High-strength cast zirconium-titanium alloy and preparation method thereof

Abstract

The invention belongs to the technical field of zirconium alloy materials, and particularly relates to a high-strength cast zirconium-titanium alloy and a preparation method thereof, and the high-strength cast zirconium-titanium alloy comprises the following components by mass percent: 30 wt.%-85 wt.% of Zr, 0.5 wt.%-13 wt.% of Al, 0.3 wt.%-8 wt.% of Mo, 0.3 wt.%-6 wt.% of Nb, and the balance of Ti and inevitable impurities. According to the invention, 0.5 wt.%-13 wt.% of the Al element, 0.3 wt.%-8 wt.% of the Mo element and 0.3 wt.%-6 wt.% of the Nb element are added into the zirconium-titanium alloy, so that the strength of the cast zirconium-titanium alloy is improved, and meanwhile, the cast zirconium-titanium alloy has better plasticity and casting performance.

Description

Technical Field

[0001] The invention belongs to the technical field of zirconium alloy materials, and specifically relates to a high-strength cast zirconium-titanium alloy and a preparation method thereof. Background Art

[0002] Zirconium alloy has several important potentials: 1) small thermal expansion coefficient and stable dimensional structure; 2) ability to resist space radiation; 3) resistance to anti-proton oxygen corrosion. Zirconium alloy is widely used in the nuclear industry for its extremely low thermal neutron absorption cross section and good resistance to high temperature and high pressure corrosion. Parts produced with zirconium alloy include fuel cladding tubes, pressure tubes and component boxes. Developed countries such as France and the United States have successively developed a series of nuclear zirconium alloys. In the past 30 years, my country has also developed a new high-performance zirconium alloy, and the corrosion resistance of its components in high-temperature water and steam has been significantly improved.

[0003] Most of the existing zirconium-titanium alloy materials are deformed zirconium-titanium alloys, mainly zirconium-titanium alloy profiles and plates, etc. At present, zirconium-titanium alloys for casting all use the alloy composition of forged titanium alloys, and the alloy composition has not been optimized according to the unique characteristics of the casting process, resulting in problems such as undercasting and easy cracking during the casting process of high-strength zirconium-titanium alloys, and they cannot be adapted to the integrated casting forming process.

[0004] Therefore, the development of high-strength cast zirconium-titanium alloy has high practical value for the integrated forming and application of zirconium-titanium alloy. Summary of the invention

[0005] The main purpose of the present invention is to provide a high-strength cast zirconium-titanium alloy and a preparation method thereof. The present invention improves the strength of the cast zirconium-titanium alloy while making the cast zirconium-titanium alloy have better plasticity and casting properties by adding 0.5wt.% to 13wt.% of Al element, 0.3wt.% to 8wt.% of Mo element and 0.3wt.% to 6wt.% of Nb element to the zirconium-titanium alloy.

[0006] In order to achieve the above objectives, the present invention provides the following technical solutions.

[0007] In a first aspect, the present invention provides a high-strength cast zirconium-titanium alloy, which includes the following components in mass percentage: Zr 30wt.%~85wt.%, Al 0.5wt.%~13wt.%, Mo 0.3wt.%~8wt.%, Nb 0.3wt.%~6wt.%, and the balance is Ti and unavoidable impurities.

[0008] In some embodiments of the present invention, the high-strength cast zirconium-titanium alloy includes the following components in mass percentage: Zr 60wt.%~70wt.%, Al 4wt.%~7wt.%, Mo 3wt.%~5wt.%, Nb 2wt.%~5wt.%, and the balance is Ti and unavoidable impurities.

[0009] In some embodiments of the present invention, the high-strength cast zirconium-titanium alloy includes the following components in mass percentage: Zr 60wt.%, Al 4wt.%, Mo 5wt.%, Nb 5wt.%, and the balance is Ti and unavoidable impurities.

[0010] In some embodiments of the present invention, the high-strength cast zirconium-titanium alloy includes the following components in mass percentage: 65wt.% Zr, 6wt.% Al, 5wt.% Mo, 5wt.% Nb, and the balance is Ti and unavoidable impurities.

[0011] In some embodiments of the present invention, the high-strength cast zirconium-titanium alloy includes the following components in mass percentage: Zr 70wt.%, Al 7wt.%, Mo 3wt.%, Nb 2wt.%, and the balance is Ti and unavoidable impurities.

