A method for electron beam fusion additive manufacturing of ti80 titanium alloy components

Abstract

The application provides a method for electron beam fuse additive manufacturing of Ti80 titanium alloy components, and belongs to the field of additive manufacturing.The method solves the problems of high cost, long period, low efficiency, low utilization, serious oxidation and poor toughness of Ti80 alloy in the prior art.The method comprises the following steps: step 1, pretreating the printing wire and the additive manufacturing substrate; step 2, establishing a three-dimensional entity model based on the target Ti80 alloy component, and carrying out slicing processing and importing; setting a scanning path, preheating parameters and printing process parameters; step 3, starting the equipment and vacuumizing to 9.9*10 ‑3 Pa, and printing the Ti80 alloy according to the set printing parameters and procedures, completing all layers, and preparing the deposited Ti80 alloy with good forming, dense structure and excellent performance.The method is mainly used for electron beam fuse additive manufacturing.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of additive manufacturing, and particularly relates to a method for electron beam fused deposition of Ti80 titanium alloy components. BACKGROUND

[0002] Titanium and titanium alloys have become one of the most ideal materials for large equipment metal structural components in the field of ocean engineering due to their excellent corrosion resistance, high toughness, high specific strength, and non-magnetic advantages. Replacing steel (nickel-based alloy, etc.) with titanium can not only significantly reduce the weight of structural components, but also significantly prolong the service life of ocean engineering equipment. It is one of the main development trends for the structural upgrade of future ocean engineering equipment. Ti80 (Ti-6Al-3Nb-2Zr-1Mo) alloy is a new type of titanium alloy developed for the field of ocean engineering. It is a near-alpha Ti alloy designed by adjusting the types and contents of elements such as Zr, Nb, and Mo to improve mechanical properties and corrosion resistance based on Ti-6Al-4V alloy. It has broad application prospects in the fields of deep-sea submersibles and offshore platforms. Compared with the most widely used Ti-6Al-4V ELI alloy, the tensile properties of Ti80 alloy are slightly lower, but the toughness is significantly better, especially the impact toughness (ak). With excellent toughness, Ti80 alloy is currently mainly used to manufacture pressure hulls for deep-sea submersibles. The traditional preparation process for Ti80 hulls is casting, forging, welding, and machining. Considering the high melting point, poor thermal conductivity, and strong chemical activity of titanium alloys at high temperatures, the tool wear is severe during machining, and the surface quality is poor. Titanium alloys are recognized as difficult-to-machine materials, and thus face challenges such as difficult preparation, low material utilization, long cycle, and high cost, which seriously hinder the in-depth development and exploration of ocean engineering equipment.

[0003] With the rapid development of metal additive manufacturing technology in recent years, many available technologies based on different heat sources and raw materials have emerged, making it possible to realize titanium alloy components with complex geometric shapes and internal structures. Electron beam fusion additive manufacturing technology with high-power heat source is suitable for rapid and high-quality preparation of large parts. Its high penetration capability is beneficial to multi-layer remelting, reduces hole defects, improves component density and can play a role in shape annealing. In addition, the high vacuum forming environment effectively avoids the introduction of high-activity titanium alloy pollution and inclusions, which can greatly improve the internal quality of the component. Moreover, compared with other additive manufacturing technologies using powder as raw material, the wire material is more uniform in composition, lower in price, higher in deposition efficiency and better in performance of the obtained component. Therefore, electron beam fusion additive manufacturing Ti80 alloy has natural advantages and brings unlimited possibilities for the preparation of large and complex Ti80 alloy components with high performance. It has broad application prospects in the field of marine engineering equipment. However, the existing technology has high cost, long cycle, low efficiency, low utilization rate, serious oxidation and poor toughness in preparing Ti80 alloy. SUMMARY

[0004] Therefore, the present application aims to provide a method for electron beam fusion additive manufacturing of Ti80 titanium alloy components to solve the problems of high cost, long cycle, low efficiency, low utilization rate, serious oxidation and poor toughness in preparing Ti80 alloy in the prior art.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A method for electron beam fusion additive manufacturing of Ti80 titanium alloy components, comprising the following steps:

[0007] Step 1: pretreatment of printing wire and additive substrate;

[0008] Step 2: establish a three-dimensional solid model based on the target Ti80 alloy component, and import after slicing processing; set the scanning path, preheating parameter and printing process parameter;

[0009] Step 3: start the equipment and vacuumize to 9.9x10 -3 Pa, and print Ti80 alloy according to the set printing parameters and program, complete all layers, and prepare deposited Ti80 alloy with good forming, dense structure and excellent performance.

[0010] Further, the additive substrate in step 1 is TA1 pure titanium substrate, the size of the additive substrate is 150mmx10mmx10mm, and the diameter of the wire is 1.6mm.

