Multi-component zirconium alloy with high yield strength to Young modulus ratio and preparation method thereof

Abstract

The invention belongs to the technical field of alloy materials, and relates to a multi-component zirconium alloy with a high ratio of yield strength to Young modulus and a preparation method of the multi-component zirconium alloy, and the multi-component zirconium alloy comprises the following metal elements in percentage by mass: 58.9-79.38% of zirconium element, 7.5-20% of titanium element, 12.0-18.0% of niobium element, 1.0-2.5% of hafnium element, 0.1-0.5% of iron element and 0.02-0.10% of boron element. The tensile yield strength of the steel is 807-941 MPa, and the Young modulus of the steel is 60-70 GPa. The preparation method comprises the following steps: S1, weighing the raw materials; s2, alloy smelting; s3, forging treatment is conducted; and S4, rolling treatment. According to the preparation method of the multi-component zirconium alloy, Ti, Nb and Hf elements and trace Fe and B elements are added, so that the zirconium alloy has relatively low elastic modulus while having relatively high yield strength; according to the preparation method of the multi-component zirconium alloy, the holding temperature in the rolling process is controlled to be 500-750 DEG C, so that the alloy has a preferable metallographic structure, and the yield strength of the alloy is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloy materials, and in particular relates to a multi-component zirconium alloy with a high ratio of yield strength to Young's modulus and a preparation method thereof. Background Art

[0002] The main problems encountered in the actual use of medical alloys include the mismatch between the elastic modulus of the alloy and the requirements of the use environment and the release of harmful metal ions leading to poor biocompatibility. Currently, conventional medical alloys are mainly titanium, while zirconium performs better than titanium in corrosion resistance and biocompatibility. It also has a low magnetic susceptibility, which can effectively avoid artifacts during magnetic resonance imaging, facilitate the inspection and renovation of implants, and has great application potential in the medical field.

[0003] However, pure zirconium metal has a low yield strength and a high elastic modulus. Long-term use can lead to deformation and even cracking, as well as stress shielding, making it difficult to use in practical applications. Zirconium alloys typically have a low elastic modulus, but the yield strength of current low-modulus zirconium alloys and titanium alloys is generally low, typically ≤600MPa, significantly limiting the widespread application of medical metal materials.

[0004] Therefore, improving the yield strength of metal zirconium and reducing its elastic modulus have extremely important social significance and economic value for the use of alloys in the medical field. In order to solve the main problems raised above, the development of alloy materials with high yield strength and low elastic modulus has become a problem that needs to be solved. Summary of the Invention

[0005] To address the problem that current alloys struggle to meet yield strength requirements while maintaining a low elastic modulus, the addition of Ti, Nb, Hf, and trace amounts of Fe and B allows zirconium alloys to achieve both high yield strength and a low elastic modulus. The present invention's multi-component zirconium alloy preparation method improves the yield strength of low-modulus alloys by controlling the holding temperature during the rolling process to 500-750°C, thereby imparting a favorable metallographic structure to the alloy. This results in a zirconium alloy with both high yield strength and a low elastic modulus. Furthermore, the present invention aims to provide a multi-component zirconium alloy with a high yield strength to Young's modulus ratio and a method for preparing the same.

[0006] The present invention provides a multi-component zirconium alloy with a high ratio of yield strength to Young's modulus, wherein the mass percentages of the elements are: 58.9-79.38% of zirconium, 7.5-20% of titanium, 12.0-18.0% of niobium, 1.0-2.5% of hafnium, 0.1-0.5% of iron, and 0.02-0.10% of boron; the tensile yield strength of the multi-component zirconium alloy is 807-941 MPa, and the Young's modulus is 60-70 GPa.

[0007] In a preferred embodiment, the mass percentages of the elements are: titanium 20%, niobium 15%, hafnium 1.5%, iron 0.2%, boron 0.04%, and zirconium 63.26%.

[0008] A second aspect of the present invention provides a method for preparing a multi-component zirconium alloy having a high ratio of yield strength to Young's modulus, comprising the following steps:

[0009] S1. Weighing raw materials: Weigh and mix industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder according to mass percentage; wherein industrial pure titanium accounts for 7.5-20% of the total mass, pure niobium accounts for 12.0-18.0% of the total mass, pure hafnium accounts for 1.0-2.5% of the total mass, iron boride powder accounts for 0.12-0.6% of the total mass, and pure zirconium accounts for 58.9-79.38% of the total mass. The mass percentage of boron to iron in the iron boride is 1:5;

[0010] S2. Alloy smelting: placing the raw materials weighed in step S1 into a vacuum suspension furnace for smelting. After smelting, the raw materials are kept warm for a certain period of time, and the furnace is cooled to room temperature to obtain an alloy ingot.

[0011] S3, forging treatment: the alloy ingot of step S2 is subjected to three-fire forging;

[0012] S4. Rolling treatment: The forged alloy ingot is kept at a temperature between 500° C. and 750° C. for a period of time, and then rolled. The rolled alloy is water-cooled to room temperature to obtain a multi-component zirconium alloy.

[0013] Preferably, in step S4, the muffle furnace is heated to 500-750°C at a rate of 10-15°C / min, the holding time is 25-35min, the deformation of each rolling process is 2-3% of the initial plate thickness, and the plate is kept warm for 5-10min after each rolling. The rolling process is repeated, and the rolling process is stopped when the total deformation of the alloy plate after rolling is 80%-82% of the initial plate thickness, and the plate is cooled to room temperature with water.