[0012] In some embodiments of the present invention, the room temperature tensile strength of the zirconium-titanium alloy is not less than 1100 MPa, the elongation is not less than 4%, the quasi-static compressive strength is not less than 1100 MPa, the failure strain rate is not less than 15%, the dynamic compressive strength is not less than 1500 MPa, and the failure strain rate is not less than 3%.

[0013] In a second aspect, the present invention provides a method for preparing the high-strength cast zirconium-titanium alloy described in the first aspect, the preparation method comprising: mixing raw materials according to a proportion according to the alloy composition of the zirconium-titanium alloy and pressing them into electrodes; subjecting the electrodes to at least one vacuum consumable smelting to obtain a zirconium-titanium alloy ingot; heating and remelting the zirconium-titanium alloy ingot in a vacuum arc shell furnace, and casting to obtain a high-strength zirconium-titanium alloy casting.

[0014] In some embodiments of the present invention, the preparation method further comprises: subjecting the obtained high-strength zirconium-titanium alloy casting to hot isostatic pressing.

[0015] In some embodiments of the present invention, the hot isostatic pressing treatment includes: heating the high-strength zirconium-titanium alloy casting to 600°C to 750°C under a protective atmosphere and a pressure of 100MPa to 140MPa, keeping it warm for 2h to 2.5h, then cooling it to below 300°C and taking it out.

[0016] In some embodiments of the present invention, during the heating and remelting process in the vacuum arc shell furnace, the melting current is 5000A to 7000A.

[0017] In some embodiments of the present invention, during the vacuum consumable smelting process, the vacuum degree is maintained below 3 Pa.

[0018] In some embodiments of the present invention, during the vacuum consumable smelting process, the smelting current is 4000A to 5000A.

[0019] In some embodiments of the present invention, the raw material is selected from sponge zirconium, sponge titanium, pure aluminum, aluminum-molybdenum alloy, and aluminum-niobium alloy.

[0020] Compared with the prior art, the present invention achieves the following technical effects:

[0021] 1. The present invention improves the strength of the cast zirconium-titanium alloy while making the cast zirconium-titanium alloy have better plasticity and casting performance by adding 0.5wt.% to 13wt.% of Al element, 0.3wt.% to 8wt.% of Mo element and 0.3wt.% to 6wt.% of Nb element to the zirconium-titanium alloy.

[0022] 2. The high-strength zirconium-titanium alloy of the present invention contains 0.5wt.% to 13wt.% Al element. The higher Al content increases the solubility of the β-stabilizing element in the α phase, plays a strengthening role, and improves the fluidity of the zirconium-titanium alloy during the casting process.

[0023] 3. The high-strength zirconium-titanium alloy of the present invention contains 0.3wt.% to 8wt.% of Mo element. The addition of Mo element can refine the grain size and significantly improve the comprehensive mechanical properties of the titanium alloy.

[0024] 4. The high-strength zirconium-titanium alloy of the present invention contains 0.3wt.% to 6wt.% of Nb element by mass, which can improve the creep resistance, thermal stability and fatigue performance of the alloy. In addition, if the Nb element content is too high, the casting performance of the alloy will be reduced. The Nb element content of less than 6wt.% by mass can ensure the casting properties of the alloy such as fluidity and filling.

[0025] 5. The high-strength zirconium-titanium alloy of the present invention can obtain higher mechanical properties through casting or hot isostatic pressing. The room temperature tensile strength of the zirconium-titanium alloy prepared by the present invention is not less than 1100MPa, the elongation is not less than 4%, the quasi-static compression strength is not less than 1100MPa, the failure strain rate is not less than 15%, the dynamic compression strength is not less than 1500MPa, and the failure strain rate is not less than 3%.

[0026] 6. The high-strength zirconium-titanium alloy of the present invention has better casting properties such as fluidity and filling properties, and its casting performance is similar to that of ZTA15, meeting the requirements of complex structure castings on titanium alloy filling performance.

[0027] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings:

[0029] Figure 1 This is a SEM microstructure photograph of the high-strength zirconium-titanium alloy obtained in Example 1 of the present invention;

[0030] Figure 2 This is a SEM microstructure photograph of the high-strength zirconium-titanium alloy prepared in Example 4 of the present invention. DETAILED DESCRIPTION

[0031] The exemplary embodiments of the present invention will be described in more detail below with reference to specific embodiments. It should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0033] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0036] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0037] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention.

