Explosive welding method for preparing radiation-proof metal composite material and metal composite material

Abstract

The application provides an explosive welding method for preparing a radiation-proof metal composite material and the metal composite material, and belongs to the technical field of metal composite materials, and comprises the following steps: carrying out heat preservation treatment and surface treatment on a first plate, a second plate and a third plate; carrying out laser treatment on the surfaces to be joined of the treated first plate and third plate; stacking the laser-treated first plate, third plate and second plate with gaps between adjacent plates, placing explosives on the upper surfaces of the stacked plates, and obtaining a metal composite plate blank through explosive welding, wherein the explosive welding process satisfies the condition that the strain is less than 10% and the strain rate is greater than or equal to 103 s-1; and then, the metal composite plate blank is straightened. Through the laser treatment on the surfaces to be joined of the composite plate and the subsequent explosive welding process, the prepared metal composite material has a room temperature tensile strength retention of more than 90% and an elongation retention of more than 90% after 50 cycles of high-low temperature cycle treatment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metal composite materials, and particularly relates to an explosive welding method for preparing a radiation-proof metal composite material and the metal composite material. BACKGROUND

[0002] With the increasing demand for lightweight multifunctional materials in the field of aerospace, laminated metal composite materials have attracted much attention due to their unique structural design advantages. Such materials can achieve a density of <3 g / cm³ while having high strength (tensile strength > 400 MPa) and multifunctionality by precisely regulating the microstructure and interface characteristics of different metal layers, and have important application value in spacecraft structural components. However, the existing technology has significant shortcomings: traditional laminated materials often have problems such as interface delamination and sudden drop in mechanical properties under extreme low temperature (-253℃) and high-low temperature alternating (-180℃~150℃) environments due to thermal expansion coefficient mismatch and interface brittle phase formation.

[0003] To overcome these limitations, adding a high-conductive and high-permeable layer to obtain a double-layer material is very significant for improving shielding performance. For example, the invention patent with application number CN201811253584.8 uses copper and permalloy 1J85 to obtain a composite strip material by solid-phase compounding, and the shielding effectiveness of the material is 80 dB at 40 GHz and 0.1 Oe. In addition, by forming more internal interfaces to change the propagation path of electromagnetic waves, the shielding performance can also be effectively improved. In particular, by using a vacuum hot pressing-thermal extrusion compounding process, the interface bonding state can be regulated at the nanoscale, and the formation of brittle phases (such as Mg 17 Al 12 ) can be effectively inhibited, which provides an important inspiration for the development of new multifunctional materials. However, the existing technology still faces challenges: first, the wide-temperature-range thermal stability of lightweight laminated materials (such as magnesium-based) is insufficient, making it difficult to meet the long-term service requirements in extreme environments; second, the process complexity increases dramatically due to the integration of multiple functions, resulting in high costs. Therefore, developing a laminated metal composite material preparation technology that integrates lightweight, high strength, electromagnetic shielding, and radiation resistance performance in one, with customizable functions, has become a key breakthrough direction in the field of aerospace materials. It is necessary to make a breakthrough in composition design (such as rare earth doping), structure optimization (gradient / pore), and preparation process, rather than simply stacking existing technologies.

[0004] Based on the above research, there is an urgent need in the field to develop an innovative laminated composite material, which should have three characteristics: (1) internal construction of a multi-level interface structure to achieve performance gradient distribution; (2) integration of high-conductive components to ensure electromagnetic shielding effectiveness (SE>60dB); (3) simultaneous optimization of radiation resistance (resistant to 1MeV gamma rays) and thermal stability (high-low temperature thermal cycle performance remains not less than 90%) through composition and process design. SUMMARY

[0005] To solve the above problems, the application provides an explosion welding method for preparing a radiation-proof metal composite material and the metal composite material.

[0006] To achieve the above object, the application adopts the following technical scheme:

[0007] The application provides an explosion welding method for preparing a radiation-proof metal composite material, which comprises: heat preservation treatment and surface treatment of a first plate, a second plate and a third plate; laser treatment of the surfaces to be joined of the treated first plate and third plate; stacking of the laser-treated first plate, third plate and second plate with gaps between adjacent plates; placing of explosives on the upper surface of the stacked plates; and explosion welding to obtain a metal composite plate blank, wherein the explosion welding process satisfies the conditions of strain less than 10% and strain rate greater than or equal to 10 3 s -1 ; and subsequent orthopedic treatment; the first plate is of HCP crystal form, the second plate is of FCC crystal form, and the third plate is of BCC crystal form; the metal composite material comprises at least one group of repeating units, and the repeating units are a first composite layer, a second composite layer and a third composite layer, which are respectively formed by explosion welding of the first plate, second plate and third plate.

[0008] Further, the ratio of the tensile strength of the materials of the first plate, second plate and third plate satisfies 1:(0.5-2.0):(1.0-2.0).

