A yttrium-lead alloy material for high-temperature-resistant middle photon composite shielding, a preparation method and applications thereof

Abstract

The application discloses a yttrium-lead alloy material for high-temperature-resistant neutron-photon composite shielding, and the main components of the yttrium-lead alloy are composed according to the following mass percentage: Pb: 1.0-30.0 wt.%, any one element or any multiple elements of Dy and Gd, wherein Dy<=20.0 wt.% and Gd<=20.0 wt.%, any one element of B or Si, wherein B<=3.0 wt.% or Si<=3.0 wt.%, and the rest components are yttrium and inevitable impurities. The material can be used as a high-temperature-resistant neutron and gamma ray composite shielding material under a high-temperature 600-1000 DEG C environment, and can shield fast neutrons, absorb thermal neutrons and shield gamma rays. After batching and special process smelting, the material is poured into a mold, and through the processes of hot forging or hot pressing, hot rolling, cold rolling, annealing and high-temperature hydrogenation, finally, the yttrium-lead alloy plate for high-temperature-resistant neutron-photon composite shielding is prepared. The application effectively refines the yttrium-based alloy grain structure, and improves the hydrogen-induced cracking resistance, heat resistance, hot workability and composite shielding capacity of the yttrium-based alloy.

Description

Technical Field

[0001] This invention relates to the field of nuclear reactor shielding materials technology, specifically to a yttrium-lead alloy material suitable for high-temperature photon shielding in microreactors and its preparation method. Background Technology

[0002] As nuclear reactor technology advances towards miniaturization and portability, it demonstrates significant strategic application value in areas such as special defense applications and distributed energy. Shielding materials, as key functional components ensuring the safe operation of the reactor and the safety of maintenance personnel, directly determine the reliability and engineering practicality of microreactors. Given the high power density, lightweight, and portability characteristics of small modular reactors, shielding materials must simultaneously meet stringent requirements such as excellent high-temperature resistance (near-core shielding temperatures reach 600-900℃), light weight, small size, and high combined neutron and gamma-ray shielding efficiency to achieve a compact and lightweight design for the reactor system.

[0003] Traditional shielding materials often suffer from limitations such as single functionality or limited high-temperature resistance. Materials like ordinary concrete, lead-boron polyethylene, and high-boron steel, due to inherent defects such as large size or poor temperature resistance, are unsuitable for the application requirements of next-generation microreactors. Metal hydrides, with their high hydrogen density providing excellent neutron moderation capabilities, along with good high-temperature stability and lightweight properties, have become important candidate systems for microreactor shielding materials. Currently developed metal hydride moderators mainly include lithium hydride, zirconium hydride, titanium hydride, and yttrium hydride. However, except for yttrium hydride, which has a decomposition temperature exceeding 900℃, other materials generally suffer from a technical bottleneck due to their relatively low upper operating temperature limit (≤600℃).

[0004] Yttrium hydride not only exhibits excellent thermal stability up to 900℃ and good structural stability, but also possesses considerable neutron moderation properties, demonstrating unique application potential in the field of microreactors. However, the engineering application of yttrium hydride still faces the following key technological challenges: First, the existing yttrium alloys generally have large grain sizes (up to hundreds of micrometers), which can easily lead to stress concentration due to local differences in hydrogen concentration during hydrogen absorption, thus causing material cracking. Secondly, yttrium has a low thermal neutron absorption cross section (only 1.28 barn) and yttrium hydride has a low density (4.38 g / cm³). 3 This results in pure yttrium hydride having insufficient shielding ability against thermal neutrons and gamma rays.