[0011] Further, the pretreatment of printing wire and additive substrate in step 1 comprises the following steps:

[0012] S1: Ti80 alloy wire is soaked and cleaned by using acetone;

[0013] S2: The cleaned alloy wire is placed in a drying oven and dried at a temperature of 60 DEG C for 4 hours;

[0014] S3: The surface of the TA1 substrate is polished by using an angle grinder;

[0015] S4: The surface of the TA1 substrate is cleaned by using acetone and alcohol in sequence;

[0016] S5: The TA1 substrate is placed in a drying oven and dried at a temperature of 60 DEG C for 4 hours.

[0017] Further, the Ti80 alloy wire in S1 is composed of Al 6.5wt.%, Nb 2.2 wt.%, Zr 2.2%wt.%, Mo.0.91 wt.%, Si≤0.05 wt.%, Fe≤0.05 wt.%, O≤0.09 wt.%, N≤0.01 wt.%, C≤0.01 wt.%, H≤0.01 wt.%, and the rest is Ti element and inevitable impurity elements, and the TA1 substrate is composed of 99.9wt.% Ti element and other avoidable impurity elements.

[0018] Further, the angle between the wire feeding nozzle of the printing wire and the TA1 substrate in step 2 is 45 DEG.

[0019] Further, the length from the wire feeding nozzle of the printing wire to the center axis of the electron beam in step 2 is 5-10mm.

[0020] Further, the preheating parameters in step 2 are as follows: the acceleration voltage is 60kV, the focusing current is 1048mA, the beam current density is 30mA, the preheating printing speed is 500mm / min, and the scanning path is a circular reciprocating linear motion path.

[0021] Further, the printing process parameters in step 2 are as follows: the acceleration voltage is 60kV, the focusing current is 1048mA, the beam current density is 40-50mA, the printing speed is 500-700mm / min, the wire feeding speed is 2m / min, the knob control speed coefficient is 100%, the interlayer cooling time is 30s, and the scanning path is a circular reciprocating linear motion path.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] 1. The method for preparing the Ti80 titanium alloy component provided by the application adopts wire as the printing material, has low material cost, high deposition efficiency, can quickly and directly form a complex Ti80 titanium alloy component, and by adjusting process parameters, a Ti80 alloy with good forming, dense structure and excellent mechanical properties can be obtained.

[0024] 2. The Ti80 alloy additive manufacturing method has the advantages of high power, high energy utilization rate, adaptation to a vacuum processing environment and high deposition efficiency, effectively prevents the generation of oxides during the printing process to affect the toughness of the material, realizes near-net rapid forming and high-quality forming of a large and complex metal component, realizes integrated preparation of shape and properties, and effectively solves the problem of preparation of a large-size Ti80 alloy component.

[0025] 3. The Ti80 alloy component prepared by the method has high density and no obvious defects such as cavities and cracks, and the density is as high as 99.99%.

[0026] 4. The Ti80 alloy obtained by the electron beam wire melting additive manufacturing method has excellent mechanical properties, the tensile yield strength is 740 MPa, and the elongation is as high as 16%; meanwhile, the interface between the deposited Ti80 alloy and the substrate can realize smooth transition without cracks and warping, and the problems of high cost and inability to mass produce caused by using the same component substrate are avoided.

[0027] 5. The Ti80 alloy additive manufacturing method has good popularization, is also suitable for rapid preparation of high-melting-point and high-activity alloys and near-net forming of complex components, realizes rapid preparation of structure-performance integration of complex structures, and has high practicability. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and serve to explain the principles of the present application. In the drawings:

[0029] Figure 1 Ti80 titanium alloy component prepared by electron beam wire melting additive manufacturing in Example 1;

[0030] Figure 2 Ti80 titanium alloy component prepared by electron beam wire melting additive manufacturing in Example 2;

[0031] Figure 3 Ti80 titanium alloy component prepared by electron beam wire melting additive manufacturing in Example 3;

[0032] Figure 4Ti80 titanium alloy component prepared by electron beam fusion additive manufacturing in Example 1;

[0033] Figure 5 Ti80 titanium alloy component prepared by electron beam fusion additive manufacturing in Example 1;

[0034] Figure 6 Macroscopic and microscopic distribution of Ti80 alloy obtained in Example 1 in the deposition direction;

[0035] Figure 7 Phase diagram of Ti80 alloy obtained in Example 1 in different regions;

[0036] Figure 8 Solidification orientation map of Ti80 alloy obtained in Example 1 in the as-deposited state;

[0037] Figure 9 Tensile stress-elongation curve of Ti80 alloy obtained in Example 1 in the as-deposited state. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only a part of the embodiments of the present application, not all the embodiments.

