CN109112356B - A kind of high-strength corrosion-resistant titanium alloy and preparation method thereof - Google Patents

Abstract

The invention provides a high-strength corrosion-resistant titanium alloy and a preparation method thereof. The titanium alloy provided by the invention includes 1.0-2.5% of Al, 0.7-2.0% of Mn, Zr (0,50%] and the balance in terms of mass content Ti. The present invention strictly controls the content of each element, and Zr and Ti are easy to form infinite solid solution, and play the effect of solid solution strengthening; Since Zr is more negative as passivation metal relative to the passivation potential of Ti, passivation ability is stronger, It is easier to generate a passivation film on the alloy surface, and the corrosion resistance of the alloy in a variety of corrosive media is improved. Experimental results show that the high-strength corrosion-resistant titanium alloy provided by the invention and the comparison alloy (Ti-2Z1 ‑1.5Mn), the corrosion resistance in sodium chloride solution is improved by 33.26-52.63%.

Description

A kind of high-strength corrosion-resistant titanium alloy and preparation method thereof

technical field

The invention relates to the technical field of titanium alloys, in particular to a high-strength corrosion-resistant titanium alloy and a preparation method thereof.

Background technique

With a series of advantages such as high specific strength, high specific modulus, and corrosion resistance, titanium alloy has a wide range of application advantages, and has been valued in many fields such as marine engineering, aerospace, biomedicine, metallurgy, chemical industry, and light industry.

Due to its high strength, good formability and welding performance, titanium alloys are mostly stamped into thin-walled parts by sheet metal, and then welded into aircraft skins and front air intake caps. Widely used in aerospace industry. However, traditional titanium alloys are mostly strengthened by deformation strengthening methods. Not only is the preparation method cumbersome, but the strength and corrosion resistance of traditional titanium alloys cannot meet the development needs of industrial production and national defense at this stage.

Contents of the invention

In view of this, the object of the present invention is to provide a high-strength corrosion-resistant titanium alloy and a preparation method thereof. The titanium alloy provided by the invention has good corrosion resistance and relatively high strength; the titanium alloy in the invention does not need to be deformed, and its strength and corrosion resistance can meet the requirements of industrial production and national defense development at the present stage under cast conditions .

The invention provides a high-strength corrosion-resistant titanium alloy, which comprises 1.0-2.5% of Al, 0.7-2.0% of Mn, Zr (0,50%) and the balance of Ti in terms of mass content.

Preferably, the high-strength corrosion-resistant titanium alloy includes 1.0-2.5% of Al, 0.7-2.0% of Mn, 10-40% of Zr and the balance of Ti.

Preferably, the high-strength corrosion-resistant titanium alloy contains a basket structure composed of acicular α' martensite phase and a metastable β phase; the width of the acicular α phase is 0.62-3.99 μm.

The present invention also provides a method for preparing the high-strength corrosion-resistant titanium alloy described in the above technical solution, comprising the following steps:

(1) Obtain the as-cast alloy billet after melting the alloy raw material;

(2) performing annealing treatment on the cast alloy billet obtained in the step (1) to obtain an annealed billet;

(3) The annealed billet obtained in the step (2) is subjected to solution treatment to obtain a high-strength corrosion-resistant titanium alloy.

Preferably, the smelting in the step (1) is vacuum arc smelting, and the temperature of the vacuum arc smelting is 2000-2500°C.

Preferably, the smelting in the step (1) is repeated more than 5 times.

Preferably, the holding temperature of the annealing treatment in the step (2) is 650-700° C., the holding time of the annealing treatment is 2-3 hours, and the cooling method of the annealing treatment is furnace cooling.

Preferably, the heat preservation process of the annealing treatment in the step (2) and the heat preservation process of the solution treatment in the step (3) are independently carried out under a protective atmosphere.

Preferably, the holding temperature of the solution treatment in the step (3) is determined according to the zirconium content in the alloy raw material, and the holding temperature decreases by 2-2.5°C from 890-930°C for every 1wt.% of Zr contained.