[0014] Preferably, step S2 includes the following specific steps:

[0015] S21, charging: placing the alloy raw materials weighed in step S1 into the charging device of the suspension melting furnace;

[0016] S22, vacuum treatment: vacuum treatment is carried out in the furnace, and argon gas is introduced when the vacuum reaches 10-3Pa or above;

[0017] S23, pre-melting: gradually increase the melting power until the surface of the raw material begins to melt and form molten droplets;

[0018] S24. Heating and melting: gradually increase the power and control the temperature at 1800℃~1900℃. When the alloy raw materials are completely melted, perform electromagnetic stirring and keep warm for 10~20 minutes, then cool the furnace to room temperature.

[0019] Preferably, in the three-fire forging process of step S3, the temperature of the first fire forging is 980-1020°C, and the holding time of the first fire forging is 1.5-2h; the temperature of the second fire forging is 890-910°C, and the holding time of the second fire forging is 1-1.5h; the temperature of the third fire forging is 830-870°C, and the holding time of the third fire forging is 1-1.2h.

[0020] Preferably, the charging order of step S21 is adjusted according to the characteristics of the alloy, with volatile or burnable elements placed at the bottom and refractory elements placed at the top. The specific order of charging is industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The method for preparing a multi-component zirconium alloy with a high yield strength to elastic modulus ratio of the present invention increases the yield strength of the zirconium alloy and reduces the elastic modulus of the alloy by introducing doping with Zr, Ti, Nb, Hf, Fe and B elements. The yield strength of the multi-component zirconium alloy of the present invention is 807 to 941 MPa, while the elastic modulus is only 60 to 70 MPa. The maximum ratio of yield strength to elastic modulus is 1.57.

[0023] 2. The preparation method of the multi-component zirconium alloy with a high yield strength to elastic modulus ratio of the present invention adopts a traditional hot rolling process and is simple to operate. In addition, the preparation method of the present invention optimizes the metallographic structure of the alloy by controlling the holding temperature of the hot rolling process. When the hot rolling holding temperature is controlled within the range of 500 to 750°C, the zirconium alloy can have a higher yield strength and a better metallographic structure while maintaining a low elastic modulus.

[0024] 3. The Nb element in the multi-component zirconium alloy with a high yield strength to elastic modulus ratio of the present invention can make the metallographic composition of the alloy more inclined to the β-type alloy, and effectively reduce the elastic modulus of the alloy by increasing the proportion of the metastable β-type alloy. In addition, the B element can cause the alloy to segregate at the grain boundaries, thereby further improving the yield strength of the alloy. The addition of trace elements such as Fe and B can refine the grains, so that the zirconium alloy has better plasticity while having a lower elastic modulus and a higher yield strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 XRD patterns of the multi-component zirconium alloys of Examples 1, 2 and 3 of the present invention;

[0026] Figure 2 The room temperature tensile engineering stress-strain curves of the multi-component zirconium alloys of Examples 1, 2 and 3 of the present invention;

[0027] Figure 3 This is a microscopic morphology of the multi-component zirconium alloy of Example 2 of the present invention;

[0028] Figure 4 EBSD image of the multi-component zirconium alloy of Example 2 of the present invention;

[0029] Figure 5 IPF diagram of the multi-component zirconium alloy of Example 2 of the present invention;

[0030] Figure 6 1 is a comparison chart of the yield strength to elastic modulus ratios of the multi-component zirconium alloys of Examples 1, 2 and 3 of the present invention and currently reported conventional alloys. DETAILED DESCRIPTION

[0031] To fully describe the technical content, objectives and effects of the present invention, the following is a detailed description with reference to the accompanying drawings.

[0032] like Figures 1-6 As shown, the multi-component zirconium alloy prepared by the present invention has a high yield strength to Young's modulus ratio, and comprises, by weight percentage, 58.9-79.38% zirconium, 7.5-20% titanium, 12.0-18.0% niobium, 1.0-2.5% hafnium, 0.1-0.5% iron, and 0.02-0.10% boron. In a preferred embodiment of the present invention, the multi-component zirconium alloy comprises 20% titanium, 15% niobium, 1.5% hafnium, 0.2% iron, 0.04% boron, and 63.26% zirconium. The term "high yield strength to Young's modulus ratio" in the present invention refers to a ratio of yield strength to Young's modulus of the multi-component zirconium alloy of the present invention that is higher than the upper limit of 1.25 for the ratio of yield strength to Young's modulus of conventional alloys.

[0033] Specifically, the higher the stability of the β-type alloy, the higher the yield strength of the alloy; the metastable β-type alloy has a lower elastic modulus. The metallographic composition of the multi-component zirconium alloy with a high ratio of yield strength to Young's modulus of the present invention is mainly composed of β-type alloy, with a small amount of α phase distributed between the β phases. By adjusting the mass percentage of the Nb element, the main metallographic phase of the zirconium alloy is transformed into a metastable β-type zirconium alloy, which reduces the elastic modulus of the zirconium alloy. In addition, the content of the Nb element has a certain effect on the stability of the metastable β-type alloy. In the β-type ZrTiNb alloy, since the Ti element and the Zr element are elements of the same group, as the mass percentage of the Ti element and the Nb element increases, the stability of the β-type ZrTiNb alloy can be improved, resulting in a solid solution strengthening effect and increasing the yield strength of the alloy. The addition of the boron element can cause the alloy to segregate at the grain boundaries to form intermetallic compounds TiB and ZrB2. The precipitation of borides realizes grain boundary modification and strengthens the grain boundary strength. In addition, the segregation of boron atoms at grain boundaries increases activation energy, affecting grain growth dynamics while restricting grain boundary movement, resulting in finer and more uniform grains. This ensures that the alloy maintains a certain degree of plasticity while increasing strength. Boron doping can be designed to precipitate ideal borides. The precipitated borides can produce a pinning effect, hindering the movement of dislocations and interfaces within the unit cell, thereby increasing the yield strength of the material. The addition of Fe stabilizes the β-Zr alloy phase.

