Target sheet and method of manufacture

Abstract

The present application relates to the technical field of nuclear energy, and particularly provides a target sheet and a manufacturing method, aiming to solve the problem of high temperature of the existing target sheet during service, insufficient heat exchange of the target sheet, and further target sheet failure. To this end, the target sheet comprises a heat conduction layer and a composite layer connected together, the heat conduction layer comprises the following components by weight percentage: 1% to 20% of Pd and 80% to 99% of Cu, through the synergistic compounding effect of the above components by weight percentage, the heat conduction layer has good heat conduction performance, and meanwhile, good connection is formed between the heat conduction layer and the composite layer.

Description

Technical Field

[0001] This invention relates to the field of nuclear energy technology, specifically providing a target sheet and its manufacturing method. Background Technology

[0002] The target sheet is a crucial component of a neutron target, used to produce neutrons. Neutrons have a wide range of applications, especially in recent years, where they have been increasingly used in the treatment of diseases. Neutron beams generated by reactors or medical particle accelerators are used to treat cancer patients, or artificial radioactive isotopes are produced using neutron radiation methods for radiological diagnosis and treatment, curing thousands of cancer patients.

[0003] To ensure the long-term use of the target, the temperature of the target needs to be controlled within a reasonable range. Currently, the target is connected by welding three material plates: beryllium, palladium and copper. Beryllium is used to generate neutrons through nuclear reaction with the ion beam, palladium is used to absorb hydrogen, and copper is used for heat conduction. However, the target temperature is high during service, and the heat exchange of the target is insufficient, which leads to the failure of the target.

[0004] Accordingly, there is a need in the field for a new target to address the aforementioned problems. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problem that the temperature of existing target chips is too high during service, the heat exchange of the target chips is insufficient, and thus the target chips fail.

[0006] In a first aspect, the present invention provides a target sheet comprising a thermally conductive layer and a composite layer connected together, the thermally conductive layer comprising the following components by weight percentage: 1% to 20% Pd and 80% to 99% Cu.

[0007] In some possible implementations, the composite layer includes a reactive layer comprising the following components by weight percentage: 80%–99% Be and 1%–20% Pd.

[0008] In some possible implementations, the composite layer further includes a first transition layer comprising the following components in weight percentages: 30%–80% Be and 20%–70% Pd.

[0009] In some possible implementations, the composite layer further includes a hydrogen-absorbing layer comprising the following components by weight percentage: 1%–29% Be, 70%–98% Pd, and 1%–29% Cu.

[0010] In some possible implementations, the composite layer further includes a second transition layer comprising the following components by weight percentage: 20%–70% Be and 30%–80% Cu.

[0011] The beneficial effects of the technical solution provided in the first aspect embodiment include at least the following:

[0012] The target sheet provided in the first aspect embodiment includes a thermally conductive layer and a composite layer connected together. The thermally conductive layer comprises the following components by weight percentage: 1% to 20% Pd and 80% to 99% Cu. Through the synergistic compounding effect of the above-mentioned components by weight percentage, it has good thermal conductivity and also enables a good connection between the thermally conductive layer and the composite layer.

[0013] In a second aspect, the present invention provides a method for manufacturing the target sheet described in the first aspect, the method comprising:

[0014] Steps for preparing gradient powder: Mix the materials that form the reaction layer, the first transition layer, the hydrogen absorption layer, the second transition layer, and the thermally conductive layer separately to form reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder;

[0015] Pressing the green body step: The reaction layer gradient powder, the first transition layer gradient powder, the hydrogen absorption layer gradient powder, the second transition layer gradient powder and the thermally conductive layer gradient powder are placed into the mold cavity layer by layer and pressed to form a composite green body;

[0016] Sintering step: The composite green body is placed in a furnace for sintering to obtain the target sheet.

[0017] In some possible implementations, in the step of preparing the gradient powder: the material of the reaction layer is 80%–99% Be and 1%–20% Pd; the material of the first transition layer is 30%–80% Be and 20%–70% Pd; the material of the hydrogen absorption layer is 1%–29% Be, 70%–98% Pd and 1%–29% Cu; the material of the second transition layer is 20%–70% Be and 30%–80% Cu; and the material of the thermally conductive layer is 1%–20% Pd and 80%–99% Cu.