[0005] As microreactor technology advances towards higher power densities and more demanding operating environments, the limitations of existing yttrium-based alloy materials in engineering applications are becoming increasingly apparent. Traditional yttrium alloys suffer from technical defects such as poor processing performance, insufficient high-temperature oxidation resistance, and limited overall shielding effectiveness, making it difficult to meet the requirements of next-generation nuclear energy systems for shielding materials that demand synergistic improvements in multiple properties, including low density, high temperature resistance, and strong shielding. Especially in special application scenarios such as space nuclear power sources and mobile reactors, materials must also possess excellent resistance to radiation swelling. This coupling of multiple performance parameters presents significant technical challenges to the development of novel yttrium-based alloys: microstructural control is needed to address hydrogenation cracking, elemental ratios must be optimized to achieve synergistic shielding against neutrons and gamma rays, while maintaining excellent high-temperature mechanical properties and radiation stability. Summary of the Invention

[0006] This invention aims to overcome the shortcomings of existing technologies by providing a yttrium-lead alloy material that is resistant to high temperatures and possesses combined neutron and gamma-ray shielding capabilities, along with its preparation method and applications. This material exhibits fine grains, uniform microstructure, and excellent radiation resistance, enabling effective shielding against fast neutrons, thermal neutrons, and gamma rays simultaneously. Furthermore, its manufacturing process is simple and easy to process, making it widely applicable to combined neutron and gamma-ray shielding components in advanced nuclear energy systems such as space reactors, mobile reactors, and fusion reactors.

[0007] To achieve the above objectives, the present invention adopts the following inventive concept: Lead (Pb) is a silvery-white heavy metal with a soft texture and high ductility. It has a low melting point of 327.5℃, a boiling point of approximately 1750℃, and a solid density as high as 11.34 g / cm³. Chemically, lead is stable in dry air at room temperature, but in humid environments containing carbon dioxide, its surface rapidly oxidizes to form a dense film of basic lead carbonate, which effectively prevents further corrosion of the internal metal. Lead is readily soluble in nitric acid, but exhibits good corrosion resistance in dilute hydrochloric acid or sulfuric acid due to the formation of an insoluble lead chloride or lead sulfate coating on its surface. In terms of nuclear properties, lead has unique advantages. Its high atomic number (82) and high density provide excellent shielding against gamma rays and X-rays. Natural lead has a relatively small thermal neutron absorption cross section, approximately 0.17 barn. Based on these characteristics, lead is widely used in the nuclear field. It is extensively manufactured into lead plates, lead bricks, or lead-containing composite materials (such as lead-boron polyethylene) for fixed and mobile radiation shielding in radiotherapy facilities, nuclear fuel cycles, and research reactors.

[0008] This invention further discovers that lead and yttrium can form the high-melting-point compound Y5Pb3. During the solidification of yttrium-based alloys, the Y5Pb3 phase can serve as an effective heterogeneous nucleation core, significantly refining the alloy grains and obtaining a fine and uniform microstructure. This fine-grained structure not only gives the yttrium-based alloy good crack resistance during subsequent hot working and high-temperature hydrogenation treatments, but also maintains its high strength and toughness. The grain-refined yttrium-based alloy thus possesses both excellent hot working properties and high-temperature stability. Based on this, this invention, through extensive experimental research, found that adding appropriate amounts of alloying elements such as Dy, Gd, B, or Si to yttrium-lead alloys, combined with a special vacuum melting process, can further optimize the microstructure and overall properties of the alloy. The prepared yttrium-lead alloy material has the characteristics of fine grains, moderate density, good strength and toughness, high-temperature oxidation resistance, and excellent shielding performance, which can meet the composite performance requirements of advanced nuclear energy systems for shielding materials.

[0009] In summary, the yttrium-lead alloy material for high-temperature photon composite shielding provided by this invention overcomes the shortcomings of existing materials, such as large grain size, easy cracking, and limited shielding capabilities, and has significant prospects for engineering applications.

[0010] Based on the above inventive concept, the present invention adopts the following technical solution: A high-temperature resistant yttrium-lead alloy material for photon composite shielding, the main components of which are composed of the following mass percentages: Pb: 1.0-30.0 wt.%, Dy≤20.0 wt.%, Gd≤20.0 wt.%, with the remainder being yttrium and unavoidable impurities.

