TA10 titanium alloy with high strength and good corrosion resistance and preparation method thereof

Abstract

The invention discloses a TA10 titanium alloy with high strength and good corrosion resistance and a preparation method of the TA10 titanium alloy, and relates to the field of metal material preparation. The invention aims to solve the problems of poor corrosion resistance and mechanical property of the existing as-cast TA10 titanium alloy. The alloy is composed of, by mass, 1%-4% of Mn, 1%-4% of V, 0.7%-0.8% of Ni, 0.2%-0.3% of Mo and the balance Ti and inevitable impurities. The method comprises: 1, raw material preparation; selecting manganese sheets and vanadium blocks or vanadium blocks, titanium sponge and molybdenum raw materials for proportioning; 2, smelting by adopting a vacuum induction smelting furnace to obtain a cast ingot with uniform components; 3, a target part is obtained through pouring; the alloy melt is poured into a preheated machining casting mold, and a casting with the required size can be obtained after the alloy melt is cooled; and 4, carrying out surface post-treatment to obtain a target part. The method is used for preparing the TA10 titanium alloy.

Description

Technical Field

[0001] The present invention relates to a method for preparing TA10 titanium alloy with enhanced properties by alloying, belonging to the technical field of metal material preparation. Specifically, it relates to a preparation process that changes the internal microstructure of as-cast TA10 titanium alloy by adding alloying elements and enhances the comprehensive properties. This alloy has high yield strength and high corrosion resistance at room temperature. Background Art

[0002] Titanium alloys have high specific strength, corrosion resistance, and good biocompatibility, so they are widely used in aerospace, seawater desalination, offshore drilling, chemical engineering, medical and other fields. The corrosion resistance of titanium alloys is not only related to the service environment but also to their own microstructure.

[0003] In an acidic environment, hydrostatic pressure promotes the selective dissolution of the passive film, affects hydrogen evolution, hydrogen absorption, and hydrogen permeation of titanium alloys, or promotes hydrogen to enter the microstructure of titanium alloys. Hydrogen induces cracks by accelerating dislocation movement, resulting in unstable properties of the passive film and promoting the corrosion process of the metal. Since there is a natural oxide film mainly composed of titanium oxide on the surface of titanium alloys, it shows excellent corrosion resistance in halogen-containing aqueous solutions.

[0004] In a strongly oxidizing environment, titanium alloys generally have corrosion resistance, such as in chromic acid, perchloric acid, and nitric acid. This environment can promote the formation of a stable passive film on titanium alloys. However, titanium alloys show relatively poor corrosion resistance in reducing acids such as sulfuric acid and hydrochloric acid, and these acids can damage the passive film of titanium alloys and thus reduce their corrosion resistance. Therefore, appropriate and effective strategies must be adopted to improve the corrosion resistance of titanium alloys in a reducing acid environment. The corrosion resistance of titanium alloys is also related to their microstructure.

[0005] Titanium alloys have three typical microstructures, namely hexagonal close-packed structure (α), body-centered cubic structure (β), and α+β duplex structure. The microstructure of titanium alloys can be regulated by heat treatment or adding alloying elements, and the microstructure of titanium alloys also determines their corrosion resistance. In titanium alloys with a hexagonal close-packed structure (α), the TA10 passive film improves the electrochemical corrosion resistance. The as-cast microstructure of TA10 alloy is an α-phase matrix and a small amount of lamellar β-phase. After hot rolling, the lamellar α-phase basically disappears and transforms into elongated α-phase.

[0006] The results of electrochemical experiments show that the alloy has a relatively stable current density, indicating that the formation rate of its passivation film is relatively fast and the stability is relatively high. From the perspective of adding alloying elements, Mo is an excellent β-phase stabilizer for Ti alloys used in biomedical applications. Both cold-rolled and solution heat-treated Ti-Mo alloys exhibit good corrosion resistance in 5M HCl solution due to the presence of a mixture of MoO3 and TiO2 in their passivation films. It can be seen that by adding alloying elements, the stability of the passivation film of titanium alloys can also be improved, new phases with better corrosion resistance can be formed, etc., enhancing the corrosion resistance of titanium alloys.

