Isometric crystal high-homogeneity titanium-niobium alloy and electric arc double-wire additive manufacturing method thereof

Abstract

The invention belongs to the technical field of additive manufacturing, and relates to an isometric crystal high-homogeneity titanium-niobium alloy and an electric arc double-wire additive manufacturing method thereof. The method comprises the following steps: mounting and fixing a pretreated pure titanium wire, a pure niobium wire and a substrate, inputting specific process parameters into a control system of electric arc double-wire additive manufacturing equipment, and carrying out electric arc double-wire deposition in a specific scanning mode to obtain the isometric crystal high-homogeneity titanium-niobium alloy. According to the method, the problem of high niobium inclusion is solved, the uniformity of titanium-niobium alloy components can be promoted, rapid preparation of the isometric crystal high-homogeneity titanium-niobium alloy can be conveniently achieved, subsequent plastic deformation of the isometric crystal high-homogeneity titanium-niobium alloy is facilitated, stable production of isometric crystal high-homogeneity titanium-niobium alloy products can be met, and the method is suitable for industrial production. And the stability of the performance of the part in service is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of additive manufacturing, and relates to an equiaxed crystal high-homogeneous titanium-niobium alloy and an arc double-wire additive manufacturing method thereof. Background Art

[0002] Titanium-niobium (Ti-Nb) alloy is a metal material that combines structure and function. Its performance shows significant differences with the change of niobium content. When the niobium content is in the range of 1at.% to 29at.%, the titanium-niobium alloy will undergo a thermoelastic martensitic phase transformation during the cooling process, and then show shape memory ability, which is widely used in many fields such as aerospace, medical equipment, and intelligent structures; when the niobium content is in the range of 34at.% to 37at.%, the titanium-niobium alloy can show superconducting properties at a specific temperature. With this characteristic, it has become the preferred alloy material for superconducting wires currently produced in commercial batches; in addition, the high niobium content Ti-45wt.%Nb alloy (titanium-45% niobium alloy) has an outstanding advantage in resisting galvanic corrosion due to its extremely small galvanic corrosion potential with titanium alloys and other metal-based composite materials. It is widely used in the field of aviation fasteners, providing important support for ensuring the reliability and durability of aviation aircraft structures.

[0003] However, the melting points of titanium and niobium differ by about 800°C, and the traditional melting and casting method for producing titanium-niobium alloys is prone to high niobium inclusion problems (such as Figures 2~4 As shown in the figure, it is a great safety hazard for the stable service of the product; if high-energy electron beam is used as a heat source to melt titanium-niobium alloy, although the niobium element can be fully melted, the large difference in melting points between the two will cause the volatilization of titanium, which cannot meet the stable production of titanium-niobium alloy products with specific components. Therefore, how to achieve a balance between the full melting of high-melting-point niobium and the control of the composition of titanium-niobium alloy is a difficult problem that needs to be solved in the stable production process of titanium-niobium alloy. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide an equiaxed high-homogeneous titanium-niobium alloy and an arc twin-wire additive manufacturing method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: An arc twin-wire additive manufacturing method for an equiaxed crystal highly homogeneous titanium-niobium alloy is characterized in that pretreated pure titanium wire, pure niobium wire and a substrate are installed and fixed, specific process parameters are input into a control system of an arc twin-wire additive manufacturing device, and arc twin-wire deposition is performed through a specific scanning mode to obtain an equiaxed crystal highly homogeneous titanium-niobium alloy.

[0006] Specifically, the method can fully melt pure niobium wire with a small diameter through a high-energy arc (150A~200A), adjust the melting quality of the pure titanium wire under a reasonable and controllable process window, solve the problem of high niobium inclusions and improve the uniformity of the titanium-niobium alloy composition, and realize the rapid preparation of equiaxed crystal high-homogeneous titanium-niobium alloy; the equiaxed crystal high-homogeneous titanium-niobium alloy prepared by the method has the characteristics of fully equiaxed crystals, ensuring the performance stability of parts made of the equiaxed crystal high-homogeneous titanium-niobium alloy during service.

[0007] The equiaxed highly homogeneous titanium-niobium alloy prepared by this method has the (011) [1-11] orientation characteristics, which belongs to the close-packed plane and close-packed direction of body-centered cubic metal, and is more conducive to the plastic deformation of the titanium-niobium alloy deposited by double-wire arc.

