Method and device for modifying sensitized metal active material through lossless impact

Abstract

The invention discloses a method and a device for modifying a sensitized metal active material through lossless impact. According to the method, accumulated dislocation and other defects are formed in the high-entropy alloy metal active material through pre-impact, stress concentration is generated, high-pressure and high-temperature hot spots are generated at the stress concentration position in the application process of the material, the hot spots induce the material to have a chemical reaction, and therefore the reaction threshold value of the high-entropy alloy metal active material is reduced. By designing the controllable pre-impact loading device, residual strain and structural damage caused by the fact that sparse waves and reflected waves are transmitted into a sample are avoided, and almost-nondestructive pre-impact modification is achieved.

Description

Technical Field

[0001] This invention relates to the field of metal active materials technology, and specifically to a method and apparatus for non-destructive impact modification of sensitized metal active materials. Background Technology

[0002] Reactive materials, due to their unique kinetic energy penetration-chemical energy release coupled damage mode, have gradually become a research hotspot in the field of novel damage. Traditional fluoropolymer reactive materials have high energy density, low reaction threshold, and significant damage enhancement effects, but they suffer from drawbacks such as low density and strength, poor penetration ability, and difficulty in withstanding explosive detonation. Metallic reactive materials, on the other hand, have high density and strength, strong penetration ability, and strong resistance to detonation loading. During penetration, the active components can undergo deflagration reactions with oxygen to release energy, exhibiting excellent damage enhancement effects. In particular, high-entropy alloy metallic reactive materials, due to their unique design concept and wide-range performance regulation capabilities, have gradually attracted the attention of relevant researchers.

[0003] However, matching the strength and plasticity with the reaction energy release performance is a challenge faced in the application of high-entropy alloy metal active materials. Higher material strength and plasticity result in stronger penetration and detonation resistance, but also lead to a higher reaction threshold and weaker reaction energy release. Conversely, higher material brittleness lowers the reaction threshold and reduces detonation resistance. To meet the application requirements of fragmentation damage elements in existing kill warheads, high-entropy alloy metal active materials with good strength and plasticity are usually selected. Their reaction thresholds often exceed 1200 m / s, leading to reduced damage effectiveness, and in some cases, even failure to release energy during reaction. This significantly limits the application of high-entropy alloy metal active materials in the field of kill warhead damage elements and the generation of novel damage capabilities. Summary of the Invention

[0004] To address the challenges of matching the strength and plasticity of existing high-entropy alloy metal active materials with their reaction energy release properties and high reaction thresholds, this invention provides a method and apparatus for non-destructive impact modification of sensitized metal active materials. By pre-impacting, accumulated point defects and dislocation defects are formed within the high-entropy alloy metal active material. During the damage process, these defects accumulate more extensively, leading to stress concentration. The stress concentration sites experience high stress and temperature, generating localized hot spots within the material. This induces chemical reactions in the material at lower impact velocities, thereby reducing the material's reaction threshold.

[0005] The present invention discloses a method for non-destructive impact modification and sensitization of metallic active materials, wherein the metallic active material is placed in a loading device; a launching device is used to drive a flying plate to impact the loading device, thereby completing the pre-impact loading of the metallic active material and realizing non-destructive impact modification and sensitization of the metallic active material; the loading device is used to eliminate the residual deformation and structural damage to the metallic active material caused by the frontal impact and rarefaction waves and reflected waves during the impact process.

[0006] Preferably, the stress amplitude of the pre-impact loading is not less than 40 times the compressive strength of the metal active material and not more than 120 times the compressive strength of the metal active material.

[0007] The present invention also provides a device for non-destructive impact modification of sensitized metal active materials, including a loading device, an emitting device, and a flying plate; The launching device is used to drive the flying plate to impact the metal active material, thereby completing the pre-impact loading of the metal active material. The loading device is used to eliminate the residual deformation and structural damage to the metallic active material caused by the frontal impact and rarefaction waves and reflected waves during the impact process.