[0007] However, the existing substrate alloy TA10 is a trial alloy with a nominal composition of Ti-0.3Mo-0.8Ni announced by the Timet Division of the American Titanium Metals Corporation in October 1974. This alloy has good processing performance, has a lower cathodic overvoltage compared to pure titanium, and has good corrosion resistance in chloride solutions and weakly reducing acids. It is found from the research that in 40%-70% HNO3 solution, the corrosion rate of TA10 titanium alloy is significantly lower than that of Ti-0.2Pd alloy. At the same time, in the currently developed titanium alloy production processes, the mechanical properties of as-cast TA10 titanium alloy are generally poor, and it is difficult to meet the requirements of marine ship materials for excellent corrosion resistance and mechanical properties of structural parts. Through literature research, the tensile strength of as-cast TA10 titanium alloy is 200-380 MPa.

[0008] In summary, the existing as-cast TA10 titanium alloy has problems of poor corrosion resistance and mechanical properties. Summary of the Invention

[0009] The purpose of the present invention is to solve the problems of poor corrosion resistance and mechanical properties of the existing as-cast TA10 titanium alloy. Furthermore, a TA10 titanium alloy with both high strength and good corrosion resistance and its preparation method are provided.

[0010] The technical solution of the present invention is as follows:

[0011] A TA10 titanium alloy with both high strength and good corrosion resistance is composed of the following elements in mass percentage: Mn 1%-4%, V 1%-4%, Ni 0.7%-0.8%, Mo 0.2%-0.3%, and the balance is Ti and inevitable impurities.

[0012] Preferably, the mass percentage of the TA10 titanium alloy with both high strength and good corrosion resistance is: Mn 4%, V 1%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities; or Mn 1%, V 4%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities.

[0013] A TA10 titanium alloy with both high strength and good corrosion resistance, which is composed of the following elements by mass percentage: V 1%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities.

[0014] The present invention also provides a preparation method of a TA10 titanium alloy with both high strength and good corrosion resistance, and the method includes the following steps:

[0015] Step 1: Preparation of raw materials;

[0016] According to the performance and cost required by the target part, design the composition for batching;

[0017] Select manganese sheets and vanadium blocks or vanadium blocks, sponge titanium and molybdenum raw materials for batching;

[0018] Step 2: Melting of raw materials;

[0019] Step 2-1: Perform 5 times of vacuum consumable melting on the batching blocks obtained in Step 1 to obtain an ingot;

[0020] Step 2-2: Use a vacuum induction melting furnace to melt the alloyed TA10 titanium alloy and obtain an ingot with uniform composition;

[0021] Step 3: Cast to obtain the target part;

[0022] Select a suitable mold according to the target part, pour the alloy melt obtained in Step 2 into the preheated machining mold, and the required-size casting can be obtained after it cools;

[0023] Step 4: Surface post-treatment;

[0024] Cut off the riser of the casting obtained in Step 3, perform surface treatment, and obtain the target part.

[0025] Further, in Step 2-2, when melting the TA10 titanium alloy, it includes the following steps:

[0026] Step S1: First put the pre-pressed raw material blocks into the crucible;

[0027] Step S2: After loading the raw material blocks into the crucible, close the furnace door and evacuate the furnace;

[0028] Step S3: Fill the furnace with high-purity argon for gas washing;

[0029] Step S4: After the cleaning is completed, start the intermediate frequency power supply to start melting;

[0030] Step S5: After complete melting, tilt the crucible for turning the materials until five times of repeated melting are completed, and finally obtain an ingot with uniform composition.

[0031] Furthermore, during the charging in step S1, more raw materials are loaded at the bottom of the crucible than at the bottom of the crucible, and the upper charge is kept in a loose state.

