Electric arc additive manufacturing method and application of TaC particle reinforced TC4 titanium-based composite material

Abstract

The invention discloses an electric arc additive manufacturing method of a TaC particle reinforced TC4 titanium-based composite material and application of the electric arc additive manufacturing method, and belongs to the technical field of metal-based composite material additive manufacturing. According to the method, TC4 titanium alloy serves as a base body, TaC particles serve as a reinforcement phase, interlayer slurry coating and a cold metal transition electric arc additive process are combined, and uniform dispersion and effective reinforcement of the TaC particles in the base body are achieved through accurate raw material proportioning, slurry system optimization and process parameter regulation and control. When the adding amount of TaC is 5 wt.%, the tensile strength of the composite material reaches 1024 MPa, the ductility is 8.2%, the average hardness is 351 HV0.5, the wear rate is 27.3 mg / g, and the comprehensive mechanical performance is optimal; when the addition amount is 7.5 wt.%, the average hardness is improved to 386 HV0.5, the wear rate is reduced to 20.7 mg / g, but the tensile property is reduced, so that the high-wear-resistance composite material is more suitable for high-wear-resistance scenes. The problems of TaC particle agglomeration, poor interface bonding and unbalanced toughness are solved, the process is simple, convenient and efficient, the cost is controllable, and the method is suitable for large-scale manufacturing of high-performance structural parts in the fields of aerospace, national defense equipment and the like.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology of metal matrix composites, specifically relating to an arc additive manufacturing method for TaC particle-reinforced TC4 titanium matrix composites and its application. Background Technology

[0002] TC4 titanium alloy, as the most widely used commercial titanium alloy, occupies a key position in aerospace, marine engineering, and biomedical fields due to its excellent specific strength, good corrosion resistance, and biocompatibility. However, its inherent insufficient high-temperature wear resistance and limited ultimate strength make it difficult to meet the service requirements of high-performance structural components under extreme working conditions.

[0003] Introducing ceramic reinforcing phases is an effective strategy to improve the properties of titanium-based composites. Tantalum carbide (TaC), as an ultra-high melting point ceramic (melting point > 3800°C), possesses extremely high hardness, excellent chemical stability, and a thermal expansion coefficient that matches well with the titanium matrix (6.3–7.0 × 10⁻⁻⁻⁴). 6 K - ¹). In addition, Ta can act as a β-stabilizing element, effectively controlling the phase composition of titanium alloys, and is therefore considered an ideal candidate phase for reinforcing TC4 titanium alloys. However, in existing preparation processes, TaC particles are prone to agglomeration, have weak interfacial bonding with the matrix, and it is difficult to synergistically improve strength and toughness, which seriously restricts its engineering applications.

[0004] Wire Arc Additive Manufacturing (WAAM) technology boasts advantages such as high deposition efficiency, low cost, and applicability to the integrated molding of large components. However, in the preparation of TaC particle-reinforced TC4 titanium matrix composites, key technical bottlenecks remain, including uneven particle dispersion, easy oxidation at high temperatures, and poor interlayer metallurgical bonding. Furthermore, the effects of different TaC addition amounts on the microstructure evolution and performance regulation of the composite material are not yet clear, making it difficult to achieve customized material performance design for specific service requirements. Therefore, there is an urgent need to develop a stable, compositionally controllable, and performance-tunable WAAM method for manufacturing TaC particle-reinforced TC4 titanium matrix composites. Summary of the Invention