[0011] Preferably, the yttrium-lead alloy material for high-temperature photon composite shielding of the present invention further contains any one of the elements B and Si, wherein B ≤ 3.0 wt.% or Si ≤ 3.0 wt.%.

[0012] Preferably, the yttrium-lead alloy material for high-temperature photon composite shielding of the present invention is composed of the following mass percentages: Pb: 5.0-20.0 wt.%, Dy≤10.0 wt.% or Gd≤10.0 wt.%, B≤1.0 wt.% or Si≤1.0 wt.%, with the remainder being yttrium and unavoidable impurities.

[0013] Preferably, the yttrium-lead alloy material for high-temperature photon composite shielding of the present invention has an alloy grain size of 10–100 μm. Yttrium reacts with lead to form a high-melting-point compound Y5Pb3, Dy or Gd is completely dissolved in yttrium, and B or Si does not react with Pd to form a compound or form a compound. B or Si reacts with yttrium to form a high-melting-point compound YB2 or Y5Si3. More preferably, the alloy grain size is 10–50 μm.

[0014] In the yttrium-lead alloy provided by this invention, the main functions of each alloying element are as follows: Yttrium (Y) has a low density, and its hydride (yttrium hydride) has a high decomposition temperature. It can maintain structural stability in high-temperature environments and exhibits excellent slowing and shielding capabilities against fast neutrons, making it the base element of this invention.

[0015] Lead (Pb) has a high atomic number and high density, exhibiting excellent shielding ability against gamma rays. Simultaneously, lead and yttrium can form the high-melting-point intermetallic compound Y5Pb3, which acts as a heterogeneous nucleation core during alloy solidification, significantly refining the grain structure and improving the mechanical and processing properties of the material. In this invention, the preferred amount of lead added is 5.0–20.0 wt.%.

[0016] Dysprosium (Dy) has a high thermal neutron absorption cross section and can enhance the material's shielding ability against gamma rays, thus contributing to improved overall shielding performance of the alloy. The preferred amount of dysprosium added in this invention is ≤10.0 wt.%.

[0017] Gadolinium (Gd) also possesses a high thermal neutron absorption cross section and can improve the shielding effect of the alloy against gamma rays, further enhancing the material's neutron recombination shielding capability. The preferred amount of gdolinium added in this invention is ≤10.0 wt.%.

[0018] Boron (B) has a large thermal neutron absorption cross-section, enabling it to effectively absorb thermal neutrons. Simultaneously, boron can refine grains during alloy solidification, thus improving the uniformity of the material's microstructure. In this invention, the preferred amount of boron added is ≤1.0 wt.%.

[0019] Silicon (Si) primarily improves the mechanical and processing properties of alloys by refining the grain structure, and is an auxiliary grain-refining element in this invention. The preferred amount of silicon added in this invention is ≤1.0 wt.%.

[0020] A method for preparing the yttrium-lead alloy material for high-temperature photon composite shielding according to the present invention comprises the following steps: a. A special vacuum melting process is used for melting. The main raw materials are proportioned as follows: Pb: 1.0-30.0 wt.%, Dy≤20.0 wt.%, Gd≤20.0 wt.%, and the remaining raw materials are yttrium and unavoidable impurities. All the weighed raw materials are smelted to obtain an alloy melt, which is then molded into an alloy ingot. b. The alloy ingot prepared in step a is subjected to hot forging or hot pressing, followed by hot rolling, cold rolling, annealing, and then high-temperature hydrogenation treatment to finally obtain a yttrium-lead alloy material for high-temperature photon composite shielding.

[0021] Preferably, in step a, a special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated until the gas pressure inside the vacuum furnace cavity is 3×10⁻⁶. -3 The temperature is increased to above Pa, and then high-purity argon gas is introduced into the furnace as a protective atmosphere; then the temperature is increased to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at that temperature for at least 10min to obtain an alloy melt, which is then cast into shape.

[0022] As a preferred preparation method of the present invention, in step a above, the main raw material components are formulated according to the following mass percentages: Pb: 5.0-20.0 wt.%, Dy≤10.0 wt.% or Gd≤10.0 wt.%, and the remaining components are yttrium and unavoidable impurities.

