity size, difficulty in diagnosis, or stringent waveform design requirements. Therefore, a novel compression scheme that can balance high compression density, controllable temperature rise, and ease of implementation is urgently needed.

[0049] Therefore, based on the unique thermodynamic and kinetic properties of mixture impact, this application proposes an innovative scheme to achieve high-density compression through a multi-component material system. For example... Figure 1 As shown, when a shock wave acts on a mixture, due to the impedance difference of each component, the shock wave will be reflected multiple times in the low-impedance material until the system reaches pressure equilibrium, so that the low-impedance material is compressed to a density state higher than that of the elemental material.

[0050] Compared to existing technologies, traditional single-impact methods can only achieve single-stage compression along the main shock wave path. This proposed method, however, utilizes material impedance matching design to naturally generate multi-stage compression effects under conventional impact loading conditions. Compared to ramp-wave loading techniques that require complex pre-compression devices or precise waveform control, this method directly utilizes the propagation characteristics of shock waves in heterogeneous materials, achieving density enhancement without additional equipment modifications. This design approach, based on the intrinsic properties of the material, significantly reduces the difficulty of experimental implementation and equipment costs.

[0051] Through the above technical solution, this application effectively solves the core problem of limited compressibility density of low-impedance materials under conventional impact loading. Utilizing the multiple pressure oscillations caused by impedance mismatch, the matrix material undergoes multi-stage cumulative compression, breaking through the physical limit of a single impact. This method, while maintaining the simplicity of traditional impact experiments, achieves a high-density compression state exceeding the main rain gonnell line, providing a new technical approach for research such as planetary interior material simulation and fusion fuel compression.

[0052] This application further proposes a step that includes determining the post-impact state, including obtaining the mass fraction, initial specific volume, and initial internal energy of the low-resistivity matrix material and the high-resistivity particles; weighted summing of the initial specific volumes of the low-resistivity matrix material and the high-resistivity particles based on the mass fraction to obtain the initial specific volume of the mixture; weighted summing of the initial internal energies of the low-resistivity matrix material and the high-resistivity particles based on the mass fraction to obtain the initial internal energy of the mixture; and solving for the post-impact state parameters of the mixture based on the laws of conservation of mass, momentum, and energy, and in conjunction with the equilibrium condition that the low-resistivity matrix material and the high-resistivity particles have equal pressure after impact.

[0053] In this context, mass fraction refers to the mass ratio of low-resistivity matrix material to high-resistivity particles in the mixture. This can be achieved by weighing each component and calculating its proportion of the total mass, characterizing the contribution weight of different components to the overall physical properties of the mixture. Initial specific volume refers to the volume occupied by a unit mass of material, which can be determined experimentally or by assigning standard values ​​from a material property database. This quantifies the compressibility of the mixture before impact loading. Initial internal energy refers to the energy stored within the material in its initial state, obtained through thermodynamic parameter measurements or calculations based on a material constitutive model. This describes the energy distribution of the mixture before impact. Weighted summation involves linearly superimposing the physical parameters of each component according to their mass fractions. This can be achieved through mathematical operations and is used to construct the equivalent initial state parameters of the mixture. Conservation laws and pressure equilibrium conditions refer to the conservation relationships of mass, momentum, and energy during impact, as well as the constraint of equal pressure in both phases. These can be determined by establishing a system of equations and solving them numerically to determine the final state parameters of the mixture after impact.

[0054] Understandably, after impact loading, the mass fractions of the low-resistivity matrix material and high-resistivity particles are first obtained experimentally or by calculation. For example, the mass fraction could be 30% low-resistivity material and 70% high-resistivity particles. Then, the initial specific volumes of both are multiplied by their respective mass fractions and summed to obtain the equivalent initial specific volume of the mixture. Similarly, the initial internal energy is weighted and summed according to the mass fraction to obtain the equivalent initial internal energy of the mixture. Based on the laws of conservation of mass, momentum, and energy, a system of equations is established that includes the overall motion and energy changes of the mixture. Simultaneously, the constraint condition of equal pressure after the two-phase impact is introduced. By solving the system of equations simultaneously, the key parameters of the mixture after impact, such as pressure, density, and temperature, are finally obtained.

