Method for optimizing mechanical property of ZTi60 titanium alloy

Abstract

The invention discloses a method for optimizing mechanical properties of a ZTi60 titanium alloy, and aims to solve the technical problems that in the prior art, the mechanical properties of the ZTi60 titanium alloy comprise the defects of low strength, low ductility and high brittleness, and use of the titanium alloy in high-performance application is limited, especially in the fields of aerospace, biomedicine and the like. According to the technical scheme, the method for optimizing the mechanical property of the ZTi60 titanium alloy comprises the following steps that firstly, according to the preset element content range, pure titanium, aluminum, molybdenum, oxygen and other elements are mixed according to a proper proportion; and 2, vacuum consumable electric arc furnace smelting is carried out under the ultralow oxygen atmosphere. The ZTi60 titanium alloy in the hot isostatic pressing state is subjected to homogenizing annealing heat treatment, and the technological parameters of the homogenizing annealing heat treatment are as follows: the heat preservation temperature is 730 + / -10 DEG C, the time is 1.5-3 hours, and furnace cooling is performed after heat preservation is finished. The method is suitable for improving the comprehensive mechanical property of the ZTi60 titanium alloy.

Description

Technical Field

[0001] The invention relates to the field of metal material science and engineering, and in particular to a method for microstructure regulation and mechanical property improvement of ZTi60 titanium alloy, which achieves the purpose of significantly improving the comprehensive mechanical properties of ZTi60 titanium alloy by precisely controlling the content and distribution of aluminum, oxygen and molybdenum elements. Background Art

[0002] Titanium alloys have been widely used in aerospace, navigation, chemical industry, automobile manufacturing, medical equipment and other fields due to their excellent specific strength, good corrosion resistance, excellent biocompatibility and high thermal stability. Among them, ZTi60, as a near-α-type titanium alloy containing aluminum, vanadium, molybdenum and other elements, has high strength and good formability, and is particularly suitable for occasions that need to withstand complex stress states and harsh environmental conditions.

[0003] However, the mechanical properties of ZTi60 titanium alloy still need to be further optimized to meet the increasingly stringent requirements of engineering applications. It is known that aluminum, as an α stabilizer, can change the phase composition of titanium alloys and increase the room temperature strength of the alloy; but excessive aluminum may cause harmful phase precipitation, reducing the plasticity and toughness of the alloy. Although oxygen is usually regarded as an impurity, within a certain range, an appropriate amount of oxygen can generate oxide particles, which has a dispersion strengthening effect on titanium alloys and improves fatigue properties. In addition, molybdenum, as a strong β stabilizer, can effectively regulate the stability of the β phase and help form favorable submicron intermetallic compounds, thereby significantly improving the hardness and high temperature strength of the alloy.

[0004] At present, the research on ZTi60 titanium alloy mainly focuses on how to achieve microstructure optimization and mechanical properties improvement by precisely controlling the content and distribution of minor alloying elements such as aluminum, oxygen, and molybdenum. However, there are many problems with the existing control methods, such as the difficulty in effectively controlling non-metallic inclusions, the difficulty in ensuring the uniform distribution of trace elements, and the incomplete phase change or excessive precipitation that may occur during the heat treatment process, which restrict the full realization of the performance potential of ZTi60 titanium alloy. Therefore, it is urgent to develop a new control method that can finely adjust the content of aluminum, oxygen, and molybdenum in ZTi60 titanium alloy, and construct an ideal microstructure by optimizing the smelting, casting, and heat treatment processes, thereby greatly improving the comprehensive mechanical properties of ZTi60 titanium alloy and expanding its application in the high-end equipment manufacturing industry. This is not only of great significance to the basic research of titanium alloys, but will also promote the technological progress and development of related industries. Summary of the invention

[0005] In order to solve the technical problems in the prior art that the mechanical properties of ZTi60 titanium alloy include low strength, low ductility and high brittleness, which limit the use of titanium alloy in high-performance applications, especially in the fields of aerospace and biomedicine, the technical solution provided by the present invention is as follows:

[0006] A method for optimizing the mechanical properties of ZTi60 titanium alloy, the method is carried out according to the following steps:

[0007] Step 1: According to the preset element content range, pure titanium is mixed with aluminum, molybdenum, oxygen and other elements in appropriate proportions.