[0034] Furthermore, the multi-component zirconium alloy with a high ratio of yield strength to Young's modulus of the present invention is based on zirconium alloy and is doped with Ti, Nb, Hf and other elements to obtain a multi-component zirconium alloy with high yield strength and low elastic modulus. The tensile yield strength of the multi-component zirconium alloy of the present invention can reach 807~941MPa, and the Young's modulus is only 60~70GPa. Since the ratio of the yield strength to Young's modulus of the alloy is generally higher than the performance of current alloys, it can be widely used in the medical field.

[0035] At the same time, the present invention provides a method for preparing a multi-component zirconium alloy with a high ratio of yield strength to Young's modulus, which specifically comprises the following steps:

[0036] S1. Weighing raw materials: Weigh industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder according to mass percentage. Among them, industrial pure titanium accounts for 7.5-20% of the total mass, pure niobium accounts for 12.0-18.0% of the total mass, pure hafnium accounts for 1.0-2.5% of the total mass, iron boride accounts for 0.12-0.6% of the total mass, and zirconium accounts for 58.9-79.38% of the total mass. The mass percentage of boron to iron in iron boride is 1:5.

[0037] S2. Alloy smelting: The raw materials weighed in step S1 are placed in a vacuum suspension furnace and argon gas is introduced. The vacuum smelting furnace is heated to 1850° C. for smelting. After the furnace is cooled to room temperature after holding for a certain period of time, an alloy ingot is obtained.

[0038] Wherein, step S2 includes the following specific steps:

[0039] S21, charging: the industrial pure titanium, pure niobium, pure hafnium, pure zirconium and iron boride powder weighed in step S1 are sequentially charged into the charging device of the suspension smelting furnace.

[0040] S22. Vacuum treatment: Close the furnace door and start the vacuum system. When the vacuum degree in the furnace reaches 10-3Pa or above, introduce argon gas and start the suspension furnace.

[0041] S23, pre-melting: gradually increase the melting power so that the surface of the raw material begins to melt and form molten droplets.

[0042] S24. Heating and melting: gradually increase the power and control the temperature at 1800℃-1900℃ to completely melt the alloy raw materials.

[0043] S25, heat preservation refining: the molten alloy melt is subjected to electromagnetic stirring and heat preservation for 10-20 minutes. After the heat preservation is completed, it is poured into a preheated casting mold for casting and cooled.

[0044] Furthermore, the order in which the raw materials weighed in step S1 are placed in the water-cooled copper crucible suspension furnace is adjusted according to the characteristics of the alloy. Volatile or burnt elements are placed at the bottom, and refractory elements are placed at the top. After ensuring the uniformity of the alloy composition, the furnace is first vacuumed. During step S22, the air is extracted and argon is introduced. The argon is kept stably introduced throughout the smelting process to prevent the alloy from undergoing oxidation and other reactions during the smelting process. During the smelting process, electromagnetic force is used to suspend the raw materials in the center of the furnace to avoid contact with the crucible.

[0045] Specifically, the original structure of the alloy ingot obtained in step S2 usually has relatively coarse columnar crystals and equiaxed crystals. Due to the coarse grains, the mechanical properties of the alloy are poor. The pre-melting process of step S23 can melt a variety of raw materials more evenly and can more accurately control the composition of the alloy; the alloy raw materials after pre-melting can produce molten droplets on the metal surface to reduce the melt splashing during the smelting process, and the pre-melting process can remove the gas in the alloy raw materials in advance to reduce the influence of the composition. The electromagnetic stirring process in step S25 can remove the gas and impurities in the melt to ensure uniform composition. When the alloy is smelted, the alloy is transferred to a crucible after completion, and circulating cooling water is passed into the bottom of the crucible through a cooling device until the alloy ingot in the crucible cools to room temperature.

[0046] S3, forging treatment: the alloy ingot of step S2 is subjected to three-fire forging; the forging furnace is heated to 980℃~1020℃ for the first fire forging, followed by the second fire forging at 890℃~910℃, and finally the third fire forging at 830℃~870℃.

[0047] Wherein, step S3 specifically includes the following steps:

[0048] S31. Place the alloy ingot obtained in step S2 into a forging furnace, heat the alloy ingot to 980-1020°C at a heating rate of 10-20°C / min, and keep it warm for 1.5-2h to obtain the alloy ingot after the first fire forging.

[0049] S32, cooling the alloy ingot obtained in step S31 after the first forging to 890°C-910°C, and keeping it at the temperature of the second forging for 1-1.5 hours to obtain the alloy ingot after the second forging.