[0018] In some possible implementations, the pressing green blank step includes: pre-pressing the reaction layer gradient powder laid in the mold cavity to form a pre-pressed blank; pre-pressing the first transition layer gradient powder laid on the pre-pressed blank to form a double-layer pre-pressed blank; pre-pressing the hydrogen-absorbing layer gradient powder laid on the double-layer pre-pressed blank to form a triple-layer pre-pressed blank; pre-pressing the second transition layer gradient powder laid on the triple-layer pre-pressed blank to form a quadruple-layer pre-pressed blank; pre-pressing the thermally conductive layer gradient powder laid on the quadruple-layer pre-pressed blank to form a five-layer pre-pressed blank; and re-pressing the five-layer pre-pressed blank with a pressure of 200-500 MPa for 2-15 minutes to obtain a composite green blank.

[0019] In some possible implementations, during the sintering step: carbon nanotube films are placed both above and below the composite green body disposed within the furnace cavity; the furnace cavity is then subjected to a vacuum of 1×10⁻⁶. -2 Pa ~ 1×10 -5 The composite green blank is subjected to vacuum treatment; the composite green blank is energized with an output current of 5-25A and an output voltage of 20-60V to raise the temperature of the composite green blank to 500-1100℃ and hold it for 2-25 minutes; after the holding period, the composite green blank is quickly de-energized and cooled at a rate of 80℃ / s-180℃ / s to obtain the target sheet.

[0020] In some possible implementations, in the phrase "the temperature of the composite green body is 500-1100℃ and held for 2-25 minutes", the temperature is 700-800℃ and held for 8-12 minutes.

[0021] The beneficial effects of the technical solution provided in the second aspect embodiment include at least the following:

[0022] The method for preparing a target sheet according to the second aspect embodiment includes the following steps: Preparing gradient powder: mixing materials for forming a reaction layer, a first transition layer, a hydrogen absorption layer, a second transition layer, and a thermally conductive layer to form reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder; Preparing gradient powder: placing the reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder into a furnace for heating to form reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder; Pressing green blank: placing the reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder layer by layer into a mold cavity for pressing to form a composite green blank; Sintering: placing the composite green blank into a furnace for sintering treatment to obtain a target sheet. This method can improve the overlap between the above material layers, avoid the risk of failure caused by welding, and improve the service life and safety of the target sheet. Attached Figure Description

[0023] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0024] Figure 1 This is a side cross-sectional view of the target sheet of the present invention;

[0025] Figure 2 This is a flowchart of the target fabrication method of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below.

[0027] Firstly, referring to Figure 1 This invention provides a target sheet comprising a thermally conductive layer 5 and a composite layer connected together. The composite layer comprises a reaction layer 1, a first transition layer 2, a hydrogen absorption layer 3, and a second transition layer 4 connected in sequence. The second transition layer 4 is connected to the thermally conductive layer 5, which comprises the following components by weight percentage: 1%–20% Pd and 80–99% Cu. The first transition layer 2 and the second transition layer 4 can mitigate the interfacial effects between layers in the target sheet, reducing the impact of abrupt interface changes in traditional structures.

[0028] The target sheet provided in this embodiment includes a thermally conductive layer 5 and a composite layer connected together. The thermally conductive layer 5 comprises the following components by weight percentage: 1% to 20% Pd and 80% to 99% Cu. Through the synergistic compounding effect of the above-mentioned components by weight percentage, it has good thermal conductivity and also enables a good connection between the thermally conductive layer 5 and the composite layer.

[0029] In the composition of the thermally conductive layer 5 in the target sheet provided in this embodiment, the weight percentage of each component includes, but is not limited to, the following, which are illustrated with examples below:

[0030] For example, the weight percentage of Pd (palladium) in the thermal conductive layer 5 is: 5%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.

