A method for regulating the springback degree of amorphous alloy by low-temperature thermal cycle
By controlling the frequency and time of low-temperature thermal cycling, the degree of rejuvenation of amorphous alloys is regulated, solving the problem of limited performance of amorphous alloys, optimizing hardness and structure, and providing a solution for large-scale zero-damage processing.
Patent Information
- Application Number
- CN202311499148.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-10
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2043-11-10
AI Technical Summary
In the existing technology, there is insufficient research on the effect of low-temperature thermal cycling frequency on the properties of amorphous alloys, which limits the application of amorphous alloys.
By controlling the single cycle time and total holding time of the low-temperature thermal cycle, the cycling frequency of the amorphous alloy can be adjusted, and the free volume of different energy barriers can be activated to achieve the rejuvenation effect of the amorphous alloy.
At the optimal cycling frequency, the hardness and internal structure of the amorphous alloy remain unchanged, exhibiting the best performance improvement and providing a zero-damage, high-volume processing solution.
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Figure CN117385247B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of amorphous alloy materials technology, specifically relating to a method for controlling the degree of rejuvenation using low-temperature thermal cycling treatment. Background Technology
[0002] Amorphous alloys are a type of metastable amorphous alloy prepared by rapidly cooling molten alloy liquid. Due to the high cooling rate, the biggest difference between amorphous alloys and traditional crystalline materials is their long-range disorder and short-range order structure. Because they do not have the defects of traditional crystalline materials, such as dislocations and grain boundaries, amorphous alloys have excellent properties such as ultra-high strength, elastic modulus and corrosion resistance. However, amorphous alloys also have the disadvantage of room temperature brittleness, which limits their wide application.
[0003] The room-temperature brittleness of amorphous alloys is mainly due to their tendency to fracture along a primary shear band when subjected to external forces. To overcome this challenge, a series of measures have been proposed to improve their properties, such as adding a ductile second phase and synthesizing new material systems by replacing or adding other elements to enhance their plasticity. The properties of amorphous alloys are also related to their internal energy levels. When they transition from a high-energy state to a low-energy state, relaxation occurs, and their properties deteriorate. Conversely, when they transition from a low-energy state to a high-energy state, rejuvenation occurs, and their properties improve.
[0004] Low-temperature thermal cycling is a treatment method that causes almost zero damage to the sample and can change its internal energy state, thereby affecting the mechanical properties of amorphous alloys. A lot of research has been done on low-temperature thermal cycling, such as the holding temperature and the number of cycles. However, the effect of the frequency of low-temperature thermal cycling on amorphous alloys is still lacking. Summary of the Invention
[0005] This invention controls the cycle time by controlling the duration of each cycle while maintaining a constant total holding time, thereby controlling the cycle frequency to activate free volumes with different energy barriers during the cycle, causing the amorphous alloy to rejuvenate, and achieving the maximum degree of rejuvenation at a certain frequency.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] A method for regulating the degree of rejuvenation using low-temperature thermal cycling treatment includes the following steps:
[0008] Lanthanum-La-based amorphous alloys are prepared, wire-cut, ground, and polished until they have a mirror-like surface.
[0009] The prepared sample was placed in liquid nitrogen and kept at a certain temperature for a period of time. Then it was quickly transferred to boiling water and kept at a certain temperature for a period of time. The time for the two processes was equal, which constituted one cycle. The time for a single cycle was set to 20s, 60s, 2min, 10min and 40min respectively, and the total holding time was kept at 40min. The sample was taken out and placed in alcohol for ultrasonic cleaning to obtain 5 groups of samples with different cycle frequencies.
[0010] Five groups of samples were subjected to hardness and thermodynamic tests after undergoing different low-temperature thermal cycling frequencies.
[0011] The composition of the lanthanum-La-based amorphous alloy is: La 55%-65%, Ni 20%-30%, Al 10%-20%.
[0012] The controlled single low-temperature thermal cycle time is 20s, 60s, 2min, 10min, and 40min. Within a total heat preservation time of 40min, the cycles are performed 120, 40, 20, 4, and 1 times respectively, thereby achieving the effect of controlling the cycle frequency.
