A short process preparation method for large-size high-strength and high-plastic TiZrNbAl series high-entropy alloy

Abstract

The present invention relates to a short-process preparation method of a large-size high-strength and plastic TiZrNbAl series high-entropy alloy, and belongs to the field of alloy technology. First, a self-consumable TiZrNbAl series high-entropy alloy cylindrical ingot with a diameter R ≥ 90 mm is forged to obtain a square billet; the deformation amount and deformation rate in different temperature ranges are controlled, and a basket structure can be obtained after forging without heat treatment. The structural characteristics of the alloy are: the aspect ratio of the intracrystalline lath α2 phase is ≥ 4, the average width of the α2 phase is 0.5~2μm, the room temperature static tensile strength of the basket structure reaches 900~1000 MPa, the plasticity reaches 7~12%, and the room temperature dynamic compression plasticity is ≥35%.

Description

Technical Field

[0001] The invention relates to a short-process preparation method of a large-size high-strength and plastic TiZrNbAl series high-entropy alloy, belonging to the technical field of alloys. Background Art

[0002] TiZrNbAl series high entropy alloys have the characteristics of low density and high specific strength, and have good market prospects. The performance of the alloy prepared by this method still needs to be further improved. The basket structure has good plasticity, impact toughness, fracture toughness and high cycle fatigue strength. This organizational structure enables the alloy to exhibit better performance when subjected to impact or cyclic loading, reducing the risk of sudden fracture. Chinese patent CN115164648B discloses a "TiZrVNbAl series energetic high entropy alloy liner and its preparation method". First, a high entropy alloy ingot is obtained by suspension smelting, and then a two-step heat treatment of solid solution + aging is performed to finally obtain a high entropy alloy with a basket structure, and its dynamic compression strength is 1400 MPa and the plasticity is 25%. However, this method is relatively cumbersome and cannot be used to mass-produce large-size basket structure high entropy alloys. As a structural material, its plasticity needs to be further improved. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a short-process preparation method for a large-size high-strength and high-plastic TiZrNbAl-based high-entropy alloy.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows.

[0005] A short-process preparation method for a large-size high-strength and high-plastic TiZrNbAl series high-entropy alloy, the method steps comprising:

[0006] (1) The consumable TiZrNbAl high entropy alloy cylindrical ingot with a diameter of R ≥ 90 mm is forged, the heating temperature is T1 °C, T1 = single-phase transformation temperature + 100~150, the heating coefficient is 0.6~0.8min / mm, the holding time is t1 min, t1 = heating coefficient value × R value, the number of deformations is 2~4 times, the single deformation amount is 40%~45%, the final forging temperature is greater than or equal to T2 °C, T2 = single-phase transformation temperature - 150, and after forging, air cooling is performed to obtain a square billet;

[0007] (2) Forging in single-phase region across dual-phase region: heat the square billet to T3℃, T3=single-phase transformation temperature+30~100, heating coefficient is 0.4~0.6min / mm, holding time is t2min, t2=heating coefficient value×minimum size of square billet side length, deformation times is 2~4 times, single deformation amount is 40%~45%; when the forging temperature is above the single-phase transformation temperature, the deformation rate is 0.05~0.1s -1, the deformation is 50%~70% of the total deformation; when the forging temperature is lower than the single-phase transformation temperature, the deformation rate is 0.01≤<0.05s -1 , the deformation is 30%~50% of the total deformation; the final forging temperature is greater than or equal to T2℃, and air cooling is performed after forging to obtain a high-strength and plastic TiZrNbAl series high-entropy alloy with basketweave structure;

[0008] Among them, the unit of single-phase transformation temperature is ℃, the unit of R is mm; the minimum dimension unit of the side length of the square billet is mm.