[0032] Furthermore, in step S4, the charge is heated at the initial stage of melting until the charge starts to melt; after the charge starts to melt, the argon injection is continued, the smelting power is increased and a reasonable melting rate is maintained.

[0033] Furthermore, the post-treatment of the casting surface described in step four is successively: surface cleaning and surface grinding.

[0034] Preferably, the surface cleaning process is: ultrasonic cleaning with anhydrous ethanol as the cleaning medium, and the cleaning time is 10 min.

[0035] Preferably, the surface grinding process is: the specimen is successively polished with 240#, 400#, 800#, 1200# and 2000# SiC sandpapers, then ultrasonically cleaned with ethanol and distilled water for 120 s in sequence, and the moisture on the surface of the specimen is dried by a dryer.

[0036] The present invention has the following effects compared with the prior art:

[0037] 1. The present invention can simultaneously improve the mechanical properties and corrosion resistance of as-cast TA10 alloy by alloying. Specifically manifested in:

[0038] (1) By adding Mn and V elements, the present invention can increase the proportion of β-phase in the alloy, thereby improving the corrosion resistance. Compared with the α-phase of titanium alloy, the β-phase has better corrosion resistance. Therefore, increasing the content of β-phase can significantly improve the corrosion resistance of the alloy matrix. At the same time, V element can participate in the formation of the passivation film on the alloy surface. It can be known from X-ray photoelectron spectroscopy test that V element participates in the formation of oxides such as V2O5, which together with titanium oxides form an oxide film, improving the ability of this alloy to form a passivation film in acid and effectively reducing the corrosion rate. At the same time, the β-phase and α-phase form a lamellar distribution, reducing the influence of galvanic corrosion between the two phases.

[0039] (2) In terms of microstructure, by adding alloying elements such as Mn and V, heterogeneous nucleation cores are provided for nucleation during the melting and casting process, and the structure is refined to a great extent. The refinement of grains can improve the mechanical properties of materials. As revealed by the Hall-Petch formula, the yield stress of the material is improved.

[0040] Therefore, through the synergistic addition of these two elements in proportion, the corrosion resistance and mechanical properties of alloyed as-cast TA10 titanium alloy are effectively improved.

[0041] 2. By adopting the alloying method, the present invention improves the microstructure of as-cast TA10 titanium alloy, and finally obtains an as-cast TA10 titanium alloy with high corrosion resistance, high yield strength and relatively high tensile ductility at room temperature, so that the as-cast TA10 alloy can have good mechanical properties and corrosion resistance after forming.

[0042] 3. By means of vacuum consumable melting, the present invention prepares an alloyed TA10 titanium alloy with good mechanical properties and corrosion resistance. The properties of this alloy are detected by tensile property test and static immersion corrosion test. The results are as follows: In terms of corrosion resistance, the minimum corrosion rate of the titanium alloy in a 5% HCl solution at 25 °C is 0.66 mm / year; in terms of mechanical properties, the maximum ultimate tensile strength is 636.9 MPa, and the fracture toughness K Q value can reach up to 57.78 MPa·m 1 / 2 .

[0043] 4. The present invention simplifies the production process of as-cast TA10 titanium alloy. Through vacuum consumable melting, the alloy melt with uniform composition is obtained after melting 5 times repeatedly. The obtained melt is poured into a mold that meets the requirements of the target part for casting. After casting is completed, it is cooled and formed. After cutting off the riser, simple surface treatment can be carried out to form the part. The processes of improving strength such as cogging forging, rolling and heat treatment are simplified, the production cost is saved, and the application scenarios of as-cast TA10 titanium alloy are broadened.

[0044] 5. By adding V and Mn elements, the present invention improves both the mechanical properties and corrosion resistance of as-cast TA10 titanium alloy. Both V and Mn elements are β-phase stabilizing elements, which help to generate more β-phase in the alloy matrix, and the β-phase has better corrosion resistance, thus improving the corrosion resistance of the alloy matrix. At the same time, V element can participate in the formation of the alloy surface oxide film, ensuring that a more stable passivation film can be formed on the alloy surface in acid.

