A method for preparing a high-strength, low-plasticity titanium alloy wire

Abstract

The application belongs to the technical field of titanium alloy, and particularly relates to a preparation method suitable for high-strength and low-plasticity titanium alloy wire rod. The wire rod preparation process comprises the following steps: alloy smelting, blank preparation, wire rod drawing, shaping treatment, surface treatment, winding and packaging. The blank is quenched to obtain a martensite structure, and the material state before drawing is controlled to be a metastable state. The wire rod drawing is a core process. The microstructure of the wire rod drawing blank is optimized and controlled, the deformation resistance is reduced, the deformation capacity is improved, and the stable and efficient preparation of the high-strength titanium alloy wire rod for additive manufacturing is realized. After the application is adopted, the wire rod variety specification is expanded to high-strength and low-plasticity materials, the material variety specification is expanded, and the development of the additive manufacturing technology based on the wire rod is promoted.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of titanium alloy, and particularly relates to a preparation method suitable for high-strength and low-plasticity titanium alloy wire. BACKGROUND

[0002] In recent years, additive manufacturing technology has developed rapidly at home and abroad, and its application has gradually expanded, and has become an indispensable advanced technology in the field of high-end manufacturing.

[0003] Metal materials have a wider application, and have become the focus of development in the field of additive manufacturing in recent years. Currently, metal material additive manufacturing mainly includes the following technologies: 1) laser direct deposition technology, the printing material is metal powder; 2) laser powder bed forming technology, the printing material is metal powder with a particle size of 15-53 μm; 3) electron beam powder bed forming technology, the heat source is an electron beam, and the printing material is metal powder with a particle size of 50-120 μm; 4) arc deposition technology, which can be divided into TIG and CMT according to the heat source, and the printing material is metal wire; 5) electron beam wire deposition technology, the heat source is an electron beam, and the printing material is metal wire.

[0004] In recent years, additive manufacturing technology using powder as raw material has developed rapidly, especially laser powder bed technology, which has rapidly developed in equipment, process and application, and has become an essential technology in the field of high-end manufacturing such as aerospace. Relatively speaking, the development of arc and electron beam deposition technology using wire as raw material is relatively lagging behind, the main reasons being: 1) arc and electron beam deposition technology prints rough parts, and the technology lacks irreplaceability; 2) wire supply is limited. From the current development status, most metal materials can be prepared into powder, but not all metal materials can be prepared into wire. It is particularly difficult to make wire from metal materials with high strength and brittleness, which greatly limits the supply of printing materials for arc and electron beam deposition technology, and to some extent, also inhibits the development of this technology.

[0005] Titanium alloy is an important metal material, and is widely used in the fields of aviation, aerospace, ocean, chemical industry and the like. Especially in the field of aviation and aerospace, titanium alloy is currently an irreplaceable key material. In recent years, the development of additive manufacturing technology has greatly liberated the structural design, and to some extent, has realized the ideal state of "as long as it is designed, it can be prepared". Therefore, titanium alloy additive manufacturing technology has developed rapidly in recent years; secondly, titanium alloy belongs to traditional metal structural materials, and additive manufacturing technology has the advantage of being able to greatly save raw materials, and is expected to greatly reduce the material cost of titanium alloy parts, thereby promoting its wider application. Therefore, from the aspects of technology development and cost control, titanium alloy additive manufacturing is undoubtedly the key development field in this field.

[0006] The advantages of the electric arc and electron beam deposition technology are to form large-size complex parts, and therefore the technical breakthrough in this field is of great significance to greatly reduce the manufacturing cost of titanium alloy materials, and is expected to become a key technology of green manufacturing in the future. Unlike other additive manufacturing technologies, the development of electric arc and electron beam deposition technology is not only limited by equipment and process, but also limited by materials, especially wire preparation technology. In recent years, metal material powder preparation technology has developed rapidly, but wire preparation technology has developed relatively slowly. At present, the titanium alloy wire that can be mass-produced in an industrialized manner mainly has the following characteristics: low alloying, low strength and low temperature resistance of the formed component, and narrow application field, which greatly limits the development of this technology.

