Explosive crystal impact response observation device based on laser driving and application

Abstract

The invention discloses an explosive crystal impact response observation device based on laser driving and application thereof, the device comprises a transparent vacuum cavity, an impact unit is arranged in the transparent vacuum cavity, the impact unit comprises a light-transmitting upper carrier and a light-transmitting lower carrier, and the upper carrier and the lower carrier are horizontally overlapped; the lower surface of the upper carrier is coated with a metal film, and the upper surface of the lower carrier is provided with a plurality of explosive particle accommodating holes which are distributed in an array; a pulse laser transmitter is arranged above the transparent vacuum cavity, and a transmitting port of the pulse laser transmitter faces the impact unit; and an optical microscope for observing the impact unit is arranged below the transparent vacuum cavity. The method comprises the steps that explosive particles are loaded into the explosive particle containing holes through the micromechanical control technology; moving the impact unit into a transparent vacuum cavity to finish vacuumizing; an explosive particle containing hole of the impact unit is moved to the position below a transmitting opening of the pulse laser transmitter; and performing laser focusing and impact test on the explosive particles under an optical microscope, and observing and recording the impact response process of the explosive particles by using a high-speed camera and a radiation spectrum.

Description

Technical Field

[0001] The present invention belongs to the technical field of energetic material testing, and particularly relates to an observation device for the impact response of explosive crystals based on laser driving and an application thereof. Background Art

[0002] Impact is the most common form of external stimulation for explosives. During the preparation, production, and transportation of explosives, it is very likely to encounter various forms of impact, and accidental accidents caused by impact are common. Therefore, the impact sensitivity of energetic materials is the focus of safety research. However, in the existing impact sensitivity experiments, the following problems still exist: (1) The test results of explosive sensitivity are affected by various factors, including the packing structure and particle size distribution of explosive particles. These factors make it difficult to accurately quantitatively evaluate the influence characteristics of impact energy on the particles themselves. Taking CL-20 as an example, under external impact, large particle CL-20 is more likely to undergo plastic deformation or even fragmentation, and this process will absorb a large amount of energy. However, when the CL-20 particles are refined to the micron or nanometer scale, the internal defects of the particles are significantly reduced, resulting in a large increase in the energy required for plastic deformation and fragmentation. In addition, the surface of ultrafine particles is smoother, the friction coefficient is reduced, which is not conducive to the formation and continuation of hot spots. Therefore, the impact sensitivity of ultrafine CL-20 will be significantly reduced. At the same time, TKX-50 with different crystal morphologies also shows significant differences in impact sensitivity. For example, the characteristic drop height of short rod-shaped TKX-50 is about 6 times that of the raw material. The combined effect of these particle characteristics (such as morphology, particle size, surface state, etc.) will have a complex impact on the sensitivity test results, thus obscuring the in-depth understanding of the response of single explosive particle characteristics to impact energy. (2) In the current impact sensitivity test methods, there is a lack of effective experimental means to conduct impact experiments on single explosive particles and observe experimental phenomena with high time resolution and spatial resolution; it is difficult to accurately observe and record the entire process phenomena of deformation, crack initiation and propagation, and ignition of explosive particles during impact, thus limiting the in-depth study of the impact ignition mechanism of explosive particles. (3) Traditional drop hammer impact tests mainly rely on artificial observation of apparent phenomena such as explosion sounds, light emission, smoke, sample color change, odor, or ablation marks to judge whether an explosion has occurred, and calculate the impact sensitivity of the tested material accordingly. However, this method is difficult to directly observe the microscopic change characteristics on the surface of explosive particles, nor can it accurately evaluate the severity of these change processes; there are problems such as large human errors, low test accuracy, and insufficient credibility of explosion probability results.

[0003] Therefore, in order to more deeply study the ignition mechanism of explosive particles during impact, it is urgent to design an observation device for the impact response of single explosive particles, so as to observe and record the response process of single explosive particles under the stimulation of impact energy, and provide data for the research on the impact ignition mechanism of explosive particles. Summary of the Invention

[0004] The object of the present invention is to provide an observation device and application for the impact response of explosive crystals based on laser driving, so as to solve the problem that it is difficult to accurately and quantitatively evaluate the influence characteristics of impact energy on individual explosive particles during the existing impact sensitivity experiments of explosive crystals.

