A Mo-containing dual-phase titanium-based alloy and preparation method thereof

Abstract

The present invention relates to the field of alloy technology, and in particular to a Mo-containing dual-phase titanium-based alloy and a preparation method thereof. The raw materials of the Mo-containing dual-phase titanium-based alloy include the following components in the following mass percentages: Al: 3.3% to 6.7%, Mo: 3% to 17%, Sn: 1.3% to 3.7%, and the remainder is Ti element and other inevitable impurities. The Mo-containing dual-phase titanium-based alloy has high strength, uniform structure and no internal stress, which ensures that the Mo-containing dual-phase titanium-based alloy has excellent mechanical properties; excellent corrosion resistance and the like, and can be used as aerospace service material.

Description

Technical Field

[0001] The invention relates to the technical field of aviation materials, and in particular to a Mo dual-phase titanium-based alloy and a preparation method thereof. Background Art

[0002] Compared with other metal materials, titanium-based alloys have the advantages of low density, high specific strength, corrosion resistance, low temperature resistance and high temperature resistance, etc. Therefore, they are widely used in military industry, nuclear industry, chemical industry and automobile industry.

[0003] α+β type titanium-based alloy is a two-phase alloy with good comprehensive properties, good organizational stability, good toughness, plasticity and high-temperature deformation performance. It can be well processed by hot pressure, and can be quenched and aged to strengthen the alloy. The strength after heat treatment is about 50% to 100% higher than that of the annealed state. It also has high high-temperature strength and can work for a long time at a temperature of 400℃ to 500℃.

[0004] Traditional titanium-based alloys for aerospace use, such as Ti-5Al-2.5Sn alloy, have low cost but low strength; Ti-6Al-4V alloy has a tensile strength of 1100-1200 MPa but has high cost.

[0005] Therefore, the traditional titanium-based alloys have problems such as low strength and high cost, and cannot meet the requirements of preparing aerospace service materials. It is particularly important to develop new low-cost, high-performance Mo-containing dual-phase titanium-based alloys. Summary of the invention

[0006] In view of the above technical problems, the present invention provides a Mo-containing dual-phase titanium-based alloy and a preparation method thereof. The dual-phase titanium-based alloy has high strength, uniform texture, no internal stress, excellent mechanical properties, lower cost than traditional titanium alloys, and can meet aerospace service requirements.

[0007] To solve the above technical problems, the embodiments of the present invention adopt the following technical solutions:

[0008] In a first aspect, an embodiment of the present invention provides a Mo-containing duplex titanium-based alloy, the raw materials of which include the following components in the following mass percentages: Al: 3.3% to 6.7%, Mo: 3% to 17%, Sn: 1.3% to 3.7%, and the remainder being Ti element and other inevitable impurities.

[0009] The Mo-containing dual-phase titanium-based alloy provided by the present invention has high strength, uniform structure and no internal stress, which ensures that the Mo-containing dual-phase titanium-based alloy has excellent mechanical properties; it has excellent corrosion resistance and can be used for aerospace service materials.

[0010] The cost of Al, Mo and Sn as alloy elements in the present invention is lower than that of titanium alloys containing V, Nb and other elements in the prior art; and the strengthening effect of Al, Mo and Sn as alloy elements in titanium-based alloys is stronger than that of Ni, Zn, Bi and other elements.

[0011] The present invention adds Al, Mo and Sn elements into the matrix titanium by alloying.

[0012] The element Al greatly improves the stability of the α phase and the β-α transition temperature. Studies have shown that for every 1% increase in Al by mass, the room temperature strength of the titanium alloy will increase by about 50MPa, and the alloy can also be lightweight to a certain extent. However, when its dosage exceeds 7% by mass, the corrosion resistance and plasticity of the alloy will decrease. In addition to stabilizing the β phase and reducing the β-α transition temperature, the element Mo also improves the room temperature and high temperature strength of the alloy and improves the creep performance. Studies have shown that the Mo element can improve the corrosion resistance of titanium alloys, especially the ability of the alloy to resist crevice corrosion in chloride solutions. A small amount of Sn can improve the room temperature and high temperature strength of the alloy and reduce the sensitivity to hydrogen embrittlement. However, when tin exceeds a certain concentration, it forms an ordered phase Ti3Sn, which will reduce the plasticity and thermal stability of the alloy. Therefore, the alloy composition selection intervals of Al, Mo, and Sn must be within the above reasonable range to ensure the corrosion resistance, plasticity, and high temperature strength of the Mo-containing duplex titanium-based alloy, as well as reduce the sensitivity to hydrogen embrittlement.