[0023] More preferably, in step a, the raw material components are formulated according to the following mass percentages: Pb: 5.0-20.0 wt.%, Dy≤10.0 wt.% or Gd≤10.0 wt.%, B≤1.0 wt.% or Si≤1.0 wt.%, with the remainder being yttrium and unavoidable impurities.

[0024] Preferably, in step b, the alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling; wherein, the hot pressing temperature is controlled to be not lower than 800°C; the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then, cold rolling is performed at least 3 times; then, argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, followed by cooling to room temperature, and finally, a high-temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance is obtained.

[0025] An application of the yttrium-lead alloy material for high-temperature photon composite shielding according to the present invention is described. In a high-temperature environment of 600-1000℃, the yttrium-lead alloy material is used as a high-temperature photon composite shielding material, which simultaneously slows down fast neutrons, absorbs thermal neutrons, and shields gamma rays.

[0026] Preferably, the yttrium-lead alloy material for high-temperature photon composite shielding described in this invention is used as a lightweight, high-efficiency, high-temperature nuclear shielding material for preparing neutron and gamma-ray composite shielding bodies or γ-ray composite shielding components in any of the advanced reactors such as space reactors, vehicle-mounted reactors, or fusion reactors.

[0027] Compared with the prior art, the present invention has the following obvious and prominent substantive features and significant advantages: 1. Compared with the neutron moderation materials commonly used in the field of nuclear shielding (such as LiH, ZrH2 and TiH2), the yttrium lead alloy material provided by this invention can be stably used in high-temperature environments of 600 to 1000°C, and is a new type of nuclear shielding material that combines high temperature resistance and high-efficiency shielding performance.

[0028] 2. This invention introduces Pb to form a high-melting-point Y5Pb3 phase, significantly refining the alloy grains. This results in a fine and uniform microstructure after subsequent hot rolling, hot pressing, and annealing, thus exhibiting significant resistance to hydrogen-induced cracking. Simultaneously, the added Dy, Gd, and B elements in the alloy possess a large thermal neutron absorption cross-section, effectively absorbing thermal neutrons. Combined with the fast neutron moderation capability of the yttrium hydride matrix and the gamma-ray shielding capability of Pb, the material of this invention can simultaneously achieve composite shielding against fast neutrons, thermal neutrons, and gamma rays. The overall shielding efficiency is significantly superior to traditional materials, making it an ideal candidate to replace existing shielding materials.

[0029] 3. The lightweight, high-efficiency, high-temperature resistant yttrium-lead alloy material for photon composite shielding of this invention has advantages such as low density, high temperature resistance, corrosion resistance, and radiation resistance, and can adapt to the harsh service environments of advanced nuclear energy systems such as space reactors, mobile reactors, and fusion reactors. Furthermore, its production process is simple, facilitating engineering fabrication and the processing of complex-shaped components, demonstrating promising application prospects and widespread value. Attached Figure Description

[0030] Figure 1 This is a metallographic photograph of the yttrium-lead alloy precursor material used for nuclear shielding in Embodiment 3 of the present invention.

[0031] Figure 2 This is a metallographic image of the yttrium lead alloy hydride (H / Y=1.85) material used for nuclear shielding in an embodiment of the present invention.

[0032] Figure 3 This is a metallographic image of the yttrium-lead alloy precursor material for octa-core shielding in an embodiment of the present invention.