Preferably, the holding temperature of the solution treatment in the step (3) is 800-910° C., the holding time of the solution treatment is 30-60 minutes, and the cooling method of the solution treatment is water quenching.

The invention provides a high-strength corrosion-resistant titanium alloy, which comprises 1.0-2.5% of Al, 0.7-2.0% of Mn, Zr (0,50%] and the rest of Ti in terms of mass content. The invention strictly controls each element In the present invention, Zr and Ti are easy to form an infinite solid solution, and the Zr element solid-dissolved into the Ti matrix plays a role of solid solution strengthening; the zirconium element in the titanium alloy is easy to form zirconium oxide in a corrosive medium. Effectively improve the structural properties of the passivation film of titanium alloys, and significantly improve the corrosion resistance of titanium alloys. With the increase of zirconium content in the alloy, the passivation current density of the alloy gradually decreases, and the alloy gradually changes from uniform corrosion to localized corrosion. Titanium The addition of Zr element in the alloy can significantly improve the corrosion resistance of the titanium alloy. After adding Zr to the titanium alloy, the ZrO2 formed _on the surface can improve the oxide protective film of the alloy, thereby improving the corrosion resistance of the alloy; at the same time, because Zr acts as a passive Compared with Ti, the passivation potential of Ti metal is more negative, the passivation ability is stronger, and it is easier to generate a passivation film on the surface of the alloy, and the corrosion resistance of the alloy in various corrosive media has been improved. Experimental results show that the present invention provides Compared with the comparison alloy (Ti-2Al-1.5Mn) obtained by the same treatment process, the high-strength corrosion-resistant titanium alloy has an improved corrosion resistance in sodium chloride solution by 33.26-42.96%.

Description of drawings

Fig. 1 is the metallographic optical micrograph of the titanium alloy that embodiment 1 makes;

Fig. 2 is the metallographic optical micrograph of the titanium alloy that embodiment 2 makes;

Fig. 3 is the metallographic optical micrograph of the titanium alloy that embodiment 3 makes;

Fig. 4 is the metallographic optical micrograph of the titanium alloy that embodiment 4 makes;

Fig. 5 is the metallographic optical micrograph of the titanium alloy that embodiment 5 makes;

Fig. 6 is the metallographic optical micrograph of the titanium alloy that comparative example 1 makes;

Fig. 7 is a dimension diagram of a tensile sample used in the tensile property test of the present invention.

Detailed ways

The present invention provides a high-strength corrosion-resistant titanium alloy, which includes Al 1.0-2.5%, Mn 0.7-2.0%, Zr (0,50%) and the balance of Ti in terms of mass content.

The high-strength corrosion-resistant titanium alloy provided by the present invention contains 1.0-2.5% Al, preferably 1.4-2.2%, more preferably 1.4-1.8% by mass content. In the present invention, the Al is a cheap but α-phase stable element with obvious strengthening effect on titanium alloys, which can greatly increase the specific strength of titanium alloys; at the same time, Al is an α-phase stable element of Ti, which has Relatively high solubility, at the same time it can also significantly improve the specific strength and specific stiffness of Ti alloys.

The high-strength corrosion-resistant titanium alloy provided by the present invention contains Mn in an amount of 0.7-2.0%, preferably 1.0-1.7%, and more preferably 1.3-1.7% in terms of mass content. In the present invention, the Mn is a β-stable element, which replaces Mo and other alloy elements with high melting point and high price; the Mn can also improve the ductility of the alloy while solid-solution strengthening, adding The Mn element can further supplement and strengthen the titanium alloy, so that the crystal form of zirconium and the corresponding crystal form of titanium form a continuous solid solution to provide corrosion resistance.