[0013] In a second aspect, an embodiment of the present invention further provides a method for preparing a Mo-containing dual-phase titanium-based alloy, which specifically includes the following operations:

[0014] Prepare raw materials according to the mass percentage of the above components, and smelt to obtain alloy ingots;

[0015] heating and rolling the alloy ingot to form an alloy plate;

[0016] Air-cooling and grinding the alloy plate to obtain a densified deformed titanium-based alloy;

[0017] The densified deformed titanium-based alloy is subjected to a structure optimization heat treatment, and after cooling, a Mo-containing dual-phase titanium-based alloy is obtained.

[0018] The preparation method provided by the embodiment of the present invention first melts the raw materials into alloy ingots to ensure that the components of each alloy are uniform; then heats and rolls the alloy ingots to deform them so that the alloy is rolled more uniformly to avoid the alloy being rolled to form fine cracks; then air cools and grinds them to obtain a densified deformed titanium-based alloy; finally, a microstructure optimization heat treatment is performed to make the distribution of each alloy component in the Ti matrix more uniform and to remove the residual stress in the deformation process to obtain a Mo-containing dual-phase titanium-based alloy.

[0019] Preferably, the smelting is carried out in a vacuum non-consumable arc melting furnace, the protective gas in the vacuum non-consumable arc melting furnace is an inert gas, and the alloy ingot is obtained by smelting. In actual operation, various raw materials should be cleaned before being placed in a water-cooled copper crucible in the vacuum non-consumable arc melting furnace, and the inner wall of the copper crucible should be cleaned and wiped clean in advance to avoid other impurities. High-purity argon can be selected as the inert gas.

[0020] In a specific implementation of the embodiment of the present invention, the vacuum degree in the furnace chamber of the vacuum non-consumable arc melting furnace can be drawn to 8×10 -3 Pa, and then high-purity argon is filled in as a protective gas. The ingot is repeatedly melted at least five times to ensure uniform composition.

[0021] Preferably, the heating is carried out in a muffle furnace, in which the alloy ingot is heated to 800° C. to 980° C. and kept warm for 10 to 40 minutes.

[0022] In a specific implementation of the embodiment of the present invention, the alloy ingot is placed in a muffle furnace, heated to a rolling temperature of 800° C. to 980° C. and kept warm for 10 to 40 minutes, and then quickly taken out and rolled on a twin-roll mill for deformation.

[0023] If the temperature is too low, the alloy may crack during rolling. If the temperature is too high, the alloy microstructure may change, which may affect the alloy performance. If the holding time is too short, the alloy is heated unevenly inside and outside, which may cause cracking and other adverse consequences during rolling. If the holding time is too long, the alloy grains may grow, affecting the alloy performance and other adverse consequences.

[0024] Therefore, the selected holding temperature is 800°C to 980°C and the holding time is 10 to 40 minutes, which can make the alloy rolled more evenly and avoid the alloy being rolled to form fine cracks.

[0025] Preferably, the rolling deformation is carried out on a twin-roll mill, and the rolling deformation is performed multiple times on the twin-roll mill, with a reduction of 1.8-2 mm in each time. After each rolling, it is placed in a muffle furnace and heated to 800°C to 980°C and kept warm for 3 to 10 minutes until the alloy ingot is rolled into an alloy plate with a thickness of 5 to 6.6 mm and a thickness deformation of 60% to 75%, thereby ensuring that the alloy plate is fully deformed.

[0026] After rolling once, the temperature of the alloy will drop significantly. It will be heated again to 800℃~980℃ and kept warm for a short time of 3~10 minutes. This is to make the alloy rolled more evenly and avoid the alloy being rolled and forming small cracks.