[0009] Preferably, in step (1), the atomic percentage expression of the TiZrNbAl high entropy alloy is Ti a Zr b Nb c Al d N x , N is one or more of Ta, V, Cr, Fe, Mo, Mg, Be, Li, Co, Ni, N, Si, B, C, N and O, 0<a≤70, 5≤b≤45, 0≤c≤30, 5≤d≤40, 0≤x≤10, and a+b+c+d+x=100. More preferably, 45<a≤70, 5≤b≤15, 0≤c≤20, 10≤d≤30, 0≤x≤10.

[0010] Preferably, in step (1), the consumable TiZrNbAl high entropy alloy cylindrical ingot has a diameter of 90-260 mm and an aspect ratio of 1-2.

[0011] Preferably, in step (1), during forging, when the temperature of the forging is lower than T2°C, the forging is returned to the furnace for heating, and the heating coefficient is 0.1-0.2 min / mm.

[0012] Preferably, in step (2), when the forging temperature is above the single-phase transformation temperature, the deformation rate is 0.06-0.08s -1 .

[0013] Preferably, in step (2), when the forging temperature is lower than the single-phase transformation temperature, the deformation rate is 0.02-0.04s -1 .

[0014] Preferably, in step (1) and step (2), the cooling rate of air cooling is ≥15°C / min.

[0015] A high-strength and high-plastic TiZrNbAl series high-entropy alloy with basketweave structure is prepared by the above method.

[0016] Preferably, in the high-strength and plastic TiZrNbAl-based high-entropy alloy, the aspect ratio of the intracrystalline lath α2 phase is ≥4, the average width of the α2 phase is 0.7~2μm, the static tensile strength at room temperature reaches 900~1000MPa, the plasticity is 7%~12%, and the dynamic compression plasticity at room temperature is ≥35%.

[0017] Beneficial Effects

[0018] The present invention provides a short-process preparation method for a large-size high-strength and plastic TiZrNbAl series high-entropy alloy. Through a one-step forging method, the deformation amount and deformation rate in different temperature ranges are controlled, and a basket structure can be obtained after forging without heat treatment. The structural characteristics of the alloy are: the aspect ratio of the intracrystalline lath α2 phase is ≥4, the average width of the α2 phase is 0.5~2μm, the room temperature static tensile strength of the basket structure reaches 900~1000 MPa, the plasticity reaches 7~12%, and the room temperature dynamic compression plasticity is ≥35%. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a microstructure diagram of the alloy obtained in Example 1.

[0020] Figure 2 This is a microstructure diagram of the alloy obtained in Example 2.

[0021] Figure 3 This is the microstructure diagram of the alloy obtained in Comparative Example 1.

[0022] Figure 4 This is the microstructure diagram of the alloy obtained in Comparative Example 2. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with specific embodiments.

[0024] Example 1

[0025] (1) Select a consumable Ti with a diameter of 200 mm and a height of 300 mm. 58 Zr 13 Nb 15 Al 14 High entropy alloy cylindrical ingot is billet A. The forging heating temperature is 1150℃ and the holding time is 2h. The single deformation amount is 40% and the total number of deformations is 4 times. After forging, it is air-cooled to room temperature to obtain billet B.

[0026] (2) Heat billet B to 1100°C, keep it at this temperature for 1.5 h, and deform it 45% each time. The total number of deformations is 4 times. Above the single phase transformation temperature, the deformation rate is 0.06 s -1 , the deformation amount completes 70% of the total deformation amount; less than 30% of the total deformation amount completed at the single-phase transformation temperature, and the deformation rate is 0.03 s-1 After forging, it is cooled to room temperature by air to obtain a high-strength plastic Ti with basketweave structure. 58 Zr 13 Nb 15 Al 14 High entropy alloy.

[0027] The alloy is a staggered basket structure, and the microstructure is as follows Figure 1 The measurement shows that the aspect ratio of the intracrystalline lath α2 phase is 6.4, the average width of the α2 phase is 0.8μm, the room temperature static tensile strength of the alloy reaches 950MPa, the plasticity reaches 8%, and the room temperature dynamic compression plasticity is 36%.