[0033] Figure 4 The metallographic structure of the yttrium lead alloy hydride (H / Y=1.85) material for octa-core shielding according to an embodiment of the present invention is shown. Detailed Implementation

[0034] The above solution will be further described below with reference to specific embodiments. The preferred embodiments of the present invention are described in detail below: Example 1

[0035] In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 1.0 wt% Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0036] Experimental testing and analysis: Experimental results show that the grain size of the alloy material prepared in this embodiment is below 100 μm. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3, achieving grain refinement. The addition of Pb provides gamma-ray shielding capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant, mid-photon composite shielding yttrium-lead alloy material. Example 2

[0037] This embodiment is basically the same as Embodiment 1, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 3.0wt%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0038] Experimental testing and analysis: Experimental results show that the grain size of the alloy material prepared in this embodiment is below 100 μm. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3, achieving grain refinement. The addition of Pb provides gamma-ray shielding capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant, mid-photon composite shielding yttrium-lead alloy material. Example 3

[0039] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 5.0 wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0040] Experimental test analysis: The experimental test results show that the grain size of the alloy material prepared in this embodiment is below 60μm, which achieves grain refinement. Figure 1 This is a metallographic photograph of the yttrium-lead alloy precursor material used for nuclear shielding in this embodiment. Figure 2This is a metallographic image of the yttrium-lead alloy hydride (H / Y=1.85) material used for nuclear shielding in this embodiment. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability. The alloy material prepared in this embodiment exhibits excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient and high-temperature resistant yttrium-lead alloy material for mid-photon composite shielding. Example 4

[0041] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 10.0 wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0042] Experimental testing and analysis: Experimental results show that the grain size of the alloy material prepared in this embodiment is below 40 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant, mid-photon composite shielding yttrium-lead alloy material. Example 5

[0043] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 15.0 wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0044] Experimental testing and analysis: Experimental results show that the grain size of the alloy material prepared in this embodiment is below 30 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant, mid-photon composite shielding yttrium-lead alloy material. Example 6

[0045] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 20.0wt%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0046] Experimental testing and analysis: Experimental results show that the grain size of the alloy material prepared in this embodiment is below 30 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant, mid-photon composite shielding yttrium-lead alloy material. Example 7

[0047] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 30.0 wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0048] Experimental testing and analysis: Experimental results show that the grain size of the alloy material prepared in this embodiment is below 30 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant, mid-photon composite shielding yttrium-lead alloy material. Example 8

[0049] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 10.0 wt.%; Dy 10.0wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0050] Experimental test analysis: The experimental test results show that the grain size of the alloy material prepared in this embodiment is below 40μm, which achieves grain refinement. Figure 3 This is a metallographic photograph of the yttrium-lead alloy precursor material used for nuclear shielding in this embodiment. Figure 4 This is the metallographic structure of the yttrium-lead alloy hydride (H / Y=1.85) material used for nuclear shielding in this embodiment. In the alloy, yttrium and lead form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability, while the introduction of Dy provides additional thermal neutron absorption capability. The alloy material prepared in this embodiment exhibits excellent high-temperature resistance and can be used as a high-temperature resistant nuclear shielding material. It is a highly efficient, high-temperature resistant neutron composite shielding yttrium-lead alloy material. Example 9

[0051] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 10.0 wt.%; Dy 20.0wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0052] Experimental Testing and Analysis: Experimental results show that the grain size of the alloy material prepared in this embodiment is below 40 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability, while the introduction of Dy provides additional thermal neutron absorption capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant neutron composite shielding yttrium-lead alloy material. Example 10

[0053] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 10.0 wt.%; Gd 10.0wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0054] Experimental Testing and Analysis: Experimental results show that the alloy material prepared in this embodiment has a grain size below 40 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability, while the introduction of Gd provides additional thermal neutron absorption capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant neutron composite shielding yttrium-lead alloy material. Example 11

[0055] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 10.0 wt.%; Gd 20.0wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0056] Experimental Testing and Analysis: Experimental results show that the alloy material prepared in this embodiment has a grain size below 40 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability, while the introduction of Gd provides additional thermal neutron absorption capability. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant neutron composite shielding yttrium-lead alloy material. Example 12

[0057] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 20.0 wt.%; Dy 10.0wt.%; Si 1.0wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0058] Experimental Testing and Analysis: Experimental results show that the alloy material prepared in this embodiment has a grain size below 30 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability, the introduction of Dy provides additional thermal neutron absorption capability, and Si further promotes grain refinement. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant neutron composite shielding yttrium-lead alloy material. Example 13