[0008] Further, the method comprises the following steps: Step 1: Pretreatment: Firstly, the pure titanium wire, the pure niobium wire and the substrate are subjected to preliminary surface treatment, and then the pure titanium wire, the pure niobium wire and the substrate are subjected to heat preservation; Step 2: Installation and fixation: Install the pure titanium wire and pure niobium wire on the wire feeding part of the arc double-wire additive manufacturing equipment, and install the base plate on the CNC forming platform; Step 3: Set parameters and modes: Input specific process parameters into the control system of the arc twin-wire additive manufacturing equipment, and perform arc twin-wire deposition through a specific scanning mode to obtain equiaxed crystal highly homogeneous titanium-niobium alloy.

[0009] Specifically, the method uses pure titanium wire and pure niobium wire as raw materials, and adopts specific process parameters and specific scanning modes through an arc twin-wire additive manufacturing device protected by an inert gas to achieve the rapid preparation of equiaxed crystal highly homogeneous titanium-niobium alloy.

[0010] Furthermore, the preliminary surface treatment of the pure titanium wire and the pure niobium wire in step 1 includes: acid washing and ultrasonic cleaning of the pure titanium wire and the pure niobium wire in sequence; The preliminary surface treatment of the substrate in step 1 includes: firstly performing double-sided milling and grinding treatment on the substrate, and then performing surface cleaning treatment on the substrate.

[0011] Specifically, the preliminary surface treatment is to first pickle the pure titanium wire and the pure niobium wire to remove the oxide film on the surface of the wire, and then use acetone and other organic solvents to ultrasonically clean them to ensure that the surface of the pure titanium wire and the pure niobium wire is free of oil stains; secondly, double-sided milling and sandpaper polishing of the substrate to ensure the roughness and smoothness of the substrate surface, and then wipe the substrate surface with alcohol and perform ultrasonic cleaning to thoroughly remove all kinds of oil stains and impurities on the substrate surface.

[0012] Furthermore, in the step 1, the pure titanium wire, pure niobium wire and substrate after preliminary treatment are placed in a drying device at a temperature of 90° C. to 100° C. and kept warm for 25 min to 35 min.

[0013] Specifically, the pure titanium wire, the pure niobium wire and the substrate are placed in a drying device for heat preservation, so that the moisture of the pure titanium wire, the pure niobium wire and the substrate is removed and the residual deformation of the pure titanium wire and the pure niobium wire is eliminated.

[0014] It should be noted that the temperature in the drying equipment can be 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C, 100°C, which can be adjusted according to actual needs. The insulation time is 25min, 26min, 27min, 28min, 29min, 30min, 31min, 32min, 33min, 34min, 35min, which can be adjusted according to actual needs. Preferably, the drying equipment uses a drying oven, the temperature in the drying oven is maintained at 100°C, and the insulation time is 35min.

[0015] Furthermore, in the step three, the specific process parameters are set as follows: the current value is 150A~200A, the starting vertical distance between the arc-starting end of the pure titanium wire and the substrate is 7.5mm~8.5mm, the starting vertical distance between the arc-starting end of the pure niobium wire and the substrate is 7.5mm~8.5mm, and the wire feeding speed of the arc twin-wire additive manufacturing equipment is 7mm / s~15mm / s.

[0016] Specifically, the reasons for adopting the specific process parameters are as follows: the preparation method provided by the present invention can fully melt the pure niobium wire with a small diameter through the high-energy arc generated by a large current, adjust the melting quality of the pure titanium wire under a reasonable and controllable process window, solve the problem of high niobium inclusions and improve the composition uniformity of the titanium-niobium alloy; by coordinating the starting vertical distance between the arc-starting end of the pure titanium wire and the substrate, the starting vertical distance between the arc-starting end of the pure niobium wire and the substrate, and the wire feeding speed of the double wire feeding nozzle of the arc double-wire additive manufacturing equipment, the rapid preparation of equiaxed crystal high-homogeneity titanium-niobium alloy is achieved.

