A solid solution strengthening multi-component molybdenum rhenium alloy with low rhenium content and a preparation method thereof
By introducing Re, Nb, Zr and/or Ti elements into molybdenum-rhenium alloys, polygonal structures and stable compounds are formed, solving the problem of insufficient mechanical properties of molybdenum-rhenium alloys with low rhenium content. This enables the preparation of high-performance, low-cost molybdenum-rhenium alloys and enhances their value in industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NUCLEAR POWER INSTITUTE OF CHINA
- Filing Date
- 2026-05-28
- Publication Date
- 2026-07-24
AI Technical Summary
Even after reducing the rhenium content, the mechanical properties and plasticity of existing molybdenum-rhenium alloys have not improved significantly enough, making it difficult to meet the needs of industrial applications.
By introducing Re, Nb, Zr and/or Ti elements into molybdenum-rhenium alloys, and utilizing the synergistic effect of these elements, polygonal structures and stable compounds are formed, improving the solid solution strengthening effect of the alloy, and reducing the Re content while maintaining or exceeding the mechanical properties of Mo-5Re alloys.
This study improved the hardness, tensile strength, and yield strength of molybdenum-rhenium alloys with low rhenium content, maintained good machinability, reduced costs, solved the bottleneck problem in Mo-Re alloy composition design, and enhanced application value.
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Figure CN122446033A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of refractory alloy technology, specifically to a solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content and its preparation method. Background Technology
[0002] Mo-Rhenium alloy (Mo-Re alloy) is a refractory alloy formed by adding metallic Re to Mo as the matrix. Its core value lies in utilizing the "Re effect" to completely solve the fatal shortcomings of pure molybdenum, such as high room temperature brittleness, difficult processing, and poor welding. At the same time, it maintains and significantly improves the high-temperature strength, creep resistance, and thermal shock resistance of Mo, making it a key material for high-temperature and extreme environments.
[0003] The mechanical properties of molybdenum-rhenium alloys are limited by the Re content. Adding Re to Mo creates the "Re effect," significantly improving Mo's room-temperature brittleness and enhancing its strength, creep resistance, and weldability. When the Re mass fraction is below 50%, the strength and ductility of Mo-Re alloys increase with increasing Re content. However, Re resources are scarce and expensive. Reducing the Re content in Mo-Re alloys is crucial for industrial applications. However, as the Re content decreases, the "Re effect" gradually weakens, and the strengthening effect, especially the improvement in ductility, becomes less pronounced. Therefore, maintaining or exceeding the mechanical properties of Mo-Re alloys with low Re content, and reducing the alloy's dependence on the "Re effect," has become a challenge in Mo-Re alloy composition design.
[0004] In conclusion, there is an urgent need to develop a low-cost, high-performance molybdenum-rhenium alloy that combines excellent performance with promising prospects for industrial application. Summary of the Invention
[0005] In view of the above-mentioned shortcomings in the prior art, the core objective of this invention is to provide a solid solution strengthened multi-component molybdenum-rhenium alloy with low rhenium content and its preparation method. It can improve the mechanical properties of molybdenum-rhenium alloy with low rhenium content through the solid solution strengthening effect generated by multi-element alloying while reducing Re content, and ultimately surpass the mechanical properties of low rhenium content molybdenum-rhenium alloys such as Mo-5Re.
[0006] This invention is achieved through the following technical solution: A solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content is composed of the following components in weight percentage: Re: 2.8%~4.0%; Nb: 1.0%~4.0%; Zr: 0.1%~0.2%; Ti: 0%~0.4%; with the balance being Mo and unavoidable impurities.