[0031] For example, the weight percentage of Cu (copper) in the thermal conductive layer 5 is: 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, etc.

[0032] Pd (palladium) has excellent physical and chemical properties, including high temperature resistance, corrosion resistance, wear resistance, and extremely high ductility.

[0033] Cu (copper) has good ductility, high thermal conductivity, and high electrical conductivity.

[0034] In summary, the target sheet provided in this application embodiment has good thermal conductivity based on the synergistic effect of the components in the above weight percentage, and also enables a good connection between the thermally conductive layer 5 and the composite layer.

[0035] In some possible examples, the composition of the thermally conductive layer 5 of the target sheet provided in the embodiments of this disclosure can be used to prepare the thermally conductive layer 5. That is, the embodiments of this disclosure provide a target sheet including a connected thermally conductive layer 5 and a composite layer, wherein the thermally conductive layer 5 comprises the following components by weight percentage: 1% to 20% Pd and 80% to 99% Cu, and the total weight percentage of the above components Pd and Cu is 100% when preparing the thermally conductive layer 5.

[0036] In some possible implementations, the reaction layer 1 in the target sheet provided in this application embodiment includes the following components by weight percentage: 80% to 99% Be and 1% to 20% Pd.

[0037] The weight percentages of each component in the reaction layer 1 of the target sheet provided in this embodiment include, but are not limited to, the following, which are illustrated with examples below:

[0038] For example, the weight percentage of Be (beryllium) is: 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, etc.

[0039] For example, the weight percentage of Pd (palladium) is: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.

[0040] The reaction layer 1 of the target sheet provided in this application embodiment increases shear strength based on the synergistic effect of the above-mentioned weight percentage components, ensuring that the reaction layer 1 interacts with the incident ion beam to produce the required neutron yield, and also enabling a good connection between the reaction layer 1 and the first transition layer 2.

[0041] In some possible examples, the composition of the reaction layer 1 of the target sheet provided in the embodiments of this disclosure can be used to prepare the reaction layer 1. That is, the embodiments of this disclosure provide a target sheet including a thermally conductive layer 5 and a reaction layer 1 in a composite layer, the reaction layer 1 comprising the following components by weight percentage: 80% to 99% Be and 1% to 20% Pd, wherein the total weight percentage of the above components Be and Pd is 100% when preparing the reaction layer 1.

[0042] In some possible implementations, the first transition layer 2 of the target sheet provided in this application embodiment includes the following components by weight percentage: 30% to 80% Be and 20% to 70% Pd.

[0043] In the composition of the first transition layer 2 in the target sheet provided in this embodiment, the weight percentage of each component includes, but is not limited to, the following, which are illustrated by examples below:

[0044] For example, the weight percentage of Be (beryllium) is: 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc.

[0045] For example, the weight percentage of Pd (palladium) is: 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, etc.

[0046] The first transition layer 2 of the target sheet provided in this application embodiment is based on the synergistic compounding effect of the components in the above weight percentage. The first transition layer 2 is located between the reaction layer 1 and the hydrogen absorption layer 3, ensuring that the first transition layer 2 can form a good connection with both the reaction layer 1 and the hydrogen absorption layer 3.

[0047] In some possible examples, the composition of the first transition layer 2 of the target sheet provided in the embodiments of this disclosure can be used to prepare the first transition layer 2. That is, the embodiments of this disclosure provide a target sheet comprising a connected thermally conductive layer 5 and a first transition layer 2 in a composite layer, the first transition layer 2 comprising the following components by weight percentage: 30% to 80% Be and 20% to 70% Pd. When preparing the first transition layer 2, the total weight percentage of the above components Be and Pd is 100%.

[0048] In some possible implementations, the hydrogen absorption layer 3 of the target sheet provided in the embodiments of this application comprises the following components by weight percentage: 1% to 29% Be, 70% to 98% Pd and 1% to 29% Cu.

[0049] The weight percentages of each component in the hydrogen absorption layer 3 of the target sheet provided in this embodiment include, but are not limited to, the following examples:

[0050] For example, the weight percentage of Be (beryllium) is: 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, etc.