[0005] To address the aforementioned problems, this invention aims to provide an arc additive manufacturing method for TaC particle-reinforced TC4 titanium-based composite materials and its applications. By synergistically optimizing the interlayer slurry coating process and cold metal transfer (CMT) arc additive forming parameters, precise control of the TaC addition amount (5 wt.% or 7.5 wt.%) and efficient preparation of composite materials are achieved. Specifically, a TaC addition amount of 5 wt.% yields a high-strength, high-toughness composite material with optimal comprehensive performance in terms of strength, plasticity, and wear resistance; while a TaC addition amount of 7.5 wt.% is suitable for specialized applications requiring higher hardness and wear resistance. This method effectively overcomes the key technical challenges of traditional preparation techniques, such as complex processes, high costs, and the difficulty in synergistically improving strength and toughness.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An arc additive manufacturing method for TaC particle-reinforced TC4 titanium matrix composite material includes the following steps: S1 Raw Material Preparation: TC4 titanium alloy welding wire is selected as the matrix material, TC4 titanium alloy substrate is selected as the substrate material, and TaC powder is selected as the reinforcing phase material; a mixed slurry is prepared by mixing TaC powder with an aqueous solution containing binder. S2 Arc Additive Deposition: Deposition is performed using a cold metal transition arc additive system; S3 Interlayer TaC Introduction: After each TC4 layer is deposited, the mixed slurry is uniformly coated on the surface of the deposited layer; S4 Cyclic Deposition: Repeat steps S2 and S3 until the target component is formed.

[0007] Furthermore, the diameter of the TC4 titanium alloy welding wire used as the base material in step S1 is adjusted according to the forming requirements of the component to ensure the stability of the mechanical properties of the base material.

[0008] Furthermore, the substrate material TC4 titanium alloy substrate mentioned in step S1 is adjusted in size according to the component forming requirements; the substrate surface is polished step by step with 180-2000# sandpaper to remove oxide film and impurities until a silvery-white metallic luster is exposed; after polishing, the substrate is wiped with acetone to remove surface impurities, and additive manufacturing is carried out within 2 hours after drying to avoid secondary oxidation of the surface.

[0009] Furthermore, the TaC powder used as the reinforcing phase material in step S1 is selected from TaC powder with a particle size of 1-3 μm and a purity of ≥99%. After drying, there are no obvious impurities or agglomerates, ensuring the strengthening effect of the reinforcing phase.

[0010] Furthermore, in step S1, hydroxyethyl cellulose is selected as the binder, deionized water is selected as the solvent, and the mass fraction of the binder is 2 wt.%, which takes into account both the coatability of the slurry and the characteristic of no residue after high-temperature decomposition.

[0011] Further, in step S1, the mixed slurry preparation involves: preparing a 2 wt.% hydroxyethyl cellulose aqueous solution at a specified ratio and stirring at room temperature for 10-15 minutes until the binder is completely dissolved, forming a uniform and transparent aqueous solution; calculating the required TaC powder mass based on the TaC addition amount of 5 wt.% to 7.5 wt.% and the required deposition mass of the component, and slowly adding the TaC powder to the aqueous solution; stirring with a magnetic stirrer for 20-40 minutes at a speed of 300-500 r / min, followed by ultrasonic vibration for 20-40 minutes to ensure that the TaC particles are uniformly dispersed in the slurry without any visible agglomerates, meeting the coating requirements. Furthermore, the TaC powder is added as a reinforcing phase at an amount of 5 wt.% or 7.5 wt.%.

[0012] Furthermore, the arc additive deposition process described in step S2 employs a cold metal transfer (CMT) arc additive manufacturing system, including a Fronius CMT Advanced 4000 welding machine, a VR 7000 CMT wire feeder, and an ABB IRB2600 six-axis robot, equipped with a trailing protective atmosphere device to prevent oxidation of the deposited layer. Process parameter settings are as follows: wire feed speed 6-8 m / min, welding torch movement speed 0.1-0.2 m / min, CMT mode selected, current and voltage automatically adjusted by the welding machine's expert system based on the wire feed speed; the shielding gas is high-purity argon (purity ≥99.99%), welding torch gas flow rate 15 L / min, trailing protective gas flow rate 25 L / min, and cooling interval between adjacent layers 100-120 s. More specifically, the welding torch movement speed is 0.12 m / min; the wire feed speed is 7.5 m / min.