[0013] The effects of this invention: The internal amorphous structure of the samples treated with different low-temperature thermal cycling frequencies remained unchanged, and they still possessed the properties of an amorphous alloy. As the low-temperature thermal cycling frequency decreased, the hardness changed, showing a trend of first decreasing and then increasing, reaching its lowest point at 2.350 GPa with a single cycle time of 2 minutes. The β-relaxation activation energy showed the same trend as the hardness, reaching its minimum at 76.78 kJ / mol with a single cycle time of 2 minutes. The activated volume showed a trend of first increasing and then decreasing, reaching its maximum value of 0.565 nm with a single cycle time of 2 minutes. 3 The relaxation enthalpy was obtained by differential scanning calorimetry (DSC). The trend of the relaxation enthalpy was consistent with the activation volume, reaching a maximum of 2.635 kJ / mol in a single 2-minute cycle. Test results of the cyclically treated samples showed that changing the low-temperature thermal cycling frequency altered the properties of the amorphous alloy, and an optimal cycling frequency maximized the internal free volume and minimized the activation energy. This treatment allows for zero-damage processing of the samples and also enables large-scale processing, providing a new approach to improving the properties of amorphous alloys. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the low-temperature thermal cycle of the present invention.
[0015] Figure 2 This is a graph showing the changes in hardness and activated volume of lanthanum-La-based amorphous alloy samples after undergoing different low-temperature thermal cycling frequencies according to the present invention.
[0016] Figure 3 This is a graph showing the relaxation enthalpy change of the lanthanum-La-based amorphous alloy after undergoing different low-temperature thermal cycling frequencies according to the present invention.
[0017] (a) Original diagram of relaxation enthalpy;
[0018] (b) Trend graph of relaxation enthalpy;
[0019] Figure 4 This is a diagram of the β-relaxation activation energy of the lanthanum-La-based amorphous alloy after treatment with different low-temperature thermal cycling frequencies according to the present invention. Detailed Implementation
[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, but is not limited thereto.
[0021] Example 1
[0022] (1) Preparation of La 60 Ni 25 Al 15 Bulk amorphous alloy: Pure metal blocks of La, Ni, and Al were mixed in an atomic ratio of 60:25:15, with a purity of ≥99.9%. The amorphous alloy blocks were prepared using a high-vacuum electric arc melting and suction casting system with argon as the protective gas. First, the metal blocks were initially melted and repeatedly melted 5 times to ensure uniform distribution of the metal elements inside, resulting in a master alloy ingot. Then, suction casting was performed, and the master alloy ingot was suction-cast into a selected copper mold. Finally, a La-based amorphous alloy as-cast sample with dimensions of 70mm×5mm×2mm was obtained.
[0023] (2) Surface treatment: The sample prepared in (1) is cut into small block samples with a size of 15mm×2mm×1.2mm by wire cutting. First, the surface of the small sample is polished with sandpaper of size #600-#4000 from small to large. Finally, it is polished until it is mirror-like.
[0024] (3) Low temperature thermal cycling treatment: The sample finally prepared in (2) is first placed in liquid nitrogen (77K) and kept at the temperature for 10s, and then quickly transferred to boiling water (373K) and kept at the temperature for 10s. The two processes constitute one cycle, and the cycle is repeated 120 times. The total time for the cycle is kept at the temperature for 40min to obtain the sample after low temperature thermal cycling treatment.
[0025] (4) The hardness, activation volume, relaxation enthalpy and β relaxation activation energy of the sample after low temperature thermal cycling treatment in (3) can be obtained by testing the sample with nanoindentation instrument, differential scanning calorimeter and dynamic thermomechanical analyzer. As can be seen from the figure, the sample after low temperature thermal cycling treatment has been rejuvenated.
[0026] Example 2
[0027] (1) Preparation of La60 Ni 25 Al 15 Bulk amorphous alloy: Pure metal blocks of La, Ni, and Al were mixed in an atomic ratio of 60:25:15, with a purity of ≥99.9%. The amorphous alloy blocks were prepared using a high-vacuum electric arc melting and suction casting system with argon as the protective gas. First, the metal blocks were initially melted and repeatedly melted 5 times to ensure uniform distribution of the metal elements inside, resulting in a master alloy ingot. Then, suction casting was performed, and the master alloy ingot was suction-cast into a selected copper mold. Finally, a La-based amorphous alloy as-cast sample with dimensions of 70mm×5mm×2mm was obtained.
[0028] (2) Surface treatment: The sample prepared in (1) is cut into small block samples with a size of 15mm×2mm×1.2mm by wire cutting. First, the surface of the small sample is polished with sandpaper of size #600-#4000 from small to large. Finally, it is polished until it is mirror-like.