[0017] It should be noted that at the beginning of the operation, the starting vertical distance between the arc-starting end of the pure titanium wire and the substrate, and the starting vertical distance between the arc-starting end of the pure niobium wire and the substrate are set to 7.5mm~8.5mm; during the operation, as the deposition continues, the vertical distance between the melting tip of the pure titanium wire and the substrate, and the vertical distance between the melting tip of the pure niobium wire and the substrate gradually increase, until the end of the operation, the final vertical distance between the melting tip of the pure titanium wire and the substrate, and the final vertical distance between the melting tip of the pure niobium wire and the substrate reach 9.5mm~10.5mm. Setting the starting vertical distance can ensure that the melting tip of the pure niobium wire is always in the area where the arc energy is most concentrated throughout the operation to provide sufficient melting temperature.

[0018] It should be noted that the current value can be 150A, 160A, 170A, 180A, 190A, 200A, which can be adjusted according to actual needs. The starting vertical distance between the arc-starting end of the pure titanium wire and the substrate, and the starting vertical distance between the arc-starting end of the pure niobium wire and the substrate can both be 7.5mm, 8mm, and 8.5mm, which can be adjusted according to actual needs. Preferably, the starting vertical distance between the arc-starting end of the pure titanium wire and the substrate, and the starting vertical distance between the arc-starting end of the pure niobium wire and the substrate are both 8mm. The wire feeding speed of the double wire feeding nozzle of the arc double-wire additive manufacturing equipment can be 7mm / s, 8mm / s, 9mm / s, 10mm / s, 11mm / s, 12mm / s, 13mm / s, 14mm / s, and 15mm / s, which can be adjusted according to actual needs.

[0019] Furthermore, the specific scanning mode is a "single-pass multi-layer-round-trip scanning" mode.

[0020] Specifically, the preset 3D model is input into the slicing software, the motion trajectory is automatically generated according to the "single-pass multi-layer-round-trip scanning" mode, and specific process parameters are called in the operation window of the arc twin-wire additive manufacturing equipment.

[0021] Furthermore, the thickness of the substrate is 50 mm to 80 mm.

[0022] Specifically, the thickness of the substrate can be 50 mm, 60 mm, 70 mm, or 80 mm, which can be adjusted according to actual needs. Preferably, the thickness of the substrate is 50 mm.

[0023] Furthermore, the substrate is a Ti-45wt.%Nb alloy substrate.

[0024] Specifically, the Ti-45wt.%Nb alloy substrate can realize the rapid preparation of equiaxed crystal highly homogeneous titanium-niobium alloy. There are two main reasons for selecting the Ti-45wt.%Nb alloy substrate: first, the Ti-45wt.%Nb alloy substrate is close to the composition range of the titanium-niobium alloy prepared by the present invention, and the substrate can be directly processed and used as a whole without removing the substrate in the later stage; second, for the arc twin-wire additive manufacturing technology, the selection of a substrate with a composition close to that of the equiaxed crystal highly homogeneous titanium-niobium alloy can effectively alleviate the thermal effect between the bottom equiaxed crystal highly homogeneous titanium-niobium alloy and the substrate, avoid cracking caused by the large difference in composition between the two, and ensure the stable and continuous preparation of the titanium-niobium alloy.

[0025] Furthermore, the diameters of the pure titanium wire and the pure niobium wire are both 1 mm to 1.2 mm.

[0026] Specifically, the diameters of the pure titanium wire and the pure niobium wire can be 1 mm, 1.05 mm, 1.1 mm, 1.15 mm, and 1.2 mm, which can be adjusted according to actual needs. Preferably, the diameters of the pure titanium wire and the pure niobium wire are both 1.2 mm.

[0027] The present invention also provides an equiaxed crystal highly homogeneous titanium-niobium alloy prepared by an arc twin-wire additive manufacturing method of the equiaxed crystal highly homogeneous titanium-niobium alloy, wherein the niobium content is 38wt.%~42wt.%.

[0028] Specifically, the preparation method provided by the present invention realizes the control of the niobium component in the titanium-niobium alloy, ensures the stability of the performance of the titanium-niobium alloy, and the prepared equiaxed crystal high homogeneous titanium-niobium alloy has no high niobium inclusions and has uniform microscopic composition. In the equiaxed crystal high homogeneous titanium-niobium alloy, the niobium content can be 38wt.%, 49wt.%, 40wt.%, 41wt.%, 42wt.%, which can be adjusted according to actual needs.