[0051] For example, the weight percentage of Pd (palladium) is: 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, etc.

[0052] For example, the weight percentage of Cu (copper) is: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, etc.

[0053] The hydrogen absorption layer 3 of the target sheet provided in this application embodiment is based on the synergistic compounding effect of the components in the above weight percentage, which ensures the hydrogen absorption capacity of the hydrogen absorption layer 3, and also enables the hydrogen absorption layer 3 to form a good connection with the first transition layer 2 and the second transition layer 4.

[0054] In some possible examples, the composition of the hydrogen-absorbing layer 3 of the target sheet provided in the embodiments of this disclosure can be used to prepare the hydrogen-absorbing layer 3. That is, the embodiments of this disclosure provide a target sheet including a thermally conductive layer 5 and a hydrogen-absorbing layer 3 in a composite layer, the hydrogen-absorbing layer 3 comprising the following components by weight percentage: 1% to 29% Be, 70% to 98% Pd and 1% to 29% Cu, wherein the total weight percentage of the above components Be, Pd and Cu is 100% when preparing the hydrogen-absorbing layer 3.

[0055] In some possible implementations, the second transition layer 4 of the target sheet provided in this application embodiment includes the following components by weight percentage: 20% to 70% Be and 30% to 80% Cu.

[0056] In the composition of the second transition layer 4 in the target sheet provided in this embodiment, the weight percentage of each component includes, but is not limited to, the following, which are illustrated by examples below:

[0057] For example, the weight percentage of Be (beryllium) is: 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, etc.

[0058] For example, the weight percentage of Cu (copper) is: 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc.

[0059] The second transition layer 4 of the target sheet provided in this application embodiment is based on the synergistic compounding effect of the components in the above weight percentage. The second transition layer 4 is located between the thermally conductive layer 5 and the hydrogen-absorbing layer 3, ensuring that a good connection can be formed between the thermally conductive layer 5 and the hydrogen-absorbing layer 3.

[0060] In some possible examples, the composition of the second transition layer 4 of the target sheet provided in the embodiments of this disclosure can be used to prepare the second transition layer 4. That is, the embodiments of this disclosure provide a target sheet including a connected thermally conductive layer 5 and a second transition layer 4 in a composite layer, the second transition layer 4 comprising the following components by weight percentage: 20% to 70% Be and 30% to 80% Cu, wherein the total weight percentage of the above components Be and Cu is 100% when preparing the second transition layer 4.

[0061] In a second aspect, embodiments of the present invention provide a method for manufacturing a target sheet for the first aspect, the method comprising a step of preparing gradient powder in step S1, a step of preparing gradient powder in step S3, a step of pressing green embryo in step S5, and a step of sintering in step S6.

[0062] S1 Gradient Powder Preparation Steps: Mix the materials forming reaction layer 1, first transition layer 2, hydrogen absorption layer 3, second transition layer 4, and thermally conductive layer 5 to form reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder.

[0063] S5 pressing green body step: The reaction layer gradient powder, the first transition layer gradient powder, the hydrogen absorption layer gradient powder, the second transition layer gradient powder and the thermally conductive layer gradient powder are put into the mold cavity layer by layer for pressing to form a composite green body.

[0064] S7 sintering step: The composite green body is placed in the furnace for sintering to obtain the target sheet.

[0065] By adopting the above technical solution, the present invention mixes the materials of the reaction layer 1, the first transition layer 2, the hydrogen absorption layer 3, the second transition layer 4, and the thermally conductive layer 5 to form reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder, respectively, and adds them to a furnace for reaction to form reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder. These are then pressed into a green blank and sintered to form a target sheet. This improves the overlap between the material layers, avoids the risk of failure caused by welding, and increases the service life and safety of the target sheet.