[0008] Step 2: Vacuum consumable arc furnace melting in ultra-low oxygen atmosphere.

[0009] Furthermore, a preferred embodiment is provided, in step 1, aluminum: 3.0% to 4.0%, oxygen: 0.10% to 0.12%, molybdenum: 1.5% to 2.5%.

[0010] Based on the same inventive concept, the present invention also provides a ZTi60 titanium alloy prepared by the method described above.

[0011] Based on the same inventive concept, the present invention also provides a method for hot isostatic pressing of ZTi60 titanium alloy, which is used to perform hot isostatic pressing on the ZTi60 titanium alloy. The hot isostatic pressing parameters are: holding temperature 920±10°C, time 2 to 2.5h, holding pressure 110 to 140MPa, and cooling with the furnace after the holding is completed.

[0012] Furthermore, a preferred embodiment is provided, wherein the furnace cooling specifically includes cooling to below 300°C.

[0013] Based on the same inventive concept, the present invention also provides a hot isostatically pressed ZTi60 titanium alloy prepared by the method.

[0014] Based on the same inventive concept, the present invention also provides a method for homogenizing annealing heat treatment of hot isostatically pressed ZTi60 alloy, which is used to perform homogenizing annealing heat treatment on the hot isostatically pressed ZTi60 titanium alloy. The homogenizing annealing heat treatment process parameters are: insulation temperature 730±10℃, time 1.5~3h, and cooling with the furnace after the insulation is completed.

[0015] Furthermore, a preferred embodiment is provided, wherein the furnace cooling specifically includes cooling to below 300°C.

[0016] Based on the same inventive concept, the present invention also provides a method for preparing a high-strength ZTi60 alloy.

[0017] Based on the same inventive concept, the present invention also provides a plate material, which is prepared by using the high-strength ZTi60 alloy.

[0018] Compared with the prior art, the technical solution provided by the present invention is beneficial in that:

[0019] Microstructure optimization: By precisely controlling the content of aluminum (Al), oxygen (O) and molybdenum (Mo) elements in ZTi60 titanium alloy, a more ideal organizational structure can be induced at the microscopic level. When the aluminum element is in the range of 3.0% to 4.0%, it not only plays an effective solid solution strengthening role, but also avoids the increase of brittleness caused by excessive content. When the oxygen element is in the limited content range of 0.10% to 0.13%, the generated oxide particles are evenly distributed in the alloy matrix, which significantly enhances the fatigue resistance of the alloy. When the molybdenum content is between 1.5% and 2.5%, it promotes the formation of beneficial intermetallic compounds, improves the hardness and high temperature strength of the alloy, and ensures sufficient toughness and durability.

[0020] Improved mechanical properties: Through the composition control and corresponding heat treatment process of the present invention, the mechanical properties of ZTi60 titanium alloy have been significantly improved, which is reflected in the tensile strength reaching 714MPa, the yield strength reaching 630MPa, and the elongation after fracture reaching 15.3%, and the mechanical properties have been greatly improved.

[0021] Process feasibility and economic efficiency: The process provided by the present invention has good operability and economic practicability. Through advanced smelting technology and precise heat treatment procedures, accurate control of alloy composition and optimization of microstructure are ensured, while reducing production costs and energy consumption, and improving the efficiency of the entire production process.

[0022] Expanded application scope: In view of the above-mentioned significant performance improvements, the ZTi60 titanium alloy of the present invention can replace or upgrade existing materials in the fields of aerospace, marine engineering, medical implants, petrochemicals, etc., broadening its ability to serve under extreme environmental conditions and its scope of application.

[0023] Furthermore, the beneficial effects brought by the present invention also include:

[0024] By optimizing the raw material ratio and adopting vacuum melting, the solution significantly reduces the oxygen content in the alloy, thereby increasing the tensile strength and yield strength of the alloy. Compared with existing research, this improvement significantly improves the mechanical properties of the material, making it more suitable for applications under high stress conditions.