[0009] Further, the first plate is a magnesium alloy; the second plate is pure aluminum, an aluminum alloy, pure copper or a copper alloy; and the third plate is pure tantalum or a tantalum alloy.

[0010] Further, the first composite layer and the second composite layer and the second composite layer and the third composite layer each have a joining interface, the length of the joining interface is at least 1.5 times the length of the interface, the joining interface is in a sawtooth interlocking form, the length-width ratio of the sawtooth is 1-500 and the length is 0.1 μm-40.0 μm, the atomic interdiffusion width of the joining interface is 0.1 μm-10.0 μm, the edge of the sawtooth has meshing teeth with a height of 10 nm-100 nm, and there are at least three meshing teeth on a single sawtooth.

[0011] Further, the thickness of the first plate material is 1mm-10mm, the thickness of the second plate material is 0.01mm-0.20mm, and the thickness of the third plate material is 1.0mm-5.0mm.

[0012] Further, the first plate material is a magnesium alloy, the temperature of the heat preservation treatment is 150℃-300℃, and the heat preservation time is 1h-3h; the second plate material is pure aluminum or an aluminum alloy, the temperature of the heat preservation treatment is 200℃-300℃, and the heat preservation time is 1h-3h; the second plate material is pure copper or a copper alloy, and the third composite layer is pure tantalum or a tantalum alloy, the temperature of the heat preservation treatment of the second plate material and the third plate material is 300℃-500℃, and the heat preservation time is 2h-4h.

[0013] Further, the laser treatment is as follows: for the surface to be joined of the first plate material, the energy is 1J-5J, the frequency is 1Hz-3Hz, and the overlap rate is 30%-50%; for the surface to be joined of the third plate material, the energy is 4J-10J, the frequency is 1Hz-5Hz, and the overlap rate is 30%-50%; the spot size is 1mm-3mm, and the scanning speed is 10mm / s-15mm / s.

[0014] Further, the explosive welding process is as follows: the impact speed is 800m / s-1000m / s, the impact angle is 10°-15°, and the explosive filling thickness ratio is 1.1-1.4.

[0015] Further, the orthopedic treatment adopts an orthopedic tool heat treatment.

[0016] The embodiment of the present application also provides a radiation-proof metal composite material prepared by the above explosive welding method.

[0017] The beneficial effects brought by the technical scheme provided by the embodiment of the present application include: the present application ensures that no cracks appear between the composite layers in the metal composite material under the condition of high and low temperature cycle environment, such as 150-200 DEG C high temperature and-196 DEG C low temperature, and the high elongation and tensile strength retention rate, i.e. thermal cycle stability, to meet the use environment; secondly, a multi-level interface structure is constructed inside to realize performance gradient distribution, integrate high-conductive components to guarantee electromagnetic shielding effectiveness (SE>60 dB), and optimize radiation resistance (1MeV gamma ray resistance) through component and process design synchronization. In order to achieve the above technical effects, higher requirements are put forward for the preparation process of the metal composite material and the finally prepared product. The present application first performs laser treatment on the to-be-bonded surface, which can harden the to-be-bonded surface and form different hardening depths at different positions of the to-be-bonded surface, and secondly, laser hardening can form micro-pits of a certain size on the to-be-bonded surface, and the micro-pit depth of the to-be-bonded surface after laser treatment in the present application is about 0.1-0.3 mm; thirdly, the selection of the first plate, the second plate and the third plate is limited, if the first plate of HCP crystal form and the second plate of BCC crystal form are directly combined by explosion welding process, the physical and metallurgical combination between the two can be realized, but the corresponding problems will also be caused, because HCP crystal form and BCC crystal form cannot effectively form solid solution, so brittle phase is easily generated, therefore, the second plate FCC crystal form is added in the present application, which can form solid solution with HCP and BCC crystal form, on the basis of laser treatment, the explosion wave in the subsequent explosion welding process is combined to form a bonding interface with a specific size and shape and a corresponding interface atomic diffusion width, so as to achieve the technical effects proposed in the present application. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows, obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 The plate surface after laser treatment provided for the embodiment 1 of the present application;

[0020] Figure 2 The metal composite material interface SEM diagram provided for the embodiment 1 of the present application;

[0021] Figure 3 The metal composite material interface density diagram provided for the embodiment 1 of the present application. DETAILED DESCRIPTION

[0022] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0023] The present application provides an explosive welding method for preparing a radiation-proof metal composite material, comprising:

[0024] S1, performing heat preservation treatment and surface treatment on the first plate, the second plate and the third plate;

[0025] S2, performing laser treatment on the joint surfaces of the treated first plate and third plate;

[0026] S3, stacking the laser-treated first plate, third plate and second plate with gaps between adjacent plates, placing explosives on the upper surface of the placed plates, and obtaining a metal composite plate blank through explosive welding, wherein the explosive welding process satisfies the conditions of strain less than 10% and strain rate greater than or equal to 10 3 s -1 ;

[0027] S4, then performing straightening;

[0028] The first plate is in HCP crystal form, the second plate is in FCC crystal form, and the third plate is in BCC crystal form;

[0029] The metal composite material comprises at least one set of repeating units, and the repeating units are first composite layers, second composite layers and third composite layers, which are respectively formed by explosive welding of the first plate, the second plate and the third plate.