[0027] Preferably, the structure optimization heat treatment is: heating the densified deformed titanium-based alloy to 900-1150° C. in an inert atmosphere and keeping the temperature for 30-180 minutes.

[0028] In the embodiment of the present invention, a vacuum tube resistance furnace using argon as a protective atmosphere can be used as a heat treatment furnace. The vacuum tube resistance furnace protected by argon can protect the titanium alloy from reacting with air during the heat treatment process.

[0029] In the embodiment of the present invention, the purpose of the above-mentioned organization optimization heat treatment is to make the distribution of alloy group elements such as Al, Mo, Sn in the Ti matrix more uniform and remove the residual stress during the deformation process. If the heating temperature of the heat treatment is too low or the holding time is too short, uneven distribution of alloy components and stress cracking are likely to occur; if the heating temperature is too high or the holding time is too long, the grains are likely to be too coarse, thereby making the strength of the α-β type dual-phase Mo-containing dual-phase titanium-based alloy of the present invention low.

[0030] Therefore, it is more reasonable to select a heating temperature of 900°C to 1150°C and a holding time of 30 to 180 minutes, which is conducive to the preparation of a Mo-containing duplex titanium-based alloy with high strength and excellent mechanical properties.

[0031] The Mo-containing dual-phase titanium-based alloy of the embodiment of the present invention has high strength, uniform structure and no internal stress, which ensures that the Mo-containing dual-phase titanium-based alloy has excellent mechanical properties and excellent corrosion resistance.

[0032] In a third aspect, the Mo-containing duplex titanium-based alloy or the Mo-containing duplex titanium-based alloy obtained by the above preparation method provided by an embodiment of the present invention is used in the preparation of materials for aerospace service. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the densification deformation treatment of the present invention.

[0034] Figure 2 It is a dimension diagram of the tensile specimen of the present invention.

[0035] Figure 3 1 is the XRD (X-ray diffraction) diagram of the titanium-based alloy ingots prepared in various embodiments of the present invention.

[0036] Figure 4 1 is an electrochemical polarization curve diagram of the titanium-based alloy ingots prepared in various embodiments of the present invention.

[0037] Figure 5 This is a metallographic optical micrograph of the Mo-containing dual-phase titanium-based alloy prepared in Example 1 of the present invention.

[0038] Figure 6This is a metallographic optical micrograph of the Mo-containing dual-phase titanium-based alloy prepared in Example 2 of the present invention.

[0039] Figure 7 This is a metallographic optical micrograph of the Mo-containing dual-phase titanium-based alloy prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] Traditional titanium-based alloys have the problems of low strength and high cost, and cannot meet the requirements for preparing materials for aerospace service. In view of this technical problem, the present invention provides a Mo-containing dual-phase titanium-based alloy and a preparation method thereof. The raw materials of the alloy include the following components in the following mass percentages: Al: 3.3% to 6.7%, Mo: 3% to 17%, Sn: 1.3% to 3.7%, and the balance is Ti element and other inevitable impurities.

[0042] The preparation method specifically comprises the following operations:

[0043] Prepare raw materials according to the mass percentage of the above components, and smelt to obtain alloy ingots;

[0044] heating and rolling the alloy ingot to form an alloy plate;

[0045] The alloy plate is air-cooled and polished to obtain a densified deformed titanium-based alloy;

[0046] The densified deformed titanium-based alloy is subjected to a microstructure optimization heat treatment, and a Mo-containing dual-phase titanium-based alloy is obtained after cooling.

[0047] The Mo-containing duplex titanium-based alloy of the embodiment of the present invention has lower cost than traditional titanium alloys, and has high strength, uniform structure and no internal stress, which ensures that the Mo-containing duplex titanium-based alloy has excellent mechanical properties and excellent corrosion resistance, and can meet aerospace service requirements.

[0048] Figure 1 Schematic diagram of densification deformation processing according to an embodiment of the present invention.