[0039] Example 1: see Figures 1-9 In this embodiment, a method for electron beam fusion additive manufacturing of Ti80 titanium alloy components is described, which comprises the following steps:

[0040] Step 1: pretreatment of the printing wire and the additive substrate;

[0041] Step 2: establish a three-dimensional solid model based on the target Ti80 alloy component, and import after slicing processing; set the scanning path, preheating parameters and printing process parameters;

[0042] Step 3: turn on the equipment and vacuum to 9.9×10 -3 Pa, and print Ti80 alloy according to the set printing parameters and procedures, complete all layers, and prepare the as-deposited Ti80 alloy with good forming, dense structure and excellent performance.

[0043] Ti80 alloy wire with a diameter of 1.6 mm is pickled to remove the surface oxide film, and then cleaned by soaking in acetone to ensure that the surface of the Ti80 alloy wire is free of oil stains and impurities. The surface of a TA1 pure titanium substrate with a size of 150 mm x 100 mm x 10 mm is polished to be smooth and clean by using an angle grinder, and then wiped with acetone to remove oil stains and impurities on the surface of the substrate. The Ti80 alloy wire and the TA1 pure titanium substrate are both placed in a drying oven and dried at a temperature of 60℃ for 4 hours to remove moisture in the Ti80 alloy wire and the TA1 pure titanium substrate and reduce residual deformation in the raw materials. The treated Ti80 alloy wire is installed on the wire feeding mechanism of the electron beam wire deposition equipment, and the treated TA1 pure titanium substrate is clamped on the motion system in the vacuum chamber of the equipment. When the vacuum degree of the vacuum chamber of the electron beam wire deposition equipment reaches the use requirement (9.9 x 10 -3 Pa), the following processing parameters are set: the acceleration voltage is 60 kV, the focusing current is 1048 mA, the wire feeding speed VF is 2 m / min, the printing speed VT is 500 mm / min, and the beam current density IB is 40 mA. The printing program under the process parameters is edited in the automatic operation window of the electron beam wire deposition equipment according to the back-and-forth scanning mode. The Ti80 alloy is prepared by electron beam wire deposition rapid manufacturing according to the printing program, and the Ti80 titanium alloy prepared by electron beam wire additive manufacturing has a length of more than 70 mm and a height of more than 50 mm. The physical map of the Ti80 titanium alloy is shown in FIG. 1.

[0044] The implementation effect of the present application is analyzed and illustrated by taking the Ti80 alloy prepared by electron beam wire additive manufacturing in Example 1 as an example, as shown in Figure 6 , Figure 7 , Figure 8 and Figure 9 .

[0045] As can be seen from the macroscopic and microscopic structures shown in Figure 6 , the microscopic structure of the Ti80 titanium alloy physical object is divided into three parts (i.e. Top, Central, Bottom in Figure 6 ) in the deposition direction according to the morphology and size of the original β crystals, wherein the bottom part is mainly composed of near-equiaxed original β crystals and fine basketweave structure inside, the middle part is mainly composed of coarse columnar crystal original β crystals and uniformly distributed cluster bands, and the top part is mainly composed of coarse columnar original β crystals and uniformly distributed fine basketweave structure, Figure 7 The phase spectrum shows that the α phase with a close-packed hexagonal structure is dominant in the upper, middle and lower regions, accompanied by a small amount of β phase with a body-centered cubic structure. The phase spectrum also shows that the peak intensity of the α phase in different regions is slightly different, which means that the orientation of the α phase changes in the deposition height direction.

[0046] In this example 1, Figure 8The EBSD orientation and morphology near the clustered zone in the central region of the deposited Ti80 titanium alloy specimen are presented. Figure 7 It can be seen that the microstructure of the deposited Ti80 titanium alloy shows that the original β crystals exist in a columnar shape; at the same time, it has strong morphology parallel to the deposition direction Z. <100> β-solidification texture, these <100> The β texture is produced by the epitaxial growth of the crystal along a specific direction according to local and global thermal gradients during the growth process. The α phase orientation in the region near the cluster zone is slightly different. There are strong textures <01-11>α / / Z and weak textures <-12-10>α / / Z in the adjacent basket structure, while there is an obvious <-12-10>α / / Z texture in the cluster zone. This means that the transformation of the basket structure to the cluster zone morphology is accompanied by different degrees of α variant selection.

[0047] Figure 9 Showing Figure 1 The tensile properties of Ti80 titanium alloy specimens deposited in the middle section under load parallel to the deposition height direction, from Figure 8 It can be seen that the deposited Ti80 titanium alloy exhibits excellent tensile yield strength of 740 MPa, while its elongation reaches 16%. Compared to near-α type titanium alloys prepared by other additive manufacturing technologies, the Ti80 alloy produced by electron beam filament additive manufacturing has greater ductility, even comparable to some heat-treated titanium alloys. This superior ductility implies its potential in demanding marine engineering applications, such as deep-sea diving equipment, where achieving a balance between strength and ductility is crucial.