[0005] In order to achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] An observation device for the impact response of explosive crystals based on laser driving, comprising a transparent vacuum chamber, an impact unit is arranged in the transparent vacuum chamber, the impact unit includes a light-transmitting upper carrier and a lower carrier, and the upper carrier and the lower carrier are arranged horizontally and overlappingly; a metal film is coated on the lower surface of the upper carrier, and a plurality of explosive particle accommodation holes arranged in an array are arranged on the upper surface of the lower carrier;

[0007] A pulsed laser emitter is arranged above the transparent vacuum chamber, and the emission port of the pulsed laser emitter faces the impact unit;

[0008] An optical microscope for observing the impact unit is arranged below the transparent vacuum chamber;

[0009] A high-speed camera for image acquisition and a radiation spectrometer for temperature measurement are also arranged outside the transparent vacuum chamber, and both the high-speed camera and the radiation spectrometer are optically connected to the optical microscope.

[0010] The present invention also has the following technical features:

[0011] Specifically, the diameter of the explosive particle accommodation hole is 1 to 1.5 times the diameter of the explosive particle, so that each explosive particle accommodation hole can accommodate one explosive particle.

[0012] Furthermore, the diameter of the explosive particle accommodation hole is 20 μm to 1000 μm, the depth is 50 μm to 1000 μm, and the distance between adjacent explosive particle accommodation holes is 100 μm to 1000 μm.

[0013] Furthermore, both the upper carrier and the lower carrier are glass slides, the glass slides are rectangular, the length of the glass slide is 5 to 10 cm, the width is 1 to 3 cm, and the thickness is 1.0 to 1.5 mm. The arrayed explosive particle accommodation holes are arranged at the center position of the lower glass slide.

[0014] Furthermore, the transparent vacuum chamber is placed on a transparent three-dimensional displacement table; a vacuum suction port is opened on the top plate of the transparent vacuum chamber.

[0015] Furthermore, the pulse width of the pulsed laser emitter is 2 to 3 ns, the wavelength is 1064 nm, and the laser energy is 0.5 to 2 J.

[0016] Further, the metal film is selected from one of an aluminum film, a gold film and a copper film, and the thickness of the metal film is 10-30 μm.

[0017] The present invention also protects the application of the above-mentioned observation device for the impact response of explosive crystals based on laser driving in the study of the impact response law of single explosive particles.

[0018] Preferably, the application specifically includes the following steps:

[0019] Step 1: Load the explosive particles into the explosive particle accommodating holes of the downloading body, and place one explosive particle in one explosive particle accommodating hole;

[0020] Step 2: Cover the upper carrier on the downloading body to form an impact unit; move the impact unit into a transparent vacuum chamber and complete vacuum pumping;

[0021] Step 3: Use a three-dimensional displacement stage to move the explosive particle accommodating hole of the impact unit to below the emission port of the pulsed laser emitter;

[0022] Step 4: Conduct a laser focusing and impact test on the explosive particles under an optical microscope, and use the optical microscope integrated with a high-speed camera and a radiation spectrometer to observe and record the impact response process of the explosive particles.

[0023] Preferably, the laser focusing and impact test on the explosive particles under the optical microscope in Step 4 specifically includes the following sub-steps:

[0024] Step 4.1: Adjust the focal length of the optical microscope to make the image of the explosive particles clear:

[0025] Step 4.2: Set the parameters of the pulsed laser emitter, start the pulsed laser emitter, so that the pulsed light beam generated by the pulsed laser emitter ablates the metal film on the upper carrier, and drives the remaining metal film fragments after ablation to fly towards the explosive particles to achieve the impact on the explosive particles.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] (1) Compared with the traditional drop hammer impact sensitivity experimental device, the device of the present invention can accurately control the number of impact particles, eliminate the interference of factors such as particle accumulation and particle size distribution, so as to achieve the accurate acquisition of the impact energy response law based on single explosive particles, and realize the observation of experimental phenomena with high time resolution and spatial resolution based on the optical microscope integrated with a high-speed camera and radiation spectrum.