[0007] The "rhenium effect" is based on the high solubility of Re in Mo. The dissolution of Re alters the electronic structure of Mo, increasing the electron concentration near the Fermi level, reducing the directionality of atomic bonds and stacking fault energy, which facilitates dislocation decomposition and slip, thus promoting plastic deformation. Simultaneously, the presence of Re provides a new deformation mechanism; the solid solution of Re lowers the twinning critical shear stress of Mo, enabling the activation of deformation twins during deformation and promoting its plastic deformation. Furthermore, the presence of Re increases the concentration of interstitial impurities in the metal solid solution. The solubility of Rhenium in Re and Mo inhibits the segregation and precipitation of carbides and oxides at grain boundaries / subgrain boundaries and lattice defects. Rhenium also segregates at grain boundaries / subgrain boundaries, displacing interstitial elements such as carbon. Furthermore, Rhenium can form MoReO4-type compounds with Mo, which, unlike MoO2, do not wet grain boundaries, thus mitigating the embrittlement effect of oxygen on grain boundaries. Moreover, Re and Mo have almost identical atomic sizes, preventing lattice distortion during alloying and effectively maintaining their plastic deformation capacity. In addition, Re metal can enhance the strength of Mo metal through solid solution strengthening. Based on these mechanisms, the excellent mechanical properties and good processing performance of Mo-Re alloys can be achieved.
[0008] For those skilled in the art, the most direct method for developing low-cost Mo alloy structural materials is to find an element that can directly replace Re, which has the same mechanism of action. However, in the long course of research, those skilled in the art have not found other low-cost elements that can replace Re. Most common solute elements either have low solubility, making it difficult to disrupt the electronic structure of Mo, or have large size differences with Mo, which can easily cause lattice distortion and affect its plastic deformation ability.
[0009] Based on a thorough study of the underlying mechanism of the "rhenium effect", this application selected four elements: Re, Nb, Zr and / or Ti. By utilizing the synergistic effect between these four elements, it was achieved that Mo-based alloys with excellent mechanical properties and good processing performance could be prepared while reducing the Re content, thus realizing the development of low-cost structural materials.
[0010] Specifically: This application uses Re, Nb, Zr and / or Ti in a certain proportion. The high solubility of Nb in Mo allows for the formation of more dislocation polygonal structures in the molybdenum-based alloy, hindering the diffusion of Mo atoms and dislocations and achieving a strengthening effect. Zr and / or Ti, as active elements, have much higher activity than Mo, Re, and Nb, and can preferentially react with interstitial impurities such as carbon and oxygen in the alloy to form stable compounds such as ZrC, ZrO2, TiC, and TiO2. This avoids the segregation and precipitation of carbon and oxygen impurities at grain boundaries / subgrain boundaries and lattice defects, eliminating grain boundary embrittlement caused by impurities. They can also act as second-phase particles to exert a dispersion strengthening effect, further improving the alloy strength. Simultaneously, this application retains a certain amount of Re, utilizing the high solubility of Re and its minimal size difference with Mo, along with the other elements mentioned above, to maintain the alloy's good plasticity.
[0011] Preferably, the low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy is composed of the following components by weight percentage: Re: 2.8%~4.0%; Nb: 1.0%~4.0%; Zr: 0.1%~0.2%; Ti: 0.1%~0.4%; with the balance being Mo and unavoidable impurities.
[0012] Preferably, the low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy is composed of the following components by weight percentage: Re: 3.2%~3.8%; Nb: 1.5%~3.5%; Zr: 0.15%~0.2%; Ti: 0.2%~0.4%; with the balance being Mo and unavoidable impurities.
[0013] Preferably, the low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy is composed of the following components in weight percentage: Re: 3.5%~3.8%; Nb: 1.5%~3.0%; Zr: 0.15%~0.2%; Ti: 0.3%~0.4%; with the balance being Mo and unavoidable impurities.
[0014] Preferably, the low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy is composed of the following components by weight percentage: Re: 3.5%; Nb: 1.5%; Zr: 0.15%; Ti: 0.4%; with the balance being Mo and unavoidable impurities.
[0015] To meet the requirements of effective miscibility of multiple elements and uniformity of alloy composition, while ensuring the purity of the alloy during preparation, this invention also provides a method for preparing the above-mentioned low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy, comprising the following steps: Step 1, Mixing and Blending Powders: Weigh out Mo powder, Re powder, Nb powder, Zr powder and Ti powder according to the specified ratio, and mix them evenly in a mixer; during mixing, a protective gas is introduced; the evenly mixed powders are quantitatively distributed to obtain the first raw material; Step 2, Powder feeding: The first raw material obtained in Step 1 is fed into and filled into the high-throughput melting position of the vacuum arc melting furnace; Step 3, Vacuum Melting: After Step 2 is completed, the first raw material in the high-throughput melting position is melted by electric arc in a vacuum electric arc melting furnace to obtain an ingot; Step 4, heat treatment: Anneal the ingot obtained after melting in step 3 to obtain the molybdenum-rhenium alloy.