[0050] S33. Cool the alloy ingot obtained in step S32 after the second forging to 830° C. to 870° C., and keep it at the temperature of the third forging for 1-1.2 hours to obtain the alloy ingot after the third forging.

[0051] Furthermore, through the first forging process in step S31, the alloy is heated to a critical temperature. The thermal deformation of the alloy at this critical temperature alters its microstructure, homogenizing the grain structure and improving the overall performance of the alloy. During the first forging process, the alloy ingot undergoes significant deformation, eliminates defects such as pores and shrinkage during the casting process, reduces the hardness of the alloy, and promotes a more uniform composition within the alloy ingot. Furthermore, the first forging process can initially refine the grains and improve density, facilitating subsequent forming and creating favorable processing conditions for subsequent forging.

[0052] Specifically, the second fire forging in step S32 is to further refine the grains and adjust the grain orientation and shape of the alloy ingot on the basis of the first fire forging to improve the anisotropy of the material. The second fire forging eliminates the residual stress in the alloy ingot processing through the thermal relaxation effect. The second fire forging process optimizes the internal structure composition of the alloy and refines the alloy grains that have undergone the first fire forging for a second time to make the grains more uniform and small, thereby improving the strength, toughness and other mechanical properties of the alloy. In addition, it can also improve the microstructure of the alloy, reduce segregation, make the second phase distribution more uniform, and further enhance the comprehensive performance of the alloy ingot.

[0053] In addition, the third fire forging in step S33 further optimizes the grain size and orientation through fine deformation of the alloy ingot, which affects the target performance orientation. The alloy ingot after treatment has properties such as high hardness or high toughness. The deformation amount and temperature and other conditions precisely controlled in the third fire forging ultimately affect the microstructure of the alloy. The third fire forging can improve the strain hardening behavior of the alloy ingot by controlling the number and distribution of twins.

[0054] S4, hot rolling treatment: the alloy ingot after the triple-fire forging in step S3 is cut into alloy plates of appropriate size, kept at 500-750° C. for a period of time, and then rolled.

[0055] Wherein, step S4 includes the following specific steps:

[0056] S41, cutting the alloy ingot after the triple-fire forging in step S3 into alloy plates of 40*40*20 mm.

[0057] S42. Heating the muffle furnace to 500-750° C. at a rate of 10-1° C. / min, maintaining the temperature for 25-35 minutes, and rolling the alloy plate after the temperature maintenance, wherein the rolling deformation is 2-3% of the initial plate thickness.

[0058] S43. Place the plate rolled in step S42 into a muffle furnace and keep it warm for 5 to 10 minutes, and repeat the rolling process in step S42.

[0059] S44, repeating the rolling process of step S42, stopping the rolling process when the deformation of the alloy plate after rolling is 80% to 82% of the initial plate thickness, and water cooling to room temperature to obtain a multi-component alloy.

[0060] Furthermore, the holding temperature before rolling is controlled at 500-750°C. The metallographic structure of the multi-component zirconium alloy of the present invention is composed of two phases, α and β. The temperature range in which the α+β phases coexist is 460-652°C. Above 552°C, the alloy is completely in the β phase and contains less than 1% of a compound phase. In this temperature range, the alloy has a low deformation resistance, enabling large plastic deformation, achieving the purpose of grain breakage, dynamic recrystallization, and grain refinement. Furthermore, the dissolution temperature of the boride is approximately 691°C. In this holding temperature range, the boride elements can diffuse and dissolve, precipitating even finer and more dispersed borides during the subsequent deformation and cooling process, thereby increasing the strength of the alloy without changing the elastic modulus or reducing the plasticity. If the holding temperature is too high, the grains will significantly coarsen after recrystallization. When the holding temperature is below 460°C, the alloy is mainly composed of α phase, which is a close-packed hexagonal phase with low plastic deformation capacity. It cannot achieve a large rolling deformation to achieve the effect of dislocation multiplication strengthening, and the rolling process is prone to cracking. When the holding temperature is between 460°C and 500°C, there is a large amount of α phase, so the holding temperature should be higher than 500°C. During the rolling process, the deformation of each rolling process is controlled at 2%-3%. Excessive downward pressure can easily cause stress concentration, resulting in small cracks inside the sample, reduced plasticity, and even cracking.

[0061] The following is a further description of a multi-component zirconium alloy with a high yield strength to Young's modulus ratio according to the present invention with reference to the following embodiments:

[0062] Example 1

[0063] S1. Raw material weighing: Weigh and mix industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder according to the mass percentages of titanium content: 7.5%, niobium content: 15.2%, hafnium content: 1.54%, iron content: 0.2%, boron content: 0.04%, and zirconium content: 75.52%.

[0064] S21, charging: the alloy raw materials weighed in step S1 are sequentially charged into the charging device of the water-cooled copper crucible suspension furnace according to industrial pure titanium, pure niobium, pure hafnium, pure zirconium and iron boride powder.

[0065] S22. Vacuum treatment: Close the furnace door and start the vacuum system. When the vacuum degree in the furnace reaches 10-3Pa or above, introduce argon gas and start the suspension furnace.

[0066] S23, pre-melting: gradually increase the melting power so that the surface of the raw material begins to melt and form molten droplets.

[0067] S24. Heating and melting: gradually increase the power and control the temperature at 1800°C to completely melt the alloy raw materials.