[0059] This embodiment is basically the same as the above embodiments, except that: In this embodiment, a method for preparing a yttrium-lead alloy material for high-temperature photon composite shielding includes the following steps: a. A special vacuum melting process is adopted, and the raw material composition is formulated according to the following mass percentages: Pb 10.0 wt.%; Dy 5.0wt.%; B 1.0wt.%; Y margin; A special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated to a vacuum level of 3×10⁻⁶. -3 The temperature is above Pa, and then high-purity argon gas is introduced as a protective atmosphere; then the temperature is raised to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at the temperature for at least 10min to obtain an alloy melt, which is then cast into an alloy ingot. b. The alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling treatment, wherein the hot pressing temperature is controlled to be not lower than 800°C and the hot rolling temperature is not lower than 850°C, and the rolling is repeated at least 3 times; then cold rolling is performed at least 3 times; then argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment are performed, and then cooled to room temperature to finally obtain a high temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

[0060] Experimental Testing and Analysis: Experimental results show that the alloy material prepared in this embodiment has a grain size below 30 μm, achieving grain refinement. Yttrium and lead in the alloy form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability, the introduction of Dy provides additional thermal neutron absorption capability, and the introduction of B further promotes grain refinement while also providing thermal neutron absorption. The alloy material prepared in this embodiment possesses excellent high-temperature resistance and can be used as a high-temperature nuclear shielding material. It is a highly efficient, high-temperature resistant neutron composite shielding yttrium-lead alloy material.

[0061] Figure 1 This is a metallographic image of the yttrium-lead alloy precursor material used for nuclear shielding in Example 3. Figure 2 This is a metallographic image of the yttrium lead alloy hydride (H / Y=1.85) material used for nuclear shielding in Example 3. Figure 3 This is a metallographic image of the yttrium-lead alloy precursor material used for eight-core shielding in Example 8. Figure 4 The metallographic structure of the yttrium lead alloy hydride (H / Y=1.85) material for nuclear shielding in Example 8 is shown. Based on the metallographic structures of the Y-5Pb alloy precursor in Example 3 and the Y-10Pb-10Dy alloy precursor in Example 8, it can be seen that the grain size of the alloy material is below 60 μm, even below 40 μm, including yttrium lead alloys with grain sizes of 40~60 μm. In the alloy, yttrium and lead form a high-melting-point compound Y5Pb3. The addition of Pb provides gamma-ray shielding capability, and the introduction of Dy provides additional thermal neutron absorption capability.

[0062] In summary, the lightweight, high-efficiency, high-temperature resistant yttrium-lead alloy material for medium-photon composite shielding described in Examples 1 to 13 has the following main components in the following mass percentages: Pb: 1.0-30.0 wt.%, Dy≤20.0 wt.% or Gd≤20.0 wt.%, B≤3.0 wt.%, or Si≤3.0 wt.%, with the remainder being yttrium and unavoidable impurities. The preferred composition of the lightweight, high-efficiency, high-temperature resistant yttrium-lead alloy material for medium-photon composite shielding in this invention is: Pb: 5.0-20.0 wt.%, Dy≤10.0 wt.% or Gd≤10.0 wt.%, B≤1.0 wt.% or Si≤1.0 wt.%, with the remainder being yttrium and unavoidable impurities. An alloy melt was obtained through batching and a special vacuum melting process; after casting, it was then subjected to hot forging or hot pressing, hot rolling, annealing, and high-temperature hydrogenation processes to finally produce a lightweight, high-efficiency, high-temperature resistant yttrium-lead alloy plate for photon shielding. The lightweight, high-efficiency, high-temperature resistant yttrium-lead alloy material for photon composite shielding described in the above embodiments of the present invention has advantages such as fine grains, good strength and toughness, corrosion resistance, and resistance to hydrogen-induced cracking. In the above embodiments, Y has a relatively low density, and yttrium hydride has a high decomposition temperature, exhibiting excellent shielding ability against fast neutrons and high-temperature resistance. Lead (Pb), as a high atomic number (82) heavy metal, has a high density (11.34 g / cm³). 3Lead possesses advantages in nuclear performance, including strong gamma-ray shielding capabilities. Furthermore, lead is chemically stable and readily forms a dense oxide film in air, exhibiting excellent corrosion resistance, and has been widely used in radiation shielding materials. Lead and yttrium can form the high-melting-point compound Y5Pb3. During the solidification process of yttrium-based alloys, Y5Pb3 refines the grain size, resulting in fine and uniform grains that do not crack during subsequent hot working and high-temperature hydrogenation. Grain-refined yttrium-based alloys exhibit excellent hot workability, high-temperature resistance, and resistance to hydrogen-induced cracking. In high-temperature environments (600-1000℃), yttrium-lead alloys for high-temperature photon composite shielding can be used as composite shielding materials for neutrons and gamma rays in high-temperature service environments, simultaneously slowing down fast neutrons, absorbing thermal neutrons, and shielding gamma rays.