[0045] 6. The present invention selects alloying to improve the overall mechanical properties of as-cast TA10 titanium alloy. Mn and V elements, as the core of heterogeneous nucleation of titanium alloy, promote the refinement of grains, effectively improving the yield strength of the alloy. At the same time, the addition of elements is beneficial to the refinement of lamellae, ensuring the initiation of slip during the tensile stress process, and making the alloy have good plasticity.

[0046] That is to say, by adding Mn and V elements in a certain proportion, the mechanical properties and corrosion resistance of as-cast TA10 titanium alloy can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1It is the microstructure morphology diagram obtained by SEM electron microscopy of the TA10-4Mn-1V alloy in the second embodiment of the present invention;

[0048] Figure 2 It is the surface microstructure morphology diagram of the TA10-4V-1Mn alloy in the first embodiment of the present invention after 10-day static immersion test in 5M HCl;

[0049] Figure 3 It is the corrosion rate change diagram of the as-cast TA10 titanium alloy doped with different alloying components in the present invention during 10-day immersion in 5M HCl;

[0050] Figure 4 It is the tensile test results of the as-cast TA10 titanium alloy doped with different alloying components in the first, second and third embodiments of the present invention. Detailed implementation manners

[0051] Detailed implementation manner one: A TA10 titanium alloy with both high strength and good corrosion resistance in this implementation manner is composed of the following elements in mass percentage: Mn 1%-4%, V 1%-4%, Ni 0.7%-0.8%, Mo 0.2%-0.3%, and the balance is Ti and inevitable impurities.

[0052] The performance of this alloy is detected by tensile property test and static immersion corrosion test in this implementation manner. The results are as follows: In terms of corrosion resistance, the lowest corrosion rate of the titanium alloy in the HCl solution with a mass fraction of 5% at 25°C is 0.66 mm / year; in terms of mechanical properties, the highest ultimate tensile strength is 636.9 MPa, and the fracture toughness K Q value can reach up to 57.78 MPa·m 1 / 2 .

[0053] Detailed implementation manner two: The mass percentage of the TA10 titanium alloy with both high strength and good corrosion resistance in this implementation manner is: Mn 4%, V 1%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities; or Mn 1%, V 4%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities.

[0054] Detailed implementation manner three: A TA10 titanium alloy with both high strength and good corrosion resistance in this implementation manner is composed of the following elements in mass percentage: V 1%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities.

[0055] Detailed implementation manner four: The preparation method of the TA10 titanium alloy with both high strength and good corrosion resistance in this implementation manner includes the following steps:

[0056] Step 1: Raw material preparation;

[0057] According to the performance and cost required by the target part, design the composition for batching;

[0058] Select manganese sheets and vanadium blocks or vanadium blocks, sponge titanium, and molybdenum raw materials for batching;

[0059] Step 2: Raw material melting;

[0060] Step 2-1: Perform 5 times of vacuum consumable melting on the batching blocks obtained in Step 1 to obtain an ingot;

[0061] Step 2-2: Use a vacuum induction melting furnace to melt the alloyed TA10 titanium alloy and obtain an ingot with uniform composition;

[0062] Step 3: Cast to obtain the target part;

[0063] Select a suitable mold according to the target part, pour the alloy melt obtained in Step 2 into the preheated machining mold, and the required-size casting can be obtained after it cools;

[0064] Step 4: Surface post-treatment;

[0065] Cut off the riser of the casting obtained in Step 3 and perform surface treatment to obtain the target part.

[0066] Other compositions and connection relationships are the same as those in the third specific implementation manner.