[0068] S25, heat preservation and refining: the molten alloy melt is subjected to electromagnetic stirring and heat preservation for 15 minutes. After the heat preservation is completed, it is poured into a preheated casting mold for casting, and cooled to obtain an alloy ingot.

[0069] S31. Place the alloy ingot obtained in step S2 into a forging furnace, heat the alloy ingot to 1000° C. at a heating rate of 15° C. / min, and keep the temperature for 2 hours to obtain the alloy ingot after the first fire forging.

[0070] S32. Cool the alloy ingot obtained in step S31 after the first forging to 900°C, and keep it at the temperature of the second forging for 1.5 hours to obtain the alloy ingot after the second forging.

[0071] S33. Cool the alloy ingot obtained in step S32 after the second forging to 850°C, and keep it at the temperature of the third forging for 1 hour to obtain an alloy ingot after the third forging.

[0072] S41, cutting the alloy ingot after the triple-fire forging in step S3 into alloy plates of 40*40*20 mm.

[0073] S42. The temperature of the muffle furnace is raised to 750° C. at a rate of 10° C. / min, and the temperature is kept at this temperature for 30 minutes. The alloy plate after the temperature is kept at this temperature is rolled, and the rolling deformation is 2.5% of the initial plate thickness.

[0074] S43. Place the plate rolled in step S42 into a muffle furnace and keep it warm for 5-10 minutes, and repeat the rolling process in step S42.

[0075] S44, repeating the rolling process of step S42, stopping the rolling process when the deformation of the alloy plate after rolling is 80% of the initial plate thickness, and water cooling to room temperature to obtain a multi-component alloy.

[0076] The multi-component zirconium alloy with a high yield strength to Young's modulus ratio obtained in this embodiment has a composition of Zr-7.5Ti-15.2Nb-1.54Hf-0.2Fe-0.04B.

[0077] Example 2

[0078] S1. Raw material weighing: Weigh and prepare industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder according to the mass percentages of titanium content: 10.2%, niobium content: 14.9%, hafnium content: 1.49%, iron content: 0.2%, boron content: 0.04%, and zirconium content: 73.17%.

[0079] S21, charging: the alloy raw materials weighed in step S1 are sequentially charged into the charging device of the water-cooled copper crucible suspension furnace according to industrial pure titanium, pure niobium, pure hafnium, pure zirconium and iron boride powder.

[0080] S22. Vacuum treatment: Close the furnace door and start the vacuum system. When the vacuum degree in the furnace reaches 10-3Pa or above, introduce argon gas and start the suspension furnace.

[0081] S23, pre-melting: gradually increase the melting power so that the surface of the raw material begins to melt and form molten droplets.

[0082] S24. Heating and melting: gradually increase the power and control the temperature at 1800°C to completely melt the alloy raw materials.

[0083] S25, heat preservation and refining: the molten alloy melt is subjected to electromagnetic stirring and heat preservation for 15 minutes. After the heat preservation is completed, it is poured into a preheated casting mold for casting, and cooled to obtain an alloy ingot.

[0084] S31. Place the alloy ingot obtained in step S2 into a forging furnace, heat the alloy ingot to 1000° C. at a heating rate of 15° C. / min, and keep the temperature for 2 hours to obtain the alloy ingot after the first fire forging.

[0085] S32. Cool the alloy ingot obtained in step S31 after the first forging to 900°C, and keep it at the temperature of the second forging for 1.5 hours to obtain the alloy ingot after the second forging.

[0086] S33. Cool the alloy ingot obtained in step S32 after the second forging to 850°C, and keep it at the temperature of the third forging for 1 hour to obtain an alloy ingot after the third forging.

[0087] S41, cutting the alloy ingot after the triple-fire forging in step S3 into alloy plates of 40*40*20 mm.

[0088] S42, heating the muffle furnace to 500° C. at a rate of 10° C. / min, maintaining the temperature for 30 minutes, and rolling the alloy plate after the temperature maintenance, with the rolling deformation amount being 2.5% of the initial plate thickness.

[0089] S43. Place the plate rolled in step S42 into a muffle furnace and keep it warm for 5-10 minutes, and repeat the rolling process in step S42.

[0090] S44, repeating the rolling process of step S42, stopping the rolling process when the deformation of the alloy plate after rolling is 80% of the initial plate thickness, and water cooling to room temperature to obtain a multi-component alloy.

[0091] The medical zirconium alloy plate prepared in this embodiment was tested to have a composition of Zr-10.2Ti-14.9Nb-1.49Hf--0.2Fe-0.04B.

[0092] Example 3

[0093] S1. Raw material weighing: Weigh and prepare industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder according to the mass percentages of titanium content: 10.2%, niobium content: 14.9%, hafnium content: 1.49%, iron content: 0.2%, boron content: 0.04%, and zirconium content: 73.17%.

[0094] S21, charging: the alloy raw materials weighed in step S1 are sequentially charged into the charging device of the water-cooled copper crucible suspension furnace according to industrial pure titanium, pure niobium, pure hafnium, pure zirconium and iron boride powder.

[0095] S22. Vacuum treatment: Close the furnace door and start the vacuum system. When the vacuum degree in the furnace reaches 10-3Pa or above, introduce argon gas and start the suspension furnace.

[0096] S23, pre-melting: gradually increase the melting power so that the surface of the raw material begins to melt and form molten droplets.

[0097] S24. Heating and melting: gradually increase the power and control the temperature at 2500°C to completely melt the alloy raw materials.