[0049] like Figure 1 As shown, the alloy ingot is added to a muffle furnace, heated to the rolling temperature and kept warm, then taken out and put into a double-roll rolling mill for rolling deformation, then put into the muffle furnace for heating and keeping warm, and then rolled and deformed again, and the alloy ingot is finally rolled into an alloy plate with a thickness of 5-6.6 mm and a thickness deformation of 60% to 75%.

[0050] The technical solution of the present invention is further described below through specific embodiments.

[0051] The muffle furnace in the embodiment of the present invention is of model KL-13, purchased from Tianjin Kaiheng Electric Heating Technology Co., Ltd. The double-roll mill is of model 200 two-roll mill, purchased from the Rolling Mill Research Institute of Yanshan University.

[0052] Example 1

[0053] Take 90g of industrial-grade sponge titanium, 3.3g of pure aluminum, 3g of pure molybdenum, and 3.7g of pure tin, immerse them in anhydrous ethanol, and after ultrasonic cleaning, mix them according to the composition ratio of 3.3% Al, 3% Mo, 3.7% Sn (mass percentage), and the balance Ti, and place them in a water-cooled copper crucible of a non-consumable vacuum arc melting furnace. The vacuum degree in the furnace chamber should be drawn to 8×10 -3 Pa, before arc melting, high-purity argon is filled as a protective gas, and then the melting is carried out; after each melting is completed, the ingot is turned over, and the ingot is repeatedly melted and turned over five times to ensure that the composition of the final ingot is uniform; then the alloy ingot is added to the muffle furnace, heated to 980℃ and kept warm for 10 minutes, and then quickly taken out and rolled on a double-roll mill, and deformed by multiple rolling passes, with a reduction of about 2mm per pass. After each rolling pass, it is placed in the muffle furnace and reheated to 980℃ and kept warm for 3 minutes, and the alloy ingot is finally rolled into an alloy plate with a thickness of 6.5mm, and its final thickness deformation reaches 60%. After the final rolling, it is cooled in the air, and the alloy plate is taken out after it is completely cooled, and the oxide layer on the surface of the alloy plate is carefully polished off, and it is cleaned to obtain a densified deformed titanium-based alloy billet. The titanium-based alloy billet is then subjected to a microstructure optimization heat treatment. A vacuum tube resistance furnace with argon as a protective atmosphere is used as a heat treatment furnace. The densified deformed titanium-based alloy billet is placed in the heat treatment furnace, heated to 1150°C, kept warm for 30 minutes, and then cooled with the furnace to obtain a Mo-containing duplex titanium-based alloy.

[0054] Example 2

[0055] Take 82.5g of industrial-grade sponge titanium, 5g of pure aluminum, 10g of pure molybdenum, and 2.5g of pure tin, immerse them in anhydrous ethanol, and after ultrasonic cleaning, mix them according to the alloy composition of 5% Al, 10% 10Mo, 2.5% Sn (mass percentage), and the balance Ti, and place them in a water-cooled copper crucible in a non-consumable vacuum arc melting furnace. The vacuum degree in the furnace chamber should be drawn to 8×10 -3Pa, before arc melting, high-purity argon is filled as a protective gas, and then the melting is carried out. After each melting is completed, the ingot is turned over, and the ingot is repeatedly melted and turned over six times to ensure that the composition of the final ingot is uniform; then the alloy ingot is added to the muffle furnace, heated to 900 ° C and kept warm for 25 minutes, and quickly taken out and rolled on a double-roll mill. After multiple rolling deformations, the reduction amount of each pass is about 2mm. After each rolling, it is put into the muffle furnace and reheated to 900 ° C and kept warm for 6 minutes. The alloy ingot is finally rolled into an alloy plate with a thickness of 5.5mm, and its final thickness deformation reaches 70%. After the final rolling, it is cooled in the air, and the alloy plate is taken out after it is completely cooled, and the oxide layer on the surface of the alloy plate is carefully polished off, and it is cleaned to obtain a densified deformed titanium-based alloy billet. The titanium-based alloy billet is then subjected to a microstructure optimization heat treatment. A vacuum tube resistance furnace with argon as a protective atmosphere is used as a heat treatment furnace. The densified deformed titanium-based alloy billet is placed in the heat treatment furnace, heated to 1000°C, kept warm for 100 minutes, and then cooled with the furnace to obtain a Mo-containing duplex titanium-based alloy.

