Method for refining ti zral si alloy by high-entropy precipitates and alloy

Abstract

The application belongs to the technical field of metal materials, and relates to a method for refining a TiZrAlSi series alloy by using high-entropy precipitated phases and the TiZrAlSi series alloy. The chemical composition of the TiZrAlSi series alloy is as follows in terms of atomic percentage: Al is 15.1-16.5%, Zr is 23.5-24.5%, Si is 0.2-0.5%, Hf+Nb+V is less than or equal to 5%, and the balance is Ti and inevitable impurities. The alloy organization contains high-entropy precipitated phases. After being processed by the process of "first refining a hot working organization by using micron-level large-size high-entropy precipitated phases, and then strengthening the alloy by using nanometer-level high-entropy precipitated phases", the content of the precipitated phases is between 5% and 12%, and the initial size of the precipitated phases is in the range of 1-5 microns. The TiZrAlSi series alloy can be used for manufacturing structural components in extreme environments such as the nuclear industry and the aerospace field.

Description

Technical Field

[0001] This invention belongs to the field of metallic materials technology, and relates to a TiZrAlSi alloy and a method for refining the TiZrAlSi alloy using high-entropy precipitates. Background Technology

[0002] Multi-principal element alloys / high-entropy alloys are a new type of metallic structural material developed in the last decade or so. Depending on the differences in their constituent elements and content, they have shown application potential in the fields of structural and functional materials. Based on the needs of different application scenarios, existing reports on high-entropy alloys mainly include lightweight high-entropy alloys, high-temperature resistant high-entropy alloys, corrosion-resistant, radiation-resistant, impact-resistant, and low-temperature resistant high-entropy alloy systems. Summary of the Invention

[0003] The purpose of this invention is to provide a TiZrAlSi alloy and a method for refining the TiZrAlSi alloy using high-entropy precipitates. The high-entropy alloy, which has low density, high strength, and radiation resistance, is used as a substitute for traditional iron-based and nickel-based alloys to achieve a significant structural weight reduction while improving component performance.

[0004] To solve this technical problem, the technical solution of the present invention is as follows:

[0005] On the one hand, a TiZrAlSi alloy is provided, wherein the chemical composition of the TiZrAlSi alloy is as follows in atomic percentage: Al: 15.1-16.5%, Zr: 23.5-24.5%, Si: 0.2-0.5%, Hf+Nb+V: ≤5%, and the balance is Ti and unavoidable impurities.

[0006] Preferably, the chemical composition of the TiZrAlSi alloy, in terms of atomic percentage, is: Al: 15.5-16.5%, Zr: 23.5-24.5%, Si: 0.2-0.5%, Hf+Nb+V: ≤4%, with the balance being Ti and unavoidable impurities.

[0007] Preferably, the chemical composition of the TiZrAlSi alloy, in terms of atomic percentage, is: Al: 15.1-16%, Zr: 23.5-24.5%, Si: 0.2-0.5%, Hf+Nb+V: ≤4%, with the balance being Ti and unavoidable impurities.

[0008] On the one hand, a method for refining TiZrAlSi alloys using high-entropy precipitates is provided, the method comprising the following steps:

[0009] S1: Ingot smelting: Prepare alloy ingots, and after ingot smelting, treat at 950℃~1000℃ for 24~48 hours, then furnace cool to obtain micron-sized high-entropy precipitates;

[0010] S2: Hot working: billet opening, billet opening temperature is controlled in the range of 950℃~1050℃, total deformation is greater than 95%, and a uniform fine-grained structure is obtained.

[0011] S3: Heat treatment: Solution treatment at 1080℃~1120℃ for 2~4 hours, followed by holding at 650~750℃ for 2~3 hours, and air cooling to obtain TiZrAlSi alloy material with nano high-entropy precipitates.

[0012] Preferably, in step S1, the alloy ingot is prepared by a three-stage vacuum consumable melting method.

[0013] In step S2, the blank is opened using either forging or extrusion. If forging is used in step S2, the deformation amount in a single forging operation shall not be less than 70%.

[0014] The method of refining TiZrAlSi alloys using high-entropy precipitates according to the present invention has a volume fraction of high-entropy precipitates between 5% and 12%, and an initial size of precipitates between 1 and 5 μm.