[0016] Preferably, in step 1, the Mo powder has a purity ≥ 99.95% and a particle size of 300-400 mesh; the Re powder has a purity ≥ 99.99% and a particle size of 300-400 mesh; the Nb powder has a purity ≥ 99.50% and a particle size of 300-400 mesh; the Zr powder has a purity ≥ 99.50% and a particle size of 300-400 mesh; and the Ti powder has a purity ≥ 99.50% and a particle size of 300-400 mesh.
[0017] Preferably, in step 1, the mixing time is 10~18h, and the protective gas is argon.
[0018] Preferably, in step 3, the vacuum degree during arc melting in a vacuum arc melting furnace is 10. -4 ~10 -5 .
[0019] Preferably, in step 4, the annealing temperature is 800~1100℃ and the annealing time is 1h~3h.
[0020] Preferably, in step 1, Mo powder, Re powder, Nb powder, Zr powder and Ti powder are weighed according to the proportions and placed in a mixer to be mixed evenly. The total amount of powder mixed in each batch is 4.0~8.0 kg, and the mixing time is 10~18h. The powder mixed in each batch is then quantitatively distributed. Each batch of mixed powder was quantitatively allocated, with 160~180g of raw material used for preparing a single high-throughput sample of solid solution strengthened multi-component molybdenum-rhenium alloy with low rhenium content. This raw material was designated as the first raw material.
[0021] Preferably, in step 2, the vacuum arc melting furnace has 1 to 56 high-throughput melting stations.
[0022] The present invention has at least the following advantages and beneficial effects: This invention adjusts the composition of Mo-Re alloys to provide a low-rhenium-content, solid-solution-strengthened multi-component molybdenum-rhenium alloy. Compared to existing low-rhenium-content Mo-5Re alloys, this invention's low-rhenium-content, solid-solution-strengthened multi-component molybdenum-rhenium alloy achieves solid-solution strengthening through multi-element alloying, reducing the Re content. It exhibits superior hardness, tensile strength, and yield strength compared to Mo-5Re alloys, while retaining and optimizing processing performance. It also reduces the dependence of Mo-Re alloys on the "rhenium effect," solving the bottleneck problem in Mo-Re alloy composition design and representing a significant advancement. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the high-throughput tensile specimen in Experiment Example 1. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the present invention will be further described below in conjunction with specific embodiments.
[0025] The following embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way.
[0026] Example 1 This embodiment provides a solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content, composed of the following components by mass percentage: 2.8% Re, 2.0% Nb, 0.15% Zr, with the balance being Mo and unavoidable impurities.
[0027] The above-mentioned method for preparing a solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content includes the following steps: Step 1: Powder Mixing and Preparation: Mo powder, Re powder, Nb powder, and Zr powder are placed in a mixer according to the specified ratio and mixed evenly. Argon gas is introduced during the mixing process. The total mass of the mixed powder is 4.0 kg, and the mixing time is 10 h. The mixed powder is then quantitatively distributed, with 160 g of raw material used for preparing a single high-throughput sample of a solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content. The Mo powder has a purity ≥ 99.95% and a particle size of 325 mesh; the Re powder has a purity ≥ 99.99% and a particle size of 325 mesh; the Nb powder has a purity ≥ 99.50% and a particle size of 325 mesh; and the Zr powder has a purity ≥ 99.50% and a particle size of 325 mesh.
[0028] Step 2, Powder Feeding: The raw materials are fed into and filled into the 24 high-throughput melting positions of the vacuum arc melting furnace. The vacuum arc melting furnace has 3 rows of high-throughput melting positions, with 8 positions in each row, for a total of 24 melting positions.