[0028] (2) By observing the impact response process of a single explosive particle, the effective acquisition of the impact energy response law based on the single characteristic of the explosive particle itself is realized. This method effectively simplifies the test results of explosive sensitivity controlled by multiple factors (such as the packing structure and particle size distribution of explosive particles), thus significantly improving the evaluation accuracy of the impact energy influence characteristics.

[0029] (3) The method of the present invention realizes the observation and recording of the whole process phenomena such as deformation, crack initiation and propagation, and ignition of explosive particles during the impact process, effectively solving the problems of large artificial errors, low test accuracy, and insufficient credibility of explosion probability results in the existing impact sensitivity test devices, and providing reliable technical support for the in-depth study of the impact ignition mechanism of explosive particles. Brief Description of the Drawings

[0030] The drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification, and are used to explain the present disclosure together with the following specific embodiments, but do not constitute a limitation to the present disclosure. In the drawings:

[0031] Figure 1 is the overall structural schematic diagram of the device of the present invention;

[0032] Figure 2 is the single-hole structural schematic diagram of the device of the present invention;

[0033] Figure 3 is the graph of temperature varying with time obtained in Example 2;

[0034] Figure 4 is the graph of radiant luminance varying with time obtained in Example 2;

[0035] Figure 5 is the graph of emissivity varying with time obtained in Example 2.

[0036] The reference numerals in the drawings indicate:

[0037] 1 - transparent vacuum chamber, 2 - impact unit, 3 - pulsed laser emitter, 4 - optical microscope, 5 - three-dimensional displacement stage; 11 - vacuum suction port; 21 - upper carrier, 22 - lower carrier, 23 - metal film, 24 - explosive particle accommodation hole. Detailed Description of the Invention

[0038] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described below in conjunction with the drawings.

[0039] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and any equivalent transformation based on the technical solution of the present application falls within the protection scope of the present invention.

[0040] The terms "upper", "lower", "front", "rear", "top", "bottom", etc. used in the present invention to indicate the orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "Inner" and "outer" refer to the inside and outside of the contour of the corresponding component, and the above terms should not be construed as limiting the present invention.

[0041] Unless otherwise specified, the components used in the present invention are commercially available.

[0042] The "explosive grains" in the present invention refer to the energetic material grains to be subjected to ignition tests.

[0043] The statement that "the diameter of the explosive grain accommodation hole in the present invention is at least 1 to 1.5 times the diameter of the explosive grain" is to ensure that the diameter of the explosive grain accommodation hole is greater than or equal to the maximum diameter of the explosive grain, so as to ensure that a single explosive grain can be accommodated in the explosive grain accommodation hole.

[0044] The technical concept of the method of the present invention lies in: using a plurality of explosive grain accommodation holes distributed in an array to control the number of explosive grains, and carrying out the observation and research on the impact response process of a single grain explosive crystal driven by laser; using a laser beam to drive an impact unit in a vacuum environment, specifically including: using the pulsed light beam generated by a pulsed laser emitter to ablate the metal film on the lower surface of the upper carrier, the laser energy vaporizes and ionizes the metal film to form a high-temperature and high-pressure plasma, the plasma generated by ablation expands rapidly to form a high-pressure detonation wave, the expansion pressure of the plasma is transmitted to the remaining unablated metal film, pushing it to break away from the upper carrier at a high speed and form a flying plate, and the flying plate flies towards the explosive grain arranged in the explosive grain accommodation hole under the drive of the plasma after experiencing an acceleration stage, and its speed can reach several kilometers per second, realizing the impact on the explosive grain.