[0098] S25, heat preservation and refining: the molten alloy melt is subjected to electromagnetic stirring and heat preservation for 15 minutes. After the heat preservation is completed, it is poured into a preheated casting mold for casting, and cooled to obtain an alloy ingot.

[0099] S31. Place the alloy ingot obtained in step S2 into a forging furnace, heat the alloy ingot to 1000° C. at a heating rate of 15° C. / min, and keep the temperature for 2 hours to obtain the alloy ingot after the first fire forging.

[0100] S32. Cool the alloy ingot obtained in step S31 after the first forging to 900°C, and keep it at the temperature of the second forging for 1.5 hours to obtain the alloy ingot after the second forging.

[0101] S33. Cool the alloy ingot obtained in step S32 after the second forging to 850°C, and keep it at the temperature of the third forging for 1 hour to obtain an alloy ingot after the third forging.

[0102] S41, cutting the alloy ingot after the triple-fire forging in step S3 into alloy plates of 40*40*20 mm.

[0103] S42. The temperature of the muffle furnace is raised to 700° C. at a rate of 10° C. / min, and the temperature is kept at 700° C. for 30 minutes. The alloy plate after the temperature is kept at 700° C. is rolled, and the rolling deformation is 2.5% of the initial plate thickness.

[0104] S43. Place the plate rolled in step S42 into a muffle furnace and keep it warm for 5-10 minutes, and repeat the rolling process in step S42.

[0105] S44, repeating the rolling process of step S42, stopping the rolling process when the deformation of the alloy plate after rolling is 80% of the initial plate thickness, and water cooling to room temperature to obtain a multi-component alloy.

[0106] The medical zirconium alloy plate prepared in this embodiment was tested to have a composition of Zr-10.2Ti-14.9Nb-1.49Hf--0.2Fe-0.04B.

[0107] Example 4

[0108] S1. Raw material weighing: Weigh and mix industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder according to the mass percentages of titanium content: 20%, niobium content: 15.4%, hafnium content: 1.29%, iron content: 0.2%, boron content: 0.04%, and zirconium content: 63.07%.

[0109] S21, charging: the alloy raw materials weighed in step S1 are sequentially charged into the charging device of the water-cooled copper crucible suspension furnace according to industrial pure titanium, pure niobium, pure hafnium, pure zirconium and iron boride powder.

[0110] S22. Vacuum treatment: Close the furnace door and start the vacuum system. When the vacuum degree in the furnace reaches 10-3Pa or above, introduce argon gas and start the suspension furnace.

[0111] S23, pre-melting: gradually increase the melting power so that the surface of the raw material begins to melt and form molten droplets.

[0112] S24. Heating and melting: gradually increase the power and control the temperature at 1800°C to completely melt the alloy raw materials.

[0113] S25, heat preservation and refining: the molten alloy melt is subjected to electromagnetic stirring and heat preservation for 15 minutes. After the heat preservation is completed, it is poured into a preheated casting mold for casting, and cooled to obtain an alloy ingot.

[0114] S31. Place the alloy ingot obtained in step S2 into a forging furnace, heat the alloy ingot to 1000° C. at a heating rate of 15° C. / min, and keep the temperature for 2 hours to obtain the alloy ingot after the first fire forging.

[0115] S32. Cool the alloy ingot obtained in step S31 after the first forging to 900°C, and keep it at the temperature of the second forging for 1.5 hours to obtain the alloy ingot after the second forging.

[0116] S33. Cool the alloy ingot obtained in step S32 after the second forging to 850°C, and keep it at the temperature of the third forging for 1 hour to obtain an alloy ingot after the third forging.

[0117] S41, cutting the alloy ingot after the triple-fire forging in step S3 into alloy plates of 40*40*20 mm.

[0118] S42, heating the muffle furnace to 500° C. at a rate of 10° C. / min, maintaining the temperature for 30 minutes, and rolling the alloy plate after the temperature maintenance, with the rolling deformation amount being 2.5% of the initial plate thickness.

[0119] S43. Place the plate rolled in step S42 into a muffle furnace and keep it warm for 5-10 minutes, and repeat the rolling process in step S42.

[0120] S44, repeating the rolling process of step S42, stopping the rolling process when the deformation of the alloy plate after rolling is 80% of the initial plate thickness, and water cooling to room temperature to obtain a multi-component alloy.

[0121] The zirconium alloy plate prepared in this embodiment has a composition of Zr-20Ti-15.4Nb-1.29Hf-0.2Fe-0.04B. In a preferred embodiment, the zirconium alloy plate prepared in the present invention can be used as a medical zirconium alloy plate.

[0122] Comparative Example 1:

[0123] S1. Raw material weighing: Weigh and prepare industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder according to the mass percentages of titanium content: 10.2%, niobium content: 14.9%, hafnium content: 1.49%, iron content: 0.2%, boron content: 0.04%, and zirconium content: 73.17%.

[0124] S21, charging: the alloy raw materials weighed in step S1 are sequentially charged into the charging device of the water-cooled copper crucible suspension furnace according to industrial pure titanium, pure niobium, pure hafnium, pure zirconium and iron boride powder.

[0125] S22. Vacuum treatment: Close the furnace door and start the vacuum system. When the vacuum degree in the furnace reaches 10-3Pa or above, introduce argon gas and start the suspension furnace.