[0007] The traditional method to reduce the material deformation resistance and improve the deformation capacity is to change the alloy type or reduce the material alloying degree without changing the alloy type. For example, increasing the content of beta stabilizing elements in titanium alloy, reducing the content of alpha stabilizing elements and interstitial elements, and changing the alloy type from alpha type or alpha+beta type to beta type can improve the material deformation capacity. In addition, reducing the content of solid solution strengthening elements and interstitial elements (such as O and C) in the alloy can also improve the material deformation capacity. For example, the high-temperature deformation capacity of TC4DT alloy is better than that of TC4 alloy. However, whether the alloy type is changed or the material alloying degree is reduced, it will have a significant impact on the mechanical properties of the material, especially the strength. For example, during the electron beam melting deposition process, the alloying elements are burned to different degrees, which reduces the strength of the accumulated parts. Therefore, it is required to compensate for the burned elements in the wire, which increases the alloying degree of the wire. Therefore, the above two technical measures have a narrow applicability to the wire for additive manufacturing. SUMMARY

[0008] The purpose of the present application is to provide a preparation method of high-strength and low-plasticity titanium alloy wire, which can reduce the deformation resistance and improve the deformation capacity by optimizing and controlling the microstructure of the wire drawing blank, and realize the stable and efficient preparation of high-strength titanium alloy wire for additive manufacturing.

[0009] The technical solution of the present application is as follows:

[0010] A preparation method of high-strength and low-plasticity titanium alloy wire, the wire preparation process is as follows: alloy smelting, blank preparation, wire drawing, shaping treatment, surface treatment, winding and packaging. The blank is quenched to obtain a martensitic structure, and the material state before drawing is controlled to be metastable. The wire drawing is the core process.

[0011] The preparation method of high-strength and low-plasticity titanium alloy wire, the blank preparation process adopts a rolled wire blank, and the diameter of the rolled wire blank is controlled to be less than 12 mm before the wire drawing process starts.

[0012] The method for preparing high-strength, low-plasticity titanium alloy wire involves quenching the rolled wire blank after heat treatment in the α+β two-phase region before the wire drawing process begins. The requirement for controlling the heat treatment temperature is to keep the volume fraction of the high-temperature β phase between 40% and 90%.

[0013] The method for preparing high-strength, low-plasticity titanium alloy wire involves the following steps: after the total deformation exceeds 54% in each wire drawing process, the intermediate billet undergoes another α+β two-phase heat treatment followed by quenching, and then is drawn again. This cycle is repeated until the wire diameter reaches the target control size.

[0014] The method for preparing high-strength, low-plasticity titanium alloy wires requires α+β two-phase heat treatment to reach a warm charge in the furnace, with a holding time of billet diameter × 0.6 + 5 to 7 min, followed by water quenching after removal from the furnace. The billet diameter is measured in mm.

[0015] The method for preparing high-strength, low-plasticity titanium alloy wires described herein involves controlling the temperature of the wire drawing process between 600℃ and 800℃.

[0016] The design concept of this invention is as follows:

[0017] 1) Utilize the principle that elements diffuse rapidly when the material is in a metastable state to improve the material's high-temperature deformation capacity. The specific measures are to control the material state to be metastable before drawing, and to perform high-temperature quenching treatment on the billet to obtain a martensitic structure. This structure has a high interface density, and the alloying elements deviate from their equilibrium positions and are in a high-energy state. Under suitable temperature conditions, because the element diffusion activation energy is low, the deformation resistance is reduced and the deformation capacity is increased.

[0018] 2) In order to ensure stable deformation of the material, the softer phase should be in the majority, and the grain growth should be controlled within the allowable range to avoid wire breakage due to strain concentration during wire drawing. Therefore, the requirement for controlling the quenching temperature is to keep the volume fraction of the high-temperature β phase between 50% and 90%.

[0019] 3) Because surface oxidation increases surface brittleness and reduces the material's deformation capacity, the surface of the wire blank needs to be coated with an anti-oxidation coating before quenching. The furnace loading temperature and holding time must be strictly controlled. Specifically, the furnace should be loaded at the required temperature, and the holding time should be controlled within the range of blank diameter (mm) × 0.6 + 5 min to 7 min.