[0029] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention fully melts the pure niobium wire with a small diameter by using a high-energy arc generated by a large current, and adjusts the melting quality of the pure titanium wire under a reasonable and controllable process window, so as to facilitate the rapid preparation of equiaxed crystal high-homogeneous titanium-niobium alloy, and meet the stable production of titanium-niobium alloy products; (2) The present invention overcomes the problem of high niobium inclusions that are easily generated in the traditional melting and casting method, and can improve the uniformity of the titanium-niobium alloy composition. The parts produced by the equiaxed high-homogeneity titanium-niobium alloy prepared by the present invention can always maintain excellent and stable performance during service; (3) The equiaxed highly homogeneous titanium-niobium alloy prepared by the present invention has a (011) [1-11] orientation characteristic, which belongs to the close-packed plane and close-packed direction of a body-centered cubic metal, and is more conducive to the subsequent plastic deformation of the titanium-niobium alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0032] Figure 1 It is a schematic diagram of the preparation method of the present invention; Figure 2 A schematic diagram of the head section of a titanium-niobium alloy containing high niobium inclusions; Figure 3 It is a schematic diagram of the middle cross section of a titanium-niobium alloy containing high niobium inclusions; Figure 4 Schematic diagram of the tail section of a titanium-niobium alloy containing high niobium inclusions; Figure 5 This is a schematic cross-sectional view of the equiaxed highly homogeneous titanium-niobium alloy in Example 1; Figure 6 This is a scanning electron microscope image of the equiaxed highly homogeneous titanium-niobium alloy in Example 1; Figure 7 It is a partial enlarged view of region b of the isoaxed highly homogeneous titanium-niobium alloy in Example 1; Figure 8 This is a scanning electron microscope image of the niobium distribution of the equiaxed highly homogeneous titanium-niobium alloy in Example 1; Fig. 9 This is a scanning electron microscope image of titanium distribution in the equiaxed highly homogeneous titanium-niobium alloy in Example 1; Fig.10 This is the solidification orientation map of the equiaxed highly homogeneous titanium-niobium alloy in Example 1; Fig.11 is the solidification orientation pole figure of the equiaxed highly homogeneous titanium-niobium alloy in Example 1; Fig.12 is the solidification orientation inverse pole figure of the equiaxed highly homogeneous titanium-niobium alloy in Example 1; Fig.13 The standard projection position diagram of the texture (011) [1-11] of the equiaxed high homogeneity titanium-niobium alloy in Example 1 on the {100} pole figure; Fig.14 The grain distribution diagram of the equiaxed high homogeneous titanium-niobium alloy in Example 1, wherein: the Chinese interpretation of the abscissa "Equivalent circular diameter" is equivalent circular diameter, in micrometers; the Chinese interpretation of the ordinate "Number" is a numerical value; Fig.15 This is the misorientation angle distribution diagram of the equiaxed high homogeneous titanium-niobium alloy in Example 1, wherein: the Chinese interpretation of the abscissa Misorientation is the misorientation angle, the unit is degree; the Chinese interpretation of the ordinate Relative frequency is relative frequency. DETAILED DESCRIPTION

[0033] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention described in detail in the appended claims.

[0034] The present invention provides an arc twin-wire additive manufacturing method for an equiaxed crystal highly homogeneous titanium-niobium alloy, wherein pretreated pure titanium wire, pure niobium wire and a substrate are installed and fixed, specific process parameters are input into a control system of an arc twin-wire additive manufacturing device, and arc twin-wire deposition is performed through a specific scanning mode to obtain an equiaxed crystal highly homogeneous titanium-niobium alloy.

[0035] Furthermore, if Figure 1 As shown, the method comprises the following steps: Step 1: Pretreatment: Firstly, the pure titanium wire, the pure niobium wire and the substrate are subjected to preliminary surface treatment, and then the pure titanium wire, the pure niobium wire and the substrate are subjected to heat preservation; Step 2: Installation and fixation: Install the pure titanium wire and pure niobium wire on the wire feeding part of the arc double-wire additive manufacturing equipment, and install the base plate on the CNC forming platform; Step 3: Set parameters and modes: Input specific process parameters into the control system of the arc twin-wire additive manufacturing equipment, and perform arc twin-wire deposition through a specific scanning mode to obtain equiaxed crystal highly homogeneous titanium-niobium alloy.