[0028] Example 2

[0029] (1) Select a consumable Ti with a diameter of 200 mm and a height of 300 mm. 58 Zr 13 Nb 15 Al 14 High entropy alloy cylindrical ingot is billet A. The forging heating temperature is 1150℃ and the holding time is 2h. The single deformation amount is 40% and the total number of deformations is 4 times. After forging, it is air-cooled to room temperature to obtain billet B.

[0030] (2) Heat the blank B to 1030℃ and keep it at this temperature for 1.5h. The single deformation is 45%, the total deformation is 2 times, 50% of the total deformation is completed above the single phase transformation temperature, and the deformation rate is 0.07 s -1 , which is less than 50% of the total deformation at the single phase transformation temperature, and the deformation rate is 0.03 s -1 After forging, it is cooled to room temperature by air to obtain a high-strength plastic Ti with basketweave structure. 58 Zr 13 Nb 15 Al 14 High entropy alloy.

[0031] The alloy is a staggered basket structure, and the microstructure is as follows Figure 2 The aspect ratio of the intragranular lath α2 phase is 4.9, the average width of the α2 phase is 1.6μm, the room temperature static tensile strength of the alloy reaches 1000 MPa, the plasticity reaches 12%, and the room temperature dynamic compression plasticity is 40%.

[0032] Comparative Example 1

[0033] (1) Select a consumable Ti with a diameter of 200 mm and a height of 300 mm. 58 Zr 13 Nb 15 Al 14High entropy alloy cylindrical ingot is billet A. The forging heating temperature is 1150℃ and the holding time is 2h. The single deformation amount is 40% and the total number of deformations is 4 times. After forging, it is air-cooled to room temperature to obtain billet B.

[0034] (2) Heat the blank B to 1100℃, keep it at this temperature for 1.5h, and deform it by 40% each time. The total number of deformations is 2 times. Above the single phase transformation temperature, the temperature is kept at 0.09 s. -1 After the total deformation is 100%, the forging is cooled to room temperature to obtain a Ti with Widmanstatten structure. 58 Zr 13 Nb 15 Al 14 High entropy alloys, such as Figure 3 The static tensile strength of the alloy at room temperature reaches 800 MPa, and the plasticity is only 2%.

[0035] Comparative Example 2

[0036] (1) Select a consumable Ti with a diameter of 200 mm and a height of 300 mm. 58 Zr 13 Nb 15 Al 14 High entropy alloy cylindrical ingot is billet A. The forging heating temperature is 1150℃ and the holding time is 2h. The single deformation amount is 40% and the total number of deformations is 4 times. After forging, it is air-cooled to room temperature to obtain billet B.

[0037] (2) Heat the blank B to 1030℃ and keep it at this temperature for 1.5h. The single deformation is 50%, the total number of deformations is 2, and the temperature is above the single phase transformation temperature at a rate of 0.03 s -1 The strain rate is 0.06s to complete 30% of the total deformation, which is less than the single-phase transformation temperature. -1 The strain rate is 70% of the total deformation. After forging, the forged Ti is cooled to room temperature to obtain a Ti with partial equiaxed structure. 58 Zr 13 Nb 15 Al 14 High entropy alloys, such as Figure 4 The static tensile strength of the tissue at room temperature reaches 850 MPa and the plasticity is 8%.

[0038] In summary, the invention includes but is not limited to the above embodiments. Any equivalent substitution or partial improvement made under the spirit and principle of the invention shall be deemed to be within the protection scope of the invention.