[0008] Preferably, the loading device includes a cover plate, an outer momentum trap ring, an inner momentum trap ring, and an anti-delamination back plate; The metallic active material is placed inside the inner momentum trap ring; the inner momentum trap ring is placed inside the outer momentum trap ring, and the upper and lower end faces are respectively covered with a cover plate and an anti-delamination back plate. The thickness of the cover plate is not less than 1 / 3 of the thickness of the metal active material; the inner diameter of the inner trap ring is equal to the diameter of the metal active material, and the outer diameter is not less than 3 times the diameter of the metal active material; the inner diameter of the outer momentum trap ring is equal to the outer diameter of the inner trap ring, and the thickness is 10~20mm; the thickness of the anti-delamination back plate is not less than 2 times the thickness of the metal active material.

[0009] Preferably, the cover plate, outer momentum trap ring, inner momentum trap ring, anti-split back plate, and high-entropy alloy metal active material are assembled by sliding fit.

[0010] Preferably, the loading device is made of the same material as the metal active material.

[0011] Preferably, the diameter of the flyer is 2 to 3 times the diameter of the metal active material, and the thickness of the flyer is 1 / 3 to 2 / 3 of the thickness of the metal active material.

[0012] Preferably, the flyer plate is made of the same material as the metal active material.

[0013] Preferably, the stress amplitude of the pre-impact loading is not less than 40 times the compressive strength of the metal active material and not more than 120 times the compressive strength of the metal active material.

[0014] Preferably, it also includes a recovery chamber; the loading device is placed inside the recovery chamber.

[0015] Beneficial effects: This invention utilizes pre-impact loading to accumulate dislocations and other defects within high-entropy alloy metal active materials, generating stress concentration. During application, this stress concentration creates high-pressure, high-temperature hotspots at the stress concentration sites, inducing chemical reactions and thus lowering the reaction threshold of the high-entropy alloy metal active material. Furthermore, this invention employs a controllable pre-impact loading device to avoid residual strain and structural damage caused by rarefaction waves and reflected waves entering the sample, achieving a virtually non-destructive pre-impact modification. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the device structure of the present invention.

[0017] Figure 2 is a schematic diagram illustrating the principle of reducing the reaction threshold of materials by pre-impact loading according to the present invention. (a) Pre-impact loading modification; (b) Mechanism for reducing the reaction threshold. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] This invention provides a device for non-destructive impact modification of sensitized metal active materials, such as... Figure 1 As shown, the device includes a loading device, a launching device, and a flyer plate. The high-entropy alloy metal active material sample is placed inside the loading device. The launching device drives the flyer plate to impact the loading device, so that the sample is only subjected to a brief positive shock wave under the protection of the loading device. This generates point defects, dislocations, and other defects inside the sample, creating a stress pre-concentration zone that does not change the properties of the metal active material. During the damage process, the metal active material is promoted to react globally under the stress pre-concentration zone, thus reducing the reaction threshold of the metal active material. The loading device includes a cover plate, an outer momentum trap ring, an inner momentum trap ring, and an anti-delamination backplate. A high-entropy alloy metal active material sample is placed inside the inner momentum trap ring, which is then placed inside the outer momentum trap ring. The upper and lower end faces are covered by the cover plate and the anti-delamination backplate, respectively. The cover plate, outer momentum trap ring, inner momentum trap ring, anti-delamination backplate, and high-entropy alloy metal active material sample are assembled via a sliding fit. A lubricant is used during the assembly of the inner and outer momentum trap rings to eliminate gas in the component gaps and promote the recovery of the high-entropy alloy metal active material sample after pre-impact loading.

[0020] The cover plate is used to protect the high-entropy alloy metal active material sample from direct impact load, thus preventing residual strain and structural damage. The cover plate material is the same as the high-entropy alloy metal active material subjected to pre-impact, and the cover plate thickness is not less than 1 / 3 of the sample thickness.

[0021] Inner and outer momentum trap rings are used to prevent lateral rarefaction waves from entering the specimen and causing residual strain and structural damage. The materials of the inner and outer momentum trap rings are consistent with the high-entropy alloy metal active material subjected to pre-impact. The inner diameter of the inner trap ring is equal to the specimen diameter, and the outer diameter is not less than three times the specimen diameter. The inner diameter of the outer momentum trap ring is equal to the outer diameter of the inner trap ring, and the difference between the outer and inner diameters is typically 10–20 mm.