[0063] In Examples 8 to 13, Dy and Gd elements can improve the thermal neutron and gamma-ray shielding capabilities of yttrium-based alloys. The above embodiments of the present invention, by adding Dy or Gd, further obtain novel yttrium-based alloy materials for neutral photon shielding with low density, high temperature resistance, oxidation resistance, and strong shielding capabilities. Furthermore, the addition of Si and B further refines the alloy grain size, with B also enhancing the material's thermal neutron absorption capacity. Through extensive experimental verification, the present invention demonstrates that by adding appropriate proportions of lead, dysprosium, or gadolinium to yttrium-based alloys, combined with a special vacuum melting process, yttrium-lead alloys with high temperature resistance, strong shielding capabilities, and good toughness can be prepared. The high-temperature resistant yttrium-lead alloy material for neutral photon composite shielding in this invention has advantages such as fine grain size, low density, resistance to hydrogen-induced cracking, high temperature resistance, and good corrosion resistance. This invention discloses a yttrium-lead alloy material for high-temperature photon composite shielding. The main components of the yttrium-lead alloy are composed of the following mass percentages: Pb: 1.0-30.0 wt.%, any one or more elements from Dy and Gd, where Dy ≤ 20.0 wt.% and Gd ≤ 20.0 wt.%, any one element from B or Si, where B ≤ 3.0 wt.% or Si ≤ 3.0 wt.%, and the remainder being yttrium and unavoidable impurities. It can be used as a high-temperature neutron and gamma-ray composite shielding material at temperatures of 600-1000℃, simultaneously shielding fast neutrons, absorbing thermal neutrons, and shielding gamma rays. The material is prepared by batching and special smelting processes, casting, and then hot forging or hot pressing, hot rolling, cold rolling, annealing, and high-temperature hydrogenation to finally obtain the yttrium-lead alloy sheet for high-temperature photon composite shielding. This invention effectively refines the grain structure of yttrium-based alloys, improving their resistance to hydrogen-induced cracking, heat resistance, hot workability, and composite shielding capabilities.

[0064] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. Various changes can be made according to the purpose of the invention. Any changes, modifications, substitutions, combinations or simplifications made based on the spirit and principle of the technical solution of the present invention shall be equivalent substitutions. As long as they meet the purpose of the invention and do not deviate from the technical principle and inventive concept of the lightweight, high-efficiency, high-temperature resistant yttrium-lead alloy material for photon composite shielding and its preparation method, they shall all fall within the protection scope of the present invention.

Claims

1. A yttrium-lead alloy material for high-temperature photon composite shielding, characterized in that, Its main components are as follows by mass percentage Composition: Pb: 1.0-30.0 wt.%, Dy≤20.0 wt.%, Gd≤20.0 wt.%, the remainder being yttrium and unavoidable impurities.