[0029] Step 3, Vacuum Melting: The raw materials in the high-throughput melting position are melted by electric arc in a vacuum arc melting furnace with a vacuum degree of 10. -4 Pa.
[0030] Step 4, heat treatment: The high-throughput ingot after melting is annealed at 800°C for 1 hour to obtain the molybdenum-rhenium alloy of this embodiment.
[0031] Example 2 This embodiment provides a solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content, which differs from Embodiment 1 in that it is composed of the following components by mass percentage: 2.8% Re, 2.0% Nb, 0.15% Zr, 0.2% Ti, with the balance being Mo and unavoidable impurities.
[0032] The preparation method of the above-mentioned solid solution strengthened multi-component molybdenum-rhenium alloy with low rhenium content is the same as that in Example 1, wherein the Ti powder has a purity of ≥99.50% and a particle size of 300~400 mesh.
[0033] Example 3 This embodiment provides a solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content, which differs from Embodiment 1 in that it is composed of the following components by mass percentage: 3.2% Re, 1.5% Nb, 0.1% Zr, 0.4% Ti, with the balance being Mo and unavoidable impurities.
[0034] The difference between the preparation method and Example 2 is as follows: Step 3, Vacuum Melting: The raw materials in the high-throughput melting position are melted by electric arc in a vacuum arc melting furnace with a vacuum degree of 10. -5 Pa.
[0035] Step 4, heat treatment: The high-throughput ingot after melting is annealed at 1100℃ for 3 hours to obtain the molybdenum-rhenium alloy of this embodiment.
[0036] Example 4 This embodiment provides a solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content, which differs from Embodiment 1 in that it is composed of the following components by mass percentage: 3.5% Re, 3.0% Nb, 0.1% Zr, 0.3% Ti, with the balance being Mo and unavoidable impurities.
[0037] The preparation method is the same as in Example 2.
[0038] Example 5 This embodiment provides a solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content, which differs from Embodiment 1 in that it is composed of the following components by mass percentage: 4.0% Re, 1.0% Nb, 0.2% Zr, 0.1% Ti, with the balance being Mo and unavoidable impurities.
[0039] The preparation method is the same as in Example 2.
[0040] Comparative Example 1 This comparative example provides a molybdenum-rhenium alloy composed of the following components by mass percentage: 5% Re, with the balance being Mo and unavoidable impurities.
[0041] The preparation method is the same as in Example 2.
[0042] Comparative Example 2 This comparative example provides a molybdenum-rhenium alloy composed of the following components by mass percentage: 3.5% Re, 3% Nb, with the balance being Mo and unavoidable impurities.
[0043] The preparation method is the same as in Example 2.
[0044] Comparative Example 3 This comparative example provides a molybdenum-rhenium alloy composed of the following components by mass percentage: 3.5% Re, 0.2% Zr, with the balance being Mo and unavoidable impurities.
[0045] The preparation method is the same as in Example 2.
[0046] Comparative Example 4 This comparative example provides a molybdenum-rhenium alloy composed of the following components by mass percentage: 3.5% Re, 0.4% Ti, with the balance being Mo and unavoidable impurities.
[0047] The preparation method is the same as in Example 2.
[0048] Experimental Example 1 The mechanical properties of the molybdenum-rhenium alloys prepared in Examples 1-5 and Comparative Examples 1-5 were tested at room temperature. The specific methods are as follows: High-throughput tensile specimens were taken from the ingot. Figure 1 The sample dimensions are given; indentation samples were taken from the ingot, with a sample size of φ10mm×4mm. Tensile tests were performed on the high-throughput tensile samples to determine Young's modulus, tensile strength, and yield strength. The hardness of the material was measured using a nanoindenter. The test results are shown in Table 1.
[0049] Table 1. Performance test results of molybdenum-rhenium alloys prepared in each embodiment and comparative example.
[0050] Based on the above test results, we can conclude that: The low rhenium content solid solution strengthened multi-component molybdenum-rhenium alloys of the various embodiments of the present invention have better mechanical properties such as hardness, tensile strength and yield strength than the Mo-5Re alloy of Comparative Example 1, and the uniform elongation of each embodiment is close to or better than that of the Mo-5Re alloy of Comparative Example 1.