[0020] The advantages and beneficial effects of this invention are:

[0021] The present application has the advantages that: 1. The process is simple and easy to operate. The present application utilizes the characteristics that the alloying elements deviate from the equilibrium position in the metastable structure of titanium alloy, are in a high-energy state and are easy to diffuse at high temperature, adopts quenching before drawing, realizes the purpose of reducing deformation resistance and improving deformation capacity, and realizes the purpose of significantly improving the production efficiency of wire materials and greatly increasing the variety and specification of wire materials;

[0022] 2. The present application is suitable for high-strength and low-plasticity titanium alloy wires. The existing titanium alloy wire drawing process is only suitable for the industrialized and stable production of medium and low strength and high plasticity titanium alloy materials. The wire materials required by the electron beam melting wire deposition technology need to compensate for some components, such as the electron beam melting wire deposition TC4 alloy, the aluminum content of which is 0.5-1.0% higher than that of the conventional TC4, which leads to a significant increase in strength and a significant decrease in plasticity (see Table 1), and the wire is frequently broken during the wire drawing process, and the wire is difficult to realize engineering stable production. If the composition of TA15 alloy is compensated, the aluminum content can be as high as 7.5%, and it is difficult to produce by using the existing process. After the present application is adopted, the high-alloyed and high-strength and low-plasticity materials have realized stable production under industrialized conditions.

[0023] 3. The present application expands the variety and specification of wire materials to high-strength and low-plasticity materials, expands the variety and specification of materials, and is beneficial to promoting the development of additive manufacturing technology based on wire materials.

[0024] Table 1 Room temperature tensile properties of several typical titanium alloy wires

[0025]

[0026] BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Figure 1 is a curve of the deformation resistance of several typical titanium alloy materials with temperature. In the figure, the abscissa Temp. represents temperature (℃), and the ordinate Stress represents deformation resistance (MPa).

[0028] Figure 2 Figure 3 is the martensite structure obtained by quenching after heat treatment in the alpha + beta phase region of a typical titanium alloy.

[0029] Figure 3 Figure 4 is a comparison diagram of 800 DEG C hot compression curves of quenched martensite structure and conventional non-martensite structure. The deformation resistance of the martensite structure is obviously lower than that of the non-martensite structure. In the figure, the abscissa Strain represents compression strain, and the ordinate Stress represents compression stress (MPa).

[0030] Figure 4 Figure 5 is a photo of the high-strength titanium alloy TC4EH wire produced by the present application.

[0031] Figure 5 Photo of high-strength titanium alloy TC4EH wire with diameter of 2.0 mm produced by the present application. DETAILED DESCRIPTION

[0032] In the specific implementation, the present application provides a preparation method suitable for high-strength and low-plasticity titanium alloy wire, which includes wire composition, wire blank diameter, α+β two-phase zone heat treatment temperature, holding time, cooling mode after heat treatment, wire drawing temperature, and wire drawing rate, etc. Among them:

[0033] 1. The wire preparation process is alloy smelting→blank preparation→wire drawing→shaping treatment→surface treatment→winding→packing, and the wire drawing is the core process;

[0034] 2. The wire blank is required to be in a rolled state, and the diameter of the wire blank is required to be controlled between 6-12 mm before the wire drawing process starts;

[0035] 3. The rolled wire blank is subjected to α+β two-phase zone heat treatment and quenching before the wire drawing process starts; the specific requirement is to load the furnace at temperature, the holding time is blank diameter (unit: mm) × 0.6 + 5-7 min, and water quenching after furnace discharge; the surface of the wire blank is brushed with an anti-oxidation coating before quenching treatment, and the quenching treatment temperature should meet the requirement that the high-temperature β phase volume fraction is between 40%-90%;

[0036] 4. The wire drawing temperature is controlled between 600-800℃, and after the total deformation of the wire drawing exceeds 54%, the blank needs to be subjected to α+β two-phase zone quenching treatment again as described in step 3 until the diameter of the wire reaches the target control size.

[0037] The present application is further described in detail through examples as follows.

[0038] Example 1:

[0039] The experimental material is titanium alloy TC4EH, the alloy composition is Ti-7.0Al-4.5V-0.2O-0.3Fe (wt%), and the phase transition point is 985℃. Compared with the traditional Ti-6Al-4V alloy composition, the alloying degree and the content of gap element O are significantly improved, which leads to a significant decrease in the deformation capacity of the material. The material state before wire drawing is a rolled disc with a diameter of 9 mm.

[0040] The wire forming steps are as follows:

[0041] 1) An anti-oxidation coating is coated on the surface of the disc wire blank, and then the blank is loaded into an electric furnace with a furnace temperature of 960℃. After the furnace temperature returns to 960℃, the timing starts, and the blank is discharged after 11 min of holding, and then water quenched. During the 960℃ holding process, the high-temperature β phase volume fraction is about 63% according to the metallographic method.