[0015] Unlike laboratory products, the TiZrAlSi alloy bars and forgings prepared by the method of this invention weigh over 100 kilograms, reaching industrial-grade dimensions.

[0016] Based on the key characteristics of the constituent phases of this alloy and the interaction between the precipitated phases and the matrix, this invention proposes to refine the alloy microstructure after hot working using high-entropy precipitates. The process involves first refining the hot-working microstructure using micron-sized high-entropy precipitates, and then strengthening the alloy using nano-sized high-entropy precipitates. Simultaneously, the size and distribution of the precipitates are controlled under operating conditions to obtain a fine-grained high-entropy alloy material with excellent mechanical properties. The refined microstructure is uniform and the grains are fine, resulting in a good balance between strength and plasticity. The strength can reach over 1250 MPa, while the elongation at break exceeds 9%, and the radiation resistance is excellent.

[0017] The beneficial effects of this invention are:

[0018] (1) This invention provides a method for refining TiZrAlSi alloys using high-entropy precipitates. The method involves first refining the heat-worked microstructure using large-scale high-entropy precipitates at the micrometer level, and then strengthening the alloy using nanoscale high-entropy precipitates, resulting in alloy bars with excellent mechanical properties. The materials and preparation method proposed in this invention are developed for applications under irradiation and high-load environments. They can serve as alternatives to traditional iron-based and nickel-based alloys, achieving significant structural weight reduction while improving component performance.

[0019] (2) This invention provides a method for refining TiZrAlSi alloys using high-entropy precipitates. This method can be processed using common melting, forging, hot rolling, and extrusion equipment, and is easy to industrialize. The processing and preparation costs are similar to those of traditional titanium alloys.

[0020] (3) The TiZrAlSi alloy of the present invention has the characteristics of low density, high strength and radiation resistance. Its ingot structure is relatively coarse. Refining and homogenizing the grain structure of this alloy is a prerequisite for the subsequent preparation of components with stable quality. Therefore, how to achieve the refinement and homogenization of the structure of the alloy involved in the present invention is the main technical difficulty to be solved by the present invention.

[0021] In traditional titanium alloys, the addition of Si results in nanoscale Ti5Si3 precipitates. Due to alloy properties, the size of these precipitates is difficult to reach the micrometer level. During hot working, these nanoscale precipitates are unsuitable as nucleation sites for dynamic recrystallization. However, the TiZrAlSi alloy proposed in this invention contains micrometer-sized (TiZr)5(AlSi)3 high-entropy precipitates in its as-cast microstructure. These precipitates, with an initial size in the micrometer range, can serve as nucleation sites for recrystallization during hot working, achieving refinement and homogenization of the alloy's microstructure after hot working. Furthermore, the (TiZr)5(AlSi)3 high-entropy precipitates can persist at the nanometer scale after subsequent solution treatment and aging, thus strengthening the alloy. These micrometer and nanometer-sized characteristics of high-entropy precipitates are not present in traditional titanium alloy silicide precipitates. Therefore, this invention proposes a process of "first refining the hot-working microstructure using large-size micrometer-sized high-entropy precipitates, and then strengthening the alloy using nanometer-sized high-entropy precipitates." Attached Figure Description

[0022] To more clearly illustrate the technical solutions implemented in this invention, the accompanying drawings used in the embodiments of this invention will be briefly explained below. Obviously, the drawings described below are merely some embodiments of this invention. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0023] Figure 1 Example 2 shows the as-cast microstructure containing micron-sized high-entropy precipitates;

[0024] Figure 2 Example 2: Microstructure of bar stock after hot working;

[0025] Figure 3 The morphology after room temperature stretching in Example 2 shows the presence of nanoscale high-entropy precipitates for reinforcement.

[0026] Figure 4 Comparative Example 1: As-cast microstructure;

[0027] Figure 5Comparative Example 3: Microstructure after room temperature stretching. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The features of various aspects of the embodiments of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can also be practiced without these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples. The invention is not limited to any specific setups and methods provided below, but covers all improvements, substitutions, etc., to product structures and methods without departing from the spirit of the invention.

[0030] In the various accompanying drawings and the following description, well-known structures and techniques are not shown in order to avoid unnecessarily obscuring the invention.

[0031] The atomic percentages of the TiZrAlSi alloys in the following examples and comparative examples are shown in Table 1. The balance is titanium and unavoidable microstructure elements.