[0056] Example 3

[0057] Take 75g of industrial-grade sponge titanium, 6.7g of pure aluminum, 17g of pure molybdenum, and 1.3g of pure tin, immerse them in anhydrous ethanol, and after ultrasonic cleaning, mix them according to the alloy composition of 6.7% Al, 17% Mo, 1.3% Sn (mass percentage), and the balance Ti, and place them in a water-cooled copper crucible of a non-consumable vacuum arc melting furnace. The vacuum degree in the furnace chamber should be drawn to 8×10 -3 Pa, before arc melting, high-purity argon is filled as a protective gas before melting. After each melting, the ingot is turned over, and the ingot is repeatedly melted and turned over seven times to ensure that the composition of the final ingot is uniform; then the alloy ingot is added to the muffle furnace, heated to 800℃ and kept warm for 40 minutes, and quickly taken out and rolled on a double-roll mill. After multiple rolling deformations, the reduction amount of each pass is about 2mm. After each rolling, it is put into the muffle furnace and reheated to 800℃ and kept warm for 10 minutes. The alloy ingot is finally rolled into an alloy plate with a thickness of 5.0mm, and its final thickness deformation reaches 75%. After the final rolling, it is cooled in the air, and the alloy plate is taken out after it is completely cooled. The oxide layer on the surface of the alloy plate is carefully polished off, and it is cleaned to obtain a densified deformed titanium-based alloy billet. The titanium-based alloy billet is then subjected to a microstructure optimization heat treatment. A vacuum tube resistance furnace with argon as a protective atmosphere is used as a heat treatment furnace. The densified deformed titanium-based alloy billet is placed in the heat treatment furnace, heated to 900°C, kept warm for 180 minutes, and then cooled with the furnace to obtain a Mo-containing duplex titanium-based alloy.

[0058] Comparative Example 1

[0059] The Ti-5Al-2.5Sn titanium-based alloy was prepared by mixing the alloy components (5% Al and 2.5% Sn by mass).

[0060] The preparation process parameters are the same as those in Example 1, except that the structure optimization heat treatment temperature is 850° C. and the heat preservation time is 45 min.

[0061] Comparative Example 2

[0062] Take 82.5g of industrial-grade sponge titanium, 5g of pure aluminum, 10g of pure molybdenum, and 2.5g of pure tin, immerse them in anhydrous ethanol, and after ultrasonic cleaning, mix them according to the alloy composition of 5% Al, 10% Mo, 2.5% Sn (mass percentage) and the balance Ti, and place them in a water-cooled copper crucible of a non-consumable vacuum arc melting furnace. The vacuum degree in the furnace chamber should be drawn to 8×10 -3 Pa, before arc melting, high-purity argon is filled as a protective gas, and then the melting is carried out. After each melting is completed, the ingot is turned over, and the melting and turning of the ingot are repeated five times to ensure that the composition of the final ingot is uniform; then the alloy ingot is added to the muffle furnace, heated to 900 ° C and kept warm for 25 minutes, and quickly taken out and rolled on a double-roll mill. After multiple rolling deformations, the reduction amount of each pass is about 2mm. After each rolling, it is put into the muffle furnace and reheated to 900 ° C and kept warm for 6 minutes. The alloy ingot is finally rolled into an alloy plate with a thickness of 5.5mm, and its final deformation amount reaches 70%. After the final rolling, it is cooled in the air, and the alloy plate is taken out after it is completely cooled, and the oxide layer on the surface of the alloy plate is carefully polished off, and it is cleaned to obtain a densified deformed titanium-based alloy billet. The titanium-based alloy billet is then subjected to a microstructure optimization heat treatment. A vacuum tube resistance furnace with argon as a protective atmosphere is used as a heat treatment furnace. The densified deformed titanium-based alloy billet is placed in the heat treatment furnace, heated to 750°C, kept warm for 600 minutes, and then cooled with the furnace to obtain a Mo-containing duplex titanium-based alloy.