[0042] 2) After quenching, the disc round billet is charged into an electric furnace at 600°C, and after holding for 20 min, it is discharged and uncoiled;

[0043] 3) First-stage drawing. The drawing operation is carried out at 680°C, the deformation is 0.5 mm / pass, and the diameter is reduced to 5.5 mm, the cumulative deformation is 92%, and the grinding is performed to remove the damage;

[0044] The drawing process occurs multiple times, and the cumulative deformation refers to the sum of the deformations of multiple times, and the percentage of the cumulative deformation = (diameter squared before deformation - diameter squared after deformation) / diameter squared before deformation * 100%.

[0045] 4) The semi-finished wire material with a diameter of 5.5 mm is charged into an electric furnace with a furnace temperature of 960°C, and after the furnace temperature returns to 960°C, the timing is started, and after holding for 9 min, it is discharged, and water quenching is performed; the water abrasive wheel is used to remove the surface oxide skin and repair the damage;

[0046] 5) Second-stage drawing. The drawing temperature is 680°C, the deformation is 0.4 mm / pass, the diameter is reduced to 3.9 mm, the cumulative deformation is 63%, and the grinding is performed to remove the damage;

[0047] 6) The semi-finished wire material with a diameter of 3.9 mm is charged into an electric furnace with a furnace temperature of 960°C, and after the furnace temperature returns to 960°C, the timing is started, and after holding for 8 min, it is discharged, and water quenching is performed; the skinning machine is used to remove the surface oxide skin;

[0048] 7) Third-stage drawing. The drawing temperature is 680°C, the deformation is 0.35 mm / pass, the diameter is reduced to 2.5 mm, and the skinning machine is used to remove the surface oxide skin and other defects;

[0049] 8) Final-stage drawing. The drawing temperature is 680°C, the deformation is 0.3 mm / pass, the diameter is reduced to 2.2 mm, and the rounding is performed; the skinning machine is used to remove the surface oxide skin and other defects, and the finished wire material with a diameter of 2.0 mm and a bright surface is obtained.

[0050] Example 2:

[0051] The experimental material is titanium alloy TA15EH, the alloy composition is Ti-7.3Al-1.8Zr-1.5Mo-1.5V (wt%), and the phase transition point is 1005°C. Compared with the TA15 standard composition Ti-6.5Al-1.8Zr-1.5Mo-1.5V, the Al element is significantly increased, and the material deformation capacity is significantly reduced. The material state before drawing is a rolled disc round with a diameter of 10 mm.

[0052] The wire forming steps are as follows:

[0053] 1) The disc round billet is coated with titanium alloy oxidation resistant KBC-12 paint on the surface, and is loaded into an electric furnace with a furnace temperature of 980°C. After the furnace temperature reaches 980°C again, timing starts. After 12 minutes of holding, the furnace is discharged and water quenched. During the 980°C holding process, the volume fraction of high-temperature beta phase is about 75% according to the metallographic method;

[0054] 2) The quenched disc round billet is loaded into a 650°C electric furnace. After 20 minutes of holding, the furnace is discharged and uncoiled;

[0055] 3) First stage wire drawing. The wire drawing operation is carried out at 800°C, with a deformation of 0.4mm / pass, the diameter is reduced to 8.0mm, the cumulative deformation is 78%, and the scratches are polished;

[0056] 4) The semi-finished wire material with a diameter of 8.0mm is loaded into an electric furnace with a furnace temperature of 980°C. After the furnace temperature rises to 980°C, timing starts. After 10 minutes of holding, the furnace is discharged and water quenched. A water abrasive wheel is used to polish and remove surface scales and other defects;

[0057] 5) Second stage wire drawing. The wire drawing temperature is 700°C, the deformation is 0.4mm / pass, and the diameter is reduced to 6.0mm until the cumulative deformation is 54%, and the scratches are polished;

[0058] 6) The semi-finished wire material with a diameter of 6.0mm is loaded into an electric furnace with a furnace temperature of 980°C. After the furnace temperature rises to 980°C, timing starts. After 9 minutes of holding, the furnace is discharged and water quenched. A scale removing machine is used to remove surface scales and other defects;

[0059] 7) Third stage wire drawing. The wire drawing temperature is 700°C, the deformation is 0.3mm / pass, and the diameter is reduced to 4.2mm until the cumulative deformation is 67%, and a scale removing machine is used to remove surface scales and other defects;

[0060] 8) The semi-finished wire material with a diameter of 4.2mm is loaded into an electric furnace with a furnace temperature of 980°C. After the furnace temperature rises to 980°C, timing starts. After 8 minutes of holding, the furnace is discharged and water quenched. A scale removing machine is used to remove surface scales and other defects;

[0061] 9) Final stage wire drawing. The wire drawing temperature is 700°C, the deformation is 0.3mm / pass, the diameter is reduced to 2.4mm, and the circle is returned. A scale removing machine is used to remove surface scales and other defects, and the finished wire material with a diameter of 2.0mm is obtained.