The high-strength corrosion-resistant titanium alloy provided by the present invention includes Zr (0,50%] in terms of mass content, more preferably Zr 10-40%, preferably 20-40%, and further preferably 30-35%. In the invention, Zr and Ti have the same outermost electron arrangement and similar mechanical and physical and chemical properties, and whether they are high-temperature β-phase (BCC) or low-temperature α-phase (HCP), they all form an infinite solid solution. The Zr element dissolved into the Ti matrix plays a role of solid solution strengthening. TiZr alloy has a relatively low melting point, is easy to smelt and can effectively reduce the oxygen absorption and hydrogen absorption during the smelting process; at the same time, the addition of Zr element will These defects will lead to the increase of nucleation points and the increase of nucleation density during the nucleation process, which will play a role in grain refinement; Zr dissolves into the Ti matrix, which improves the strength and durability of the alloy. Corrosion performance, so that it has excellent corrosion resistance in most acids, alkalis, and salt media, and Zr has excellent biocompatibility; the addition of Zr elements can not only improve through solid solution strengthening and fine grain strengthening mechanisms The mechanical properties of the alloy can be optimized, the microstructure of the alloy can be optimized, the corrosion resistance of the alloy can be enhanced, and the phase transition temperature of the alloy can be appropriately reduced.

The high-strength corrosion-resistant titanium alloy provided by the present invention includes, in terms of mass content, Ti in addition to the above-mentioned elements.

In the present invention, the high-strength corrosion-resistant titanium alloy preferably contains a basket structure composed of acicular α' phase martensite phase (ie, α phase phase) and a metastable β phase; the acicular α' phase martensite is finely The strength and toughness of corrosion-resistant titanium alloys can be improved.

The present invention also provides a method for preparing the high-strength corrosion-resistant titanium alloy described in the above technical solution, comprising the following steps:

(1) Obtain the as-cast alloy billet after melting the alloy raw material;

(2) performing annealing treatment on the cast alloy billet obtained in the step (1) to obtain an annealed billet;

(3) The annealed billet obtained in the step (2) is subjected to solution treatment to obtain a high-strength corrosion-resistant titanium alloy.

In the invention, the alloy raw material is smelted to obtain the cast alloy billet. In the present invention, there is no special limitation on the type of the alloy raw material, and the alloy raw material smelted by titanium alloy well-known to those skilled in the art shall be based on the titanium alloy that can obtain the target composition. In the present invention, the alloy raw materials preferably include sponge titanium, sponge zirconium, pure aluminum, pure niobium and pure tantalum. In the present invention, there is no special limitation on the ratio of various alloy raw materials, as long as the final alloy composition can meet the requirements.

In the present invention, the smelting is preferably vacuum arc smelting, the temperature of the vacuum arc smelting is preferably 2000-2500°C, more preferably 2200-2400°C, most preferably 2250-2300°C; the smelting time is preferably 3 to 5 minutes, more preferably 4 minutes. In the present invention, the vacuum degree of the vacuum arc melting is preferably 0.04-0.05 MPa, and it is carried out under a certain argon gas condition. When vacuum arc melting is adopted, the present invention preferably evacuates the vacuum in the furnace cavity to below 9×10 ^{- 3} Pa, and then introduces argon gas; The amount can be. The present invention has no special requirements on the specific implementation of the vacuum arc smelting, and those familiar to those skilled in the art can be used. In the present invention, the method of vacuuming first and then introducing argon gas can firstly prevent Ti and Zr from absorbing a large amount of hydrogen, oxygen and nitrogen at high temperature, resulting in oxidation, and can also provide ionized gas for arc smelting.

In the present invention, during smelting, the beta phase preferentially nucleates and grows in the process of transforming the smelting liquid into a solid state to obtain a beta phase green body, which provides a basis for subsequent annealing treatment and solid solution treatment to obtain the alpha' martensite phase.

In the present invention, the smelting is preferably repeated 5 times or more, more preferably 6-10 times, and the as-cast alloy billet is obtained after smelting. In the present invention, when the smelting is repeated, the smelting is preferably carried out in a vacuum arc melting furnace; specifically: the metal raw material is smelted in an electric arc melting furnace to obtain a smelting liquid; then cooled to obtain a slab, and then turned over Smelting after casting the slab to obtain the smelting liquid again, cooling the smelting liquid again to obtain the slab, and repeating this for more than 5 times to ensure that the composition of the obtained as-cast slab is uniform.