[0029] (3) Low temperature thermal cycling treatment: The sample finally prepared in (2) is first placed in liquid nitrogen (77K) and kept at the temperature for 30s, and then quickly transferred to boiling water (373K) and kept at the temperature for 30s. The two processes constitute one cycle, and the cycle is repeated 40 times. The total time for the cycle is kept at the temperature for 40 minutes to obtain the sample after low temperature thermal cycling treatment.
[0030] (4) The hardness, activation volume, relaxation enthalpy and β relaxation activation energy of the sample after low temperature thermal cycling treatment in (3) can be obtained by testing the sample with nanoindentation instrument, differential scanning calorimeter and dynamic thermomechanical analyzer. As can be seen from the figure, the sample after low temperature thermal cycling treatment has been rejuvenated.
[0031] Example 3
[0032] (1) Preparation of La 60 Ni 25 Al 15 Bulk amorphous alloy: Pure metal blocks of La, Ni, and Al were mixed in an atomic ratio of 60:25:15, with a purity of ≥99.9%. The amorphous alloy blocks were prepared using a high-vacuum electric arc melting and suction casting system with argon as the protective gas. First, the metal blocks were initially melted and repeatedly melted 5 times to ensure uniform distribution of the metal elements inside, resulting in a master alloy ingot. Then, suction casting was performed, and the master alloy ingot was suction-cast into a selected copper mold. Finally, a La-based amorphous alloy as-cast sample with dimensions of 70mm×5mm×2mm was obtained.
[0033] (2) Surface treatment: The sample prepared in (1) is cut into small block samples with a size of 15mm×2mm×1.2mm by wire cutting. First, the surface of the small sample is polished with sandpaper of size #600-#4000 from small to large. Finally, it is polished until it is mirror-like.
[0034] (3) Low temperature thermal cycling treatment: The sample finally prepared in (2) is first placed in liquid nitrogen (77K) and kept at the temperature for 1 min, and then quickly transferred to boiling water (373K) and kept at the temperature for 1 min. The two processes constitute one cycle, and the cycle is repeated 20 times. The total time for the cycle is 40 min to obtain the sample after low temperature thermal cycling treatment.
[0035] (4) The hardness, activation volume, relaxation enthalpy and β relaxation activation energy of the sample after low temperature thermal cycling treatment in (3) can be obtained by testing the sample with nanoindentation instrument, differential scanning calorimeter and dynamic thermomechanical analyzer. As can be seen from the figure, the sample after low temperature thermal cycling treatment has been rejuvenated, and its rejuvenation degree reaches the maximum when the single cycle time is 2 min.
[0036] Example 4
[0037] (1) Preparation of La 60 Ni 25 Al 15 Bulk amorphous alloy: Pure metal blocks of La, Ni, and Al were mixed in an atomic ratio of 60:25:15, with a purity of ≥99.9%. The amorphous alloy blocks were prepared using a high-vacuum electric arc melting and suction casting system with argon as the protective gas. First, the metal blocks were initially melted and repeatedly melted 5 times to ensure uniform distribution of the metal elements inside, resulting in a master alloy ingot. Then, suction casting was performed, and the master alloy ingot was suction-cast into a selected copper mold. Finally, a La-based amorphous alloy as-cast sample with dimensions of 70mm×5mm×2mm was obtained.
[0038] (2) Surface treatment: The sample prepared in (1) is cut into small block samples with a size of 15mm×2mm×1.2mm by wire cutting. First, the surface of the small sample is polished with sandpaper of size #600-#4000 from small to large. Finally, it is polished until it is mirror-like.
[0039] (3) Low temperature thermal cycling treatment: The sample finally prepared in (2) is first placed in liquid nitrogen (77K) and kept at the temperature for 5 min. Then it is quickly transferred to boiling water (373K) and kept at the temperature for 5 min. The two processes constitute one cycle. The cycle is repeated 4 times, and the total time for the cycle is kept at the temperature is 40 min to obtain the sample after low temperature thermal cycling treatment.
[0040] (4) The hardness, activation volume, relaxation enthalpy and β relaxation activation energy of the sample after low temperature thermal cycling treatment in (3) can be obtained by testing the sample with nanoindentation instrument, differential scanning calorimeter and dynamic thermomechanical analyzer. As can be seen from the figure, the sample after low temperature thermal cycling treatment has been rejuvenated.