[0025] The combination of hot isostatic pressing and homogenization annealing makes the alloy's microstructure more uniform, reducing internal defects and non-uniform distribution of phases. Compared with traditional heat treatment technology, this method can effectively improve the ductility and toughness of the alloy, reduce the risk of brittle fracture, and thus extend its service life.

[0026] Finally, comprehensive mechanical properties and microstructure testing were performed to ensure the high performance stability of the optimized ZTi60 titanium alloy. This systematic verification method is relatively rare in current research and helps to improve the reliability of materials and meet the strict requirements of industrial applications.

[0027] It is suitable for use in improving the comprehensive mechanical properties of ZTi60 titanium alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram showing the comparison of tensile strength and yield strength before and after regulation according to the method provided by the present invention;

[0029] Figure 2 The figure is a schematic diagram comparing the elongation after break before and after regulation according to the method provided by the present invention. DETAILED DESCRIPTION

[0030] In order to make the advantages and benefits of the technical solution provided by the present invention more clearly reflected, the technical solution provided by the present invention is now further described in detail with reference to the accompanying drawings, specifically:

[0031] Embodiment 1: This embodiment provides a method for optimizing the mechanical properties of ZTi60 titanium alloy, which is performed in the following steps:

[0032] Step 1: According to the preset element content range, pure titanium is mixed with aluminum, molybdenum, oxygen and other elements in appropriate proportions.

[0033] Step 2: Vacuum consumable arc furnace melting in ultra-low oxygen atmosphere.

[0034] Embodiment 2. This embodiment further limits the method for optimizing the mechanical properties of ZTi60 titanium alloy provided in embodiment 1. In step 1, the aluminum content is 3.0% to 4.0%, the oxygen content is 0.10% to 0.12%, and the molybdenum content is 1.5% to 2.5%.

[0035] Embodiment 3: This embodiment provides a ZTi60 titanium alloy obtained by the method provided in any one of embodiments 1 to 2.

[0036] Embodiment 4. This embodiment provides a method for hot isostatic pressing of ZTi60 titanium alloy, which is used to perform hot isostatic pressing on the ZTi60 titanium alloy provided by Embodiment 3. The hot isostatic pressing parameters are: holding temperature 920±10°C, time 2~2.5h, holding pressure 110~140MPa, and cooling with the furnace after the holding is completed.

[0037] Embodiment 5: This embodiment further limits the method for hot isostatic pressing of the ZTi60 titanium alloy provided in Embodiment 4, and the furnace cooling specifically includes cooling to below 300°C.

[0038] Embodiment 6: This embodiment provides a hot isostatically pressed ZTi60 titanium alloy produced by the method provided in embodiment 4.

[0039] Embodiment 7. This embodiment provides a method for homogenizing annealing heat treatment of hot isostatically pressed ZTi60 alloy, which is used to perform homogenizing annealing heat treatment on the hot isostatically pressed ZTi60 titanium alloy provided by embodiment 6. The homogenizing annealing heat treatment process parameters are: holding temperature 730±10℃, time 1.5~3h, and cooling with the furnace after the holding is completed.

[0040] Specifically,

[0041] Step 1: Raw material ratio and ingredients

[0042] Refine the selection of raw materials:

[0043] Select high-purity titanium raw materials (such as pure titanium powder or titanium ingots), and ensure that the sources of elements such as aluminum, molybdenum, and oxygen are also high-purity to avoid impurities affecting the properties of the alloy.

[0044] Elemental analysis and control:

[0045] Before mixing, chemical analysis equipment (such as a spectrometer) is used to test the purity and content of each element to ensure that the raw materials used in mixing meet the preset standards.

[0046] Step 2: Vacuum melting

[0047] Melting equipment preparation:

[0048] Before smelting, ensure that the vacuum consumable arc furnace is well sealed and perform a vacuum test to confirm that the oxygen content is lower than the set value.