[0067] In this implementation manner, an alloyed TA10 titanium alloy with good mechanical properties and corrosion resistance is prepared by the method of vacuum consumable melting. It is composed of the following elements in mass percentage: Mn 1%-4%, V 1%-4%, Ni 0.7%-0.8%, Mo 0.2%-0.3%, and the balance is Ti and inevitable impurities. The performance of this alloy is detected through tensile property tests and static immersion corrosion tests. The results are as follows:

[0068] In terms of corrosion resistance, the lowest corrosion rate of the titanium alloy in a 5% HCl solution at 25°C is 0.66 mm / year; in terms of mechanical properties, the highest ultimate tensile strength is 636.9 MPa, and the fracture toughness K Q value can reach up to 57.78 MPa·m 1 / 2 .

[0069] Among them, the calculation formula for the K Q value is:

[0070]

[0071] Where S is the specimen support span, B is the specimen thickness, BN is the net specimen thickness, W is the specimen width, a is the crack size, and P is the force. Q Meet the following conditions: (1) B ≥ 2.5 (K Q / σ 0.2 ) 2 ;(2)a≥2.5(K Q / σ 0.2 ) 2 ;(3)P MAX / P Q <1.1; (4)K MAX <0.7K Q , K Q K IC Since it is generally difficult to satisfy K IC Condition, so K Q As a reference value of fracture toughness.

[0072] Specific embodiment 5: In step 22 of this embodiment, when TA10 titanium alloy is melted, the following steps are included:

[0073] Step S1: firstly put the pre-pressed raw material block into the crucible;

[0074] Step S2: After the raw material blocks are placed in the crucible, the furnace door is closed and the furnace is evacuated;

[0075] Step S3: Filling the furnace with high-purity argon gas for gas washing;

[0076] Step S4: After cleaning is completed, the medium frequency power supply is started to start smelting;

[0077] Step S5: After the melting is complete, the crucible is tilted to turn the material over until five remelting cycles are completed, ultimately obtaining an ingot with uniform composition. Other components and connection relationships are the same as those in the fourth embodiment.

[0078] Specific embodiment 6: In step S1 of this embodiment, when loading, the raw material is loaded at the bottom of the crucible more than the bottom of the crucible, and the upper charge is kept loose. Other components and connection relationships are the same as those of specific embodiment 5.

[0079] Specific embodiment 7: In step S4 of this embodiment, the charge is heated slowly during the initial melting phase until it begins to melt. After the charge begins to melt, argon is continuously introduced, the melting power is increased, and a reasonable melting rate is maintained. Other components and connections are the same as those in specific embodiment 6.

[0080] Embodiment VIII: The post-treatment of the casting surface in Step 4 of this embodiment is successively: surface cleaning and surface grinding. Other compositions and connection relationships are the same as those in Embodiment VII.

[0081] Embodiment IX: The surface cleaning process of this embodiment is: ultrasonic cleaning is carried out with absolute ethanol as the cleaning medium, and the cleaning time is 10 min. Other compositions and connection relationships are the same as those in Embodiment VIII.

[0082] Embodiment X: The surface grinding process of this embodiment is: the specimen is successively ground with 240#, 400#, 800#, 1200# and 2000# SiC sandpapers, and then ultrasonically cleaned with ethanol and distilled water for 120 s in sequence, and the surface moisture of the specimen is dried by a dryer. Other compositions and connection relationships are the same as those in Embodiment IX.

[0083] Example 1:

[0084] The as-cast alloyed TA10 titanium alloy of this example is composed of the following elements in mass percentage: Ni 0.8%, Mo 0.3%, Mn 4%, V 1%, and the balance is Ti and unavoidable impurities. It specifically includes the following steps:

[0085] Step 1: Raw material preparation;

[0086] According to the required performance and cost of the target part, batching is carried out according to the designed composition TA10-4Mn-1V. Select manganese flakes, vanadium blocks, nickel blocks, sponge titanium and molybdenum raw materials for batching;

[0087] Step 2: Raw material melting;