Before the smelting, the alloy raw material is preferably ultrasonically cleaned in the present invention; the present invention has no special requirements for the specific implementation of the ultrasonic cleaning, and those well-known to those skilled in the art can be used.

After the obtained cast alloy billet, the present invention performs annealing treatment on the cast alloy billet to obtain the annealed billet. In the present invention, the holding temperature of the annealing treatment is preferably 650-700°C, more preferably 650-680°C; the holding time of the annealing treatment is preferably 2-3h, more preferably 2.2-2.8h, more preferably 2.5h; the cooling method of the annealing treatment is preferably furnace cooling. In the present invention, the heat preservation process of the annealing treatment is preferably carried out under a protective atmosphere, and the protective atmosphere is specifically an argon protective atmosphere. In the present invention, the annealing treatment can effectively eliminate the residual stress formed in the smelting process and eliminate some microscopic defects, further homogenize the alloy composition, improve the processing performance of the alloy and also improve the corrosion resistance of the alloy.

After the annealed billet is obtained, the present invention performs solid solution treatment on the annealed billet to obtain a high-strength corrosion-resistant titanium-titanium alloy. In the present invention, the heat preservation temperature of the solution treatment is determined according to the content of zirconium in the alloy raw material, preferably the heat preservation temperature is lowered by 2 to 2.5°C from 890 to 930°C for every 1wt. The holding temperature of Zr decreased by 2-2.5°C from 920°C.

In the present invention, the holding temperature of the solution treatment is preferably 800-910°C, more preferably 825-900°C, more preferably 850-875°C. In the present invention, the holding time of the solution treatment is preferably 30-60 min, more preferably 35-55 min, and more preferably 45-50 min. In the present invention, the cooling method of the solution treatment is preferably water quenching. The present invention has no special requirements on the specific implementation of the solid solution treatment, and implementations well known to those skilled in the art can be used. In the present invention, the heat preservation process of the solution treatment is preferably carried out under a protective atmosphere, and the protective atmosphere is specifically an argon protective atmosphere. In the present invention, the solid solution treatment process obtains the α' martensite phase and the metastable β phase that can produce a strengthening effect; and the α' martensite phase structure is finer, which can ensure good strength while improving the strength. plasticity.

After the solid solution treatment, the present invention preferably removes the solid solution steel to remove the surface scale to obtain the corrosion-resistant titanium alloy. In the present invention, the cooling method is preferably furnace cooling; in the present invention, the surface oxide scale is preferably removed by grinding.

In order to further illustrate the present invention, the high-strength corrosion-resistant titanium alloy provided by the present invention and its preparation method are described in detail below in conjunction with examples, but they should not be construed as limiting the protection scope of the present invention.

Example 1

According to the alloy composition Ti-10Zr-1Al-0.7Mn (mass percentage), weigh raw materials (total weight 100g) zirconium sponge 10g, aluminum 1g, manganese 0.7g, the balance is industrial grade titanium sponge soaked in absolute ethanol , air-dried after ultrasonic cleaning, put it into the water-cooled copper crucible of non-consumable vacuum arc melting furnace, the vacuum degree in the furnace cavity should be pumped below 9×10 ^-3 Pa, and high-purity argon gas should be filled as protective gas before arc melting (vacuum degree reaches 0.04 ~ 0.05MPa), magnetic levitation stirring is carried out during the smelting process to mix the smelting liquid evenly. The arc temperature is about 2500°C during each smelting, and the smelting time is about 3 minutes. After each smelting, it is cooled to obtain Cast ingots, and then turn over the ingots for smelting, so as to smelt-cast ingots and repeatedly smelt and turn over the ingots 7 times to ensure that the finally obtained ingots are evenly composed; Polish off the surface oxide layer and clean with alcohol.