[0049] Melting parameter setting:

[0050] Set the melting current and voltage to optimize the melting process. Usually the current is between 200-400A and the voltage is between 20-50V. The specific parameters need to be adjusted according to the actual conditions of the equipment and alloy.

[0051] Melting process monitoring:

[0052] Monitor the temperature and vacuum during the melting process to ensure that a low oxygen environment is maintained during the melting process. An infrared thermometer can be used to monitor temperature changes in real time.

[0053] Step 3: Hot isostatic pressing

[0054] Equipment Calibration:

[0055] Before hot isostatic pressing, ensure that the equipment is calibrated, especially the pressure sensor and temperature control system, to ensure the accuracy of the set parameters.

[0056] Gas selection and filling:

[0057] High-purity argon (99.99%) is selected as the protective gas, and it needs to be filtered before filling to avoid the influence of gas impurities on the performance of the alloy.

[0058] Step 4: Homogenization annealing

[0059] Heat treatment furnace settings:

[0060] Before homogenization annealing, ensure that the air leakage rate of the vacuum heat treatment furnace is ≤1.3Pa / 1h and the pressure rise rate is normal to avoid oxygen infiltration during the heat treatment process.

[0061] Temperature and time optimization:

[0062] According to the alloys with different aluminum and molybdenum contents, the holding time is optimized (e.g. 1.5 to 3 hours) to ensure that the alloy is fully dissolved and reaches a homogenized state. For different batches of alloys, small-scale tests can be carried out to determine the best processing parameters.

[0063] Step 5: Performance testing and verification

[0064] Mechanical properties test method:

[0065] Use standardized tensile tests (such as GB / T 228-2010) to determine tensile strength, yield strength and elongation. Ensure that the testing equipment meets national standards and is calibrated regularly.

[0066] Microstructure Analysis:

[0067] Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to observe the microstructure of the alloy, evaluate the distribution and size of the phases, and ensure that the internal structure of the alloy meets the design requirements.

[0068] Fatigue performance test:

[0069] In addition to tensile tests, fatigue tests are performed to evaluate the durability and fatigue life of the alloy under actual service conditions.

[0070] The technical solution provided by this embodiment has the following beneficial effects:

[0071] By precisely controlling the contents of aluminum, oxygen, and molybdenum, the method provided in this embodiment can significantly improve the fatigue life of ZTi60 titanium alloy. This optimized microstructure enables the alloy to exhibit higher fatigue resistance under repeated loads, thereby improving its reliability in dynamic working environments.

[0072] This method enhances the high temperature resistance of ZTi60 titanium alloy. Through appropriate element ratio and heat treatment process, the stability of the alloy under high temperature conditions can be effectively improved, and the risk of performance degradation caused by phase change under high temperature can be reduced, which is suitable for high temperature application scenarios.

[0073] The method provided in this embodiment improves the weldability and processability of the alloy. The optimized composition design enables the ZTi60 titanium alloy to exhibit better fluidity and lower thermal cracking tendency during welding and processing, reduces defects in the production process, and improves the yield rate.

[0074] The optimized ZTi60 titanium alloy also has good biocompatibility and is suitable for use in medical devices. By controlling the oxygen content, a more stable passivation film can be formed on the alloy surface, thereby improving its corrosion resistance and biocompatibility in biological environments.

[0075] The process of this method has strong repeatability and stability, which is conducive to large-scale production. Due to the precise setting of composition control and heat treatment conditions, the performance consistency between different batches of products can be ensured, meeting the consistency requirements of material performance in the high-end equipment manufacturing industry.

[0076] Through comprehensive process optimization, the method provided in this embodiment may also reduce production costs and energy consumption. Accurate material ratio and optimized heat treatment process not only improve material properties, but also reduce energy consumption during smelting and heat treatment, which helps to achieve sustainable production goals.

[0077] Embodiment 8: This embodiment further limits the homogenization annealing heat treatment method for the hot isostatically pressed ZTi60 alloy provided in Embodiment 7, and the furnace cooling specifically includes: cooling to below 300°C.