[0030] The beneficial effects brought by the technical scheme provided by the embodiment of the present application include: the present application is aimed at a high-low temperature cycle environment, such as the high temperature of 150-200 DEG C and the low temperature of -196 DEG C in the present application, and under the condition of cycle alternation, the cracks between the composite layers in the metal composite material are prevented, and the high elongation and tensile strength retention rate, i.e. thermal cycle stability, are ensured to meet the use environment; secondly, a multi-level interface structure is constructed inside to realize the performance gradient distribution, and a high-conductivity component is integrated to guarantee the electromagnetic shielding effectiveness (SE>60 dB), and the radiation resistance (1 MeV gamma ray resistance) is simultaneously optimized through component and process design. In order to achieve the above technical effects, higher requirements are put forward for the preparation process of the metal composite material and the finally prepared product. The present application first performs laser treatment on the to-be-bonded surface, the laser treatment can harden the to-be-bonded surface, and different hardening depths are formed at different positions of the to-be-bonded surface, secondly, the laser hardening can form micro-pits of a certain size on the to-be-bonded surface, and the micro-pit depth of the to-be-bonded surface after laser treatment in the present application is about 0.1-0.3 mm; thirdly, the selection of the first plate, the second plate and the third plate is limited, if the first plate of HCP crystal form and the second plate of BCC crystal form are directly combined by explosion welding process, the physical and metallurgical combination between the two can be realized, but the corresponding problems will also be caused, because the HCP crystal form and the BCC crystal form cannot effectively form solid solution, so brittle phase is easily generated, therefore, the second plate FCC crystal form is added in the present application, which can form solid solution with HCP and BCC crystal forms, on the basis of laser treatment, the explosion wave generated after subsequent explosion welding forms a bonding interface with a specific size and shape and a corresponding interface atomic diffusion width, so that the technical effects proposed in the present application are achieved.

[0031] Although there is a way of using explosion welding to composite materials in the prior art, including the composite of metal and metal and the composite of metal and non-metal, which can form a bonding interface with a certain waveform and has a certain bonding strength, but this process only realizes the successful combination of layered materials, but how to meet the thermal stability, electromagnetic shielding effectiveness and radiation resistance performance proposed in the present application needs to improve the existing process.

[0032] It can be understood that the repeating unit in the present application is the minimum unit required to form two bonding interfaces, such as the minimum repeating unit formed by the first plate | the second plate | the third plate in the present application, the three plates are bonded to form two bonding interfaces, and then the repeating can be performed, such as the first plate | the second plate | the third plate | the second plate | the first plate, which is two groups of repeating units, and the like, i.e. a plurality of first plates and third plates are arranged alternately, and the second plate is arranged between the first plate and the third plate, the number of the second plate represents the formation of a corresponding number of two connecting interfaces and a corresponding number of minimum repeating units.

[0033] The surface treatment is: firstly, surface mechanical treatment is performed on the plate to polish the surface of the metal material, so that the surface roughness of the plate is less than or equal to 3.5 um; then, organic solvent is used to clean the surface of the plate and dry it, and the organic solvent is preferably anhydrous ethanol.

[0034] Specifically, the ratio of the tensile strength of the materials of the first plate, the second plate and the third plate satisfies 1:(0.5-20): (1.0-2.0).

[0035] Specifically, the first plate is a magnesium alloy; the second plate is pure aluminum, an aluminum alloy, pure copper or a copper alloy; and the third plate is pure tantalum or a tantalum alloy. Specifically, the magnesium alloy is one or more of AZ31B, ZK60 and Mg-RE, the aluminum alloy is one or more of 1060 and 6061, and the copper alloy and the tantalum alloy are existing copper alloys and tantalum alloys.

[0036] Specifically, the first composite layer and the second composite layer and the second composite layer and the third composite layer each have a bonding interface, the interface line length of the bonding interface is at least 1.5 times the interface length, the bonding interface is in a zigzag interlocking form, the zigzag length-width ratio is 1-500 and the length is 0.1 um-40.0 um, the atomic interdiffusion width of the bonding interface is 0.1 um-10.0 um, the edge of the zigzag has meshing teeth with a height of 10 nm-100 nm, and there are at least 3 meshing teeth on a single zigzag. Preferably, there are no more than 10 meshing teeth per um on a single zigzag. Too many meshing teeth will reduce the strength of the zigzag, generate cracks in the subsequent high-low temperature cycle process, and reduce the cycle number. Secondly, the size of the meshing teeth is also very important. The size of the meshing teeth is related to the size of the micro-pits in the laser treatment process and the surface hardening. If the micro-pits are larger and the surface hardening depth is deeper, the height of the meshing teeth increases, and there is a problem of low bonding strength of the meshing teeth and the zigzag in the explosive welding process, and there is a possibility of tearing between the hardened and non-hardened parts, and the creep resistance is reduced. If the size of the micro-pits is too small and the surface hardening depth is shallow, the number of meshing teeth on a single zigzag increases, but the strength of the meshing teeth is low, which weakens the high-low temperature cycle performance. Finally, under the above size limitation, the requirements for radiation resistance can be met. Although a large number of meshing teeth on a single zigzag can increase the radiation resistance, it will affect the high-low temperature cycle performance of the prepared material.