[0063] Verification Example 1

[0064] Figure 2 The dimensions of the tensile specimens of the present invention are shown in FIG. 1 . The Mo-containing dual-phase titanium-based alloys prepared in Examples 1 to 3 and the Ti-5Al-2.5Sn titanium-based alloy prepared in Comparative Example 1 are cut into the following shapes by an electric spark cutting machine: Figure 2 After the tensile test was performed, the mechanical properties of Examples 1-3 and Comparative Example 1 were obtained as shown in Table 1.

[0065] Table 1 Mechanical properties test results of alloys of Examples 1-3 and Comparative Example 1

[0066]

[0067]

[0068] It can be seen from Table 1 that the yield strength and tensile strength of the Mo-containing dual-phase titanium-based alloys prepared in Examples 1-3 are much higher than the Ti-5Al-2.5Sn titanium-based alloy in Comparative Example 1, which fully demonstrates that the Mo-containing dual-phase titanium-based alloy of the present invention has excellent mechanical properties.

[0069] Figure 3 It is the XRD (X-ray diffraction) of the titanium-based alloy ingots prepared in various embodiments of the present invention.

[0070] like Figure 3 As shown, the diffraction peaks of the Mo-containing dual-phase titanium-based alloy of the present invention are obvious and no compounds exist, indicating that the Mo-containing dual-phase titanium-based alloy has uniform composition and no internal stress exists, thus ensuring the excellent mechanical properties of the alloy.

[0071] Verification Example 2

[0072] The self-corrosion potential and corrosion current density of the Mo-containing dual-phase titanium-based alloys obtained in Examples 1-3 and the Ti-5Al-2.5Sn titanium-based alloy obtained in Comparative Example 1 were measured in a 3.5% NaCl aqueous solution, as shown in Table 2.

[0073] Table 2 Test results of self-corrosion potential and corrosion current density of alloys of Examples 1-3 and Comparative Example 1

[0074] serial number Self-corrosion potential (V) <![CDATA[Corrosion current density (A / cm 2 )]]> Example 1 -0.563 <![CDATA[4.1×10 -6 ]]> Example 2 -0.455 <![CDATA[2.8×10 -6 ]]> Example 3 -0.526 <![CDATA[7.6×10 -6 ]]> Comparative Example 1 -0.624 <![CDATA[5.5×10 -5 ]]>

[0075] It can be seen from Table 2 that the self-corrosion potential of the Mo-containing dual-phase titanium-based alloys prepared in Examples 1-3 is higher than that of the Ti-5Al-2.5Sn titanium-based alloy in Comparative Example 1, and the corrosion current density is much lower than that of the Ti-5Al-2.5Sn titanium-based alloy, which fully demonstrates that the Mo-containing dual-phase titanium-based alloy has excellent corrosion resistance.

[0076] Figure 4 1 is an electrochemical polarization curve diagram of the titanium-based alloy ingots prepared in various embodiments of the present invention.

[0077] from Figure 4 It can be seen that the self-corrosion potential of the Mo-containing dual-phase titanium-based alloys in Examples 1-3 is higher than that of the Ti-5Al-2.5Sn titanium-based alloy in Comparative Example 1, and the corrosion current density is lower than that of the Ti-5Al-2.5Sn titanium-based alloy, which indicates that the Ti-5Al-2.5Sn titanium-based alloy of the present invention has excellent corrosion resistance.

[0078] Figure 5 This is a metallographic optical micrograph of the Mo-containing dual-phase titanium-based alloy prepared in Example 1 of the present invention.

[0079] Figure 6This is a metallographic optical micrograph of the Mo-containing dual-phase titanium-based alloy prepared in Example 2 of the present invention.

[0080] Figure 7 This is a metallographic optical micrograph of the Mo-containing dual-phase titanium-based alloy prepared in Example 3 of the present invention. Figure 5-7 The metallographic optical micrographs of Examples 1-3 are shown in FIG. Figure 5-7 It can be seen that the metallographic structure diagram of the Mo-containing dual-phase titanium-based alloy prepared in Examples 1-3 shows that the alloy structure is uniform and has no obvious defects.