[0032] Table 1 Alloy composition

[0033]

[0034]

[0035] Example 1:

[0036] TiZrAlSi alloys contain, by atomic percentage, 16% Al, 24% Zr, 0.5% Si, with the balance being Ti and unavoidable impurities. The raw materials used include grade zero sponge titanium, 99.99% Zr, A00 grade high-purity aluminum, and AlSi master alloy.

[0037] This embodiment utilizes a method for refining TiZrAlSi alloys using high-entropy precipitates, which is prepared through the following steps:

[0038] Step (1): Prepare raw materials according to the 100kg ingot weight, press the electrode; use the three-stage vacuum self-consumable melting method to prepare an ingot with a diameter of 220mm; after the ingot is melted, treat it at 1000℃ for 48 hours and then furnace cool it.

[0039] Step (2): The blank is opened by extrusion at a temperature of 1050℃ and the total deformation is greater than 95%.

[0040] Step (3): Heat treatment is performed on the extruded bar, with solution treatment at 1100℃ for 2 hours, followed by air cooling treatment at 750℃ for 3 hours to obtain TiZrAlSi alloy material with nano high-entropy precipitates.

[0041] Dissection analysis of the obtained rods revealed that the rods have a uniform and fine microstructure with an average grain size of 90 micrometers. The rods have an elongation at room temperature after fracture of more than 8% and a strength of 1100 MPa.

[0042] Example 2:

[0043] TiZrAlSi alloys contain, by atomic percentage: 15.6% Al, 24.5% Zr, 0.4% Si, 0.5% Hf, 1% Nb, 0.2% V, with the balance being Ti and unavoidable impurities. The raw materials used include grade zero sponge titanium, 99.99% Zr, A00 grade high-purity aluminum, AlSi master alloy, high-purity Hf, AlNb, AlV, etc.

[0044] This embodiment utilizes a method for refining TiZrAlSi alloys using high-entropy precipitates, which is prepared through the following steps:

[0045] Step (1): Prepare raw materials according to the 100kg ingot weight, press the electrode; use the three-stage vacuum self-consumable melting method to prepare an ingot with a diameter of 220mm; after the ingot is melted, treat it at 1000℃ for 48 hours and then furnace cool it.

[0046] Step (2): The billet is opened by forging, the opening temperature is 1050℃, the total deformation is greater than 95%, and the deformation in a single forging is greater than 70%.

[0047] Step (3): Heat treatment is performed on the extruded bar, with solution treatment at 1100℃ for 2 hours, followed by air cooling treatment at 700℃ for 3 hours to obtain TiZrAlSi alloy material with nano high-entropy precipitates.

[0048] Dissection analysis of the obtained bars revealed that the bar structure is uniform and fine, with an average grain size of 95 micrometers. The elongation at room temperature after fracture is greater than 10%, and the strength reaches 1150 MPa.

[0049] Table 2 lists the elemental contents of the micron- and nano-scale high-entropy precipitates in Example 2. The results show that the precipitates are four-principal-element high-entropy precipitates containing TiZrAlSi.

[0050] Table 2. Elemental content of the high-entropy precipitated phase in Example 2

[0051]

[0052] Example 3:

[0053] TiZrAlSi alloys contain, by atomic percentage: 15.1% Al, 23.5% Zr, 0.2% Si, 2% Hf, 1% Nb, 1% V, with the balance being Ti and unavoidable impurities. The raw materials used include grade zero sponge titanium, 99.99% Zr, A00 grade high-purity aluminum, AlSi master alloy, high-purity Hf, AlNb, AlV, etc.

[0054] This embodiment utilizes a method for refining TiZrAlSi alloys using high-entropy precipitates, which is prepared through the following steps:

[0055] Step (1): Prepare raw materials according to the 100kg ingot weight, press the electrode; use the three-stage vacuum self-consumable melting method to prepare an ingot with a diameter of 220mm; after the ingot is melted, treat it at 1000℃ for 48 hours and then furnace cool it.

[0056] Step (2): The blank is opened by extrusion at a temperature of 1000℃ and the total deformation is greater than 95%.

[0057] Step (3): Heat treatment is performed on the extruded bar, with solution treatment at 1100℃ for 2 hours, followed by air cooling treatment at 700℃ for 3 hours to obtain TiZrAlSi alloy material with nano high-entropy precipitates.