[0037] In the embodiment of the present application, the "interface line length of the bonding interface" refers to the length of the curve formed by the interface after explosive compounding; and the "interface length" refers to the measured interface length when the to-be-bonded surface is a plane before explosive compounding.

[0038] The thickness of the first plate is 1mm-10mm, the thickness of the second plate is 0.01mm-0.20mm, and the thickness of the third plate is 1.0mm-5.0mm.

[0039] Specifically, the first plate is a magnesium alloy, the temperature of the heat preservation treatment is 150℃-300℃, and the heat preservation time is 1h-3h; the second plate is pure aluminum or an aluminum alloy, the temperature of the heat preservation treatment is 200℃-300℃, and the heat preservation time is 1h-3h; the second plate is pure copper or a copper alloy, and the third composite layer is pure tantalum or a tantalum alloy, the temperature of the heat preservation treatment of the second plate and the third plate is 300℃-500℃, and the heat preservation time is 2h-4h.

[0040] Specifically, the laser treatment is: for the to-be-bonded surface of the first plate, the energy is 1J-5J, the frequency is 1Hz-3Hz, and the overlap rate is 30%-50%; for the to-be-bonded surface of the third plate, the energy is 4J-10J, the frequency is 1Hz-5Hz, and the overlap rate is 30%-50%; the spot size is 1mm-3mm, and the scanning speed is 10mm / s-15mm / s. Through this process, the to-be-bonded surface can be hardened and micro-pits of a certain size can be generated. The micro-pit depth of the to-be-bonded surface is about 0.1mm-0.3mm, and the hardening depth is 0.1mm-0.5mm. The present application only performs laser treatment on the to-be-bonded surface of the first plate and the second plate, and does not perform laser treatment on the surface of the second plate. The above micro-pit depth and hardening depth are average sizes. The micro-pit depth is detected by a surface roughness instrument, and the hardening depth can be detected by a hardness instrument to obtain the average value of the hardening depth of at least 10 positions.

[0041] Specifically, the explosive welding process is: the impact speed is 800m / s-1000m / s, the impact angle is 10°-15°, and the explosive filling thickness ratio is 1.1-1.4. The explosive can be emulsion explosive, and by adding inert fillers, the impact speed can be between 800m / s-1000m / s. The explosive filling thickness is 1.1-1.4 times the total thickness of the plate.

[0042] Preferably, gaps are provided between the various plates in the present application, if the size of the plates is small, support columns are placed between the plates, if the size of the plates is large, tool clamps are provided on the edges of the plates to pull the plates flat, and each plate is arranged according to a predetermined order and a predetermined distance; in the embodiment of the present application, the gap between the first plate and the second plate is 5-10mm, and the gap between the second plate and the third plate is not more than 1mm, when there are multiple repeating units, the gap between the first plate and the second plate is also 5-10mm, and the gap between the second plate and the third plate is not more than 1mm. Preferably, the second plate and the third plate are laid flat and stacked together.

[0043] Specifically, during preparation, the ground surface of the explosive welding site is leveled, the third plate is placed on the leveled foundation, the corresponding plates are arranged according to the predetermined position by using support columns, then a protective plate is arranged on the uppermost layer, the size of the protective plate is larger than that of the first plate, the second plate and the third plate, then explosives are laid on the protective plate according to the predetermined thickness, and a detonator is inserted into the middle position of the edge of the explosives.

[0044] The orthopedic device is subjected to orthopedic tool heat treatment, the process of the orthopedic tool is to keep the temperature at 180-240℃ for 1.5-2.5h, the orthopedic tool is two parallel rigid planes, the prepared metal composite material is placed between the two parallel rigid planes, and the predetermined temperature and predetermined time are maintained. The pressure applied by the orthopedic tool does not exceed the yield strength of any layer of the metal composite material.

[0045] The embodiment of the present application also provides a radiation-proof metal composite material prepared by the above method.

[0046] In order to better illustrate the embodiments of the present application, the present application will be further described in detail through specific examples.