[0078] Embodiment 9: This embodiment provides a high-strength ZTi60 alloy prepared according to the method provided in embodiment 7.

[0079] Embodiment 10: This embodiment provides a plate, which is prepared by using the high-strength ZTi60 alloy provided in embodiment 9.

[0080] Implementation Method XI: Combination Figure 1-2 This embodiment is described in detail by using specific examples to further describe the technical solution provided above. Specifically:

[0081] The purpose of this embodiment is to provide a method for significantly optimizing the mechanical properties of Ti60 titanium alloy by precisely controlling the content of aluminum (Al), oxygen (O) and molybdenum (Mo) elements. Specifically, this embodiment aims to solve the problem of unstable alloy performance and failure to fully exert the alloy performance due to inaccurate control of element content in the prior art. Through innovative composition design and process flow, ZTi60 titanium alloy can significantly improve its tensile strength, yield strength, fracture toughness and fatigue performance while maintaining good processability and corrosion resistance.

[0082] One of the purposes of this embodiment is to provide an optimized composition design and smelting process method, wherein the process method is carried out in the following steps:

[0083] Step 1: Raw material ratio of titanium alloy ingot.

[0084] Step 2: Vacuum melting.

[0085] In step 1, pure titanium is mixed with aluminum, molybdenum, oxygen and other elements in appropriate proportions according to a preset element content range;

[0086] In step 1, ensure that the aluminum content in the final alloy is between 3.0% and 4.0%;

[0087] In step 1, ensure that the oxygen content in the final alloy is between 0.10% and 0.13%;

[0088] In step 1, ensure that the molybdenum content in the final alloy is between 1.5% and 2.5%;

[0089] In step 1, high-precision weighing equipment is used to ensure that each element is added accurately;

[0090] In step 2, vacuum consumable arc furnace smelting is required in an ultra-low oxygen atmosphere to ensure that aluminum, oxygen, and molybdenum elements are evenly dispersed in the molten titanium alloy.

[0091] The second purpose of this embodiment is to provide a suitable hot isostatic pressing process to optimize the microstructure of Ti60 titanium alloy. The hot isostatic pressing process is carried out according to the following steps:

[0092] Step 1: Check whether the hot isostatic pressing furnace is in normal working condition.

[0093] Step 2: Place the ZTi60 titanium alloy into a hot isostatic pressing furnace and set the process parameters.

[0094] In step 1, check whether the indicators of the power distribution cabinet are normal;

[0095] Check in step 1 whether there is a gap between the sweat wiper plug and the frame;

[0096] In step 1, check whether the internal circulation pump is normal, whether the positions of the valves in the water system are normal, and whether the water volume of the internal circulation water is normal;

[0097] In step 1, check whether the lifting equipment and other tools used for loading the furnace meet the use requirements and whether they are damaged and cannot be used;

[0098] In step 2, set the insulation temperature to 920±10℃;

[0099] In step 2, the holding pressure is set to 110-140 MPa;

[0100] In step 2, argon gas (99.99%) is filled;

[0101] In step 2, the insulation time is set to 2 to 2.5 hours.

[0102] The cooling method in step 2 is furnace cooling;

[0103] In step 2, the furnace temperature is ≤300°C;

[0104] The third purpose of this embodiment is to provide a suitable homogenization annealing process to improve the mechanical properties of Ti60 titanium alloy. The thermal homogenization heat treatment process is carried out according to the following steps:

[0105] Step 1: Check whether the vacuum heat treatment furnace is in normal working condition.

[0106] Step 2: Place the ZTi60 titanium alloy into a vacuum heat treatment furnace and set the process parameters.

[0107] In step 1, the leakage rate of the vacuum heat treatment furnace should be monitored, and the pressure rise rate should be ≤1.3Pa / 1h;

[0108] In step 2, the vacuum degree at the start of temperature rise is set to ≤1Pa;

[0109] In step 2, the insulation temperature is set to 730±10℃.

[0110] In step 2, set the insulation time to 1.5 to 3 hours.