[0066] In some possible examples, in step S1 of preparing the gradient powder: the materials Be and Pd for the reaction layer 1 are placed in a first container and stirred evenly for later use; the materials Be and Pd for the first transition layer 2 are placed in a second container and stirred evenly for later use; the materials Be, Pd, and Cu for the hydrogen absorption layer 3 are placed in a third container and stirred evenly for later use; the materials Be and Cu for the second transition layer 4 are placed in a fourth container and stirred evenly for later use; and the materials Pd and Cu for the thermally conductive layer 5 are placed in a fifth container and stirred evenly for later use. The specific weight percentages are: the materials for the reaction layer 1 are 80%–99% Be and 1%–20% Pd; the materials for the first transition layer 2 are 30%–80% Be and 20%–70% Pd; the materials for the hydrogen absorption layer 3 are 1%–29% Be, 70%–98% Pd, and 1%–29% Cu; the materials for the second transition layer 4 are 20%–70% Be and 30%–80% Cu; and the materials for the thermally conductive layer 5 are 1%–20% Pd and 80%–99% Cu.

[0067] In particular, Pd was added to the material of reaction layer 1. With the synergistic effect of Pd and Be, reaction layer 1 reacts with the ion beam to produce neutron yield that meets the application requirements, while also increasing shear strength.

[0068] Among them, Be and Cu were added to the material of hydrogen absorption layer 3. The synergistic effect of Be and Cu with Pd enables hydrogen absorption layer 3 to absorb hydrogen elements deposited in the target.

[0069] Among them, Pd was added to the material of the thermally conductive layer 5. With the synergistic effect of Pd and Cu, the heat generated by the reaction between the ion beam and the target element was carried away by utilizing the good thermal conductivity of Pd.

[0070] In this process, by adding a first transition layer 2 consisting of Be and Pd, and a second transition layer 4 consisting of Pd and Cu, a good connection is formed between the reaction layer 1, the hydrogen absorption layer 3, and the thermally conductive layer 5.

[0071] In some possible examples, in the S5 pressing green preform step: the reaction layer gradient powder is uniformly spread in the pre-pressing mold cavity and subjected to a first pre-pressing treatment at room temperature, with a pre-pressing pressure of 30-60 MPa and a pre-pressing time of 25-60 s, to obtain a one-layer pre-pressed preform. The first transition layer gradient powder is uniformly spread on top of the one-layer pre-pressed preform and subjected to a second pre-pressing treatment at room temperature, with a pre-pressing pressure of 30-60 MPa and a pre-pressing time of 25-60 s, to obtain a two-layer pre-pressed preform. The hydrogen absorption layer gradient powder is uniformly spread on top of the two-layer pre-pressed preform and subjected to a third pre-pressing treatment at room temperature, with a pre-pressing pressure of 30-60 MPa and a pre-pressing time of 25-60 s, to obtain a three-layer pre-pressed preform. The second transition layer gradient powder is uniformly spread on top of the three-layer pre-pressed preform and subjected to a fourth pre-pressing treatment at room temperature, with a pre-pressing pressure of 30-60 MPa and a pre-pressing time of 25-60 s, to obtain a four-layer pre-pressed preform. The thermally conductive gradient powder is evenly spread on top of the four-layer pre-compressed blank and subjected to a fifth pre-compressing treatment at room temperature. The pre-compressing pressure is 30-60 MPa, and the pre-compressing time is 25-60 s, resulting in a five-layer pre-compressed blank. The five-layer pre-compressed blank is then pre-compressed at a pressure of 200-500 MPa for 2-15 min to obtain a composite green blank. The composite green blank obtained through the above pre-compressing process has good connectivity and improved bonding strength.

[0072] In some possible examples, the S5 pressing green blank step also includes "pre-pressing the five-layer pre-pressed blank at a pressure of 200-500 MPa for 2-15 minutes to obtain a composite green blank", followed by re-pressing the composite green blank at a pressure of 200-500 MPa for 2-15 minutes, so as to compact each layer and between layers, and ensure porosity and connectivity.

[0073] Preferably, the pre-compression pressure of the first to fifth layers of pre-compression billet is 45 MPa and the pre-compression time is 45 s. The five layers of pre-compression billet are pre-compressed at a pressure of 350 MPa for 10 min to obtain a composite green billet. The composite green billet is then re-compressed at a pressure of 350 MPa for 10 min.