[0062] Example 3:

[0063] The experimental material is titanium alloy TC11, the alloy composition is Ti-6.8Al-1.5Zr-3.5Mo-0.3Si (wt%), and the phase transition point is 995°C. The material state before wire drawing is a rolled disc round with a diameter of 9mm.

[0064] The wire forming step is as follows:

[0065] 1) The titanium alloy oxidation resistant KBC-12 paint is coated on the surface of the round billet, and the electric furnace with a furnace temperature of 970°C is loaded. After the furnace temperature returns to 970°C, the timing starts, and the furnace is kept for 11 minutes. After the furnace is discharged, water quenching is performed. During the 970°C holding process, the volume fraction of high-temperature β phase is about 72% according to the metallographic method;

[0066] 2) The quenched round billet is loaded into the electric furnace at 650°C, and the furnace is kept for 20 minutes before being discharged and uncoiled;

[0067] 3) First stage wire drawing. The wire drawing operation is performed at 690°C, and the deformation is 0.5mm / pass until the diameter is reduced to 6.5mm, and the cumulative deformation is 61%, and the scratches are polished;

[0068] 4) The semi-finished wire with a diameter of 6.5mm is loaded into the electric furnace with a furnace temperature of 970°C. After the furnace temperature returns to 970°C, the timing starts, and the furnace is kept for 9 minutes before being discharged. Water quenching is performed. The surface scales and other defects are removed by using a skinning machine;

[0069] 5) Second stage wire drawing. The wire drawing temperature is 690°C, and the deformation is 0.4mm / pass until the diameter is reduced to 4.1mm, and the cumulative deformation is 85%. The surface scales and other defects are removed by using a skinning machine;

[0070] 6) The semi-finished wire with a diameter of 4.1mm is loaded into the electric furnace with a furnace temperature of 970°C. After the furnace temperature returns to 970°C, the timing starts, and the furnace is kept for 8 minutes before being discharged. Water quenching is performed. The surface scales and other defects are removed by using a skinning machine;

[0071] 7) Diameter 2.0mm wire preparation. The wire drawing temperature is 690°C, the deformation is 0.3mm / pass, the diameter is reduced to 2.3mm, and the roundness is restored. The surface scales and other defects are removed by using a skinning machine to obtain the finished wire with a diameter of 2.0mm and a bright surface;

[0072] 8) Diameter 1.6mm wire preparation. The wire drawing temperature is 690°C, the semi-finished wire with a diameter of 2.3mm obtained in step 7) is used as the billet, the deformation is 0.2mm / pass, the diameter is reduced to 1.8mm, and the roundness is restored. The surface scales and other defects are removed by using a skinning machine to obtain the finished wire with a diameter of 1.6mm and a bright surface;

[0073] 9) Diameter 1.2mm wire preparation. The wire drawing temperature is 690°C, the semi-finished wire with a diameter of 1.8mm obtained in step 8) is used as the billet, the deformation is 0.2mm / pass, the diameter is reduced to 1.4mm, and the roundness is restored. The surface scales and other defects are removed by using a skinning machine to obtain the finished wire with a diameter of 1.2mm and a bright surface;

[0074] 10) Preparation of 1.0mm diameter wire. The drawing temperature is 670℃. Using the 1.4mm diameter semi-finished wire obtained in step 9) as the blank, the deformation is 0.2mm / pass, the diameter is reduced to 1.2mm, and rounded. The surface oxide scale and other defects are removed by a peeling machine to obtain a finished wire with a bright surface and a diameter of 1.0mm.

[0075] Example 4:

[0076] The experimental material was TC17 titanium alloy, with an alloy composition of Ti-5Al-2Zr-2Sn-4Mo-4Cr-0.1O (wt%) and a phase transformation point of 880℃. The material was in a rolled coil state before drawing, with a billet diameter of 7mm.

[0077] The wire forming steps are as follows:

[0078] 1) Coat the surface of the coiled wire blank with KBC-12 anti-oxidation coating, put it into an electric furnace at a furnace temperature of 865℃, start timing after the furnace temperature rises to 850℃, hold for 10 minutes and then take it out of the furnace and water quench it; during the 865℃ holding process, the volume fraction of the high temperature β phase is estimated to be about 87% according to metallographic method.