[0038] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0039] The invention provides a high-strength cast zirconium-titanium alloy, which comprises the following components in mass percentage: 30wt.%-85wt.% Zr, 0.5wt.%-13wt.% Al, 0.3wt.%-8wt.% Mo, 0.3wt.%-6wt.% Nb, and the balance is Ti and unavoidable impurities.

[0040] In the embodiment of the present invention, by adding 0.5wt.% to 13wt.% of Al element, 0.3wt.% to 8wt.% of Mo element, and 0.3wt.% to 6wt.% of Nb element to the zirconium-titanium alloy, the strength of the cast zirconium-titanium alloy is improved, and the cast zirconium-titanium alloy has better plasticity and casting properties.

[0041] The room temperature tensile strength of the high-strength cast zirconium-titanium alloy in the present invention is not less than 1100MPa, the elongation is not less than 4%, the quasi-static compressive strength is not less than 1100MPa, the failure strain rate is not less than 15%, the dynamic compressive strength is not less than 1500MPa, the failure strain rate is not less than 3%, and the alloy fluidity is equivalent to that of ZTA15 alloy, meeting the application requirements of cast zirconium-titanium alloy.

[0042] In some embodiments of the present invention, the high-strength cast zirconium-titanium alloy includes the following components in mass percentage: Zr 60wt.% to 70wt.%, Al 4wt.% to 7wt.%, Mo 3wt.% to 5wt.%, Nb 2wt.% to 5wt.%, and the balance is Ti and unavoidable impurities.

[0043] In some embodiments of the present invention, the mass percentage of Zr element in the high strength cast zirconium-titanium alloy can be one of 30wt.%, 32wt.%, 34wt.%, 36wt.%, 38wt.%, 40wt.%, 42wt.%, 44wt.%, 46wt.%, 48wt.%, 50wt.%, 52wt.%, 54wt.%, 56wt.%, 58wt.%, 60wt.%, 61wt.%, 62wt.%, 63wt.%, 64wt.%, 65wt.%, 66wt.%, 67wt.%, 68wt.%, 69wt.%, 70wt.%, 72wt.%, 74wt.%, 76wt.%, 78wt.%, 80wt.%, 82wt.%, 85wt.% or any value that meets the above range.

[0044] In some embodiments of the present invention, the mass percentage of Al element in the high-strength cast zirconium-titanium alloy is 0.5wt.% to 13wt.%, and a higher Al content increases the solubility of the β-stabilizing element in the α phase, plays a strengthening role, and improves the fluidity of the zirconium-titanium alloy during the casting process. Exemplarily, the mass percentage of the Al element can be one of 0.5wt.%, 0.8wt.%, 1wt.%, 2wt.%, 3wt.%, 4wt.%, 5wt.%, 6wt.%, 7wt.%, 8wt.%, 9wt.%, 10wt.%, 11wt.%, 12wt.%, 13wt.%, or any value that meets the above range.

[0045] In some embodiments of the present invention, the mass percentage of Mo element in the high-strength cast zirconium-titanium alloy is 0.3wt.% to 8wt.%. The addition of Mo element can refine the grain size and significantly improve the comprehensive mechanical properties of the titanium alloy. Exemplarily, the mass percentage of Mo element can be one of 0.3wt.%, 0.5wt.%, 0.8wt.%, 1wt.%, 2wt.%, 3wt.%, 4wt.%, 5wt.%, 6wt.%, 7wt.%, 8wt.%, or any value that meets the above range.

[0046] In some embodiments of the present invention, the mass percentage of Nb element in the high-strength cast zirconium-titanium alloy is 0.3wt.% to 6wt.%. Nb element can improve the creep resistance, thermal stability and fatigue performance of the alloy. In addition, if the Nb element content is too high, the casting performance of the alloy will be reduced. The Nb element content of less than 6wt.% by mass can ensure the casting properties such as fluidity and filling of the alloy. Exemplarily, the mass percentage of Nb element can be one of 0.3wt.%, 0.5wt.%, 0.8wt.%, 1wt.%, 2wt.%, 3wt.%, 4wt.%, 5wt.%, 6wt.%, or any value that meets the above range.

[0047] In some embodiments of the present invention, the high-strength cast zirconium-titanium alloy includes the following components in mass percentage: 60 wt.% Zr, 4 wt.% Al, 5 wt.% Mo, 5 wt.% Nb, and the balance is Ti and unavoidable impurities.