[0088] The batching blocks obtained in Step 1 are subjected to 5 times of vacuum consumable melting to obtain an ingot. When melting the alloyed TA10 titanium alloy by a vacuum induction melting furnace, first put the pre-pressed raw material blocks into the crucible. When loading the materials, more materials should be filled at the bottom of the crucible, and the upper charge should be kept loose to accelerate the melting speed of the charge, so as to prevent jamming of the charge when it descends during the melting process. After the charge is loaded into the crucible, close the furnace door and evacuate the furnace. To reduce the oxygen content in the melting chamber, high-purity argon is filled into the furnace for gas washing. After the washing is completed, start the intermediate frequency power supply to start melting. At the initial stage of melting, a lower power should be maintained to heat the charge until the charge starts to melt. After the charge starts to melt, continue to keep argon filled and increase the melting power to maintain a reasonable melting speed. After complete melting, tilt the crucible to turn the charge until five times of repeated melting are completed, and finally obtain an ingot with uniform composition.

[0089] Step 3: Casting to obtain the target part;

[0090] Select a suitable mold according to the target part, pour the alloy melt obtained in the second step into the preheated machined mold, and the casting with the required size can be obtained after it cools down.

[0091] Step Four: Surface post-treatment;

[0092] Cut off the riser from the casting obtained in the third step, and perform surface treatment to obtain the target part.

[0093] Furthermore, the surface treatment of the casting in Step Four is successively surface cleaning, surface grinding, and surface sandblasting. Among them, the surface cleaning process is: ultrasonic cleaning with anhydrous ethanol as the cleaning medium for 10 minutes; the surface grinding process is: successively grind the specimen with 240#, 400#, 800#, 1200#, and 2000# SiC sandpapers, then ultrasonically clean with ethanol and distilled water for 120 seconds successively, and dry the moisture on the surface of the specimen with a dryer.

[0094] Detect its corrosion resistance and mechanical properties, and the results are as follows: In terms of corrosion resistance, the corrosion rate of the titanium alloy in 5M HCl solution at 25°C is 1.07 mm / year; in terms of mechanical properties, the ultimate tensile strength is 636.9 MPa, the elongation is 16.8%, and the fracture toughness K Q value is 57.78 MPa·m 1 / 2 .

[0095] Example Two:

[0096] The difference between this example and Example One is that the as-cast alloyed TA10 titanium alloy in this example is composed of the following elements by mass percentage: Ni 0.8%, Mo 0.3%, Mn 1%, V 4%, and the balance is Ti and unavoidable impurities.

[0097] The test results are as follows: In terms of corrosion resistance, the corrosion rate of the titanium alloy in 5M HCl solution at 25°C is 0.66 mm / year; in terms of mechanical properties, the ultimate tensile strength is 517.5 MPa, the elongation is 25.5%, and the fracture toughness K Q value is 52.43 MPa·m 1 / 2 .

[0098] Example Three:

[0099] The difference between this example and Example One is that the as-cast alloyed TA10 titanium alloy in this example is composed of the following elements by mass percentage: Ni 0.8%, Mo 0.3%, Mn 1%, and the balance is Ti and unavoidable impurities.

[0100] The test results are as follows: In terms of corrosion resistance, the corrosion rate of the titanium alloy in 5M HCl solution at 25°C is 1.99mm / year; in terms of mechanical properties, the ultimate tensile strength is 418.6MPa, the elongation is 22.6%, and the fracture toughness K Q The value is 45.72 MPa·m 1 / 2 .

[0101] Example 4:

[0102] The difference between this embodiment and the first embodiment is that the cast alloyed TA10 titanium alloy of this embodiment is composed of the following elements in percentage by mass: Ni 0.8%, Mo 0.3%, V 1%, and the balance being Ti and unavoidable impurities.

[0103] The test results are as follows: In terms of corrosion resistance, the corrosion rate of the titanium alloy in 5M HCl solution at 25°C is 1.27mm / year; in terms of mechanical properties, the ultimate tensile strength is 378.3MPa, the elongation is 24.9%, and the fracture toughness K Q The value is 41.82 MPa·m 1 / 2 .