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Example 1

[0037] This embodiment provides an arc twin-wire additive manufacturing method for equiaxed crystal high homogeneous titanium-niobium alloy, which specifically includes the following steps: Step 1: Pretreatment: Firstly, the pure titanium wire, the pure niobium wire and the substrate are subjected to preliminary surface treatment, and then the pure titanium wire, the pure niobium wire and the substrate are subjected to heat preservation; Specifically, the preliminary surface treatment of the pure titanium wire, the pure niobium wire and the substrate respectively includes: firstly pickling the pure titanium wire and the pure niobium wire with a diameter of 1.2 mm to remove the oxide film on the surface of the wire, and then ultrasonic cleaning with acetone to ensure that the surface of the pure titanium wire and the pure niobium wire is free of oil pollution; at the same time, double-sided milling and sandpaper polishing of the Ti-45wt.%Nb alloy substrate with a length of 150 mm, a width of 150 mm and a thickness of 50 mm are performed to ensure the roughness and smoothness of the surface of the substrate, and then the surface of the substrate is wiped with alcohol and ultrasonic cleaning is performed to completely remove various oil impurities on the surface of the substrate; The pure titanium wire, the pure niobium wire and the substrate are all heat-insulated, including: placing the pure titanium wire, the pure niobium wire and the Ti-45wt.%Nb alloy substrate, which have been preliminarily treated on the surface, in a drying oven at 100°C for 25 minutes, removing the moisture on the surface of the pure titanium wire, the pure niobium wire and the Ti-45wt.%Nb alloy substrate and eliminating the residual deformation of the pure titanium wire and the pure niobium wire; Step 2: Installation and fixation: Install the pure titanium wire and pure niobium wire on the wire feeding part of the arc double-wire additive manufacturing equipment, and install the base plate on the CNC forming platform; Specifically, the pure titanium wire and the pure niobium wire processed in step 1 are added to the wire feeding part of the arc twin-wire additive manufacturing equipment, and the Ti-45wt.%Nb alloy substrate processed in step 1 is installed on a CNC forming platform that can be moved by CNC; Step 3: Setting parameters and modes: Inputting specific process parameters into the control system of the arc twin-wire additive manufacturing equipment, and performing arc twin-wire deposition through a specific scanning mode to obtain equiaxed crystal highly homogeneous titanium-niobium alloy; Specifically, argon gas is first introduced into the wire feeding part of the arc twin-wire additive manufacturing equipment for protection, and reasonable and controllable specific process parameters are input into the arc twin-wire additive manufacturing equipment. The specific process parameters are set as follows: the current value is 200A, the starting vertical distance between the arc striking end of the pure titanium wire and the substrate is 8mm, the starting vertical distance between the arc striking end of the pure niobium wire and the substrate is 8mm, and the wire feeding speed of the arc twin-wire additive manufacturing equipment is 7mm / s; Input the preset 3D model into the slicing software, automatically generate the motion trajectory according to the "single-pass multi-layer-round-trip scanning" mode, and call specific process parameters in the arc twin-wire additive manufacturing equipment operation window; According to the set control program, arc twin-wire deposition of titanium-niobium alloy is completed to obtain equiaxed crystal highly homogeneous titanium-niobium alloy, wherein the niobium content of the equiaxed crystal highly homogeneous titanium-niobium alloy is 42wt.%. Example 2