[0126] S23, pre-melting: gradually increase the melting power so that the surface of the raw material begins to melt and form molten droplets.

[0127] S24. Heating and melting: gradually increase the power and control the temperature at 1800°C to completely melt the alloy raw materials.

[0128] S25, heat preservation and refining: the molten alloy melt is subjected to electromagnetic stirring and heat preservation for 15 minutes. After the heat preservation is completed, it is poured into a preheated casting mold for casting, and cooled to obtain an alloy ingot.

[0129] S31. Place the alloy ingot obtained in step S2 into a forging furnace, heat the alloy ingot to 1000° C. at a heating rate of 15° C. / min, and keep the temperature for 2 hours to obtain the alloy ingot after the first fire forging.

[0130] S32. Cool the alloy ingot obtained in step S31 after the first forging to 900°C, and keep it at the temperature of the second forging for 1.5 hours to obtain the alloy ingot after the second forging.

[0131] S33. Cool the alloy ingot obtained in step S32 after the second forging to 850°C, and keep it at the temperature of the third forging for 1 hour to obtain an alloy ingot after the third forging.

[0132] S41, cutting the alloy ingot after the triple-fire forging in step S3 into alloy plates of 40*40*20 mm.

[0133] S42. The temperature of the muffle furnace is raised to 750° C. at a rate of 10° C. / min, and the temperature is kept at this temperature for 30 minutes. The alloy plate after the temperature is kept at this temperature is rolled, and the rolling deformation is 2.5% of the initial plate thickness.

[0134] S43. Place the plate rolled in step S42 into a muffle furnace and keep it warm for 5-10 minutes, and repeat the rolling process in step S42.

[0135] S44, repeating the rolling process of step S42, stopping the rolling process when the deformation of the alloy plate after rolling is 80% of the initial plate thickness, and water cooling to room temperature to obtain a multi-component alloy.

[0136] Comparative Example 2:

[0137] The rolling holding temperature of Comparative Example 2 is 800° C., and the other operating steps are the same as those of Comparative Example 1.

[0138] The results of the tests of Examples 1, 2 and 3 of the present invention were as follows: Figure 1 As shown, Examples 1 and 2 have the same alloying element content but different rolling and holding temperatures, while Examples 1 and 3 have the same rolling and holding temperatures but different alloying element contents. Variations in Ti content and process parameters do not change the metallographic composition of the multi-component zirconium alloy. The metallographic structures of Examples 1, 2, and 3 are all dominated by β phase, accompanied by a small amount of α phase. However, due to the changes in the content of each element in Examples 1 and 3, that is, as the Ti content increases, the content of α phase increases slightly.

[0139] like Figure 3As shown, in β-type TiZrNb alloys, the stability of the β phase increases with increasing niobium content. During deformation, β-type Ti-Zr alloys deform through various mechanisms, including phase transformation, twinning, or dislocation slip, depending on the stability of the β phase. The α+β phase temperature range for this alloy family is 460-652°C. Above 552°C, the alloy is entirely in the β phase with less than 1% compound phase. Within this temperature range, the alloy exhibits low deformation resistance, enabling significant plastic deformation, which results in grain breakage, dynamic recrystallization, and grain refinement. Furthermore, the dissolution temperature of borides is approximately 691°C. Within this temperature range, elemental diffusion and dissolution of the borides allow for the precipitation of fine, dispersed borides during cooling after deformation, significantly increasing the alloy's strength without changing the elastic modulus or reducing its ductility. However, if the temperature is too high, significant grain coarsening occurs after recrystallization. When the temperature is below 460°C, the alloy is mainly composed of the α phase, which is a close-packed hexagonal phase with low plastic deformation capacity. It cannot achieve large rolling deformation to achieve the effect of dislocation multiplication strengthening, and it is prone to cracking during the rolling process. At the same time, boron precipitates from the β phase and undergoes eutectic reaction at the grain boundaries to form intermetallic compounds TiB and ZrB2. The boride will pin the grain boundaries and hinder grain growth. These intermetallic compounds are conducive to providing significant grain refinement, improving the cohesion of the previous β grain boundaries and inhibiting intergranular fracture, thereby improving the mechanical properties of the alloy.

[0140] Figure 4 This is the EBSD image of Example 2. As shown in the figure, the grains with a size of less than 10μm in the alloy account for about 70% of the total area fraction, the average grain size is 8.9μm, and the grains with different orientations can be clearly distinguished. Figure 5 As shown in the figure, the red color may represent α-Zr grains with a specific crystal orientation parallel to the sample surface, while the blue color represents β-Zr grains with another crystal orientation. The distribution and orientation changes of the grains can be intuitively observed from the IPF image of Example 2.

[0141] Tensile tests were performed on the multi-component zirconium alloy plates prepared in Examples 1, 2, 3, Comparative Examples 1, and 2. At least five tensile specimens were cut from each sample and polished to a smooth surface. Mechanical properties were measured using a room temperature uniaxial tensile test. During the test, an extensometer was used to monitor the tensile displacement of the specimens. The tensile force was strain-controlled at a rate of 5 × 10⁻⁴ s. -1 The test results are shown in Table 1. Figure 2 is the stress-strain diagram for Example 1, Example 2 and Example 3. Figure 2 As can be seen from Table 1, the yield strength of the prepared material can reach 807-941 MPa and the Young's modulus can reach 60-70 GPa, and it has the performance characteristics of a high ratio of yield strength to elastic modulus.