[0104] Comparative Example 1:

[0105] The as-cast TA10 titanium alloy of this comparative example is composed of the following elements by weight: 0.8% Ni, 0.3% Mo, the balance being Ti, and unavoidable impurity elements. The method for preparing the as-cast TA10 titanium alloy of this comparative example comprises the following steps:

[0106] Step 1: Select nickel block, titanium sponge and molybdenum raw materials according to the designed composition of the target product, and put them into a crucible for smelting;

[0107] Step 2: The smelted material in step 1 is subjected to vacuum consumable melting 5 times to obtain a TA10 ingot with uniform texture;

[0108] Step 3: Cut the ingot obtained in step 2 according to step 4 of Example 1, polish and clean the surface to obtain the test parts. The test results are as follows: In terms of corrosion resistance, the corrosion rate of the titanium alloy in 5M HCl solution at 25°C is 1.19mm / year; in terms of mechanical properties, the ultimate tensile strength is 338.7MPa, the elongation is 26.6%, and the fracture toughness K Q The value is 35.99 MPa·m 1 / 2 .

[0109] The corrosion properties and tensile properties of the alloyed as-cast TA10 titanium alloys of Examples 1 to 4 of the present invention and the as-cast TA10 titanium alloy of Comparative Example 1 were tested and analyzed. The specific process is as follows:

[0110] The results of the experiments in Examples 1 to 4 and Comparative Example 1 were subjected to a corrosion resistance test in accordance with JBT7901-2023:

[0111] The titanium alloys obtained from the experiments were respectively wire-cut to produce static immersion specimens with dimensions (length × width × height) of 10 mm × 10 mm × 10 mm. Three specimens were cut from each titanium alloy ingot to ensure the repeatability of the experiment.

[0112] The surfaces of the specimens were treated as follows: The static immersion specimens were successively polished with 240#, 400#, 800#, 1200#, and 2000# SiC sandpapers, and then ultrasonically cleaned with ethanol and distilled water for 120 s in sequence. The moisture on the surfaces of the specimens was dried using a dryer.

[0113] After completing the preparations before the experiment, the specimens were respectively immersed in containers containing 100 ml of natural gas-filled test solution, meeting the requirement of the minimum solution volume to specimen area ratio (0.20 ml / mm 2 ), and the exposed area of each specimen was independently calculated from the geometric dimensions.

[0114] Within 10 days of immersion, the static immersion specimens were taken out every 2 days and successively cleaned with ethanol and distilled water to remove corrosion products. After drying, they were weighed. Three parallel samples were selected each time to ensure the repeatability rate, and the average value was taken. The corrosion rate R was calculated using the following formula corr :

[0115]

[0116] where m represents the mass of the specimen before the test, in g; m1 represents the mass of the specimen after the test, in g; t represents the time of the static immersion corrosion test, in hours; A represents the area of the specimen exposed to the test solution, in cm 2 ; and ρ represents the density of the specimen to be tested, in g / cm 2 . The results are as Figure 3 shown.

[0117] The results of the experiments in Examples 1 to 4 and Comparative Example 1 were subjected to mechanical property tests:

[0118] For the tensile property experiment, an electronic universal testing machine was used, and the tensile rate was kept constant at 0.5 mm / min. Dog-bone-shaped tensile specimens with a total length of 25 mm, a tensile region length of 10 mm, and a thickness of 2 mm were used to conduct the room-temperature tensile test on the alloyed as-cast TA10 titanium alloy. To eliminate process errors, three samples of each alloy were tested respectively. The measurement of tensile properties was carried out according to the standard test method of ASTM E1876. For the fracture toughness test, standard single-edge notch bending [SE(B)] specimens were used, and the measurement of fracture toughness was tested according to the ASTM E1820-20b standard.