[0038] This embodiment provides an arc twin-wire additive manufacturing method for equiaxed crystal high homogeneous titanium-niobium alloy, which specifically includes the following steps: Step 1: Pretreatment: Firstly, the pure titanium wire, the pure niobium wire and the substrate are subjected to preliminary surface treatment, and then the pure titanium wire, the pure niobium wire and the substrate are subjected to heat preservation; Specifically, the preliminary surface treatment of the pure titanium wire, the pure niobium wire and the substrate respectively includes: firstly pickling the pure titanium wire and the pure niobium wire with a diameter of 1.1 mm to remove the oxide film on the surface of the wire, and then ultrasonic cleaning with acetone to ensure that the surface of the pure titanium wire and the pure niobium wire is free of oil pollution; at the same time, double-sided milling and sandpaper polishing of the Ti-45wt.%Nb alloy substrate with a length of 150 mm, a width of 150 mm and a thickness of 65 mm are performed to ensure the roughness and smoothness of the surface of the substrate, and then the surface of the substrate is wiped with alcohol and ultrasonic cleaning is performed to completely remove various oil impurities on the surface of the substrate; The pure titanium wire, the pure niobium wire and the substrate are all heat-insulated, including: placing the pure titanium wire, the pure niobium wire and the Ti-45wt.%Nb alloy substrate, which have been preliminarily treated on the surface, in a drying oven at 95°C for 30 minutes, removing moisture from the pure titanium wire, the pure niobium wire and the Ti-45wt.%Nb alloy substrate and eliminating residual deformation of the pure titanium wire and the pure niobium wire; Step 2: Installation and fixation: Install the pure titanium wire and pure niobium wire on the wire feeding part of the arc double-wire additive manufacturing equipment, and install the base plate on the CNC forming platform; Specifically, the pure titanium wire and the pure niobium wire processed in step 1 are added to the wire feeding part of the arc twin-wire additive manufacturing equipment, and the Ti-45wt.%Nb alloy substrate processed in step 1 is installed on a CNC forming platform that can be moved by CNC; Step 3: Setting parameters and modes: Inputting specific process parameters into the control system of the arc twin-wire additive manufacturing equipment, and performing arc twin-wire deposition through a specific scanning mode to obtain equiaxed crystal highly homogeneous titanium-niobium alloy; Specifically, argon gas is first introduced into the wire feeding part of the arc twin-wire additive manufacturing equipment for protection, and reasonable and controllable specific process parameters are input into the arc twin-wire additive manufacturing equipment. The specific process parameters are set as follows: the current value is 175A, the starting vertical distance between the arc striking end of the pure titanium wire and the substrate is 7.5mm, the starting vertical distance between the arc striking end of the pure niobium wire and the substrate is 7.5mm, and the wire feeding speed of the arc twin-wire additive manufacturing equipment is 11mm / s; Input the preset 3D model into the slicing software, automatically generate the motion trajectory according to the "single-pass multi-layer-round-trip scanning" mode, and call specific process parameters in the arc twin-wire additive manufacturing equipment operation window; According to the set control program, arc twin-wire deposition of titanium-niobium alloy is completed to obtain equiaxed crystal highly homogeneous titanium-niobium alloy, wherein the equiaxed crystal highly homogeneous titanium-niobium alloy has a niobium content of 40wt.%. Example 3

[0039] This embodiment provides an arc twin-wire additive manufacturing method for equiaxed crystal high homogeneous titanium-niobium alloy, which specifically includes the following steps: Step 1: Pretreatment: Firstly, the pure titanium wire, the pure niobium wire and the substrate are subjected to preliminary surface treatment, and then the pure titanium wire, the pure niobium wire and the substrate are subjected to heat preservation; Specifically, the preliminary surface treatment of the pure titanium wire, the pure niobium wire and the substrate respectively includes: firstly pickling the pure titanium wire and the pure niobium wire with a diameter of 1 mm to remove the oxide film on the surface of the wire, and then ultrasonic cleaning with acetone to ensure that the surface of the pure titanium wire and the pure niobium wire is free of oil pollution; at the same time, double-sided milling and sandpaper polishing of the Ti-45wt.%Nb alloy substrate with a length of 150 mm, a width of 150 mm and a thickness of 80 mm are performed to ensure the roughness and smoothness of the surface of the substrate, and then the surface of the substrate is wiped with alcohol and ultrasonic cleaning is performed to completely remove various oil impurities on the surface of the substrate; The pure titanium wire, the pure niobium wire and the substrate are all heat-insulated, including: placing the pure titanium wire, the pure niobium wire and the Ti-45wt.%Nb alloy substrate, which have been preliminarily treated on the surface, in a drying oven at 90°C for 35 minutes, removing moisture from the pure titanium wire, the pure niobium wire and the Ti-45wt.%Nb alloy substrate and eliminating residual deformation of the pure titanium wire and the pure niobium wire; Step 2: Installation and fixation: Install the pure titanium wire and pure niobium wire on the wire feeding part of the arc double-wire additive manufacturing equipment, and install the base plate on the CNC forming platform; Specifically, the pure titanium wire and the pure niobium wire processed in step 1 are added to the wire feeding part of the arc double-wire additive manufacturing equipment, and the Ti-45wt.%Nb alloy substrate processed in step 1 is installed on a CNC forming platform that can be moved by CNC; Step 3: Setting parameters and modes: Inputting specific process parameters into the control system of the arc twin-wire additive manufacturing equipment, and performing arc twin-wire deposition through a specific scanning mode to obtain equiaxed crystal highly homogeneous titanium-niobium alloy; Specifically, argon gas is first introduced into the wire feeding part of the arc twin-wire additive manufacturing equipment for protection, and reasonable and controllable specific process parameters are input into the arc twin-wire additive manufacturing equipment. The specific process parameters are set as follows: the current value is 150A, the starting vertical distance between the arc striking end of the pure titanium wire and the substrate is 8.5mm, the starting vertical distance between the arc striking end of the pure niobium wire and the substrate is 8.5mm, and the wire feeding speed of the arc twin-wire additive manufacturing equipment is 15mm / s; Input the preset 3D model into the slicing software, automatically generate the motion trajectory according to the "single-pass multi-layer-round-trip scanning" mode, and call specific process parameters in the arc twin-wire additive manufacturing equipment operation window; According to the set control program, arc twin-wire deposition of titanium-niobium alloy is completed to obtain equiaxed crystal highly homogeneous titanium-niobium alloy, wherein the niobium content of the equiaxed crystal highly homogeneous titanium-niobium alloy is 38wt.%.