[0079] 2) After quenching, the coiled wire blank is placed in a 650℃ electric furnace, held for 20 minutes, and then uncoiled.

[0080] 3) First stage wire drawing. The wire drawing operation is carried out at 670℃, with a deformation of 0.5mm / pass, until the diameter is reduced to 4.5mm, with a cumulative deformation of 81%, followed by grinding and repair.

[0081] 4) The semi-finished wire with a diameter of 4.5 mm was loaded into an electric furnace at a temperature of 850℃. After the furnace temperature rose back to 850℃, the timer was started. After holding at this temperature for 8 minutes, the wire was removed from the furnace and water-quenched. The surface oxide scale and other defects were removed using a peeling machine. During the 850℃ holding process, the volume fraction of the high-temperature β phase was estimated to be 71% based on metallographic methods.

[0082] 5) Second stage wire drawing. The wire drawing temperature is 670℃, and the deformation is 0.4mm / pass, until the diameter is reduced to 2.5mm. A peeling machine is used to remove the surface oxide scale and other defects.

[0083] 6) Finished product stage: drawing. The drawing temperature is 650℃, the deformation is 0.3mm / pass, the diameter is reduced to 2.2mm, and it is rounded. The surface oxide scale and other defects are removed by a peeling machine to obtain a finished wire with a bright surface and a diameter of 2.0mm.

[0084] like Figure 1 As shown in the curves of deformation resistance versus temperature for several typical titanium alloys, it can be seen that different types of titanium alloys have different phase transformation points and their deformation resistance varies significantly with temperature.

[0085] As Figure 2 shown, the martensite structure obtained by quenching after heat treatment of typical titanium alloy alpha + beta phase region can be seen, there are a large number of acicular phase in the quenched structure, this acicular phase is unstable at high temperature, which is beneficial to reduce the deformation resistance of the material.

[0086] As Figure 3 shown, the 800 DEG C hot compression curve of quenched martensite structure and conventional non-martensite structure can be seen, compared with the air-cooled structure, the deformation resistance of the quenched structure is reduced by about 100 MPa.

[0087] As Figure 4 shown, the good shape high strength titanium alloy TC4EH wire produced by the present application can be seen from the photo, the wire curvature is consistent, the different positions are smoothly transitioned, and there is no problem of distortion and entanglement.

[0088] As Figure 5 shown, the high strength titanium alloy TC4EH wire with a diameter of 2.0 mm produced by the present application can be seen from the photo, the surface of the whole disc wire is bright, and there is no hard bending and distortion, and the shape control is good.

[0089] In summary, based on theoretical analysis and experimental research, according to the application requirements of high strength titanium alloy wire by electron beam melting wire deposition and arc melting wire deposition and other additive manufacturing technologies, a preparation method suitable for high strength and low plasticity titanium alloy wire is proposed. The method can reduce the deformation resistance in the wire drawing process, improve the deformation ability, help to improve the efficiency of wire preparation, reduce the preparation difficulty of high strength titanium alloy wire, and is conducive to promoting the industrialization production and application of difficult-to-process titanium alloy wire, which is used for additive manufacturing of large-size high-strength titanium alloy parts for aircraft or spacecraft, and has wide application prospect.

Claims

1. A method for preparing high-strength, low-plasticity titanium alloy wire suitable for additive manufacturing, characterized in that, The wire preparation process is as follows: alloy melting → billet preparation → wire drawing → shaping treatment → surface treatment → winding → packaging; among them, quenching the billet to obtain martensitic structure and controlling the material state to be metastable before drawing are the core processes. The blank preparation process uses rolled wire blanks. Before the wire drawing process begins, the diameter of the rolled wire blanks must be controlled within 12mm. Before the wire drawing process begins, the rolled wire blank is heat-treated in the α+β two-phase region and then quenched. The requirement for controlling the heat treatment temperature is to keep the volume fraction of the high-temperature β phase between 40% and 90%. After the total deformation exceeds 54% in each wire drawing process, the intermediate billet undergoes another α+β two-phase heat treatment followed by quenching, and then is drawn again. This cycle continues until the wire diameter reaches the target control size. The α+β two-phase region heat treatment requires charging into the furnace at the specified temperature, holding time of billet diameter × 0.6 + 5~7 min, followed by water quenching after removal from the furnace. The billet diameter is in mm. The temperature of the wire drawing process is controlled between 600℃ and 800℃.

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