[0119] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those skilled in the art can also make other changes within the spirit of the present invention and apply them to fields not mentioned in the present invention. Of course, all these changes made according to the spirit of the present invention should be included within the scope claimed by the present invention.

Claims

1. A TA10 titanium alloy with both high strength and good corrosion resistance, characterized in that: It is composed of the following elements by mass percentage: Mn 1% - 4%, V 1% - 4%, Ni 0.7% - 0.8%, Mo 0.2% - 0.3%, and the balance is Ti and inevitable impurities.

2. The TA10 titanium alloy with both high strength and good corrosion resistance according to claim 1, wherein: The TA10 titanium alloy with both high strength and good corrosion resistance has the following mass percentages: Mn 4%, V 1%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities; or Mn 1%, V 4%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities.

3. A TA10 titanium alloy with both high strength and good corrosion resistance, characterized in that: It is composed of the following elements by mass percentage: V 1%, Ni 0.8%, Mo 0.3%, and the balance is Ti and inevitable impurities.

4. The preparation method of a TA10 titanium alloy with both high strength and good corrosion resistance as described in claim 1 or 2 or 3, characterized in that: The method includes the following steps: Step 1: Preparation of raw materials; According to the required properties and cost of the target part, design the composition for batching; Select manganese sheets and vanadium blocks or vanadium blocks, sponge titanium, and molybdenum raw materials for batching; Step 2: Melting of raw materials; Step 2-1: Perform 5 times of vacuum consumable melting on the batching blocks obtained in Step 1 to obtain an ingot; Step 2-2: Use a vacuum induction melting furnace to melt the alloyed TA10 titanium alloy and obtain an ingot with uniform composition; Step 3: Cast to obtain the target part; Select a suitable mold according to the target part, pour the alloy melt obtained in Step 2 into the preheated machining mold, and after it cools, the casting with the required size can be obtained; Step 4: Surface post-treatment; Cut off the riser of the casting obtained in Step 3, perform surface treatment, and obtain the target part.

5. The preparation method of a TA10 titanium alloy with both high strength and good corrosion resistance according to claim 4, characterized in that: In Step 2-2, when melting the TA10 titanium alloy, it includes the following steps: Step S1: First, put the pre-pressed raw material blocks into the crucible; Step S2: After loading the raw material blocks into the crucible, close the furnace door and evacuate the furnace; Step S3: Fill the furnace with high-purity argon for gas washing; Step S4: After the cleaning is completed, start the intermediate frequency power supply to start melting; Step S5: After complete melting, tilt the crucible for turning the charge until five times of repeated melting are completed, and finally obtain an ingot with uniform composition.

6. The preparation method of a TA10 titanium alloy with both high strength and good corrosion resistance according to claim 5, characterized in that: In Step S1 during loading, load more raw materials at the bottom of the crucible than at the bottom of the crucible, and keep the upper charge in a loose state.

7. The preparation method of a TA10 titanium alloy with both high strength and good corrosion resistance according to claim 6, characterized in that: In Step S4, heat the charge at the initial stage of melting until the charge starts to melt; after the charge starts to melt, continue to keep argon filled, increase the melting power and maintain a reasonable melting speed.

8. The preparation method of a TA10 titanium alloy with both high strength and good corrosion resistance according to claim 7, characterized in that: The surface post-treatment of the casting described in Step 4 is successively: surface cleaning and surface grinding.

9. The preparation method of a TA10 titanium alloy with both high strength and good corrosion resistance according to claim 8, characterized in that: The surface cleaning process is: perform ultrasonic cleaning with anhydrous ethanol as the cleaning medium, and the cleaning time is 10 min.

10. The preparation method of a TA10 titanium alloy with both high strength and good corrosion resistance according to claim 9, characterized in that: The surface grinding process is: successively grind the specimen with 240#, 400#, 800#, 1200#, and 2000# SiC sandpapers, then ultrasonically clean with ethanol and distilled water for 120 s successively, and use a dryer to dry the moisture on the surface of the specimen.

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