[0048] In some embodiments of the present invention, the high-strength cast zirconium-titanium alloy includes the following components in mass percentage: 65wt.% Zr, 6wt.% Al, 5wt.% Mo, 5wt.% Nb, and the balance is Ti and unavoidable impurities.

[0049] In some embodiments of the present invention, the high-strength cast zirconium-titanium alloy includes the following components in mass percentage: Zr 70wt.%, Al 7wt.%, Mo 3wt.%, Nb 2wt.%, and the balance is Ti and unavoidable impurities.

[0050] The present invention also provides a method for preparing a high-strength cast zirconium-titanium alloy, the key of which is to obtain N ingots (N≥1) by vacuum consumable smelting, and to heat and remelt in a vacuum arc solidification furnace to obtain a high-strength cast zirconium-titanium alloy by casting.

[0051] The method for preparing the high-strength cast zirconium-titanium alloy of the present invention is specifically carried out according to the following steps.

[0052] (1) Prepare alloy raw materials according to the target alloy composition ratio.

[0053] In the embodiment of the present invention, raw materials of various elements are fully mixed in proportion according to the target alloy composition.

[0054] In some embodiments of the present invention, the mixed material after being fully mixed can be cleaned according to actual conditions or requirements, such as by using conventional cleaning methods in the prior art.

[0055] In some embodiments of the present invention, the raw material is selected from zirconium sponge, titanium sponge, pure aluminum, aluminum-molybdenum alloy, and aluminum-niobium alloy.

[0056] (2) Pressing electrodes.

[0057] In an embodiment of the present invention, the mixed material is pressed after being fully mixed to form an electrode.

[0058] In some embodiments of the present invention, the electrode may be, but is not limited to, a rod-shaped structure, and its size may be set according to actual conditions.

[0059] (3) Vacuum consumable melting.

[0060] In an embodiment of the present invention, the electrode obtained by pressing is subjected to at least one vacuum consumable melting in a vacuum consumable electrode arc furnace to obtain a zirconium-titanium alloy ingot.

[0061] In some embodiments of the present invention, the vacuum consumable electrode smelting is performed at least once, such as twice or three times, and of course four or five times according to actual needs, without specific limitation. For example, the secondary zirconium-titanium alloy ingot is obtained by smelting twice in a vacuum consumable electrode arc furnace.

[0062] In some embodiments of the present invention, during the vacuum consumable smelting process, the vacuum degree is maintained below 3 Pa.

[0063] In some embodiments of the present invention, during the vacuum consumable melting process, the melting current is 4000A to 5000A. For example, the melting current may be one of 4000A, 4100A, 4200A, 4300A, 4400A, 4500A, 4600A, 4700A, 4800A, 4900A, 5000A or any value satisfying the above range.

[0064] (4) Remelting and pouring.

[0065] In an embodiment of the present invention, the zirconium-titanium alloy ingot obtained in step (3) is heated and remelted in a vacuum arc furnace, and then cast to obtain a zirconium-titanium alloy casting.

[0066] In some embodiments of the present invention, the zirconium-titanium alloy secondary ingot is peeled and cleaned, then melted in a vacuum arc shell furnace and poured into a casting cavity, such as a precision casting shell or a graphite or sand mold cavity, and a high-strength zirconium-titanium alloy casting is obtained after cooling.

[0067] In some embodiments of the present invention, during the smelting process in the vacuum arc condensation furnace, the smelting current may be 5000A to 7000A. For example, the smelting current may be one of 5000A, 5100A, 5200A, 5300A, 5400A, 5500A, 5600A, 5700A, 5800A, 5900A, 6000A, 6100A, 6200A, 6300A, 6400A, 6500A, 6600A, 6700A, 6800A, 6900A, 7000A or any value satisfying the above range.

[0068] The present invention also provides a method for preparing a high-strength cast zirconium-titanium alloy, the key of which is to subject the cast high-strength cast zirconium-titanium alloy to hot isostatic pressing to improve the density and comprehensive performance of the cast zirconium-titanium alloy, wherein the density reaches more than 99.8%.

[0069] The method for preparing the high-strength cast zirconium-titanium alloy of the present invention is specifically carried out according to the following steps.

[0070] (1) Prepare alloy raw materials according to the target alloy composition ratio.