[0142] Table 1

[0143]

[0144]

[0145] Figure 6 The following is a comparison chart of the yield strength and elastic modulus of the multi-component zirconium alloy with a high ratio of yield strength to Young's modulus of the present invention and the alloys of currently commonly used alloy materials, wherein the ordinate is the yield strength and the abscissa is the elastic modulus. The blue area in the figure is the maximum yield strength and the lowest elastic modulus limit that the alloys can achieve. As shown in the figure, the multi-component zirconium alloy of the present invention is compared with the alloys based on Ti. 15 Mo, Ti 45 Other medical alloys represented by Nb and Ti6Al4V have great advantages in yield tensile stress and elastic modulus. The elastic modulus is usually determined by tensile testing, and the method of using the extensometer during stretching is related to the final elastic modulus result. In superelastic materials, it is often expressed as the average elastic modulus of the entire elastic stage. Some materials also do not take into account the ductility of the material, sacrificing ductility in exchange for mechanical strength, resulting in limited elongation of high-strength materials. Finally, the large deformation process of the cold-rolled specimen limits the size and use of the sample by reducing the volume by 90%. Compared with most other alloys, the multi-component zirconium alloy prepared by other embodiments of the present invention has the characteristics of high strength and low elastic modulus. These properties are achieved through simple alloying and only through hot rolling, which effectively reduces the convenience of the processing technology.

[0146] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A multi-component zirconium alloy having a high ratio of yield strength to Young's modulus, characterized in that: The mass percentages of the elements are: zirconium 58.9-79.38%, titanium 7.5-20%, niobium 12.0-18.0%, hafnium 1.0-2.5%, iron 0.1-0.5% and boron 0.02-0.10%; its tensile yield strength is 807-941 MPa and its Young's modulus is 60-70 GPa.

2. The multi-component zirconium alloy with a high yield strength to Young's modulus ratio according to claim 1, characterized in that: The mass percentages of the elements are: titanium 20%, niobium 15%, hafnium 1.5%, iron 0.2%, boron 0.04% and zirconium 63.26%.

3. A method for preparing a multi-component zirconium alloy with a high yield strength to Young's modulus ratio according to claim 1, characterized in that: The specific steps include: S1. Weighing raw materials: Weigh and mix industrial pure titanium, pure niobium, pure hafnium, pure zirconium, and iron boride powder according to mass percentage; wherein industrial pure titanium accounts for 7.5-20% of the total mass, pure niobium accounts for 12.0-18.0% of the total mass, pure hafnium accounts for 1.0-2.5% of the total mass, iron boride powder accounts for 0.12-0.6% of the total mass, and pure zirconium accounts for 58.9-79.38% of the total mass. The mass percentage of boron to iron in the iron boride is 1:5; S2. Alloy smelting: placing the raw materials weighed in step S1 into a vacuum suspension furnace for smelting. After smelting, the raw materials are kept warm for a certain period of time, and the furnace is cooled to room temperature to obtain an alloy ingot. S3, forging treatment: the alloy ingot of step S2 is subjected to three-fire forging; S4. Rolling treatment: The forged alloy ingot is kept at a temperature between 500° C. and 750° C. for a period of time, and then rolled. The rolled alloy is water-cooled to room temperature to obtain a multi-component zirconium alloy.

4. The method for preparing a multi-component zirconium alloy with a high ratio of yield strength to Young's modulus according to claim 3, characterized in that: In step S4, the muffle furnace is heated to 500-750°C at a rate of 10-15°C / min, and the holding time is 25-35 minutes. The rolling deformation of each rolling process is 2-3% of the initial alloy ingot thickness. After each rolling, the heat is kept for 5-10 minutes, and the rolling process is repeated. When the total deformation of the alloy plate after rolling is 80%-82% of the initial alloy ingot thickness, the rolling process is stopped and the plate is cooled to room temperature with water.

5. The method for preparing a multi-component zirconium alloy with a high ratio of yield strength to Young's modulus according to claim 3, characterized in that: Step S2 includes the following specific steps: S21, charging: placing the alloy raw materials weighed in step S1 into the charging device of the suspension melting furnace; S22, vacuum treatment: vacuum treatment is performed in the suspension melting furnace, and argon gas is introduced when the vacuum reaches 10-3Pa or above; S23, pre-melting: gradually increase the melting power until the surface of the raw material begins to melt and form molten droplets; S24. Heating and melting: gradually increase the power and control the temperature at 1800-1900°C. When the alloy raw materials are completely melted, perform electromagnetic stirring and keep warm for 10-20 minutes, then cool the furnace to room temperature.

6. The method for preparing a multi-component zirconium alloy with a high ratio of yield strength to Young's modulus according to claim 3, characterized in that: In the three-fire forging process of step S3, the temperature of the first fire forging is 980-1020°C, and the holding time of the first fire forging is 1.5-2 hours; the temperature of the second fire forging is 890-910°C, and the holding time of the second fire forging is 1-1.5 hours; the temperature of the third fire forging is 830-870°C, and the holding time of the third fire forging is 1-1.2 hours.

7. The method for preparing a multi-component zirconium alloy with a high ratio of yield strength to Young's modulus according to claim 3, characterized in that: The order of charging in step S21 is adjusted according to the characteristics of the alloy, and the order of charging is industrial pure titanium, pure niobium, pure hafnium, pure zirconium and iron boride powder.

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