[0013] Furthermore, the interlayer TaC introduction process described in step S3: After each TC4 titanium alloy layer is deposited and cooled, the protective gas is turned off, and the mixed slurry is uniformly coated onto the surface of the deposited layer. The coating quality is controlled in real time using an electronic balance to ensure that it matches the mass and TaC specific gravity of the single-layer deposited TC4 alloy. After coating, the layer is left to stand for 2-4 minutes, and the residual heat of the deposited layer is used to evaporate the moisture in the slurry. Hydroxyethyl cellulose firmly bonds the TaC particles to the surface of the deposited layer, preventing them from being blown away by the protective gas during subsequent deposition. Cyclic forming: Repeat the arc deposition and interlayer coating steps 2-3 times until the pre-set size component is formed.

[0014] A TaC particle-reinforced TC4 titanium matrix composite material prepared by the above method.

[0015] The above-mentioned TaC particle-reinforced TC4 titanium-based composite material is used in the fabrication of high-performance structural components. Its application areas include: aerospace, marine engineering and shipbuilding, biomedicine, automotive and rail transportation, energy and chemical engineering, military and special equipment, and precision instruments.

[0016] The beneficial effects of this invention are: This invention achieves differentiated customization of composite material properties by precisely controlling the addition amount of TaC particles to 5 wt.% or 7.5 wt.% and matching corresponding optimized process parameters: when the TaC addition amount is 5 wt.%, the material has the best comprehensive mechanical properties, combining high strength and good plasticity; when the TaC addition amount is 7.5 wt.%, the material exhibits excellent wear resistance properties, which can meet the specific application requirements under high wear conditions.

[0017] TaC particles were introduced using an interlayer slurry coating method. The slurry was prepared using magnetic stirring and ultrasonic vibration dispersion techniques, which effectively suppressed the agglomeration of the reinforcing phase, ensuring that the TaC particles were uniformly distributed in the TC4 matrix and formed an in-situ (Ti,Ta)C solid solution phase. This phase had a clean and coherent interface with the matrix, significantly improving the strengthening effect.

[0018] Specifically, the 5wt.% TaC composite material achieves a good synergy of strength, plasticity, and wear resistance: tensile strength reaches 1024MPa, elongation is 8.2%, microhardness is 351HV0.5, and wear rate is 27.3mg / g, effectively breaking through the technical bottleneck of traditional titanium-based composite materials where strength and toughness are difficult to balance; while the 7.5wt.% TaC composite material, while sacrificing a small amount of tensile properties (tensile strength 973MPa, elongation 6.3%), increases the microhardness to 386HV0.5 and further reduces the wear rate to 20.7mg / g, making it more suitable for service environments with stringent wear resistance requirements.

[0019] This process is based on CMT arc additive manufacturing technology and has advantages such as high deposition efficiency, controllable cost, and material utilization rate of ≥90%. It is suitable for the integrated forming of large and complex structural parts and is easy to integrate with digital intelligent manufacturing systems, thus having broad prospects for industrial application. Attached Figure Description

[0020] Figure 1 : Schematic diagram of the electric arc additive manufacturing process. 1-Welding torch, 2-TC4 welding wire, 3-Electric arc, 4-Molten pool, 5-TaC mixed slurry coating layer, 6-Argon gas, 7-Trailing atmosphere protective cover, 8-Deposited layer, 9-TC4 substrate.

[0021] Figure 2Macroscopic microstructure improvement diagrams. (a) is pure TC4 alloy, (b) is Example 1 (5wt.% TaC), and (c) is Example 2 (7.5wt.% TaC), which visually demonstrate the transformation effect of primary β grains towards equiaxed and smaller grains.

[0022] Figure 3 : Reinforcing phase distribution diagram. (a) The figure shows the distribution state of the reinforcing phase in Example 1; (b) The figure shows the coherent interface between the (Ti,Ta)C reinforcing phase and the matrix in Example 1; (c) The figure shows the distribution state of the reinforcing phase in Example 2.