[0047] Embodiment 1

[0048] The embodiment of the present application provides an explosive welding method for preparing a radiation-proof metal composite material and a metal composite material, which comprises the following steps:

[0049] S1, the first plate, the second plate and the third plate are subjected to heat preservation treatment and surface treatment.

[0050] In this embodiment of the present invention, the first plate is AZ31B magnesium alloy, the second plate is 1060 aluminum foil, and the third plate is pure Ta. The dimensions of the first plate are 100 mm × 100 mm × 2 mm, the second plate is 100 mm × 100 mm × 0.01 mm, and the third plate is 100 mm × 100 mm × 1 mm. The plates are subjected to thermal insulation treatment: the first plate is kept at 200°C for 2 hours, the second plate is kept at 200°C for 2 hours, and the third plate is kept at 400°C for 3 hours. The surface treatment is then performed.

[0051] S2. Performing laser processing on the surfaces to be joined of the processed first plate and the third plate.

[0052] For the surface of the first plate to be joined, the laser treatment process is: 3J, frequency 2Hz, overlap rate 40%, spot size 2mm, scanning speed 10mm / s. For the surface of the third plate to be joined, the laser treatment process is: 7J, frequency 3Hz, overlap rate 40%, spot size 2mm, scanning speed 10mm / s. The surface of the plate after treatment is as follows Figure 1 As shown, Figure 1 a in the figure is the surface of the third plate after laser treatment. Figure 1 b is the surface of the first plate after treatment. The average depth of the micro-pits on the surface to be joined of the first plate is 0.2 mm, and the hardening depth is 0.2 mm. The depth of the micro-pits on the surface to be joined of the third plate is approximately 0.25 mm, and the hardening depth is 0.3 mm.

[0053] S3, stacking the laser-treated first plate, the third plate, and the second plate with gaps between adjacent plates, placing explosives on the upper surfaces of the placed plates, and obtaining a metal composite plate blank by explosive welding, wherein the explosive welding process satisfies the requirements of strain less than 10% and strain rate ≥10 3 s -1 .

[0054] The explosive welding process is as follows: by adjusting the explosive ratio, the impact speed is 900m / s, the impact angle is 15 degrees, and the explosive filling thickness ratio is 1.1.

[0055] S4, then correct the deformity;

[0056] The correction was performed using a hot tool and kept at a temperature of 200°C for 2h.

[0057] The cross section of the prepared metal composite material was observed. Figure 2 As shown, Figure 2 a is the overall SEM image of the metal composite material. Figure 2 b is the SEM image of Ta / Al interface. Figure 2c in FIG. 1 is an SEM image of the Al / AZ31B interface, wherein the c is an SEM image of the Al / AZ31B interface, Figure 2 d in FIG. 1 is an SEM image of the serration tooth, wherein the d is an SEM image of the serration tooth, and it can be seen that the serration tooth of the metal composite material prepared in the embodiment has a serration length-width ratio of 1-500 and a length of 0.1-40.0 μm, and the edge of the serration tooth has a meshing tooth with a height of 50 nm. The atomic interdiffusion width of the bonding interface is 5 μm.

[0058] Figure 3 a in FIG. 1 is a Ta / Al interface density map, Figure 3 b in FIG. 1 is an Al / AZ31B interface density map, and it can be seen that the metal composite material prepared in the application has a high interface density, thereby having excellent radiation resistance and electromagnetic shielding performance.

[0059] Embodiment 2

[0060] The embodiment of the application provides an explosion welding method for preparing a radiation-proof metal composite material and the metal composite material, and the method comprises the following steps:

[0061] S1, performing heat preservation treatment and surface treatment on the first plate, the second plate and the third plate.

[0062] The first plate is selected from AZ31B magnesium alloy, the second plate is selected from 1060 aluminum foil, and the third plate is selected from pure Ta plate. The size of the first plate is 100 mm*100 mm*1 mm, the size of the second plate is 100 mm*100 mm*0.05 mm, and the size of the third plate is 100 mm*100 mm*3 mm. The heat preservation treatment is performed on the plates, the heat preservation temperature of the first plate is 150 DEG C for 1 h, the heat preservation temperature of the second plate is 200 DEG C for 1 h, and the heat preservation temperature of the third plate is 300 DEG C for 2 h. Then, the surface is treated.

[0063] S2, performing laser treatment on the to-be-bonding surfaces of the treated first plate and the third plate.

[0064] For the to-be-bonding surface of the first plate, the laser treatment process is as follows: 1 J, 1 Hz of frequency, 30% of lap rate, 1 mm of spot size and 10 mm / s of scanning speed. For the to-be-bonding surface of the third plate, the laser treatment process is as follows: 4 J, 1 Hz of frequency, 30% of lap rate, 1 mm of spot size and 10 mm / s of scanning speed. The average depth of the micro-pits of the to-be-bonding surface of the first plate is 0.1 mm, the hardening depth is 0.1 mm, and the depth of the micro-pits of the to-be-bonding surface of the third plate is about 0.1 mm, and the hardening depth is 0.1 mm.