[0051] Comparing the results of each embodiment and Comparative Example 2, it can be seen that when only some Nb elements are replaced with some Re elements, although the mechanical properties such as tensile strength and yield strength are improved, the processing performance will decrease.
[0052] Comparing the results of each embodiment and Comparative Examples 3 and 4, it can be seen that when Zr and Ti are combined with Re-Mo to form alloys, the mechanical properties such as tensile strength and yield strength are improved or not significantly changed, but the processing performance is significantly reduced, and the Re effect of Mo-Re alloys cannot be effectively utilized.
[0053] In summary, the low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy of the present invention can effectively reduce the dependence of Mo-Re alloys on the "rhenium effect", significantly reduce raw material costs, solve the bottleneck problem of Mo-Re alloy composition design, and enhance its application value and prospects in meeting the needs of industrialization and mass production.
[0054] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.
Claims
1. A solid solution-strengthened multi-component molybdenum-rhenium alloy with low rhenium content, characterized in that, It consists of the following components by weight percentage: Re: 2.8%~4.0%; Nb: 1.0%~4.0%; Zr: 0.1%~0.2%; Ti: 0%~0.4%; the balance being Mo and unavoidable impurities.
2. The low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to claim 1, characterized in that, It consists of the following components by weight percentage: Re: 2.8%~4.0%; Nb: 1.0%~4.0%; Zr: 0.1%~0.2%; Ti: 0.1%~0.4%; the balance being Mo and unavoidable impurities.
3. The low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to claim 1, characterized in that, It consists of the following components by weight percentage: Re: 3.2%~3.8%; Nb: 1.5%~3.5%; Zr: 0.15%~0.2%; Ti: 0.2%~0.4%; the balance being Mo and unavoidable impurities.
4. The low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to claim 1, characterized in that, It consists of the following components by weight percentage: Re: 3.5%~3.8%; Nb: 1.5%~3.0%; Zr: 0.15%~0.2%; Ti: 0.3%~0.4%; the balance being Mo and unavoidable impurities.
5. The low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to claim 1, characterized in that, It consists of the following components by weight percentage: Re: 3.5%; Nb: 1.5%; Zr: 0.15%; Ti: 0.4%; the balance being Mo and unavoidable impurities.
6. The method for preparing a low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1, Mixing and Blending Powders: Weigh out Mo powder, Re powder, Nb powder, Zr powder and Ti powder according to the specified ratio, and mix them evenly in a mixer; during mixing, a protective gas is introduced; the evenly mixed powders are quantitatively distributed to obtain the first raw material; Step 2, Powder feeding: The first raw material obtained in Step 1 is fed into and filled into the high-throughput melting position of the vacuum arc melting furnace; Step 3, Vacuum Melting: After Step 2 is completed, the first raw material in the high-throughput melting position is melted by electric arc in a vacuum electric arc melting furnace to obtain an ingot; Step 4, heat treatment: Anneal the ingot obtained after melting in step 3 to obtain the molybdenum-rhenium alloy.
7. The method for preparing a low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to claim 6, characterized in that, In step 1, the Mo powder has a purity ≥ 99.95% and a particle size of 300-400 mesh; the Re powder has a purity ≥ 99.99% and a particle size of 300-400 mesh; the Nb powder has a purity ≥ 99.50% and a particle size of 300-400 mesh; the Zr powder has a purity ≥ 99.50% and a particle size of 300-400 mesh; and the Ti powder has a purity ≥ 99.50% and a particle size of 300-400 mesh.
8. The method for preparing a low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to claim 6, characterized in that, In step 1, the mixing time is 10~18h, and the protective gas is argon.
9. The method for preparing a low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to claim 6, characterized in that, In step 3, the vacuum degree during arc melting in a vacuum arc melting furnace is 10. -4 ~10 -5 .
10. The method for preparing a low-rhenium-content solid solution-strengthened multi-component molybdenum-rhenium alloy according to claim 6, characterized in that, In step 4, the annealing temperature is 800~1100℃ and the annealing time is 1h~3h.