[0055] Compared to existing technologies, traditional methods typically ignore the compositional differences of multiphase materials when determining the post-impact state, relying solely on a single-material model for approximate calculations, resulting in insufficient prediction accuracy. In contrast, this proposed method, by introducing a mass fraction weighted summation and pressure equilibrium conditions, can accurately characterize the initial state of multiphase mixtures and establish rigorous mathematical relationships based on conservation laws, significantly improving the accuracy of post-impact state parameter calculations.

[0056] Through the above technical solution, this application realizes a quantitative description of the state of multiphase mixtures after impact, solves the problem of state prediction deviation caused by neglecting component differences in traditional methods, provides a reliable theoretical basis for experimental design, and avoids complex multiphysics coupling calculations, thus simplifying the analysis process.

[0057] This application further proposes that, when solving for the post-impact state parameters, the post-impact pressure of the low-resistivity matrix material and the high-resistivity particles are characterized as the sum of the hot-pressure component and the cold-pressure component, respectively, and the post-impact internal energy is characterized as the sum of the thermal energy component and the cold energy component, respectively. Based on the Grüneisen equation of state, a proportional relationship between the hot-pressure component and the thermal energy component of each component is established. Using the proportional relationship, the hot-pressure component and the thermal energy component in the pressure balance condition and the energy conservation relationship are substituted to obtain the post-impact pressure.

[0058] The thermocompression component refers to the pressure contribution generated by the thermal motion of the material, which can be realized using the temperature-dependent terms in the Grüneisen equation of state. It characterizes the pressure increment formed by the conversion of thermal energy during impact. The cold compression component refers to the pressure contribution generated by interatomic interactions in the material at zero temperature. It can be realized using the derivative of the cold energy function corresponding to volume compression, and is used to characterize the basic pressure value formed during adiabatic compression. The Grüneisen equation of state describes the relationship between the thermodynamic properties of the material and volume changes. It can be implemented using a volume-temperature-dependent parameterized form to establish a linear proportional relationship between the thermocompression component and the thermal energy component.

[0059] Understandably, after shock wave loading, the pressure equilibrium condition for the low-resistivity matrix material and the high-resistivity particles requires that their total pressures be equal. By decomposing the total pressure into hot-pressure and cold-pressure components, and the total internal energy into thermal and cold energy components, the thermodynamic and mechanical compressive responses of the material during the impact process can be handled separately. Based on the Grüneisen equation of state, the hot-pressure and thermal energy components are proportionally related through Grüneisen parameters, thus transforming the thermodynamic variables in the energy conservation equation into expressions containing only the cold-pressure and cold energy components. By simultaneously solving the mass, momentum, and energy conservation equations, and combining them with the pressure equilibrium condition, the hot-pressure and thermal energy components can be eliminated, and the post-impact pressure value can be directly obtained.

[0060] Compared to existing technologies, traditional methods typically use a single equation of state to describe the overall behavior of the mixture when solving for the post-impact state, failing to distinguish the independent contributions of hot and cold pressure components. This leads to repeated iterative solutions to nonlinear equations during the calculation process, resulting in low computational efficiency and susceptibility to errors. In contrast, this scheme decomposes the pressure and internal energy components and uses the Grüneisen equation of state to establish the proportional relationship between hot pressure and thermal energy, simplifying the complex multivariate coupled problem into a system of linear algebraic equations, significantly reducing computational complexity.

[0061] Through the above technical solution, this application can more accurately solve the pressure and internal energy distribution of the mixture after impact loading, avoiding the calculation deviation caused by the failure to distinguish between the thermodynamic and mechanical responses of the material in the traditional method. This provides a reliable theoretical basis for the subsequent optimization of the volume fraction and size parameters of high-resistivity particles, thereby supporting the realization of density compression of low-resistivity matrix materials above the main rain-Gonne state.

[0062] This application further proposes that the characteristic size range of the high-resistivity particles is from 1 micrometer to 100 micrometers, so that the high-resistivity particles and the low-resistivity matrix material can simultaneously achieve pressure and temperature equilibrium within the 100 nanosecond timescale of shock wave loading.