Subsequently, the alloy ingot was put into a vacuum/atmosphere tube furnace for annealing treatment, and the holding temperature of the annealing treatment was controlled to be 700° C., and the holding time was 120 minutes, and then cooled to room temperature with the furnace.

Then take out the alloy ingot and put it into a vacuum/atmosphere tube furnace (SK-G06143 Tianjin Zhonghuan Experimental Electric Furnace Co., Ltd.), fill it with protective gas argon and carry out solid solution treatment: reheat to 900°C and keep at 900°C for 30min , then removed from the tube furnace and quickly water quenched.

After the alloy ingot is completely cooled, take it out, carefully polish off the oxide layer on the surface of the alloy ingot, wash it and air-dry it to obtain a corrosion-resistant titanium alloy.

Example 2

According to the alloy composition Ti-20Zr-1.4Al-1.0Mn (mass percentage), weigh raw materials (total weight is 100g) zirconium sponge 20g, aluminum 1.4g, manganese 1.0g, the balance is industrial grade titanium sponge immersed in anhydrous In ethanol, ultrasonically cleaned and air-dried, placed in a water-cooled copper crucible in a non-consumable vacuum arc melting furnace, the vacuum in the furnace cavity should be pumped below 9×10 ^-3 Pa, and high-purity argon gas should be filled before arc melting as After shielding gas (vacuum degree reaches 0.04-0.05MPa), magnetic levitation stirring is carried out during the smelting process to mix the smelting liquid evenly. The arc temperature is about 2500°C during each smelting, and the smelting time is about 3 minutes. After each smelting The ingot is obtained by cooling, and then the ingot is turned over for smelting, so as to smelt-cast the ingot and repeatedly smelt and turn over the ingot 7 times to ensure that the composition of the finally obtained ingot is uniform; after each smelting, the ingot is turned over Sand off the surface oxide on a grinding wheel and clean with alcohol.

Subsequently, the alloy ingot was put into a vacuum/atmosphere tube furnace for annealing treatment, and the holding temperature of the annealing treatment was controlled to be 700° C., and the holding time was 120 minutes, and then cooled to room temperature with the furnace.

Then take out the alloy ingot and put it into a vacuum/atmosphere tube furnace (SK-G06143 Tianjin Zhonghuan Experimental Electric Furnace Co., Ltd.), fill it with protective gas argon and carry out solid solution treatment: reheat to 875°C and keep at 875°C for 30min , then removed from the tube furnace and quickly water quenched.

After the alloy ingot is completely cooled, take it out, carefully polish off the oxide layer on the surface of the alloy ingot, wash it and air-dry it to obtain a corrosion-resistant titanium alloy.

Example 3

According to the alloy composition Ti-30Zr-1.8Al-1.3Mn (mass percentage), weigh raw materials (total weight is 100g) zirconium sponge 30g, aluminum 1.8g, manganese 1.3g, the balance is industrial grade titanium sponge immersed in anhydrous In ethanol, ultrasonically cleaned and air-dried, placed in a water-cooled copper crucible in a non-consumable vacuum arc melting furnace, the vacuum in the furnace cavity should be pumped below 9×10 ^-3 Pa, and high-purity argon gas should be filled before arc melting as After shielding gas (vacuum degree reaches 0.04-0.05MPa), magnetic levitation stirring is carried out during the smelting process to mix the smelting liquid evenly. The arc temperature is about 2500°C during each smelting, and the smelting time is about 3 minutes. After each smelting The ingot is obtained by cooling, and then the ingot is turned over for smelting, so as to smelt-cast the ingot and repeatedly smelt and turn over the ingot 7 times to ensure that the composition of the finally obtained ingot is uniform; after each smelting, the ingot is turned over Sand off the surface oxide on a grinding wheel and clean with alcohol.

Subsequently, the alloy ingot was put into a vacuum/atmosphere tube furnace for annealing treatment, and the holding temperature of the annealing treatment was controlled to be 700° C., and the holding time was 120 minutes, and then cooled to room temperature with the furnace.