[0045] Example 1

[0046] Complying with the above technical solution, as shown in the attached Figure 1 This embodiment provides an observation device for the impact response of an explosive crystal based on laser drive, including a transparent vacuum chamber 1. An impact unit 2 is arranged in the transparent vacuum chamber 1. The impact unit 2 includes a light-transmitting upper carrier 21 and a lower carrier 22, and the upper carrier 21 and the lower carrier 22 are horizontally overlapped; a metal film 23 is coated on the lower surface of the upper carrier 21, and a plurality of explosive grain accommodation holes 24 distributed in an array are arranged on the upper surface of the lower carrier 22;

[0047] A pulsed laser emitter 3 is arranged above the transparent vacuum chamber 1, and the emission port of the pulsed laser emitter 3 faces the impact unit 2;

[0048] An optical microscope 4 for observing the impact unit 2 is arranged below the transparent vacuum chamber 1;

[0049] Outside the transparent vacuum chamber 1, there are also a high-speed camera for image acquisition and a radiation spectrometer for temperature measurement. Both the high-speed camera and the radiation spectrometer are optically connected to the optical microscope.

[0050] As a preferred solution of this embodiment, the diameter of the explosive particle accommodation hole 24 is 1 to 1.5 times the diameter of the explosive particle, so that each explosive particle accommodation hole 24 can accommodate one explosive particle. The explosive particles in this embodiment are CL-20 crystal particles.

[0051] As a preferred solution of this embodiment, the diameter of the explosive particle accommodation hole 24 is 200 μm, the depth is 300 μm, and the distance between adjacent explosive particle accommodation holes 24 is 500 μm.

[0052] As a preferred solution of this embodiment, both the upper carrier 21 and the lower carrier 22 are glass slides. The glass slides are rectangular, with a length of 7 cm, a width of 2 cm, and a thickness of 1.0 mm;

[0053] The explosive particle accommodation holes 24 arranged in an array are set at the central position of the lower glass slide 22.

[0054] As a preferred solution of this embodiment, the transparent vacuum chamber 1 is placed on a transparent three-dimensional displacement stage 5; a vacuum suction port 11 is opened on the top plate of the transparent vacuum chamber 1.

[0055] As a preferred solution of this embodiment, the pulse width of the pulsed laser emitter 3 is 2 ns, the wavelength is 1064 nm, and the laser energy is 1 J.

[0056] As a preferred solution of this embodiment, the metal film is an aluminum film, and the thickness of the metal film is 20 μm.

[0057] Embodiment 2

[0058] This embodiment discloses the application of the laser-driven explosive crystal impact response observation device of Embodiment 1 in the study of the impact response law of a single explosive particle, specifically including the following steps:

[0059] Step 1: Use the existing micro-mechanical manipulation technology to load the CL-20 crystal particles into the explosive particle accommodation holes of the lower carrier, and place one CL-20 crystal particle in each explosive particle accommodation hole;

[0060] Step 2: Cover the upper carrier on the lower carrier to form an impact unit; move the impact unit into the transparent vacuum chamber and complete the evacuation;

[0061] Step 3: Use the three-dimensional displacement stage to move the explosive particle accommodation hole of the impact unit containing the explosive particles to below the emission port of the pulsed laser emitter;

[0062] Step 4: Conduct a laser focusing and impact test on CL-20 crystal particles under an optical microscope, and use an optical microscope integrated with a high-speed camera and radiation spectrum to observe and record the impact response process of the explosive particles;

[0063] Step 4.1: Adjust the focal length of the optical microscope to make the image of the CL-20 crystal particles clear:

[0064] Step 4.2: Set the parameters of the pulsed laser emitter, start the pulsed laser emitter, and make the pulsed light beam generated by the pulsed laser emitter ablate the upper carrier metal film, and drive the remaining metal film layer after ablation to fly towards the explosive particles to achieve the impact on the CL-20 crystal particles.

[0065] After the impact test, obtain the temperature-time change diagram, radiation brightness-time change diagram, and emissivity-time change diagram during the impact process according to the collected data, and the results are as shown in Figure 3 、 Figure 4 and Figure 5 .

[0066] It can be observed from Figures 3 to 5 that: during the process of the flyer impacting the crystal particles, hot spots are formed inside the CL-20 crystal particles and flames are triggered. Through the analysis and calculation of the radiation flames, it is found that the temperature of the hot spots rapidly rises to a relatively high value (5924.9 K) in a short time, accompanied by a relatively low emissivity. Subsequently, the temperature gradually decreases to around 3000 K. Figure 4 The peak radiation brightness that appears around 30 ns in

[0067] may come from the radiation of the flyer itself. The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0068] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination methods.