[0063] The characteristic size range of high-impedance particles refers to the average particle size distribution range in the mixture, which can be achieved by controlling particle size through mechanical grinding, chemical synthesis, or graded screening processes. This range is selected based on the matching relationship between shock wave propagation time and thermal diffusion time, ensuring that during loading on the order of hundreds of nanoseconds, the stress wave is reflected multiple times within the particles, transferring energy, while heat is fully diffused through the particle interface. Pressure and temperature equilibrium refer to the homogenization process of the stress and temperature fields among the components in the mixture under the action of the shock wave. This can be achieved by adjusting the acoustic impedance difference between the particle size and the matrix material. This equilibrium condition shortens the energy exchange time between the particles and the matrix, avoiding material failure caused by localized stress concentration or temperature gradients.

[0064] Understandably, during shock wave loading, the size of the high-resistivity particles is controlled on the micrometer scale, for example, between 1 micrometer and 100 micrometers. This size range ensures that the propagation time of the stress wave inside the particle is on the same order of magnitude as the thermal diffusion time of the matrix material, for example, on the order of hundreds of nanoseconds. When the shock wave is reflected at the particle-matrix interface, the particle size is small enough to ensure that the stress wave undergoes multiple reflections within the loading time, while the particle size is large enough to avoid the delaying effect of interfacial thermal resistance on temperature equilibrium. Thus, the rate of mechanical and thermal energy exchange between the particles and the matrix is ​​simultaneously increased, thereby satisfying the global equilibrium conditions of pressure and temperature within a finite loading time.

[0065] Specifically, based on the timescale differences between pressure equilibrium and temperature equilibrium, this application can divide the mixture impact process into three typical scales: long-scale (force equilibrium and heat exchange are completed after the impact), medium-scale (force equilibrium is completed during the impact, and heat transfer is completed after the impact), and short-scale (force and heat equilibrium are completed simultaneously during the impact). The critical size boundary is jointly determined by the characteristic timescale S×(particle diameter / sound speed) and the heat diffusion timescale. Experiments show that this boundary is on the order of 100 micrometers to 1 micrometer.

[0066] The sizes and boundaries of the three post-impact equilibrium parameters are on the order of 100 micrometers and 1 micrometer. Particle size only affects the time difference in pressure and density equilibrium after impact; here, particles smaller than 1 micrometer are used, and the smaller the size, the faster the equilibrium. High-resistivity particles typically do not exceed 74% of the volume due to the principle of dense distribution. Generally, to ensure a mixed state, a stable state of 30% to 60% is easily achievable.

[0067] Understandably, mixture models assume that the internal energy and density of a mixture are related to a weighted sum of the properties of its individual components. The mixture model used in this application is a molecular-level mixture based on molar amounts. The mixing formula based on mass fraction is:

[0068]

[0069] Where V is the specific volume of the mixture, E is the internal energy of the mixture, Xa is the mass fraction of component a, Va and Vb are the specific volumes of components a and b respectively, and Ea and Eb are the internal energies of components a and b respectively. This is a mixture of two components, and the internal energy and specific volume of the mixture can be expressed by the internal energy and specific volume of the components.

[0070] For the state where temperature and pressure are directly in equilibrium after the impact, three major conservation equations can be obtained:

[0071]

[0072] Where A and B are components, 1 and 0 are the impact state and initial state, respectively, ρ is the density (00AB represents the initial state of the mixture, and 14B represents the state after impact), Cs is the shock wave velocity, u1 is the particle velocity, P1 and P0 are the pressure after impact and the initial pressure, respectively, x is the mass fraction of component A (equivalent to Xa), and V00AB and V14B are the specific volumes of the mixture at the initial and after impact, respectively. Based on the pressure balance of the mixture, and considering that energy and pressure can both be divided into thermal and volumetric compressibility components (cold components):

[0073]

[0074] ETA and ETB are the thermal energy components of components A and B, respectively; EEA and EEB are the cold energy (volume compressibility energy) components of components A and B, respectively; PTA and PTB are the hot pressure components of components A and B, respectively; and PEA and PEB are the cold pressure components of components A and B, respectively. According to the Grüneisen formula, thermal energy and hot pressure can be expressed by the following equations:

[0075]

[0076] Where γ0A and γ0B are the Grünesen parameters of components A and B, respectively, and V0A and V0B are the initial specific volumes of components A and B, respectively; substituting the hot and cold components, we can obtain:

[0077]

[0078] Where λA and λB are the compressibility ratios of components A and B, respectively, φ is the volume parameter of the mixture, and σ and η are intermediate calculation parameters. Based on the above calculation formula, this application can calculate the impact insulation line of liquid hydrogen and water, as well as the impact insulation line of their mixture of nickel and tantalum. Figure 3 As shown, Figure 3 In the method for achieving high-density compression provided in the embodiments of this application, the isentropic lines and impact adiabatic lines of hydrogen and water, as well as the impact adiabatic lines of their mixture of nickel and tantalum, show that under the same pressure, the compressibility density of the mixture is significantly greater than that of the elements, and its density of state is not greater than that of the isentropic compressibility density.

[0079] Compared to existing technologies, traditional methods do not explicitly link particle size selection to the loading timescale and equilibrium conditions. For example, when the particle size is too large, the stress wave propagation time exceeds the loading duration, preventing pressure equilibrium from being achieved; when the particle size is too small, the interfacial thermal resistance effect is significant, and temperature equilibrium lags behind pressure equilibrium. This solution, by limiting the particle size range, constrains both the stress wave propagation time and the heat diffusion time to the order of hundreds of nanoseconds, thus solving the problem that a single equilibrium condition is difficult to satisfy in existing technologies.

[0080] Through the above technical solution, this application can achieve a dual equilibrium state of the mixture target within the time window of a conventional impact loading experiment, avoiding non-uniform material compression caused by pressure or temperature imbalance. This solution improves the stability of the low-resistivity matrix material during impact compression by matching particle size with loading time, providing controllable physical conditions for high-density compression.

[0081] This application further proposes to calculate the impedance matching ratio Zp / Zb based on the initial acoustic impedance Zb of the low-impedance matrix material and the acoustic impedance Zp of the high-impedance particles before impact loading, wherein the impedance matching ratio is greater than 3; and to determine the volume fraction of the high-impedance particles in the mixture based on the target compressibility density and the impedance matching ratio, wherein the volume fraction is greater than or equal to 10% and less than or equal to 60%.

[0082] Impedance matching ratio refers to the ratio of acoustic impedance of high-impedance particles to that of the low-impedance matrix material. It can be calculated by multiplying sound velocity and density, and is used to quantify the difference in dynamic response between the two materials under shock wave action. A higher impedance matching ratio can enhance the reflection effect of the shock wave at the interface, thereby promoting the compression of the low-impedance matrix material. Volume fraction refers to the volume proportion of high-impedance particles in the mixture, which can be achieved by adjusting the particle addition amount, and is used to balance the overall compression efficiency of the mixture and the stability of the material. Too low a volume fraction will lead to insufficient impedance mismatch effect, while too high a volume fraction may cause material structural damage; therefore, it needs to be optimized by combining the target compression density and impedance matching ratio.

[0083] Understandably, before impact loading, the acoustic impedance values ​​of the low-impedance matrix material and the high-impedance particles are first obtained through measurement or known data, and their ratio is calculated and ensured to exceed 3. This condition ensures that the shock wave generates significant multiple reflections at the particle-matrix interface, thereby accumulating higher compressive energy during pressure equilibrium. Subsequently, based on the target compressibility density requirement and the impedance matching ratio, the volume fraction range of the high-impedance particles is determined through theoretical models or experimental calibration. For example, when the target compressibility density is high, a volume fraction close to 60% can be selected to enhance the impedance mismatch effect; when material stability needs to be considered, a lower volume fraction is selected. Thus, through the synergistic control of the impedance matching ratio and volume fraction, efficient compression of the low-impedance matrix material can be achieved under conventional impact loading conditions.

[0084] Compared to existing technologies, which do not explicitly establish the relationship between impedance matching ratio and volume fraction, compression efficiency is limited. For example, traditional methods adjust the compression process using only a single parameter, failing to simultaneously meet the requirements of impedance mismatch effect and material stability. This proposed solution, however, introduces dual constraints of impedance matching ratio threshold and volume fraction range, forming an optimized parameter combination. This allows the low-impedance matrix material to achieve more sufficient energy accumulation during shock wave reflection, thereby overcoming the density limitation of the primary rain-gunny state.