[0065] S3, the first plate, the third plate and the second plate after laser treatment are stacked, the gap is between the adjacent plates, the explosive is placed on the placed plate upper surface, the metal composite plate blank is obtained through explosion welding, and the explosion welding process meets that the strain is less than 10% and the strain rate is greater than or equal to 10 3 s -1 .

[0066] The explosion welding process is: by adjusting the explosive ratio, so that the impact velocity is 800 m / s, the impact angle is 10 degrees, and the explosive filling thickness ratio is 1.1.

[0067] S4, then the orthopaedic is performed;

[0068] The orthopaedic is performed by using a hot tool, and the temperature is kept at 180 DEG C for 1.5 h.

[0069] The metal composite material prepared in the embodiment has sawteeth with a length-width ratio of 1-500 and a length of 0.1 mu m-40.0 mu m, and the edges of the sawteeth have meshing teeth with a height of 10 nm, and the atomic interdiffusion width of the joint interface is 0.1 mu m.

[0070] Example 3

[0071] The embodiment of the application provides an explosion welding method for preparing a radiation-proof metal composite material and the metal composite material, and the method comprises the following steps:

[0072] S1, the first plate, the second plate and the third plate are subjected to heat preservation treatment and surface treatment.

[0073] The first plate of the embodiment of the application is selected from AZ31B magnesium alloy, the second plate is selected from 1060 aluminum foil, and the third plate is selected from pure Ta plate, the size of the first plate is 100mm*100mm*10mm, the size of the second plate is 100mm*100mm*0.2mm, and the size of the third plate is 100mm*100mm*5mm. The plate is subjected to heat preservation treatment, the first plate is subjected to heat preservation treatment at a temperature of 300 DEG C for 3h, the second plate is subjected to heat preservation treatment at a temperature of 300 DEG C for 3h, and the third plate is subjected to heat preservation treatment at a temperature of 500 DEG C for 4h. Then the surface is treated.

[0074] S2, the first plate and the third plate after treatment are subjected to laser treatment.

[0075] The laser treatment process for the surface to be joined of the first plate is: 5J, frequency 3Hz, overlap rate 50%, spot size 3mm, scanning speed 15mm / s. The laser treatment process for the surface to be joined of the third plate is: 10J, frequency 5Hz, overlap rate 50%, spot size 3mm, scanning speed 15mm / s. The average depth of the micro-pits on the surface to be joined of the first plate is 0.3mm, and the hardening depth is 0.45mm. The depth of the micro-pits on the surface to be joined of the third plate is about 0.3mm, and the hardening depth is 0.5mm.

[0076] S3, the first plate, the third plate and the second plate after laser treatment are stacked with a gap between adjacent plates, and explosives are placed on the upper surface of the placed plate, and a metal composite plate blank is obtained by explosive welding, and the explosive welding process satisfies that the strain is less than 10% and the strain rate is greater than or equal to 10 3 s -1 .

[0077] The explosive welding process is: by adjusting the explosive ratio to make the impact speed 1000m / s, the impact angle 15°, and the explosive filling thickness ratio 1.4.

[0078] S4, then perform straightening;

[0079] The straightening is performed by using a hot tool, and the temperature is kept at 200℃ for 2h.

[0080] The metal composite material prepared in this embodiment has sawteeth with a length-width ratio of 1-500 and a length of 0.1μm-40.0μm, and the edges of the sawteeth have meshing teeth with a height of 100nm, and the atomic interdiffusion width of the joint interface is 10μm.

[0081] Example 4

[0082] Different from example 1, in this embodiment, the second plate is a pure copper foil with a size of 100mm×100mm×0.05mm, and the temperature is kept at 300℃ for 2h.

[0083] In step S2 of this embodiment, the average depth of the micro-pits on the surface to be joined of the first plate after laser treatment is 0.2mm, and the hardening depth is 0.3mm. The depth of the micro-pits on the surface to be joined of the second plate is about 0.25mm, and the hardening depth is 0.3mm.

[0084] The metal composite material prepared in this embodiment has sawteeth with a length-width ratio of 1-500 and a length of 0.1μm-40.0μm, and the edges of the sawteeth have meshing teeth with a height of 55nm, and the atomic interdiffusion width of the joint interface is 4.5μm.

[0085] Example 5

[0086] Different from example 1, in this example, the first plate material is ZK60 magnesium alloy, and the second plate material is pure copper foil. The size of the first plate material is 100mmx100mmx2mm, and the size of the second plate material is 100mmx100mmx0.05mm. The first plate material is kept at 150℃ for 2h, and the second plate material is kept at 300℃ for 2h.

[0087] In step S2 of this example, the average depth of the micro-pits on the surface of the first plate material after laser treatment is 0.25mm, the hardening depth is 0.33mm, the depth of the micro-pits on the surface of the second plate material is about 0.2mm, and the hardening depth is 0.35mm.