[0111] The cooling method in step 2 is furnace cooling, and the product can be taken out of the furnace when it is cooled to below 300°C.

[0112] A fourth purpose of this embodiment is to provide a ZTi60 titanium alloy with high strength mechanical properties.

[0113] Combination Figure 1 and 2, which is a schematic diagram comparing the tensile strength and yield strength before and after regulation by the method provided in this embodiment, and a schematic diagram comparing the elongation after fracture.

[0114] The specific embodiment is:

[0115] Implementation Case 1: A preparation process of a high-performance ZTi60 titanium alloy is carried out in the following steps:

[0116] Step 1:

[0117] According to the pre-designed element content range, pure titanium is mixed with aluminum, molybdenum, oxygen and other elements in appropriate proportions to ensure that the final alloy contains 3.0-4.0wt(%) Al, 0.10-0.13wt(%) O and 1.5-2.5wt(%) Mo. High-precision weighing equipment is used to ensure accurate addition of each element.

[0118] Step 2:

[0119] Vacuum consumable arc furnace melting is carried out in an ultra-low oxygen atmosphere to ensure that aluminum, oxygen and molybdenum elements are evenly dispersed in the molten titanium alloy, avoid the formation of non-metallic inclusions, and ensure the purity and consistency of the alloy.

[0120] Step 3:

[0121] After the alloy ingot is cooled, it is first subjected to hot isostatic pressing. By controlling the holding time and temperature, a uniform, fine and reasonably distributed strengthening phase is formed inside the alloy.

[0122] Step 4:

[0123] Next, homogenization heat treatment is carried out to allow aluminum and molybdenum elements to fully dissolve and reduce casting stress.

[0124] Testing and Inspection

[0125] After completing the above preparation process, a tensile test was carried out on the alloy samples to verify the significant improvement of the mechanical properties such as tensile strength, yield strength, and elongation after fracture of the regulated ZTi60 titanium alloy.

[0126] The technical solution provided by the present invention is further described in detail above through several specific implementation modes in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the several specific implementation modes described above are not intended to be used as limitations on the present invention. Any reasonable modification and improvement of the present invention, combination of implementation modes and equivalent substitution within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for optimizing the mechanical properties of ZTi60 titanium alloy, characterized in that: The method proceeds as follows: Step 1: According to the preset element content range, pure titanium is mixed with aluminum, molybdenum, oxygen and other elements in appropriate proportions. Step 2: Vacuum consumable arc furnace melting in ultra-low oxygen atmosphere.

2. The method according to claim 1, characterized in that In step 1, aluminum: 3.0% to 4.0%, oxygen: 0.10% to 0.12%, and molybdenum: 1.5% to 2.5%.

3. ZTi60 titanium alloy obtained by the method described in any one of claims 1-2.

4. A method for hot isostatic pressing of a ZTi60 titanium alloy, for hot isostatic pressing of the ZTi60 titanium alloy according to claim 3, characterized in that: The hot isostatic pressing parameters are: holding temperature 920±10℃, time 2~2.5h, holding pressure 110~140MPa, and cooling with the furnace after the holding is completed.

5. The method for hot isostatic pressing of ZTi60 titanium alloy according to claim 4, characterized in that: The furnace cooling specifically includes cooling to below 300°C.

6. The hot isostatically pressed ZTi60 titanium alloy obtained by the method according to claim 4.

7. A method for homogenizing annealing heat treatment of hot isostatically pressed ZTi60 alloy, which is used for homogenizing annealing heat treatment of the hot isostatically pressed ZTi60 titanium alloy according to claim 6, characterized in that: The homogenization annealing heat treatment process parameters are: holding temperature 730±10℃, time 1.5~3h, and cooling with the furnace after the holding is completed.

8. The homogenization annealing heat treatment method for hot isostatically pressed ZTi60 alloy according to claim 7, characterized in that: The furnace cooling specifically includes cooling to below 300°C.

9. The method of claim 7 is used to prepare a high-strength ZTi60 alloy.

10. A sheet material, characterized in that: The plate is made of the high-strength ZTi60 alloy described in claim 9.

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