[0074] The reaction layer gradient powder, the first transition layer gradient powder, the hydrogen absorption layer gradient powder, the second transition layer gradient powder, and the thermally conductive layer gradient powder are mixed in a mass ratio of 1:1:1.

[0075] Preferably, the five-layer pre-pressed billet is re-pressed at a pressure of 350 MPa for 10 minutes to obtain a composite green billet.

[0076] In some possible examples, during the S7 sintering step: the composite green body is adhered to a sample holder in the furnace using conductive silver paste; carbon nanotube films are placed above and below the composite green body within the furnace cavity; and the furnace cavity is sintered at a vacuum of 1×10⁻⁶. -2 Pa ~ 1×10 -5The process involves vacuuming the composite green compact; energizing it with an output current of 5–25 A and an output voltage of 20–60 V to raise its temperature to 500–1100 °C; connecting the electrode clamp and energizing it to reach the target temperature within 2 seconds, then holding it at that temperature for 2–25 minutes; finally, rapidly de-energizing the green compact after holding and cooling it at a rate of 80 °C / s–180 °C / s to obtain the target sheet. This method transforms the mechanical interlocking of the raw material powder particles into atomic crystalline bonding, reducing porosity and increasing structural strength. The target sheet has a density of 97%–99.9% and a thermal conductivity of 240–380 W·m⁻². -1 ·k -1 In the case of "the temperature of the composite green body is 500-1100℃ and the holding time is 2-25 min", the temperature is 700-800℃ and the holding time is 8-12 min.

[0077] Preferably, the output current is 15A, the output voltage is 40V, the temperature is 800℃, the electrode clamp is connected and powered on, and the temperature is maintained for 15 minutes.

[0078] The implementation of this application will be described in further detail below with more specific embodiments. Specific techniques or conditions are not specified in the following embodiments; they are based on techniques or conditions described in the literature in the art or in the product manual.

[0079] Example 1

[0080] This embodiment 1 provides a target sheet, which includes a connected thermally conductive layer 5 and a composite layer. The thermally conductive layer 5 includes the following components by weight percentage: 1% to 20% Pd and 80% to 99% Cu. The thickness of the thermally conductive layer 5 is 0.5 mm as an example.

[0081] Test Example 1

[0082] In this test example 1, neutrons were produced using the target sheet provided in Example 1. Neutrons were produced continuously for 5 days, with three hours of continuous production each day, and the thermal conductivity was recorded.

[0083] The test results are shown below:

[0084] The thermal conductivity of the target sheet prepared using Example 1 was 280 W / m·K, 278 W / m·K, 279 W / m·K, 281 W / m·K, and 281 W / m·K over five days, with an average thermal conductivity of 279.8 W / m·K. Traditional target sheets used only a single copper thermally conductive layer with a thickness of 0.5 mm. Neutrons were continuously produced for five days, three hours per day, and the thermal conductivity was recorded. The thermal conductivity over five days was 201 W / m·K, 200 W / m·K, 199 W / m·K, 197 W / m·K, and 202 W / m·K, with an average thermal conductivity of 200 W / m·K. The test results show that the target sheet prepared using the technical solution of Example 1 has high thermal conductivity, resulting in excellent heat dissipation.

[0085] Example 2

[0086] This embodiment 2 provides a target sheet, which includes a thermally conductive layer 5 and a composite layer connected together. The composite layer includes the following components by weight percentage: 80% to 99% Be and 1% to 20% Pd reaction layer 1. The thickness of the reaction layer 1 is 0.5 mm as an example.

[0087] Test Example 2

[0088] In this test example 2, the target sheet provided in Example 2 was subjected to five shear strength tests using the existing target sheet shear strength testing method, and the results were recorded.