[0023] Figure 4: Overall performance diagram. (a) Tensile properties comparison diagram; (b) Microhardness comparison diagram; (c) Wear rate comparison diagram, clearly showing the performance differences between the two embodiments and pure TC4 alloy. Detailed Implementation

[0024] The specific implementation methods of the present invention will be described in detail below. The specific implementation methods described herein are for illustration and explanation only and are not intended to limit the present invention.

[0025] Example 1: An arc additive manufacturing method for TaC particle-reinforced TC4 titanium matrix composite material TaC addition of 5 wt.% (optimal overall performance) The designed TaC addition amount is 5 wt.%, and the actual TaC addition mass calculation process is as follows: the required TaC addition amount for a single-layer TC4 titanium alloy deposition layer can be calculated using Formula 1:

[0026] In formula (1): For wire feeding speed, The welding torch moving speed, d The diameter of the welding wire. The density of TC4 titanium alloy, l The length of a single deposition channel. Add a ratio to the designed TaC. In this embodiment, =7.5 m / min, =0.12 m / min, =4.5 g / cm 3 , l =100 mm, t p =5%, and the required coating mass for a single layer deposition can be calculated as 1.57 g using Formula 1. In this embodiment, a 10-layer composite material sample is prepared, therefore the required TaC mass can be calculated to be 15.7 g.

[0027] An arc additive manufacturing method for TaC particle-reinforced TC4 titanium matrix composite material includes the following steps: (1) Raw material preparation: TC4 titanium alloy welding wire (diameter 1.2mm), TC4 substrate (200×200×6mm), TaC powder (particle size 1-3μm, purity 99.5%), hydroxyethyl cellulose (NATROSOL 250HBR), deionized water, high purity argon gas; (2) Slurry preparation: Prepare 20 g of 2 wt.% hydroxyethyl cellulose aqueous solution, add 15.7 g TaC powder, stir magnetically for 30 min at 100 r / min, and after stirring, perform ultrasonic vibration for 30 min to prepare a uniformly mixed slurry; (3) Substrate pretreatment: After the substrate is sanded step by step with 180-2000# sandpaper, it is wiped clean with acetone 3 times and dried with a fan for 2 hours before additive manufacturing. (4) Arc additive deposition: wire feed speed 7.5 m / min, welding torch moving speed 0.12 m / min, welding torch argon flow rate 15 L / min, trailing shielding gas flow rate 25 L / min, interlayer cooling time 120 s; a single-layer multi-pass single-wall configuration was used for fabrication, with a length of 100 mm and a height of 50 mm. (5) Interlayer coating: After each layer has been deposited and cooled, a slurry is uniformly coated. The coating quality of the slurry is controlled in real time using an electronic balance. Each layer is coated with 3.57 g of mixed slurry. (6) Cyclic deposition: Repeat the steps of arc additive deposition and interlayer coating 10 times to prepare 10 layers of components with a height of nearly 50 mm; Microstructure and properties of the obtained 5 wt.% TaC composite material: The primary β grains are equiaxed (see...). Figure 2 The reinforcing phase is uniformly dispersed and coherent with the matrix interface without defects (see...). Figure 3 Tensile strength 1024 MPa, elongation 8.2%, hardness 351 HV0.5, abrasion rate 27.3 mg / g (see...) Figure 4 (It has the best overall performance.)

[0028] Example 2: An arc additive manufacturing method for TaC particle-reinforced TC4 titanium matrix composite material TaC addition amount 7.5wt.% (high wear resistance) The designed TaC addition amount is 7.5 wt.%, and the actual TaC addition mass calculation process is as follows, with adjustments made in Example 2 compared to Example 1. t pThe required TaC content is 7.5%. Using Formula 1, the amount of TaC required to deposit the single-layer TC4 titanium alloy layer in Example 2 is calculated to be 2.35 g. In this example, a 10-layer composite material sample was prepared, therefore the required TaC mass can be calculated to be 23.5 g.