[0058] Dissection analysis of the obtained rods revealed that the rods have a uniform and fine microstructure with an average grain size of 90 micrometers. The elongation at room temperature after fracture is greater than 10%, and the strength reaches 1100 MPa.

[0059] To illustrate the effect of the process of refining TiZrAlSi alloys using high-entropy precipitates on the final alloy material properties, the following comparative examples were made.

[0060] Comparative Example 1:

[0061] The chemical composition of this comparative example is the same as that of Example 2, the only difference being that the ingot was not treated at 1000°C after melting; the subsequent hot working and heat treatment processes are the same as those of Example 2.

[0062] Dissection analysis of the obtained bars revealed that the bar structure was not sufficiently refined and homogenized. The bar strength reached 1100 MPa, but the elongation at room temperature after fracture was below 6%.

[0063] Comparative Example 2:

[0064] The chemical composition of this comparative example is the same as that of Example 2. The only difference is the subsequent hot working process. The blank is opened by forging, the blanking temperature is 1050°C, the total deformation is greater than 95%, but the deformation in a single heat is 57%.

[0065] Dissection analysis of the obtained bars revealed that the bar structure was not sufficiently refined and homogenized. The bar strength reached 1100 MPa, but the elongation at room temperature after fracture was less than 5%.

[0066] Comparative Example 3:

[0067] The chemical composition of this comparative example is the same as that of Example 2. The only difference is the subsequent heat treatment process, which involves solution treatment at 1100°C for 2 hours, followed by air cooling at 600°C for 3 hours.

[0068] Dissection analysis of the obtained bars revealed that the bar structure was uniform and fine, but no high-entropy precipitates were present. The room temperature elongation after fracture was above 10%, but the strength was less than 1000 MPa.

[0069] From the appendix Figure 4 , Figure 5 It can be seen that, compared with the tissue morphology of the embodiments processed by the process of the present invention ( Figures 1-3 Because the comparative samples did not strictly undergo the process of this invention, their microstructures are different, and the final room temperature elongation after fracture and bar strength do not meet the performance indicators of the examples. Furthermore, the bar weight of this example reaches industrial-grade dimensions.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A method for refining TiZrAlSi alloys using high-entropy precipitates, characterized in that: The method includes the following steps: S1: Ingot smelting: Prepare alloy ingots, and after ingot smelting, treat at 950℃~1000℃ for 24~48 hours, then furnace cool to obtain micron-sized high-entropy precipitates; S2: Hot working: billet opening, billet opening temperature is controlled in the range of 950℃~1050℃, total deformation is greater than 95%, and a uniform fine-grained structure is obtained. S3: Heat treatment: Solution treatment at 1080℃~1120℃ for 2~4 hours, followed by holding at 650~750℃ for 2~3 hours, and air cooling to obtain TiZrAlSi alloy material with nano high-entropy precipitates. The chemical composition of the TiZrAlSi alloy, in atomic percentage, is as follows: Al: 15.1-16.5%, Zr: 23.5-24.5%, Si: 0.2-0.5%, Hf+Nb+V: ≤5%, with the balance being Ti and unavoidable impurities.

2. The method according to claim 1, characterized in that: In step S1, alloy ingots are prepared by a three-stage vacuum consumable melting method.

3. The method according to claim 1, characterized in that: In step S2, the blank is opened by forging or extrusion.

4. The method according to claim 1, characterized in that: If forging is used to open the billet in step S2, the deformation amount of a single forging operation shall not be less than 70%.

5. The method according to claim 1, characterized in that: The volume fraction of the high-entropy precipitated phase is between 5% and 12%.

6. The method according to claim 1, characterized in that: The initial size of the high-entropy precipitated phase is in the range of 1 to 5 μm.

7. The method according to claim 1, characterized in that: The chemical composition of the TiZrAlSi alloy, in atomic percentage, is as follows: Al: 15.5-16.5%, Zr: 23.5-24.5%, Si: 0.2-0.5%, Hf+Nb+V: ≤4%, with the balance being Ti and unavoidable impurities.

8. The method according to claim 1, characterized in that: The chemical composition of the TiZrAlSi alloy, in atomic percentage, is as follows: Al: 15.1-16%, Zr: 23.5-24.5%, Si: 0.2-0.5%, Hf+Nb+V: ≤4%, with the balance being Ti and unavoidable impurities.

Images