[0048] In summary, the additive manufacturing method provided by this invention can realize the preparation of Ti80 alloy. By adjusting the process window and selecting the optimal deposition process, Ti80 alloy with good shape, dense structure, specific structural orientation, and excellent mechanical properties can be obtained. It plays a significant role in shortening the processing flow and preparing Ti80 alloy parts with complex configurations. Furthermore, it can be extended to the near-net-shape forming of other high-melting-point and high-activity alloys, realizing the rapid preparation of complex configurations with integrated structure and performance.

[0049] Example 2: The only difference between this example and Example 1 is the processing parameters. The processing parameters in this example are: accelerating voltage of 60kV, focusing current of 1048mA, and wire feed speed V. F The printing speed V is 2m / min. T The electron beam current is 500 mm / min. B The current is 45mA. The remaining processing technology and steps are the same as in Example 1. The actual image of the Ti80 titanium alloy obtained in this example is shown below. Figure 2 As shown.

[0050] Example 3: The only difference between this example and Example 1 is the processing parameters. The processing parameters in this example are: accelerating voltage of 60kV, focusing current of 1048mA, and wire feed speed V. F The printing speed V is 2m / min. T The electron beam current is 500 mm / min. B The current is 50mA. The remaining processing technology and steps are the same as in Example 1. The actual image of the Ti80 titanium alloy obtained in this example is shown below. Figure 3 As shown.

[0051] Example 4: The only difference between this example and Example 1 is the processing parameters. The processing parameters in this example are: accelerating voltage of 60kV, focusing current of 1048mA, and wire feed speed V. F The printing speed V is 2m / min. T The electron beam current is 600 mm / min. B The current is 45mA. The remaining processing technology and steps are the same as in Example 1. The actual image of the Ti80 titanium alloy obtained in this example is shown in Figure 4.

[0052] Example 5: The only difference between this example and Example 1 is the processing parameters. The processing parameters in this example are: accelerating voltage of 60kV, focusing current of 1048mA, and wire feed speed V. F The printing speed V is 2m / min. T The electron beam current is 700 mm / min. B The current is 45mA. The remaining processing technology and steps are the same as in Example 1. The actual image of the Ti80 titanium alloy obtained in this example is shown below. Figure 5 As shown.

[0053] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A method for electron beam filament additive manufacturing of Ti80 titanium alloy components, characterized in that: It includes the following steps: Step 1: Pre-treat the printing filament and additive substrate; Step 2: Create a 3D solid model based on the target Ti80 alloy component, and import it after slicing; set the scanning path, preheating parameters, and printing process parameters; Step 3: Turn on the equipment and evacuate to 9.9 × 10⁻⁶ -3 Pa, and according to the set printing parameters and program, Ti80 alloy was printed to complete all layers, and a well-formed, dense, and high-performance deposited Ti80 alloy was prepared. In step 1, the additive substrate is a TA1 pure titanium substrate with dimensions of 150mm × 10mm × 10mm and a wire diameter of 1.6mm. The printing wire is a Ti80 alloy wire with the following composition: Al 6.5wt.%, Nb 2.2wt.%, Zr 2.2wt.%, Mo 0.91wt.%, Si≤0.05wt.%, Fe≤0.05wt.%, O≤0.09wt.%, N≤0.01wt.%, C≤0.01wt.%, H≤0.01wt.%. The TA1 substrate contains 99.9wt.% Ti. In step 2, the angle between the filament feed nozzle and the TA1 substrate is 45°, and the length from the filament feed nozzle to the electron beam center axis is 5-10 mm. In step 2, the preheating parameters are as follows: accelerating voltage is 60kV, focusing current is 1048mA, electron beam current is 30mA, preheating printing speed is 500 mm / min, and scanning path is a cyclic reciprocating linear motion path. The printing process parameters in step 2 are as follows: acceleration voltage is 60kV, focusing current is 1048mA, electron beam current is 40-50mA, printing speed is 500-700 mm / min, filament feed speed is 2 m / min, knob control speed coefficient is 100%, interlayer cooling time is 30s, and the scanning path is a cyclic reciprocating linear motion path.

2. The method for electron beam filament additive manufacturing of Ti80 titanium alloy components according to claim 1, characterized in that: Step 1 involves the following pretreatment steps for the printing filament and additive substrate: S1: Clean the Ti80 alloy wire by soaking it in acetone; S2: Place the cleaned alloy wire in a drying oven and dry it at a constant temperature of 60°C for 4 hours; S3: Use an angle grinder to polish the surface of the TA1 substrate; S4: Wipe the surface of the TA1 substrate with acetone and alcohol in sequence, and then clean it by soaking in acetone. S5: Place the TA1 substrate in a drying oven and dry it at a constant temperature of 60°C for 4 hours.

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