[0071] In the embodiment of the present invention, raw materials of various elements are fully mixed in proportion according to the target alloy composition.

[0072] In some embodiments of the present invention, the mixed material after being fully mixed can be cleaned according to actual conditions or requirements, such as by using conventional cleaning methods in the prior art.

[0073] In some embodiments of the present invention, the raw material is selected from zirconium sponge, titanium sponge, pure aluminum, aluminum-molybdenum alloy, and aluminum-niobium alloy.

[0074] (2) Pressing electrodes.

[0075] In an embodiment of the present invention, the mixed material is pressed after being fully mixed to form an electrode.

[0076] In some embodiments of the present invention, the electrode may be, but is not limited to, a rod-shaped structure, and its size may be set according to actual conditions.

[0077] (3) Vacuum consumable melting.

[0078] In an embodiment of the present invention, the electrode obtained by pressing is subjected to at least one vacuum consumable melting in a vacuum consumable electrode arc furnace to obtain a zirconium-titanium alloy ingot.

[0079] In some embodiments of the present invention, the vacuum consumable electrode smelting is performed at least once, such as twice or three times, and of course four or five times according to actual needs, without specific limitation. For example, the secondary zirconium-titanium alloy ingot is obtained by smelting twice in a vacuum consumable electrode arc furnace.

[0080] In some embodiments of the present invention, during the vacuum consumable smelting process, the vacuum degree is maintained below 3 Pa.

[0081] In some embodiments of the present invention, during the vacuum consumable melting process, the melting current is 4000A to 5000A. For example, the melting current may be one of 4000A, 4100A, 4200A, 4300A, 4400A, 4500A, 4600A, 4700A, 4800A, 4900A, 5000A or any value satisfying the above range.

[0082] (4) Remelting and pouring.

[0083] In an embodiment of the present invention, the zirconium-titanium alloy ingot obtained in step (3) is heated and remelted in a vacuum arc furnace, and then cast to obtain a high-strength zirconium-titanium alloy casting.

[0084] In some embodiments of the present invention, the zirconium-titanium alloy secondary ingot is peeled and cleaned, then melted in a vacuum arc shell furnace and poured into a casting cavity, such as a precision casting shell or a graphite or sand mold cavity, and a high-strength zirconium-titanium alloy casting is obtained after cooling.

[0085] In some embodiments of the present invention, during the smelting process in the vacuum arc condensation furnace, the smelting current is 5000A to 7000A. For example, the smelting current can be one of 5000A, 5100A, 5200A, 5300A, 5400A, 5500A, 5600A, 5700A, 5800A, 5900A, 6000A, 6100A, 6200A, 6300A, 6400A, 6500A, 6600A, 6700A, 6800A, 6900A, 7000A or any value satisfying the above range.

[0086] (5) Hot isostatic pressing.

[0087] In an embodiment of the present invention, the high-strength zirconium-titanium alloy casting obtained in step (4) is subjected to hot isostatic pressing.

[0088] In some embodiments of the present invention, the hot isostatic pressing treatment includes: heating the high-strength zirconium-titanium alloy casting to 600°C to 750°C in a protective atmosphere and a pressure of 100MPa to 140MPa, keeping it warm for 2h to 2.5h, then cooling it to below 300°C and taking it out.

[0089] In some embodiments of the present invention, the pressure of the hot isostatic pressing treatment can be one of 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, or any value satisfying the above range. The temperature of the hot isostatic pressing treatment can be one of 600°C, 650°C, 700°C, 750°C, or any value satisfying the above range. The time of the hot isostatic pressing treatment can be one of 2 h, 2.1 h, 2.2 h, 2.3 h, 2.4 h, 2.5 h, or any value satisfying the above range.

[0090] In some embodiments of the present invention, the protective atmosphere may be, but is not limited to, a nitrogen atmosphere.

[0091] In some embodiments of the present invention, the hot isostatic pressing process is performed according to the following steps.

[0092] (5.1) The high-strength zirconium-titanium alloy casting is placed in a sealed pressure-resistant container, and after evacuation, argon gas with a pressure of 100 MPa to 140 MPa is introduced.

[0093] (5.2) Heat the sealed pressure vessel at a temperature of 600°C to 750°C for 2h to 2.5h.

[0094] (5.3) Close the pressure vessel and air cool it to below 300°C, then take out the high-strength zirconium-titanium alloy casting.