[0088] The metal composite material prepared in this example has sawteeth with a length-width ratio of 1-500 and a length of 0.1μm-40.0μm, and the edges of the sawteeth have engaging teeth with a height of 54nm. The atomic interdiffusion width of the interface is 6μm.

[0089] Comparative Example 1

[0090] Different from example 1, in this example, step S2 is omitted.

[0091] The metal composite material prepared in this example does not have engaging teeth.

[0092] Comparative Example 2

[0093] Different from example 1, in step S2 of this example, for the surface of the first plate material to be joined, the laser treatment process is: 0.8J, frequency 2Hz, overlap rate 40%, spot size 2mm, and scanning speed 10mm / s. For the surface of the third plate material to be joined, the laser treatment process is: 3J, frequency 3Hz, overlap rate 40%, spot size 2mm, and scanning speed 10mm / s.

[0094] In step S2 of this example, the average depth of the micro-pits on the surface of the first plate material after laser treatment is 0.05mm, the hardening depth is 0.06mm, the depth of the micro-pits on the surface of the second plate material is about 0.07mm, and the hardening depth is 0.06mm.

[0095] The edges of the sawteeth have engaging teeth with a height of 8nm.

[0096] Comparative Example 3

[0097] Different from example 1, in step S2 of the present comparative example, the laser processing for the surface to be joined of the first plate is 6J, 2Hz, 40% of overlapping rate, 2mm of spot size, and 10mm / s of scanning speed. The laser processing for the surface to be joined of the third plate is 12J, 3Hz, 40% of overlapping rate, 2mm of spot size, and 10mm / s of scanning speed.

[0098] In step S2 of the present example, the average depth of the micro-pits of the surface to be joined of the first plate after laser processing is 0.4mm, the hardening depth is 0.6mm, the depth of the micro-pits of the surface to be joined of the second plate is about 0.6mm, and the hardening depth is 0.6mm.

[0099] The edge of the sawtooth has an engagement tooth with a height of 110nm.

[0100] Comparative example 4

[0101] Different from example 1, in step S2 of the present comparative example, the laser processing for the surface to be joined of the first plate is 3J, 4Hz, 40% of overlapping rate, 2mm of spot size, and 10mm / s of scanning speed. The laser processing for the surface to be joined of the third plate is 7J, 6Hz, 40% of overlapping rate, 2mm of spot size, and 10mm / s of scanning speed.

[0102] In step S2 of the present example, the average depth of the micro-pits of the surface to be joined of the first plate after laser processing is 0.2mm, the hardening depth is 0.6mm, the depth of the micro-pits of the surface to be joined of the second plate is about 0.2mm, and the hardening depth is 0.6mm.

[0103] The edge of the sawtooth has an engagement tooth with a height of 110nm.

[0104] Comparative example 5

[0105] Different from example 1, in step S2 of the present comparative example, the laser processing for the surface to be joined of the first plate is 3J, 4Hz, 40% of overlapping rate, 2mm of spot size, and 10mm / s of scanning speed. The laser processing for the surface to be joined of the third plate is 7J, 6Hz, 40% of overlapping rate, 2mm of spot size, and 10mm / s of scanning speed.

[0106] Comparative example 6

[0107] Different from example 1, in step S3 of the present comparative example, the impact speed is 700m / s and the impact angle is 8° by adjusting the explosive ratio.

[0108] Comparative example 7

[0109] Different from example 1, in step S3 of the present comparative example, the impact speed is 1100m / s and the impact angle is 16° by adjusting the explosive ratio.

[0110] In order to characterize the effect of the technical scheme, the following indexes are used for determination:

[0111] (1) Electromagnetic shielding performance and radiation resistance performance detection.

[0112] (2) High and low temperature thermal cycle performance. The prepared metal composite material is subjected to static mechanical property tensile test after being subjected to high temperature 150℃, low temperature -196℃, each for 2h, and being cycled for 50 times. The test items include yield strength attenuation, tensile strength attenuation and elongation attenuation. The attenuation rate is calculated by comparing the data obtained after 50 cycles with the original data, that is:

[0113] ;

[0114] Wherein r is the attenuation rate, v 原 is the related performance data of the metal composite material before cycling, v 后 is the related performance data of the metal composite material after cycling.

[0115] The determination results are shown in Table 1.