[0069] Furthermore, any combination can be made between various different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. An observation device for the impact response of an explosive crystal based on laser driving, comprising a transparent vacuum chamber (1), characterized in that, A collision unit (2) is arranged inside the transparent vacuum chamber (1). The collision unit (2) includes a light-transmitting upper carrier (21) and a lower carrier (22), and the upper carrier (21) and the lower carrier (22) are arranged horizontally and overlappingly; a metal film (23) is coated on the lower surface of the upper carrier (21), and a plurality of explosive particle accommodation holes (24) distributed in an array are arranged on the upper surface of the lower carrier (22); A pulsed laser emitter (3) is arranged above the transparent vacuum chamber (1), and the emission port of the pulsed laser emitter (3) faces the collision unit (2); An optical microscope (4) for observing the collision unit (2) is arranged below the transparent vacuum chamber (1); A high-speed camera for image acquisition and a radiation spectrometer for temperature measurement are further arranged outside the transparent vacuum chamber (1), and both the high-speed camera and the radiation spectrometer are optically connected to the optical microscope.

2. The laser-driven explosive crystal impact response observation device according to claim 1, wherein The diameter of the explosive particle accommodation hole (24) is 1 to 1.5 times the diameter of the explosive particle, so that each explosive particle accommodation hole (24) can accommodate one explosive particle.

3. The observation device for the impact response of an explosive crystal based on laser driving according to claim 1, wherein The diameter of the explosive particle accommodation hole (24) is 20 μm to 1000 μm, the depth is 50 μm to 1000 μm, and the distance between adjacent explosive particle accommodation holes (24) is 100 μm to 2000 μm.

4. The laser-driven explosive crystal impact response observation device according to claim 1, characterized in that Both the upper carrier (21) and the lower carrier (22) are glass slides. The glass slides are rectangular, with a length of 5 to 10 cm, a width of 1 to 3 cm, and a thickness of 1.0 to 1.5 mm; The array-distributed explosive particle accommodation holes (24) are arranged at the central position of the lower glass slide (22).

5. The observation device for the impact response of an explosive crystal based on laser driving according to claim 1, characterized in that The transparent vacuum chamber (1) is placed on a transparent three-dimensional displacement stage (5); a vacuum suction port (11) is opened on the top plate of the transparent vacuum chamber (1).

6. The observation device for the impact response of an explosive crystal based on laser driving according to claim 1, characterized in that The pulse width of the pulsed laser emitter (3) is 2 to 3 ns, the wavelength is 1064 nm, and the laser energy is 0.5 to 2 J.

7. The laser-driven explosive crystal impact response observation device according to claim 1, wherein The metal film (23) is selected from one of an aluminum film, a gold film, and a copper film, and the thickness of the metal film is 10 to 30 μm.

8. Application of the laser-driven explosive crystal impact response observation device according to any one of claims 1 to 7 in the study of the impact response law of a single explosive particle.

9. The application according to claim 8, characterized in that, Specifically, it includes the following steps: Step 1: Load explosive particles into the explosive particle accommodation holes of the lower carrier through micro-mechanical manipulation technology, and place one explosive particle in one explosive particle accommodation hole; Step 2: Cover the upper carrier on the lower carrier to form a collision unit; move the collision unit into the transparent vacuum chamber and complete vacuum pumping; Step 3: Use the three-dimensional displacement stage to move the explosive particle accommodation hole of the collision unit containing explosive particles below the emission port of the pulsed laser emitter; Step 4: Conduct laser focusing and impact tests on the explosive particles under the optical microscope, and use the high-speed camera, the radiation spectrometer, and the optical microscope to observe and record the impact response process of the explosive particles.

10. The application according to claim 8, wherein, The laser focusing and impact test on the explosive particles under the optical microscope in Step 4 specifically includes the following sub-steps: Step 4.1: Adjust the focal length of the optical microscope to make the image of the explosive particle clear: Step 4.2: Set the parameters of the pulsed laser emitter, start the pulsed laser emitter, so that the pulsed laser beam generated by the pulsed laser emitter ablates the upper carrier metal film, and drive the remaining metal film layer after ablation towards the explosive particles to achieve impact on the explosive particles.

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