[0040] Taking the equiaxed crystal highly homogeneous titanium-niobium alloy deposited by double-wire arc in Example 1 as an example, the implementation effect of the present invention is analyzed and explained: The specific process parameters for depositing equiaxed crystal highly homogeneous titanium-niobium alloy using double-wire arc in Example 1 of the present invention include: current value 200A, starting vertical distance between the arc-starting end of the pure titanium wire and the substrate 8mm, starting vertical distance between the arc-starting end of the pure niobium wire and the substrate 8mm, wire feeding speed of the double-wire arc additive manufacturing equipment 7mm / s. The cross section of the equiaxed crystal highly homogeneous titanium-niobium alloy prepared under the process parameters is as follows: Figure 5 As shown, Figures 2~4 In comparison, the equiaxed highly homogeneous titanium-niobium alloy prepared in Example 1 has a uniform macroscopic morphology and exhibits the characteristics of stable forming, indicating that the process parameters are well adapted.

[0041] Figures 6 to 9 The energy spectrum results and microstructure characteristics of the isoaxially oriented highly homogeneous titanium-niobium alloy in Example 1 are presented. After analysis, it can be seen that: (1) Figures 6 and 7 As shown, the microstructure of the equiaxed high homogeneous titanium-niobium alloy prepared in Example 1 is characterized by equiaxed crystals, and the niobium content is 42wt.%; (2) Figures 8 and 9 As shown, in the equiaxed high homogeneous titanium-niobium alloy prepared in Example 1, the titanium element and the niobium element are evenly distributed, and there is no high niobium inclusion and element segregation phenomenon; Figures 6 to 9 It can be seen that under reasonable and controllable process parameters, equiaxed crystal highly homogeneous titanium-niobium alloy can be quickly deposited by double-wire arc.

[0042] Figures 10 to 15 This is the solidification orientation characteristic of the equiaxed crystal highly homogeneous titanium-niobium alloy in Example 1 of the present invention. Fig.10 The presented large-area solidification orientation map fully confirms that the equiaxed crystal highly homogeneous titanium-niobium alloy prepared according to the process parameters of Example 1 has a microstructure that is completely equiaxed; Figures 11 to 13 As shown in the figure, the equiaxed highly homogeneous titanium-niobium alloy exhibits a certain (011)[1-11] orientation characteristic along the deposition direction, which belongs to the close-packed plane and close-packed direction of body-centered cubic metal, and is more conducive to the subsequent plastic deformation of the titanium-niobium alloy.