[0029] An arc additive manufacturing method for TaC particle-reinforced TC4 titanium matrix composite material includes the following steps: (1) Raw material preparation: Same as in Example 1; (2) Slurry preparation: Prepare 30g of 2wt.% hydroxyethyl cellulose aqueous solution, add 23.5g TaC powder, stir magnetically for 30 min at 100 r / min, and after stirring, perform ultrasonic vibration for 30 min to prepare a uniformly mixed slurry; (3) Substrate pretreatment: Same as in Example 1; (4) Arc additive manufacturing process: Same as in Example 1; (5) Interlayer coating: After each layer has been deposited and cooled, a slurry is uniformly coated. The coating quality of the slurry is controlled in real time using an electronic balance. Each layer is coated with 5.35 g of mixed slurry. (6) Cyclic deposition: Same as in Example 1.

[0030] The properties of the obtained 7.5 wt.% TaC composite material are as follows: primary β grains undergo equiaxed transformation (see Figure 2); slight agglomeration exists in the local area of ​​the reinforcing phase, but there are no obvious pores and cracks (see Figure 3); tensile strength and elongation decrease slightly to 973 MPa and 6.3%, respectively; hardness and wear rate reach the optimal values ​​of 386 HV0.5 and 20.7 mg / g, respectively (see Figure 4); it has excellent wear resistance and is more suitable for environments with high wear resistance requirements.

[0031] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An arc additive manufacturing method for TaC particle-reinforced TC4 titanium-based composite materials, characterized in that, Includes the following steps: S1 Raw Material Preparation: TC4 titanium alloy welding wire and substrate are selected as the composite matrix, and TaC powder is used as the reinforcing phase; a mixed slurry is prepared by mixing TaC powder with an aqueous solution containing binder. S2 Arc Additive Deposition: Deposition was performed using a cold metal transition arc additive system; S3 Interlayer TaC Introduction: After each TC4 layer is deposited, the mixed slurry is uniformly coated on the surface of the deposited layer; S4 Cyclic Deposition: Repeat steps S2 and S3 until the target component is formed.

2. The method according to claim 1, characterized in that: The TaC powder mentioned in step S1 is added in an amount of 5 wt.% to 7.5 wt.% as a reinforcing phase.

3. The method according to claim 2, characterized in that: The TaC powder mentioned in step S1 is added as a reinforcing phase at an amount of 5 wt.%, or 7.5 wt.%.

4. The method according to claim 1, characterized in that: The binder mentioned in step S1 is hydroxyethyl cellulose, which has a mass fraction of 2 wt.% in aqueous solution. The mixed slurry is prepared by magnetic stirring combined with ultrasonic vibration treatment to ensure that TaC particles are uniformly dispersed and do not agglomerate.

5. The method according to claim 1, characterized in that: The arc additive deposition process parameters in step S2 are as follows: a cold metal transition arc additive system is used, the welding torch is equipped with a trailing protective atmosphere device, the welding torch moving speed is 0.1-0.2 m / min, the wire feed speed is 6-8 m / min, high-purity argon is used as the protective gas, the welding torch gas flow rate is 15 L / min, and the protective cover gas flow rate is 25 L / min.

6. The method according to claim 5, characterized in that: The welding torch moving speed is 0.12 m / min; the wire feeding speed is 7.5 m / min.

7. The method according to claim 1, characterized in that: The interlayer TaC introduction process described in step S3 is as follows: after completing the single-layer deposition, the interlayer is cooled for 100-120 seconds and then a slurry coating process is performed. The quality of the single-layer slurry coating is controlled in real time using an electronic balance, and the moisture in the slurry is evaporated using the residual heat of the deposition layer.

8. A TaC particle-reinforced TC4 titanium matrix composite material prepared by the method described in any one of claims 1–7.

9. The application of the TaC particle-reinforced TC4 titanium matrix composite material as described in claim 8 in the preparation of high-performance structural components.

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