[0085] Through the above technical solution, this application can achieve high-density compression of low-impedance matrix materials by optimizing the impedance matching ratio and volume fraction without relying on complex driving sources or precise waveform control. This solution solves the problem of limited compression ratio in traditional impact loading, while avoiding the shortcomings of excessively small sample cavity size in pre-compression methods or excessively difficult waveform control in ramp loading techniques, providing an efficient and stable operating path for conventional impact experiments.

[0086] refer to Figure 4 , Figure 4 In the method for achieving high-density compression provided in the embodiments of this application, the MOP directly measures the emissivity operation flowchart, in some embodiments, the method includes: first, confirming the composition and volume ratio of the mixture sample; then, assembling the mixture target structure according to the determined composition and volume ratio, and accurately measuring the mass and thickness parameters of the mixture to confirm its volume; next, conducting impact loading experiments and optical measurements on the assembled mixture target using an experimental device; calculating its impact adiabatic line relationship based on the experimentally measured mixture state parameters; and finally, processing and analyzing the experimentally measured data, and comparing and verifying the results with theoretically calculated data.

[0087] This application further proposes a mixture target, including a container and a mixture contained within the container, the mixture comprising a low-resistivity matrix material and high-resistivity particles, the mixture target being used to achieve high-density compression by shock wave loading.

[0088] The container refers to a closed or semi-closed structure used to hold the mixture, which can be made of metal, ceramic, or composite materials. Its function is to provide physical constraint for the mixture and transmit shock waves. The low-impedance matrix material refers to a material with an acoustic impedance lower than that of the high-impedance particles, which can be hydrogen, water, or polymer materials. Its function is to achieve multiple compressions under the action of shock waves through the impedance mismatch effect. The high-impedance particles refer to discrete phase materials with an acoustic impedance significantly higher than that of the matrix material. They can be metal, metal oxide, or silicon carbide particles. Their function is to improve compression efficiency by inducing shock wave reflection through the impedance difference with the matrix material. The mixture can be an alloy, a mixed liquid, a solid-liquid mixture, or a solid sample formed by powder compression. Different combinations of forms can be selected according to the application scenario. Its function is to optimize the compression path through the synergistic response of multiphase materials. The characteristic size range of the high-impedance particles is 1 micrometer to 100 micrometers. They can be prepared by mechanical grinding or chemical synthesis. Their function is to achieve pressure and temperature equilibrium within a hundred nanosecond timescale of shock wave loading.

[0089] Understandably, during shock wave loading, the high-resistivity particles and the low-resistivity matrix material in the mixed target undergo multiple reflections due to impedance differences, causing the shock wave to repeatedly bounce back at the particle-matrix interface until pressure equilibrium is reached. This process induces multi-stage compression of the matrix material, breaking through the main resistance line limitation of a single impact. The container structure can be designed in a layered form, with flyers on the impact loading side to precisely control the shock wave input, and windows on the back impact side for optical or X-ray diagnostics. Uniform particle distribution in the mixture is achieved through mechanical stirring or ultrasonic dispersion, ensuring that the impedance mismatch effect occurs uniformly as the shock wave propagates within the material. Particle size is controlled within a specific range, allowing sufficient time for pressure transfer and energy exchange between the particles and the matrix within the impact duration, which is on the order of hundreds of nanoseconds.

[0090] Compared to existing technologies, traditional high-density compression schemes rely on complex pre-compression devices or precise oblique wave loading techniques. This scheme, however, achieves equivalent results under conventional impact loading conditions by optimizing the structure and material combination of the hybrid target. Existing single-material targets cannot generate impedance mismatch effects, resulting in limited compression paths. This scheme introduces high-impedance particles, naturally forming a multi-stage compression mechanism during shock wave propagation. Existing composite material targets do not control particle size and distribution uniformity, making pressure balance difficult to achieve. This scheme ensures efficient conversion of shock wave energy into compression work by limiting particle characteristic size and dispersion patterns.