Then take out the alloy ingot and put it into a vacuum/atmosphere tube furnace (SK-G06143 Tianjin Zhonghuan Experimental Electric Furnace Co., Ltd.), fill it with protective gas argon and carry out solid solution treatment: reheat to 850°C and keep at 850°C for 30min , then removed from the tube furnace and quickly water quenched.

After the alloy ingot is completely cooled, take it out, carefully polish off the oxide layer on the surface of the alloy ingot, wash it and air-dry it to obtain a corrosion-resistant titanium alloy.

Example 4

According to the alloy composition Ti-40Zr-2.2Al-1.7Mn (mass percentage), weigh raw materials (total weight is 100g) zirconium sponge 40g, aluminum 2.2g, manganese 1.7g, the balance is industrial grade titanium sponge immersed in anhydrous In ethanol, ultrasonically cleaned and air-dried, placed in a water-cooled copper crucible in a non-consumable vacuum arc melting furnace, the vacuum in the furnace cavity should be pumped below 9×10 ^-3 Pa, and high-purity argon gas should be filled before arc melting as After shielding gas (vacuum degree reaches 0.04-0.05MPa), magnetic levitation stirring is carried out during the smelting process to mix the smelting liquid evenly. The arc temperature is about 2500°C during each smelting, and the smelting time is about 3 minutes. After each smelting The ingot is obtained by cooling, and then the ingot is turned over for smelting, so as to smelt-cast the ingot and repeatedly smelt and turn over the ingot 7 times to ensure that the composition of the finally obtained ingot is uniform; after each smelting, the ingot is turned over Sand off the surface oxide on a grinding wheel and clean with alcohol.

Subsequently, the alloy ingot was put into a vacuum/atmosphere tube furnace for annealing treatment, and the holding temperature of the annealing treatment was controlled to be 700° C., and the holding time was 120 minutes, and then cooled to room temperature with the furnace.

Then take out the alloy ingot and put it into a vacuum/atmosphere tube furnace (SK-G06143 Tianjin Zhonghuan Experimental Electric Furnace Co., Ltd.), fill it with protective gas argon and carry out solid solution treatment: reheat to 825°C and keep it at 825°C for 30min , then removed from the tube furnace and quickly water quenched.

After the alloy ingot is completely cooled, take it out, carefully polish off the oxide layer on the surface of the alloy ingot, wash it and air-dry it to obtain a corrosion-resistant titanium alloy.

Example 5

According to the alloy composition Ti-50Zr-2.5Al-2.0Mn (mass percentage), weigh raw materials (total weight is 100g) zirconium sponge 40g, aluminum 2.5g, manganese 2.0g, the balance is industrial grade titanium sponge immersed in anhydrous In ethanol, ultrasonically cleaned and air-dried, placed in a water-cooled copper crucible in a non-consumable vacuum arc melting furnace, the vacuum in the furnace cavity should be pumped below 9×10 ^-3 Pa, and high-purity argon gas should be filled before arc melting as After shielding gas (vacuum degree reaches 0.04-0.05MPa), magnetic levitation stirring is carried out during the smelting process to mix the smelting liquid evenly. The arc temperature is about 2500°C during each smelting, and the smelting time is about 3 minutes. After each smelting The ingot is obtained by cooling, and then the ingot is turned over for smelting, so as to smelt-cast the ingot and repeatedly smelt and turn over the ingot 7 times to ensure that the composition of the finally obtained ingot is uniform; after each smelting, the ingot is turned over Sand off the surface oxide on a grinding wheel and clean with alcohol.

Subsequently, the alloy ingot was put into a vacuum/atmosphere tube furnace for annealing treatment, and the holding temperature of the annealing treatment was controlled to be 700° C., and the holding time was 120 minutes, and then cooled to room temperature with the furnace.