[0089] The test results are shown below:

[0090] The target sheet prepared using the method described in Example 2 above underwent five shear strength tests, yielding shear strengths of 305 MPa, 300 MPa, 300 MPa, 295 MPa, and 310 MPa, with an average shear strength of 302 MPa. A conventional target sheet also underwent five shear strength tests, yielding shear strengths of 200 MPa, 210 MPa, 205 MPa, 200 MPa, and 195 MPa, with an average shear strength of 202 MPa. The test results indicate that the target sheet prepared using the method described in Example 2 possesses good shear strength.

[0091] Example 3

[0092] This embodiment 3 provides a target sheet, which includes a thermally conductive layer 5 and a composite layer connected together. The composite layer includes a first transition layer 2 made of the following components by weight percentage: 30% to 80% Be and 20% to 70% Pd. The first transition layer 2 has a thickness of 0.1 mm as an example.

[0093] Test Example 3

[0094] In this test example 3, the target sheet provided in Example 3 was subjected to five shear strength tests using the existing target sheet shear strength testing method, and the results were recorded.

[0095] The test results are shown below:

[0096] Using the target sheet prepared in Example 3 above, the five shear strength tests of the target sheet were as follows: shear strength 300 MPa, shear strength 310 MPa, shear strength 305 MPa, shear strength 295 MPa, and shear strength 315 MPa, with an average shear strength of 305 MPa. The conventional target sheet, which does not have a first transition layer 2, also underwent five shear strength tests: shear strength 210 MPa, shear strength 190 MPa, shear strength 195 MPa, shear strength 200 MPa, and shear strength 205 MPa, with an average shear strength of 200 MPa. The test results show that the target sheet prepared by the technical solution of Example 3 has good shear strength, and a good connection is formed between the hydrogen absorption layer 3 and the reaction layer 1.

[0097] Example 4

[0098] This embodiment 4 provides a target sheet, which includes a thermally conductive layer 5 and a composite layer connected together. The composite layer includes a hydrogen-absorbing layer 3 made of the following components by weight percentage: 1% to 29% Be, 70% to 98% Pd and 1% to 29% Cu. The hydrogen-absorbing layer 3 has a thickness of 0.1 mm as an example.

[0099] Test Example 4

[0100] In this test example 4, the target sheet provided in Example 4 continuously produced neutrons for 5 days, with three hours of continuous production each day, and the hydrogen absorption limit was recorded.

[0101] The test results are shown below:

[0102] The target sheet prepared using the above-described Example 4 has the following five hydrogen absorption limits: hydrogen absorption limit 1.4 × 10⁻⁶. 20 cm -2 Hydrogen absorption limit: 1.6 × 10⁻⁶ 20 cm -2 Hydrogen absorption limit: 1.55 × 10⁻⁶ 20 cm -2 Hydrogen absorption limit: 1.2 × 10⁻⁶ 20 cm -2 The hydrogen absorption limit is 1.4 × 10⁻⁶. 20 cm -2 The average hydrogen absorption limit for the five tests was 1.43 × 10⁻⁶. 20 cm -2Traditional target sheets use palladium as the hydrogen absorption layer, with a thickness of 0.1 mm. Neutrons are continuously produced for 5 days, three hours per day, and hydrogen absorption limits are recorded. The hydrogen absorption limits for the 5 days are: 0.9 × 10⁻⁶. 20 cm -2 Hydrogen absorption limit 1×10 20 cm -2 The hydrogen absorption limit is 0.95 × 10⁻⁶. 20 cm -2 The hydrogen absorption limit is 0.95 × 10⁻⁶. 20 cm -2 The hydrogen absorption limit is 0.9 × 10⁻⁶. 20 cm -2 The average hydrogen absorption limit for the five tests was 0.94 × 10⁻⁶. 20 cm -2 Test results show that the target sheet prepared by the technical solution in Example 4 has a high hydrogen absorption rate, thus exhibiting outstanding hydrogen absorption effect.

[0103] Example 5

[0104] This embodiment 5 provides a target sheet, which includes a connected thermally conductive layer 5 and a composite layer. The composite layer includes the following components by weight percentage: a second transition layer 4 made of 20% to 70% Be and 30% to 80% Cu, with the second transition layer 4 having a thickness of 0.1 mm as an example.