[0095] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the amounts of the experimental reagents, unless otherwise specified, are the amounts of reagents used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0096] Example 1

[0097] Disclosed are a high-strength cast zirconium-titanium alloy and a preparation method thereof. The high-strength cast zirconium-titanium alloy comprises the following components in percentage by mass: 60% Zr, 4% Al, 5% Mo, 5% Nb, and the remainder Ti and unavoidable impurities.

[0098] The preparation method of the high-strength cast zirconium-titanium alloy is as follows:

[0099] (1) According to the alloy ratio, the materials are prepared and sponge titanium, sponge zirconium, pure aluminum, Al-Mo alloy, and Al-Nb alloy are weighed respectively.

[0100] (2) After cleaning the raw materials, electrodes are pressed.

[0101] (3) The electrode is melted twice in a vacuum consumable arc furnace. During the melting process, the vacuum degree is maintained at 1 Pa and the melting current is 4800 A to obtain a secondary zirconium-titanium alloy ingot.

[0102] (4) After the zirconium-titanium alloy secondary ingot is peeled and cleaned, it is melted in a vacuum arc shell furnace with a melting current of 7000A, poured into a precision casting shell, and cooled to obtain a high-strength zirconium-titanium alloy casting.

[0103] Example 2

[0104] The remaining operations are the same as those in Example 1, except that the high-strength cast zirconium-titanium alloy in Example 2 includes the following components in mass percentage: Zr 60%, Al 6.0%, Mo 5%, Nb 5%, and the balance is Ti and unavoidable impurities.

[0105] Example 3

[0106] The remaining operations are the same as those in Example 1, except that the high-strength cast zirconium-titanium alloy in Example 3 includes the following components in mass percentage: Zr 65%, Al 7.0%, Mo 4%, Nb 3%, and the balance is Ti and unavoidable impurities.

[0107] Performance Testing

[0108] The room temperature tensile strength is tested in accordance with the standard GB / T228.1-2010.

[0109] Quasi-static compressive strength is tested in accordance with standard GB / T7314-2017.

[0110] Dynamic compressive strength is tested in accordance with standard GJB 8799-2015.

[0111] The performance tests were carried out on the high-strength zirconium-titanium alloy castings prepared in Examples 1 to 3, and the test results are shown in Table 1.

[0112] Table 1 Summary of properties of high-strength zirconium-titanium alloy castings obtained in Examples 1-3

[0113]

[0114]

[0115] See also Figure 1Combined with the data in Table 1, it can be seen that the room temperature tensile strength of the zirconium-titanium alloy prepared in the present invention is not less than 1100 MPa, the elongation is not less than 4%, the quasi-static compressive strength is not less than 1100 MPa, the failure strain rate is not less than 15%, the dynamic compressive strength is not less than 1500 MPa, and the failure strain rate is not less than 3%.

[0116] At the same time, the higher the Al content in the zirconium-titanium alloy of the present invention, the higher the room temperature tensile strength of the corresponding zirconium-titanium alloy.

[0117] Example 4

[0118] The remaining operations are the same as those in Example 1, except that in Example 4, the obtained high-strength zirconium-titanium alloy casting is further subjected to hot isostatic pressing. The specific steps of the hot isostatic pressing are as follows:

[0119] (5.1) The high-strength zirconium-titanium alloy casting is placed in a sealed pressure-resistant container, evacuated and then introduced with argon gas at a pressure of 100 MPa.

[0120] (5.2) Heat the sealed pressure vessel and control the temperature at 650°C for 2 hours.

[0121] (5.3) Air cool the sealed pressure vessel to below 300°C and take out the high-strength zirconium-titanium alloy casting.

[0122] Example 5

[0123] The remaining operations are the same as those in Example 2, except that in Example 5, the obtained high-strength zirconium-titanium alloy casting is further subjected to hot isostatic pressing. The specific steps of the hot isostatic pressing are as follows:

[0124] (5.1) The high-strength zirconium-titanium alloy casting is placed in a sealed pressure-resistant container, evacuated and then introduced with argon gas at a pressure of 100 MPa.

[0125] (5.2) Heat the sealed pressure vessel and control the temperature at 650°C for 2 hours.

[0126] (5.3) Air cool the sealed pressure vessel to below 300°C and take out the high-strength zirconium-titanium alloy casting.