[0043] like Fig.14 As shown, the maximum grain size of the equiaxed high homogeneous titanium-niobium alloy prepared in Example 1 is 1842.2 μm, the minimum grain size is 17.8 μm, the average grain size is 242.2 μm; the standard deviation is 220.2 μm; and, as Fig.15As shown, the average misorientation angle of the equiaxed highly homogeneous titanium-niobium alloy prepared in Example 1 is above 30°. Figures 14 and 15 It can be seen that the equiaxed highly homogeneous titanium-niobium alloy has the characteristics of mainly large-angle grain boundaries, which is beneficial to the subsequent plastic deformation of the equiaxed highly homogeneous titanium-niobium alloy. This shows that by using the arc twin-wire deposition technology under reasonable and controllable process parameters, a fully equiaxed titanium-niobium alloy with a specific orientation and conducive to subsequent plastic deformation can be prepared.

[0044] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0045] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. An arc twin-wire additive manufacturing method for equiaxed high-homogeneous titanium-niobium alloy, characterized in that: The pretreated pure titanium wire, pure niobium wire and substrate are installed and fixed, the specific process parameters are input into the control system of the arc twin-wire additive manufacturing equipment, and the arc twin-wire deposition is performed through a specific scanning mode to obtain equiaxed crystal highly homogeneous titanium-niobium alloy.

2. The arc twin-wire additive manufacturing method of an equiaxed crystal high homogeneous titanium-niobium alloy according to claim 1, characterized in that: The method comprises the following steps: Step 1: Pretreatment: Firstly, the pure titanium wire, the pure niobium wire and the substrate are subjected to preliminary surface treatment, and then the pure titanium wire, the pure niobium wire and the substrate are subjected to heat preservation; Step 2: Installation and fixation: Install the pure titanium wire and pure niobium wire on the wire feeding part of the arc double-wire additive manufacturing equipment, and install the base plate on the CNC forming platform; Step 3: Set parameters and modes: Input specific process parameters into the control system of the arc twin-wire additive manufacturing equipment, and perform arc twin-wire deposition through a specific scanning mode to obtain equiaxed crystal highly homogeneous titanium-niobium alloy.

3. The arc twin-wire additive manufacturing method of an equiaxed crystal high homogeneous titanium-niobium alloy according to claim 2, characterized in that: The preliminary surface treatment of the pure titanium wire and the pure niobium wire in step 1 includes: pickling the pure titanium wire and the pure niobium wire and ultrasonic cleaning them in sequence; The preliminary surface treatment of the substrate in step 1 includes: firstly performing double-sided milling and grinding treatment on the substrate, and then performing surface cleaning treatment on the substrate.

4. The arc twin-wire additive manufacturing method of an equiaxed crystal high homogeneous titanium-niobium alloy according to claim 2, characterized in that: In the step 1, the preliminarily treated pure titanium wire, pure niobium wire and substrate are placed in a drying device at a temperature of 90° C. to 100° C. and kept warm for 25 min to 35 min.

5. The arc twin-wire additive manufacturing method of an equiaxed crystal high homogeneous titanium-niobium alloy according to claim 2, characterized in that: In the step three, the specific process parameters are set as follows: the current value is 150A~200A, the starting vertical distance between the arc-starting end of the pure titanium wire and the substrate is 7.5mm~8.5mm, the starting vertical distance between the arc-starting end of the pure niobium wire and the substrate is 7.5mm~8.5mm, and the wire feeding speed of the arc twin-wire additive manufacturing equipment is 7mm / s~15mm / s.

6. The arc twin-wire additive manufacturing method of an equiaxed crystal high homogeneous titanium-niobium alloy according to claim 5, characterized in that: The specific scanning mode is the "single-pass multi-layer - round-trip scanning" mode.

7. The arc twin-wire additive manufacturing method of an equiaxed high homogeneous titanium-niobium alloy according to any one of claims 1 to 6, characterized in that: The thickness of the substrate is 50 mm to 80 mm.

8. The arc twin-wire additive manufacturing method of an equiaxed high homogeneous titanium-niobium alloy according to any one of claims 1 to 6, characterized in that: The substrate is a Ti-45wt.%Nb alloy substrate.

9. The arc twin-wire additive manufacturing method of an equiaxed crystal high homogeneous titanium-niobium alloy according to any one of claims 1 to 6, characterized in that: The diameters of the pure titanium wire and the pure niobium wire are both 1 mm to 1.2 mm.

10. An equiaxed high homogeneous titanium-niobium alloy prepared by the arc twin-wire additive manufacturing method of the equiaxed high homogeneous titanium-niobium alloy according to any one of claims 1 to 9, characterized in that: The niobium content is 38wt.%~42wt.%.

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