[0091] Through the above technical solution, this application enables efficient compression of low-impedance materials in conventional impact loading experiments without relying on precise waveform control or micro-sample preparation techniques. The structural design of the mixed target simplifies experimental setup, while the impedance matching relationship between the particles and the matrix allows the material to automatically deviate from its dominant state under the action of the shock wave, achieving a higher compression density. The layered structure, combined with the diagnostic window, provides real-time observation conditions for the experimental process, facilitating in-depth analysis of the dynamic response characteristics of multiphase materials.

[0092] This application further proposes the uniform distribution of high-impedance particles in a low-impedance matrix material.

[0093] Uniform distribution refers to the dispersion of high-resistivity particles in a low-resistivity matrix material in a non-aggregated and non-directional manner. This can be achieved through mechanical stirring, ultrasonic dispersion, or ball milling in powder metallurgy processes, ensuring that the particles exhibit a statistically significant uniform dispersion in the three-dimensional space of the matrix material. This distribution method allows shock waves to produce uniform reflection from the particle surface during propagation, avoiding delays or fluctuations in the pressure equilibrium process caused by local particle density differences.

[0094] Understandably, during shock wave loading, a dense network of impedance interfaces forms between uniformly distributed high-impedance particles and the low-impedance matrix material. As the shock wave passes through each particle sequentially, the impedance difference between the particle and the matrix triggers multiple reflections, resulting in a superimposed compression effect. Due to the uniform particle distribution, the reflected waves create a uniform pressure field within the matrix material, allowing the material as a whole to simultaneously withstand compression at the microscale, preventing localized obstruction of pressure transmission paths or uneven energy dissipation caused by particle aggregation. Therefore, the low-impedance matrix material can achieve more efficient energy absorption and density enhancement during shock wave loading.

[0095] Compared to existing technologies, traditional methods often result in localized agglomeration or gradient distribution of high-resistivity particles due to limitations in the mixing process, leading to discontinuous shock wave reflection paths and pressure oscillations or energy losses during compression. This solution, through a uniform distribution design, optimizes the interaction mode between particles and the matrix, enabling shock wave energy to be continuously converted into compression work through a dense and uniform reflection interface, thereby improving pressure balance efficiency.

[0096] Through the above technical solution, this application can ensure that a stable pressure field distribution is formed when the shock wave propagates in the mixed target, avoiding local stress concentration or compression delay caused by uneven particle distribution, so that the low impedance matrix material can achieve a higher and more uniform density increase in a single impact loading process.

[0097] This application further proposes that the mixture target has a layered structure, and also includes a flyer plate disposed on the impact loading side of the container and a window disposed on the back impact side of the container.

[0098] The "flying plate" refers to the shock wave transmission medium installed on the impact loading side of the container. It can be implemented using a thin metal sheet or a polymer film. Its function is to generate a uniform shock wave through controlled deformation and transmit it to the mixture target. The "window" refers to the transparent observation structure set on the impact side of the container. It can be implemented using sapphire, quartz, or diamond materials. Its function is to allow laser interferometers or high-speed photography equipment to observe the impact compression process in real time.

[0099] Understandably, the layered mixture target receives the initial shock wave generated by the external loading device via a flyer plate. This shock wave, shaped by the flyer plate, forms a waveform with a specific pressure gradient and is transmitted to the mixture layer. The window on the impact-side maintains the container's airtightness while allowing optical diagnostic equipment to penetrate the observation interface and capture dynamic parameters such as particle velocity and density changes generated as the shock wave propagates within the mixture. This structure, through the synergistic effect of the flyer plate and the window, achieves a dual improvement in the controllability of the impact loading process and the measurability of experimental data.

[0100] Through the above technical solution, this application effectively solves the technical contradiction that traditional impact loading devices cannot simultaneously achieve waveform control and process monitoring, and provides a reliable experimental platform for accurate analysis of the dynamic compression process under impedance mismatch effect.

[0101] This application further proposes mixtures that are alloys, mixed liquids, solid-liquid mixtures, or solid samples formed by pressing powder.