[0022] The anti-split backing plate is used to prevent reflected waves from converging inside the specimen and generating tensile waves, which could cause residual strain and structural damage. The anti-split backing plate material is the same as the high-entropy alloy metal active material subjected to pre-impact, and the thickness of the anti-split backing plate is not less than twice the thickness of the specimen.

[0023] The loading device is placed in a recovery chamber with one open end, and a launching device is used to drive the flying piece to impact the cover plate. The launching device is a light air cannon, ballistic gun, or other similar device. The flying piece is flat and its material is the same as the high-entropy alloy metal active material that is being pre-impacted. The diameter of the flying piece is 2 to 3 times the diameter of the sample, and the thickness of the flying piece is 1 / 3 to 2 / 3 of the thickness of the sample.

[0024] The initial velocity of the flyer plate is positively correlated with the pre-impact loading amplitude. If the pre-impact loading amplitude is too low, there will be less dislocation accumulation and the effect of reducing the reaction threshold will not be significant. If the pre-impact loading amplitude is too high, there will be too much dislocation accumulation, which will cause a decrease in the structural strength of the material. Therefore, the stress amplitude of the pre-impact loading is usually not less than 40 times the compressive strength of the specimen and not more than 120 times the compressive strength of the specimen.

[0025] This invention utilizes pre-impact loading. When a shock wave sweeps across the sample, the compressive stress wave causes strong mechanical disturbance, leading to point defects, dislocations, and other defects within the sample. Trap rings and anti-split-crack backing plates prevent reflected waves and radial rarefaction waves from converging inside the sample and generating tensile waves that could cause macroscopic deformation or damage. The shock wave's action time is short; after the shock wave rapidly sweeps across the sample, the sample is quickly unloaded, leaving insufficient time for defects to recover, thus freezing them inside the sample and achieving the accumulation of internal defects. In this process, if the pre-impact loading amplitude is too low, insufficient defect accumulation inside the sample will result in an insignificant sensitization effect; if the pre-impact loading amplitude is too high, excessive defect accumulation will lead to reduced sample strength, increased brittleness, and even macroscopic damage during pre-loading. In practical applications, the specimens subjected to the pre-impact loading of this invention exhibit a more pronounced effect compared to conventional reactive material specimens. During the target collision, the accumulated defects from the pre-impact loading accumulate at locations such as grain boundaries as the specimen deforms, creating stress concentration zones. The strain and strain rate at these locations are significantly higher than in the surrounding areas, and the plastic work is almost entirely converted into internal energy, resulting in a significant increase in local temperature and the generation of local hot spots. At these local hot spots, the material is first induced to react, further promoting a global reaction in the specimen. This allows the material to undergo chemical reactions and release energy at lower impact velocities, thereby achieving the sensitization of reactive materials and reducing their reaction threshold.

[0026] Example 1, The high-entropy alloy metal active material is AlNbTiZrV, with a density of 5.8 g / cm³. 3 The compressive strength is approximately 1432 MPa. The high-entropy alloy metal active material sample is a cylinder with dimensions of Ф10mm×10mm.

[0027] The cover plate is made of the same high-entropy alloy metal active material that is subjected to pre-impact, and the cover plate is a cylinder with dimensions of Ф40mm×4mm.

[0028] The material of the inner momentum trap ring is the same as that of the high-entropy alloy metal active material subjected to pre-impact. The inner trap ring is a circular ring with an inner diameter of Ф10mm and an outer diameter of Ф37mm×10mm.

[0029] The material of the outer momentum trap ring is the same as that of the high-entropy alloy metal active material subjected to pre-impact. The outer trap ring is a circular ring with an inner diameter of Ф37mm and an outer diameter of Ф42mm×14mm.

[0030] The anti-plaque backing material is the same as the high-entropy alloy metal active material subjected to pre-impact, and the thickness of the anti-plaque backing is a cylinder with dimensions of Ф38mm×24mm.