[0127] Example 6

[0128] The remaining operations are the same as those in Example 3, except that in Example 6, the obtained high-strength zirconium-titanium alloy casting is subjected to hot isostatic pressing. The specific steps of the hot isostatic pressing are as follows:

[0129] (5.1) The high-strength zirconium-titanium alloy casting is placed in a sealed pressure-resistant container, evacuated and then introduced with argon gas at a pressure of 100 MPa.

[0130] (5.2) Heat the sealed pressure vessel and control the temperature at 700°C for 2 hours.

[0131] (5.3) Air cool the sealed pressure vessel to below 300°C and take out the high-strength zirconium-titanium alloy casting.

[0132] Table 2 Summary of properties of high-strength zirconium-titanium alloy castings obtained in Examples 4-6

[0133]

[0134] See also Figure 2 Combined with the data in Table 2, it can be seen that after the hot isostatic pressing treatment, the mechanical properties of the zirconium-titanium alloy in the present invention are further improved, while achieving better density, thereby significantly improving the comprehensive performance of the zirconium-titanium alloy.

[0135] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A high-strength cast zirconium-titanium alloy, characterized in that: It includes the following components in percentage by mass: Zr 30wt.% ~ 85wt.%, Al 0.5wt.% ~ 13wt.%, Mo 0.3wt.% ~ 8wt.%, Nb 0.3wt.% ~ 6wt.%, and the balance is Ti and inevitable impurities.

2. The high-strength cast zirconium-titanium alloy according to claim 1, characterized in that: It includes the following components in percentage by mass: Zr 60wt.%~70wt.%, Al 4wt.%~7wt.%, Mo 3wt.%~5wt.%, Nb 2wt.%~5wt.%, and the balance is Ti and inevitable impurities.

3. The high-strength cast zirconium-titanium alloy according to claim 1 or 2, characterized in that: It includes the following components in percentage by mass: Zr 60wt.%, Al 4wt.%, Mo 5wt.%, Nb 5wt.%, and the balance is Ti and inevitable impurities.

4. The high-strength cast zirconium-titanium alloy according to claim 1 or 2, characterized in that: It includes the following components in percentage by mass: Zr 65wt.%, Al 6wt.%, Mo 5wt.%, Nb 5wt.%, and the balance is Ti and inevitable impurities.

5. The high-strength cast zirconium-titanium alloy according to claim 1 or 2, characterized in that: It includes the following components in percentage by mass: Zr 70wt.%, Al 7wt.%, Mo 3wt.%, Nb 2wt.%, and the balance is Ti and inevitable impurities.

6. The high-strength cast zirconium-titanium alloy according to any one of claims 1 to 5, characterized in that: The room temperature tensile strength of the zirconium-titanium alloy is not less than 1100 MPa, the elongation is not less than 4%, the quasi-static compression strength is not less than 1100 MPa, the failure strain rate is not less than 15%, the dynamic compression strength is not less than 1500 MPa, and the failure strain rate is not less than 3%.

7. A method for preparing the high-strength cast zirconium-titanium alloy according to any one of claims 1 to 6, characterized in that: The preparation method comprises: The raw materials are mixed according to the alloy composition of the zirconium-titanium alloy and then pressed into electrodes; The electrode is subjected to vacuum consumable smelting at least once to obtain a zirconium-titanium alloy ingot; The zirconium-titanium alloy ingot is heated and remelted in a vacuum arc furnace, and then cast to obtain a high-strength zirconium-titanium alloy casting.

8. The preparation method according to claim 7, characterized in that: The preparation method further comprises: subjecting the obtained high-strength zirconium-titanium alloy casting to hot isostatic pressing; Preferably, the hot isostatic pressing treatment comprises: heating the high-strength zirconium-titanium alloy casting to 600°C to 750°C under a protective atmosphere and a pressure of 100MPa to 140MPa, keeping the temperature for 2h to 2.5h, then cooling it to below 300°C and taking it out.

9. The preparation method according to claim 7, characterized in that: During the heating and remelting process in the vacuum arc shell furnace, the melting current is 5000A to 7000A; Preferably, during the vacuum consumable smelting process, the smelting current is 4000A to 5000A, and the vacuum degree is maintained below 3Pa.

10. The preparation method according to claim 7, characterized in that: The raw materials are selected from sponge zirconium, sponge titanium, pure aluminum, aluminum-molybdenum alloy, and aluminum-niobium alloy.

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