[0105] Test Example 5

[0106] In this test example 5, the target sheet provided in Example 5 was subjected to five shear strength tests using the existing target sheet shear strength testing method, and the results were recorded.

[0107] The test results are shown below:

[0108] The target sheet prepared using the method described in Example 5 above underwent five shear strength tests, yielding shear strengths of 310 MPa, 315 MPa, 310 MPa, 295 MPa, and 305 MPa, with an average shear strength of 307 MPa. A conventional target sheet, lacking the second transition layer 4, also underwent five shear strength tests, yielding shear strengths of 200 MPa, 190 MPa, 200 MPa, 205 MPa, and 190 MPa, with an average shear strength of 197 MPa. The test results demonstrate that the target sheet prepared using the method described in Example 5 exhibits good shear strength, thereby ensuring a good connection between the hydrogen absorption layer 3 and the thermally conductive layer 5.

[0109] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A target sheet, characterized by, The target sheet includes a connected thermally conductive layer and a composite layer, the thermally conductive layer comprising the following components by weight percentage: 1%~20% Pd and 80%~99% Cu; The composite layer includes a reactive layer, which comprises the following components by weight percentage: 80%~99% Be and 1%~20% Pd; The composite layer further includes a first transition layer, which comprises the following components by weight percentage: 30%~80% Be and 20%~70% Pd; The composite layer further includes a hydrogen-absorbing layer, which comprises the following components by weight percentage: It contains 1%~29% Be, 70%~98% Pd and 1%~29% Cu.

2. The target sheet according to claim 1, wherein The composite layer further includes a second transition layer, which comprises the following components by weight percentage: It contains 20%~70% Be and 30%~80% Cu.

3. A method for making the target sheet of claim 2, characterized by, The method includes: Steps for preparing gradient powder: Mix the materials that form the reaction layer, the first transition layer, the hydrogen absorption layer, the second transition layer, and the thermally conductive layer separately to form reaction layer gradient powder, first transition layer gradient powder, hydrogen absorption layer gradient powder, second transition layer gradient powder, and thermally conductive layer gradient powder; Pressing the green body step: The reaction layer gradient powder, the first transition layer gradient powder, the hydrogen absorption layer gradient powder, the second transition layer gradient powder and the thermally conductive layer gradient powder are placed into the mold cavity layer by layer and pressed to form a composite green body; Sintering step: The composite green body is placed in a furnace for sintering to obtain the target sheet.

4. The method of claim 3, wherein, In the step of pressing the embryo: The reaction layer gradient powder, pre-pressed and laid in the mold cavity, forms a pre-pressed blank; The first transition layer gradient powder, pre-compressed and laid on the first layer of pre-compressed blank, forms a double-layer pre-compressed blank; The hydrogen-absorbing gradient powder, pre-compressed onto the double-layer pre-compressed blank, forms a three-layer pre-compressed blank; The second transition layer gradient powder, pre-compressed and laid on the three-layer pre-compressed blank, forms a four-layer pre-compressed blank; The thermally conductive gradient powder, which is pre-pressed onto the four-layer pre-pressed blank, forms a five-layer pre-pressed blank. The five-layer pre-pressed billet is re-pressed at a pressure of 200~500Mpa for 2~15min to obtain a composite green billet.

5. The method of claim 3, wherein, In the sintering step: Carbon nanotube films are placed above and below the composite green body placed inside the furnace cavity; The furnace chamber is subjected to a vacuum degree of 1 x 10 -2 Pa~1 x 10 -5 Pa of the vacuum process; The composite green body is energized with an output current of 5~25A and an output voltage of 20~60V to maintain the temperature of the composite green body at 500~1100℃ for 2~25 minutes. After the heat preservation is completed, the composite green compact is quickly de-energized and cooled at a rate of 80℃ / s to 180℃ / s to obtain the target sheet.

6. The method of claim 3, wherein, In the phrase "the temperature of the composite green body is 500~1100℃ and held for 2~25 minutes", the temperature is 700~800℃ and held for 8~12 minutes.

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