[0031] The launching device uses a ballistic gun to drive a flyer plate to impact the cover plate. The flyer plate material is the same as the high-entropy alloy metal active material being pre-impacted. The flyer plate is a cylinder with dimensions of Ф22mm × 5mm. The velocities of the flyer plate colliding with the high-entropy alloy metal active material sample are 240.3m / s, 315.7m / s, and 463.1m / s, respectively. The relationship between the pre-impact loading amplitude of the sample and the initial velocity of the flyer plate can be calculated using the following formula: (1) In the formula, P This represents the pre-impact loading amplitude. ρ The density of the sample; v The initial velocity of the flying plate; C The velocity of sound in the sample; s This is a constant related to the properties of the sample material.

[0032] High-entropy alloy metal active material samples, both unloaded and preloaded with flyer plates at different velocities, were impinged into a 27L sealed pressure vessel at an impact velocity of 1000 m / s. The quasi-static overpressures recorded by the pressure sensor were 0.02 MPa, 0.03 MPa, 0.05 MPa, 0.07 MPa, and 0.10 MPa, respectively. The reaction energy release of the high-entropy alloy metal active material samples gradually increased at the same impact velocity, and the reaction threshold of the material significantly decreased.

[0033] Table 1 Effects of pre-impact loading on sensitized active materials

[0034] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for non-destructive impact modification of sensitized metal active materials, characterized in that, The metallic active material is placed inside the loading device; a launching device is used to drive the flying plate to impact the loading device, thereby completing the pre-impact loading of the metallic active material and realizing the non-destructive impact modification and sensitization of the metallic active material; the loading device is used to eliminate the residual deformation and structural damage to the metallic active material caused by the frontal impact and rarefaction waves and reflected waves during the impact process.

2. The method as described in claim 1, characterized in that, The stress amplitude of the pre-impact loading shall not be less than 40 times the compressive strength of the metal active material and not more than 120 times the compressive strength of the metal active material.

3. A device for non-destructive impact modification and sensitization of metal active materials, characterized in that, Includes loading device, launching device, and flying plate; The launching device is used to drive the flying plate to impact the metal active material, thereby completing the pre-impact loading of the metal active material. The loading device is used to eliminate the residual deformation and structural damage to the metallic active material caused by the frontal impact and rarefaction waves and reflected waves during the impact process.

4. The apparatus as described in claim 3, characterized in that, The loading device includes a cover plate, an outer momentum trap ring, an inner momentum trap ring, and an anti-delamination back plate; The metallic active material is placed inside the inner momentum trap ring; the inner momentum trap ring is placed inside the outer momentum trap ring, and the upper and lower end faces are respectively covered with a cover plate and an anti-delamination back plate. The thickness of the cover plate is not less than 1 / 3 of the thickness of the metal active material; the inner diameter of the inner trap ring is equal to the diameter of the metal active material, and the outer diameter is not less than 3 times the diameter of the metal active material; the inner diameter of the outer momentum trap ring is equal to the outer diameter of the inner trap ring, and the thickness is 10~20mm; the thickness of the anti-delamination back plate is not less than 2 times the thickness of the metal active material.

5. The apparatus as described in claim 4, characterized in that, The cover plate, outer momentum trap ring, inner momentum trap ring, anti-delamination back plate, and high-entropy alloy metal active material are assembled through sliding fit.

6. The apparatus as described in claim 3, 4, or 5, characterized in that, The loading device uses the same material as the metal active material.

7. The apparatus as claimed in claim 3, characterized in that, The diameter of the flyer is 2 to 3 times the diameter of the metal active material, and the thickness of the flyer is 1 / 3 to 2 / 3 of the thickness of the metal active material.

8. The apparatus as claimed in claim 3 or 7, characterized in that, The flying plate is made of the same material as the metal active material.

9. The apparatus as claimed in claim 3, characterized in that, The stress amplitude of the pre-impact loading shall not be less than 40 times the compressive strength of the metal active material and not more than 120 times the compressive strength of the metal active material.

10. The apparatus as claimed in claim 3, characterized in that, It also includes a recovery compartment; the loading device is placed inside the recovery compartment.

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