Claims

1. A short-process preparation method for a large-size, high-strength and high-plastic TiZrNbAl-based high-entropy alloy, characterized in that: The method steps include: (1) The consumable TiZrNbAl high entropy alloy cylindrical ingot with a diameter of R ≥ 90 mm is forged, the heating temperature is T1 °C, T1 = single-phase transformation temperature + 100~150, the heating coefficient is 0.6~0.8min / mm, the holding time is t1 min, t1 = heating coefficient value × R value, the number of deformations is 2~4 times, the single deformation amount is 40%~45%, the final forging temperature is greater than or equal to T2 °C, T2 = single-phase transformation temperature - 150, and after forging, air cooling is performed to obtain a square billet; (2) Forging in single-phase region across dual-phase region: heat the square billet to T3℃, T3=single-phase transformation temperature+30~100, heating coefficient is 0.4~0.6min / mm, holding time is t2min, t2=heating coefficient value×minimum size of square billet side length, deformation times is 2~4 times, single deformation amount is 40%~45%; when the forging temperature is above the single-phase transformation temperature, the deformation rate is 0.05~0.1s -1 , the deformation is 50%~70% of the total deformation; when the forging temperature is lower than the single-phase transformation temperature, the deformation rate is 0.01≤<0.05s -1 , the deformation is 30%~50% of the total deformation; the final forging temperature is greater than or equal to T2℃, and air cooling is performed after forging to obtain a high-strength and plastic TiZrNbAl series high-entropy alloy with basketweave structure; Among them, the unit of single-phase transformation temperature is ℃, the unit of R is mm; the minimum dimension unit of the side length of the square billet is mm.

2. A short-process preparation method for a large-size, high-strength and high-plastic TiZrNbAl-based high-entropy alloy as claimed in claim 1, characterized in that: In step (1), the atomic percentage expression of the TiZrNbAl high entropy alloy is denoted as Ti a Zr b Nb c Al d N x , N is one or more of Ta, V, Cr, Fe, Mo, Mg, Be, Li, Co, Ni, N, Si, B, C, N and O, 0<a≤70, 5≤b≤45, 0≤c≤30, 5≤d≤40, 0≤x≤10, and a+b+c+d+x=100.

3. A short-process preparation method for a large-size high-strength and high-plastic TiZrNbAl-based high-entropy alloy as claimed in claim 2, characterized in that: 45<a≤70, 5≤b≤15, 0≤c≤20, 10≤d≤30, 0≤x≤10.

4. A short-process preparation method for a large-size high-strength and high-plastic TiZrNbAl-based high-entropy alloy as claimed in claim 1, characterized in that: In step (1), the consumable TiZrNbAl high entropy alloy cylindrical ingot has a diameter of 90-260 mm and an aspect ratio of 1-2.

5. A short-process preparation method for a large-size high-strength and high-plastic TiZrNbAl-based high-entropy alloy as claimed in claim 1, characterized in that: In step (1), during forging, when the temperature of the forging is lower than T2°C, the forging is returned to the furnace for heating, and the heating coefficient is 0.1~0.2min / mm.

6. A short-process preparation method for a large-size high-strength and high-plastic TiZrNbAl-based high-entropy alloy as claimed in claim 1, characterized in that: In step (2), when the forging temperature is above the single-phase transformation temperature, the deformation rate is 0.06~0.08s -1 .

7. A short-process preparation method for a large-size high-strength and high-plastic TiZrNbAl-based high-entropy alloy as claimed in claim 1, characterized in that: In step (2), when the forging temperature is lower than the single-phase transformation temperature, the deformation rate is 0.02~0.04s -1 .

8. A short-process preparation method for a large-size high-strength and high-plastic TiZrNbAl-based high-entropy alloy as claimed in claim 1, characterized in that: In step (1) and step (2), the cooling rate of air cooling is ≥15°C / min.

9. A high-strength and high-plastic TiZrNbAl high-entropy alloy with basketweave structure, characterized in that: It is prepared by the method according to any one of claims 1 to 8.

10. The high-strength and high-plasticity TiZrNbAl-based high-entropy alloy with basketweave structure according to claim 9, characterized in that: In the high-strength and plastic TiZrNbAl series high-entropy alloy, the aspect ratio of the intracrystalline lath α2 phase is ≥4, the average width of the α2 phase is 0.7-2 μm, the static tensile strength at room temperature reaches 900-1000 MPa, the plasticity is 7%-12%, and the dynamic compression plasticity at room temperature is ≥35%.

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