Then take out the alloy ingot and put it into a vacuum/atmosphere tube furnace (SK-G06143 Tianjin Zhonghuan Experimental Electric Furnace Co., Ltd.), fill it with protective gas argon and carry out solid solution treatment: reheat to 800°C and keep at 800°C for 30min , then removed from the tube furnace and quickly water quenched.

After the alloy ingot is completely cooled, take it out, carefully polish off the oxide layer on the surface of the alloy ingot, wash it and air-dry it to obtain a corrosion-resistant titanium alloy.

Comparative example 1

According to the method of Example 1, an alloy composition Ti-2Al-1.5Mn titanium alloy was prepared.

The metallographic structures of the titanium alloys obtained in Examples 1-5 and Comparative Example 1 were respectively observed, and the results are shown in Figures 1-6 respectively.

It can be seen from Figures 1 to 5 that the titanium alloy obtained in the embodiment of the present invention is composed of a basket structure composed of relatively fine acicular α' phases and a metastable β phase; wherein the acicular α' phases and martensite phases are interlaced;

Compared with the metallographic diagram of the comparative sample, the acicular structure obtained by the present invention is more obvious, and the acicular structure is obviously thinner. These changes have also led to higher tensile strength of the material; compared with the metallographic diagram of Example 1, the titanium alloy obtained in Example 2 has a denser acicular structure, and the acicular structure is finer. With the increase of Zr content, the grain refinement is obvious, and the mechanical properties of the material are improved;

Compared with the metallographic diagram of Example 2, the metallographic structure of the titanium alloy obtained in Example 3 has more acicular structures per unit area, which means that the metallographic structure of the material is more than that of adding 20% Zr , the grain refinement is more obvious, and the mechanical properties of the material are also improved accordingly;

Compared with the metallographic diagram of Example 3, the needle-like structure per unit area in the titanium alloy metallographic structure obtained in Example 4 is further improved, which means that the metallographic structure of the material is finer, and the flakes can be observed at the same time. The layer thickness is slightly reduced;

Compared with the metallographic diagrams of the previous four examples, the titanium alloy metallographic structure obtained in Example 5 has the most needle-like structure per unit area, which means that the metallographic structure of the material is finer, and it can be observed that The sheet thickness is slightly reduced.

The titanium alloys prepared in Examples 1 to 5 and Comparative Example 1 were respectively cut into tensile samples as shown in Figure 7 by wire cutting, and tensile tests were carried out to obtain data related to their mechanical properties. The test results are shown in the table 1.

The mechanical property test and grain size result of the titanium alloy that table 1 embodiment 1～5 and comparative example 1 obtain

It can be seen from Table 1 that the basket structure composed of acicular α-phase in the titanium alloy obtained by the present invention has greatly improved the yield strength and tensile strength of the alloy, and the yield strength of the comparison alloy has increased by 25.4%. , the tensile strength increased by 19.66%.

At the same time, the titanium alloys obtained in Examples 1 to 5 were cut out by wire cutting into corrosion resistance test samples with a size of 10 mm × 10 mm × 2 mm, and three samples were cut out of each titanium alloy ingot to ensure the repeatability of the experiment. . And the six sides of the sample were polished to 3000# with SiC sandpaper, then cleaned and dried with cold air. Before the start of the experiment, measure the original mass of the sample on the balance, weigh each sample three times, take the average value to ensure its accuracy, and make corresponding records. Based on GB10124-1988, according to the national standard, soak in the HCL solution with a concentration of 5mol/L at a constant temperature of 25°C for 10 days, change the solution every two days, clean the sample in alcohol with ultrasonic wave for 15 minutes, and weigh it with a balance. After 10 days of corrosion, the weight loss data are shown in Table 2. Corrosion performance data for this material were thus obtained.

The corrosion resistance test test result of the titanium alloy that table 2 embodiment 1～5 and comparative example 1 obtain

project Weight loss (g/m²) Increase Example 1 73.1880234 33.26% Example 2 61.43154002 43.98% Example 3 51.94439509 52.63% Example 4 54.84623576 49.98% Example 5 60.54876259 42.96% Comparative Alloy 109.6553527 ------

As can be seen from Table 2, in the present invention, the increase of Zr content makes its anti-corrosion performance more excellent, compares with the comparison alloy (Ti-2Al-1.5Mn) that same treatment process obtains, and the anti-corrosion ability in sodium chloride solution The improvement rate is 33.26-52.63%.