2. The yttrium-lead alloy material for high-temperature photon composite shielding according to claim 1, characterized in that: Its composition also contains any one of the elements B and Si, where B ≤ 3.0 wt.% or Si ≤ 3.0 wt.%.

3. The yttrium-lead alloy material for high-temperature photon composite shielding according to claim 1 or 2, characterized in that, Its composition is as follows by mass percentage: Pb: 5.0-20.0 wt.%, Dy≤10.0 wt.% or Gd≤10.0 wt.%, B≤1.0 wt.% or Si≤1.0 wt.%, with the remainder being yttrium and unavoidable impurities.

4. The yttrium-lead alloy material for high-temperature photon composite shielding according to claims 1-3, characterized in that: The alloy grain size is 10-100 μm. Yttrium and lead form a high-melting-point compound Y5Pb3. Dy or Gd is completely dissolved in yttrium. B or Si does not react with Pd to form a compound. B or Si forms a high-melting-point compound YB2 or Y5Si3 with yttrium.

5. A method for preparing the yttrium-lead alloy material for high-temperature photon composite shielding as described in claim 1, characterized in that, The steps are as follows: a. A special vacuum melting process is used for melting. The main raw materials are proportioned as follows: Pb: 1.0-30.0 wt.%, Dy≤20.0 wt.%, Gd≤20.0 wt.%, and the remaining raw materials are yttrium and unavoidable impurities. All the weighed raw materials are smelted to obtain an alloy melt, which is then molded into an alloy ingot. b. The alloy ingot prepared in step a is subjected to hot forging or hot pressing, followed by hot rolling, cold rolling, annealing, and then high-temperature hydrogenation treatment to finally obtain a yttrium-lead alloy material for high-temperature photon composite shielding.

6. The preparation method of the yttrium-lead alloy material for high-temperature photon composite shielding according to claim 5, characterized in that: In step a), a special vacuum melting process is used, in which the prepared raw materials are placed in a vacuum furnace and evacuated until the gas pressure inside the vacuum furnace chamber is 3×10⁻⁶. -3 The temperature is increased to above Pa, and then high-purity argon gas is introduced into the furnace as a protective atmosphere; then the temperature is increased to not less than 1700℃ at a heating rate of not less than 10℃ / min, and held at that temperature for at least 10min to obtain an alloy melt, which is then cast into shape.

7. The preparation method of the yttrium-lead alloy material for high-temperature photon composite shielding according to claim 5, characterized in that: In step a above, the main raw material components are formulated according to the following mass percentages: Pb: 5.0-20.0 wt.%, Dy≤10.0 wt.% or Gd≤10.0 wt.%, with the remainder being yttrium and unavoidable impurities.

8. The preparation method of the yttrium-lead alloy material for high-temperature photon composite shielding according to claim 5, characterized in that: In step b, the alloy ingot obtained by casting the alloy melt prepared in step a is subjected to hot pressing and hot rolling. The hot pressing temperature is controlled to be no less than 800°C, the hot rolling temperature is no less than 850°C, and the rolling is repeated at least 3 times. Then, it is cold rolled at least 3 times. Then, it is subjected to argon protective atmosphere annealing heat treatment and hydrogenation process heat treatment, and then cooled to room temperature to finally obtain a high-temperature resistant yttrium lead alloy material plate for photon composite shielding and hydrogen-induced cracking resistance.

9. The application of the yttrium-lead alloy material for high-temperature photon composite shielding as described in claim 1, characterized in that, In a high-temperature environment of 600-1000℃, the yttrium-lead alloy material is used as a high-temperature resistant photon composite shielding material, which simultaneously slows down fast neutrons, absorbs thermal neutrons, and shields gamma rays.

10. The application of the yttrium-lead alloy material for high-temperature photon composite shielding according to claim 9, characterized in that: The yttrium-lead alloy material for high-temperature photon composite shielding is used to prepare neutron and gamma-ray composite shields in any of the advanced reactors, such as space reactors, vehicle-mounted reactors, or fusion reactors.

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