[0116] Table 1 Detection results of each example and comparative example

[0117]

[0118] It can be seen from Example 1 and Comparative Example 1 that the layered composite prepared without laser treatment of the surfaces of the first and second plates does not have engagement teeth, and the plate cracks along the Mg alloy interface after five cycles; it can be seen from Example 1, Comparative Examples 2, 3 and 4 that the size of the engagement teeth is also very important, the size of the engagement teeth is related to the size of the micro-pits and the surface hardening during laser treatment, if the micro-pits are larger and the surface hardening depth is deeper, the height of the engagement teeth increases, the engagement of the engagement teeth and the serrations during explosive welding has a low bonding strength and there is a possibility of tearing between the hardened and non-hardened parts, and the creep resistance is reduced; if the size of the micro-pits is too small and the surface hardening depth is shallow, the number of engagement teeth on a single serration increases, but the strength of the engagement teeth is low, which weakens the high-low temperature cycle performance, so the performance of Comparative Examples 2 and 3 is much worse than that of Example 1, and it can be seen from Comparative Example 4 that although other parameters are within the scope of the present application, the laser treatment frequency is higher, which increases the hardening depth and makes the size of the engagement teeth too large, thereby weakening the bonding strength of the serrations. It can be seen from Example 1 and Comparative Example 5 that since the second plate is removed, the first and third plates cannot be well solid solution strengthened, and thus the plate cracks along the Mg interface after three cycles during the cold and hot cycle process. It can be seen from Example 1, Comparative Examples 6 and 7 that the performance of the prepared metal composite can be improved if the explosive welding process is compatible with the surface treatment process, and if the shock wave of the explosive welding is too weak or too strong, it will affect the engagement between the plates, especially the formation of the engagement teeth, resulting in a weak performance of the prepared metal composite.

[0119] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An explosive welding method for preparing radiation-proof metal composite materials, characterized in that: include: Performing thermal insulation treatment and surface treatment on the first plate, the second plate and the third plate; performing laser processing on the surfaces to be joined of the processed first plate and the third plate; The first plate, the third plate and the second plate after laser treatment are stacked with gaps between adjacent plates, explosives are placed on the upper surface of the placed plates, and a metal composite plate blank is obtained by explosion welding. The explosive welding process satisfies the requirements of strain less than 10% and strain rate ≥10 3 s -1 ; Correction can then be performed; The first plate is an HCP crystal form, the second plate is an FCC crystal form, and the third plate is a BCC crystal form; The metal composite material comprises at least one set of repeating units, wherein the repeating units are a first composite layer, a second composite layer and a third composite layer, wherein the first composite layer, the second composite layer and the third composite layer are formed by explosion welding of a first plate, a second plate and a third plate respectively; A bonding interface is provided between the first composite layer and the second composite layer, and between the second composite layer and the third composite layer. The interface line length of the bonding interface is at least 1.5 times the interface length. The bonding interface is in the form of a sawtooth interlocking structure. The sawtooth aspect ratio is 1-500 and the length is 0.1 μm-40.0 μm. The atomic interdiffusion width of the bonding interface is 0.1 μm-10.0 μm. The edge of the sawtooth has meshing teeth with a height of 10 nm-100 nm, and a single sawtooth has at least three meshing teeth. The first plate is a magnesium alloy, and the heat preservation treatment temperature is 150°C-300°C, and the heat preservation time is 1h-3h; The second plate is made of pure aluminum or aluminum alloy, and the temperature of the heat preservation treatment is 200-300°C, and the heat preservation time is 1-3 hours; The second plate is pure copper or copper alloy and the third composite layer is pure tantalum or tantalum alloy. The second plate and the third plate are subjected to a heat preservation treatment temperature of 300°C-500°C and a heat preservation time of 2h-4h. The laser treatment is as follows: for the surface to be joined of the first plate, energy 1J-5J, frequency 1Hz-3Hz, overlap rate 30%-50%; for the surface to be joined of the third plate, energy 4J-10J, frequency 1Hz-5Hz, overlap rate 30%-50%; The spot size is 1mm-3mm, and the scanning speed is 10mm / s-15mm / s; The interface line length of the bonding interface refers to the length of the curve formed by the interface after explosive recombination; the interface length refers to the interface length measured when the bonding surface is flat before explosive recombination.

2. The explosive welding method according to claim 1, characterized in that: The ratio of the tensile strength of the materials used for the first plate, the second plate and the third plate satisfies 1:(0.5-2.0):(1.0-2.0).

3. The explosive welding method according to claim 2, characterized in that: The first plate is a magnesium alloy; The second plate is made of pure aluminum, aluminum alloy, pure copper or copper alloy; The third plate material is pure tantalum or tantalum alloy.

4. The explosive welding method according to claim 1, characterized in that: The thickness of the first plate is 1 mm to 10 mm, the thickness of the second plate is 0.01 mm to 0.20 mm, and the thickness of the third plate is 1.0 mm to 5.0 mm.

5. The explosive welding method according to claim 1, characterized in that: The explosive welding process is as follows: the impact speed is 800m / s-1000m / s, the impact angle is 10°-15°, and the explosive filling thickness ratio is 1.1-1.

4.

6. The explosive welding method according to claim 1, characterized in that: The correction is performed by heat treatment of correction tooling.

7. A radiation-proof metal composite material, characterized in that: The metal composite material is prepared by the explosion welding method according to any one of claims 1 to 6.

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