[0081] Verification Example 3

[0082] The alloy composition of Example 2 and Comparative Example 2 is the same, but the heat treatment temperature and time are different. The mechanical properties of the Mo-containing duplex titanium-based alloys obtained in Example 2 and Comparative Example 2 are compared. The results are shown in Table 3.

[0083] Table 3 Comparison of mechanical properties of Mo-containing dual-phase titanium-based alloys obtained in Example 2 and Comparative Example 2

[0084] serial number Yield strength (MPa) Tensile strength(MPa) Example 2 1041.61 1247.11 Comparative Example 2 791.25 886.25

[0085] As can be seen from Table 3, the yield strength and tensile strength of Comparative Example 2 are much lower than those of Example 2, which indicates that the heat treatment temperature selected by the present invention is 900-1150°C, and the temperature range and insulation time of 30-180min are more reasonable, which is conducive to the preparation of a Mo-containing duplex titanium-based alloy with high strength and excellent mechanical properties.

[0086] From the above results, it can be seen that the Mo-containing dual-phase titanium-based alloy provided by the present invention has high strength, uniform structure and no internal stress, which ensures that the Mo-containing dual-phase titanium-based alloy has excellent mechanical properties and excellent corrosion resistance, and can be used for aerospace service materials. And this effect is significantly better than that of comparative example 1.

[0087] The cost of Al, Mo and Sn as alloy elements in the present invention is lower than that of titanium alloys containing V, Nb and other elements in the prior art; and the strengthening effect of Al, Mo and Sn as alloy elements in titanium-based alloys is stronger than that of Ni, Zn, Bi and other elements.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A Mo-containing dual-phase titanium-based alloy, characterized in that: The raw materials include the following components in the following mass percentages: Al: 3.3%~6.7%, Mo: 3%~17%, Sn: 1.3%~3.7%, and the balance is Ti element and other inevitable impurities; the Mo-containing dual-phase titanium-based alloy is prepared by smelting, heating, rolling, air cooling, grinding and microstructure optimization heat treatment, the temperature of the microstructure optimization heat treatment is 900℃~1150℃, the insulation time is 30~180min, and then cooled with the furnace.

2. A method for preparing a Mo-containing dual-phase titanium-based alloy, characterized in that: The specific operations include: Prepare raw materials according to the mass percentage of each component in claim 1, and smelt to obtain an alloy ingot; heating and rolling the alloy ingot to form an alloy plate; Air-cooling and grinding the alloy plate to obtain a densified deformed titanium-based alloy; The densified deformed titanium-based alloy is subjected to a structure optimization heat treatment, and after cooling, a Mo-containing dual-phase titanium-based alloy is obtained.

3. The preparation method according to claim 2, characterized in that: The smelting is carried out in a vacuum non-consumable arc melting furnace, the protective gas in the vacuum non-consumable arc melting furnace is an inert gas, and the alloy ingot is obtained by smelting.

4. The preparation method according to claim 2, characterized in that: The heating is carried out in a muffle furnace, in which the alloy ingot is heated to 800° C. to 980° C. and kept warm for 10 to 40 minutes.

5. The preparation method according to claim 2, characterized in that: The rolling is carried out on a twin-roll mill, and the alloy ingot is deformed by multiple rolling passes on the twin-roll mill, with a reduction of 1.8-2 mm in each pass. After each rolling pass, it is placed in a muffle furnace and heated to 800° C.~980° C. and kept warm for 3~10 minutes until the alloy ingot is rolled into an alloy plate with a thickness deformation of 60%~75%.

6. The preparation method according to claim 2, characterized in that: The structure optimization heat treatment is as follows: heating the densified deformed titanium-based alloy to 900° C. to 1150° C. in an inert atmosphere, keeping the temperature for 30 to 180 minutes, and then cooling it with the furnace.

7. Use of the Mo-containing duplex titanium-based alloy according to claim 1 or the Mo-containing duplex titanium-based alloy obtained by the preparation method according to any one of claims 2 to 6 in the preparation of aerospace service materials.

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