[0102] Among these, alloys refer to homogeneous materials formed by the molten mixing of two or more metallic elements, such as aluminum-copper alloys and iron-nickel alloys, which are intermetallic compounds. Their crystal structure maintains uniform impedance mismatch characteristics under shock wave loading. Mixed liquids refer to uniformly dispersed systems of two or more liquid substances, such as a mixture of silicone oil and metallic mercury. The fluidity of the liquid matrix and particles helps achieve dynamic pressure balance during shock wave propagation. Solid-liquid mixtures refer to composite systems where solid particles are dispersed in a liquid matrix, such as silicon carbide particles suspended in liquid hydrogen. The liquid matrix enhances energy absorption efficiency through particle interface reflection during impact compression. Powder-pressed solid samples refer to dense masses formed by cold or hot pressing of metallic or non-metallic powders, such as a mixture of copper powder and polyethylene powder. The porous structure between powder particles promotes multipath wave reflection during shock wave loading.

[0103] Understandably, when alloys are used as mixtures, the atomic-level bonding between metallic elements allows high-resistivity particles to form a continuous phase with the low-resistivity matrix. Multiple reflections of the shock wave at grain boundaries accelerate the pressure equilibrium process. The liquid matrix in the mixture buffers stress concentration between particles through viscous flow, preventing material fracture caused by localized pressure imbalances. During impact loading, the solid particles act as rigid support units, limiting the volume expansion of the liquid matrix, while the liquid medium reduces the shock wave propagation speed through viscous dissipation. Powder-pressed samples optimize the shock wave reflection path by adjusting particle size and pressing density to control the internal porosity of the mixture.

[0104] In some specific embodiments, the alloy can be a tungsten-copper composite material, in which copper serves as a low-resistivity matrix and tungsten serves as a high-resistivity particle; the mixed liquid can be a combination of liquid argon and alumina microspheres; the solid-liquid mixture can be a system in which nanodiamond particles are dispersed in liquid methane; the powder-pressed sample can be formed by uniformly mixing aluminum powder and polytetrafluoroethylene powder through ball milling and then cold pressing.

[0105] Compared to existing technologies, traditional impact loading experiments often use materials in a single form, such as pure metal blocks or pure liquid samples. Their impedance matching methods are limited and the pressure balance path cannot be flexibly adjusted. This approach, however, utilizes a mixture of multiple physical states, allowing for the selection of an appropriate mixture form based on material properties under the same impact loading conditions. For example, a liquid matrix can be used in scenarios requiring rapid temperature equilibrium, while a powder-pressed solid can be used in scenarios requiring enhanced structural stability.

[0106] Through the above technical solution, this application solves the problem of limited compression efficiency caused by the single material form in traditional impact loading. It achieves active control of the shock wave reflection path by selecting a multi-state mixture, and provides scalable sample preparation methods for different experimental conditions. For example, it uses mixed liquids to avoid matrix solidification in extreme low temperature environments, or uses alloy materials in scenarios requiring high mechanical strength.

[0107] This application further proposes that the characteristic size range of high-resistivity particles is from 1 micrometer to 100 micrometers.

[0108] The characteristic size range refers to the diameter or equivalent diameter of the particles, which can be measured and screened using laser particle size analysis or sieving methods. This size range ensures pressure equilibrium between the particles and the matrix material within a hundred nanosecond timescale of shock wave loading. Pressure equilibrium refers to the equalization of pressure between the two phases through multiple reflections of the shock wave at the particle-matrix interface. This size range, by controlling the propagation time of the shock wave within the particles, prevents the pressure equilibrium time from exceeding the loading time window due to excessively large particles, or prevents interface effects caused by excessively small particles from interfering with the compression process.

[0109] Understandably, during shock wave loading, the size of the high-resistivity particles is controlled between 1 and 100 micrometers. When the shock wave propagates in the mixture, the impedance difference between the particles and the matrix material triggers wave reflection, and the particle size directly affects the number of reflections and the pressure equilibrium speed. If the particle size is too small, for example, less than 1 micrometer, the interface area increases sharply, leading to a significant heat conduction effect and potentially causing local temperature gradients. If the particle size exceeds 100 micrometers, the time required for the shock wave to propagate within the particles is prolonged, making it impossible to achieve pressure equilibrium within the loading time on the order of hundreds of nanoseconds. By limiting this size range, it is possible to ensure pressure equilibrium efficiency while avoiding energy dissipation or uneven compression caused by extreme particle sizes.