As can be seen from the above examples, the present invention can greatly improve the tensile strength and yield strength by controlling the content of each element; the formation of zirconium oxide by zirconium in the corrosive medium can effectively improve the structure of the passivation film of titanium alloy Performance, significantly improve the corrosion resistance of titanium alloys, with the increase of zirconium content in the alloy, the passivation current density of the alloy gradually decreases, and the alloy gradually changes from uniform corrosion to localized corrosion. Adding Zr elements to titanium alloys can significantly improve the corrosion resistance of titanium alloys. After adding Zr to titanium alloys, the ZrO2 formed _on the surface can improve the oxide protective film of the alloy, thereby improving the corrosion resistance of the alloy. The corrosion resistance of the titanium alloy obtained in the invention is also significantly improved in the sodium chloride solution.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any form. It should be pointed out that those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims (10)

1. a kind of high-strength corrosion-resistant loses titanium alloy, based on mass content, including Al 1.0~2.5%, Mn 0.7~2.0%, Zr (0, 50%] and the Ti of surplus；

The preparation method of the high-strength corrosion-resistant erosion titanium alloy, comprising the following steps:

(1) cast alloy base will be obtained after alloy raw material melting；

(2) the cast alloy base that the step (1) obtains is made annealing treatment, obtains annealed state base；

(3) the annealed state base for obtaining the step (2) carries out solution treatment, obtains high-strength corrosion-resistant erosion titanium alloy；

The holding temperature of the annealing is 650~700 DEG C, and the soaking time of annealing is 2~3h.

2. high-strength corrosion-resistant according to claim 1 loses titanium alloy, which is characterized in that the high-strength corrosion-resistant loses titanium alloy and includes The Ti of Al 1.0~2.5%, Mn 0.7~2.0%, Zr 10~40% and surplus.

3. high-strength corrosion-resistant according to claim 1 or 2 loses titanium alloy, which is characterized in that the high-strength corrosion-resistant loses titanium alloy By acicular α ' phase composition mesh basket tissue and metastable β phase composition.

4. high-strength corrosion-resistant described in claims 1 to 3 any one erosion titanium alloy preparation method, which is characterized in that including with Lower step:

(1) cast alloy base will be obtained after alloy raw material melting；

(2) the cast alloy base that the step (1) obtains is made annealing treatment, obtains annealed state base；

(3) the annealed state base for obtaining the step (2) carries out solution treatment, obtains high-strength corrosion-resistant erosion titanium alloy；

The holding temperature of the annealing is 650~700 DEG C, and the soaking time of annealing is 2~3h.

5. the preparation method according to claim 4, which is characterized in that melting is vacuum arc melting in the step (1), The temperature of the vacuum arc melting is 2000~2500 DEG C.

6. preparation method according to claim 4 or 5, which is characterized in that melting is repeated 5 times in the step (1) More than.

7. the preparation method according to claim 4, which is characterized in that the type of cooling made annealing treatment in the step (2) It is cold with furnace.

8. the preparation method according to claim 4, which is characterized in that the insulating process of the step (2) annealing and The insulating process of solution treatment independently carries out under protective atmosphere in step (3).

9. the preparation method according to claim 4, which is characterized in that the holding temperature of solution treatment in the step (3) It is determined according to zirconium content in alloy raw material, often the Zr holding temperature containing 1wt.% reduces by 2~2.5 DEG C from 890~930 DEG C.

10. the preparation method according to claim 4 or 9, which is characterized in that the heat preservation of solution treatment in the step (3) Temperature is 800~910 DEG C, and the soaking time of solution treatment is 30~60min, and the type of cooling of solution treatment is water quenching.