[0041] Example 5
[0042] (1) Preparation of La 60 Ni 25 Al 15 Bulk amorphous alloy: Pure metal blocks of La, Ni, and Al were mixed in an atomic ratio of 60:25:15, with a purity of ≥99.9%. The amorphous alloy blocks were prepared using a high-vacuum electric arc melting and suction casting system with argon as the protective gas. First, the metal blocks were initially melted and repeatedly melted 5 times to ensure uniform distribution of the metal elements inside, resulting in a master alloy ingot. Then, suction casting was performed, and the master alloy ingot was suction-cast into a selected copper mold. Finally, a La-based amorphous alloy as-cast sample with dimensions of 70mm×5mm×2mm was obtained.
[0043] (2) Surface treatment: The sample prepared in (1) is cut into small block samples with a size of 15mm×2mm×1.2mm by wire cutting. First, the surface of the small sample is polished with sandpaper of size #600-#4000 from small to large. Finally, it is polished until it is mirror-like.
[0044] (3) Low temperature thermal cycling treatment: The sample finally prepared in (2) is first placed in liquid nitrogen (77K) and kept at the temperature for 20 min. Then it is quickly transferred to boiling water (373K) and kept at the temperature for 20 min. The two processes constitute one cycle. The cycle is repeated once, and the total holding time is 40 min to obtain the sample after low temperature thermal cycling treatment.
[0045] (4) The hardness, activation volume, relaxation enthalpy and β relaxation activation energy of the sample after low temperature thermal cycling treatment in (3) can be obtained by testing the sample with nanoindentation instrument, differential scanning calorimeter and dynamic thermomechanical analyzer. As can be seen from the figure, the sample after low temperature thermal cycling treatment has been rejuvenated.
Claims
1. A method for controlling the degree of rejuvenation of amorphous alloys using low-temperature thermal cycling, characterized in that, Includes the following steps: Step 1: Prepare, wire cut, grind and polish the lanthanum-based amorphous alloy until it has a mirror-like surface; Step 2: Place the prepared sample in liquid nitrogen and keep it warm for 10s-20min. Then quickly transfer it to boiling water and keep it warm for 10s-20min. The time for the two processes is equal, and the total is one cycle. Step 3: By keeping the total holding time of the low-temperature thermal cycle constant, the time of each single cycle is changed by 20s-40min. This allows the sample to undergo different number of cycles (120-1) while keeping the total holding time constant. This controls the frequency of the low-temperature thermal cycle. As the holding time decreases, the cycle frequency increases, eventually causing different changes in the microstructure inside the sample, thus obtaining different degrees of rejuvenation. The sample is then removed. The duration of a single low-temperature thermal cycle was adjusted to 20s, 60s, 2min, 10min, and 40min. The cycle frequency was controlled to be 120, 40, 20, 4, and 1 cycles respectively within a total heat preservation time of 40 minutes.
2. The method for controlling the rejuvenation degree of amorphous alloys using low-temperature thermal cycling as described in claim 1, characterized in that, The lanthanum-La-based amorphous alloy is composed of lanthanum (La), nickel (Ni), and aluminum (Al).
3. The method for controlling the rejuvenation degree of amorphous alloys using low-temperature thermal cycling as described in claim 2, characterized in that, The atomic ratio of the lanthanum-La-based amorphous alloy is: La 55%-65%, Ni 20%-30%, Al 10%-20%.
4. The method for controlling the rejuvenation degree of amorphous alloys using low-temperature thermal cycling as described in claim 1, characterized in that, The size of the sample prepared in step one is 10-20mm × 1-3mm × 1-1.4mm.
5. The method for controlling the rejuvenation degree of amorphous alloys using low-temperature thermal cycling as described in claim 1, characterized in that... Therefore, in the low-temperature thermal cycling process described in step two, the low-temperature range is liquid nitrogen (77K) and the high-temperature range is boiling water (373K).
6. The method for controlling the rejuvenation degree of amorphous alloys using low-temperature thermal cycling as described in claim 1, characterized in that, During the low-temperature thermal cycling process described in step three, the low-temperature and high-temperature holding times remain equal, and the total holding time is fixed.
7. The method for controlling the rejuvenation degree of amorphous alloys using low-temperature thermal cycling as described in claim 1, characterized in that, After removing the sample as described in step three, it is placed in alcohol for ultrasonic cleaning.