[0110] Compared to existing technologies, traditional methods do not correlate the size selection of high-resistivity particles with the impact loading timescale. For example, when using nanoscale particles, the interface effect dominates the compression process, causing the thermodynamic state to deviate from expectations; while when using millimeter-scale particles, the pressure equilibrium time far exceeds the loading duration, making effective compression impossible. This solution dynamically matches the particle size with the shock wave propagation time, solving the problems of low compression efficiency or poor experimental repeatability caused by improper size selection in existing technologies.

[0111] Through the above technical solution, this application can ensure that high-resistivity particles and low-resistivity matrix materials reach pressure balance within a limited loading time under conventional impact loading conditions, thereby stably achieving high-density compression of low-resistivity materials, while avoiding additional energy loss or experimental complexity caused by improper particle size.

[0112] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for achieving high-density compression, characterized in that, The method is applied to a mixture target, the mixture target comprising a container and a mixture contained within the container, the mixture comprising a low-resistivity matrix material and high-resistivity particles; the method includes: The mixture target is subjected to a single impact loading using a shock wave; In the single impact loading process, the impedance mismatch between the high-resistivity particles and the low-resistivity matrix material is utilized to compress the low-resistivity matrix material to a density higher than its primary state during the single impact.

2. The method according to claim 1, characterized in that, The method further includes the step of determining the post-impact state, including: The mass fraction, initial specific volume, and initial internal energy of the low-resistivity matrix material and the high-resistivity particles are obtained. Based on the mass fraction, the initial specific volume of the mixture is obtained by weighted summation of the initial specific volumes of the low-resistivity matrix material and the high-resistivity particles. Based on the mass fraction, the initial internal energy of the low-resistivity matrix material and the high-resistivity particles are weighted and summed to obtain the initial internal energy of the mixture. Based on the laws of conservation of mass, momentum, and energy, and combined with the equilibrium condition that the low-resistivity matrix material and the high-resistivity particles have equal pressure after impact, the post-impact state parameters of the mixture are obtained by solving.

3. The method according to claim 2, characterized in that, The post-impact state parameters obtained by solving include: The impact pressure of the low-resistivity matrix material and the high-resistivity particles is characterized as the sum of their hot-pressing and cold-pressing components, respectively. The internal energy of the low-resistivity matrix material and the high-resistivity particles after impact is characterized as the sum of their thermal and cold energy components, respectively. Based on the Grüneisen equation of state, the proportional relationship between the thermo-pressure component and the thermal energy component of each component is established; By using the aforementioned proportional relationship, the thermal pressure and thermal energy components in the pressure balance condition and energy conservation relationship are substituted to obtain the post-impact pressure.

4. The method according to claim 1, characterized in that, The high-resistivity particles have a characteristic size range of 1 micrometer to 100 micrometers, which allows the high-resistivity particles and the low-resistivity matrix material to simultaneously achieve pressure and temperature equilibrium within the 100 nanosecond timescale of the single impact loading.

5. The method according to claim 1, characterized in that, Prior to the single impact loading, the method further includes: Based on the initial acoustic impedance Zb of the low-impedance matrix material and the acoustic impedance Zp of the high-impedance particles, the impedance matching ratio Zp / Zb is calculated, wherein the impedance matching ratio is greater than 3. The volume fraction of the high-resistivity particles in the mixture is determined based on the target compressibility density and the impedance matching ratio, wherein the volume fraction is greater than or equal to 10% and less than or equal to 60%.

6. A mixture target, characterized in that, include: container; A mixture contained within the container, the mixture comprising a low-resistivity matrix material and high-resistivity particles; The mixture target is used to implement the method as described in any one of claims 1 to 5.

7. The mixture target according to claim 6, characterized in that, The high-resistivity particles are uniformly distributed in the low-resistivity matrix material.

8. The mixture target according to claim 6, characterized in that, The mixture target has a layered structure and also includes a flyer plate disposed on the impact loading side of the container and / or a window disposed on the back impact side of the container.

9. The mixture target according to claim 6, characterized in that, The mixture is an alloy, a mixed liquid, a solid-liquid mixture, or a solid sample formed by pressing powder.

10. The mixture target according to claim 6, characterized in that, The characteristic size range of the high-resistivity particles is 1 micrometer to 100 micrometers.

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