A method for accelerating the martensitic decomposition of additive titanium alloys using high-energy short-time pulsed current

Abstract

This invention belongs to the field of materials processing and preparation technology, and provides a method for accelerating the martensitic decomposition of additive titanium alloys with high-energy short-time pulsed current. By designing pulsed current parameters, this invention establishes a quantitative relationship between current density, action time and microstructure evolution, thereby effectively suppressing grain coarsening while efficiently driving the rapid decomposition of acicular martensite. Ultimately, it breaks through the traditional constraint between strength and plasticity in additively manufactured titanium alloys, and achieves significant optimization of its comprehensive mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of materials processing and preparation technology, specifically relating to a method for accelerating the martensitic decomposition of additive titanium alloys using high-energy short-time pulsed current. Background Technology

[0002] Titanium and titanium alloys, with their low density, high strength and toughness, and excellent corrosion resistance, have important applications in aerospace, shipbuilding, and biomedical fields. However, in traditional processing, titanium alloys often suffer from low plasticity, significant work hardening, and severe springback, limiting their wider application. Additive manufacturing (AM) technology, especially laser powder bed melting (LPBF) technology, provides a new approach for the fabrication of complex titanium alloy components. This technology, based on a three-dimensional model, uses a high-energy laser to selectively melt metal powder layer by layer, achieving near-net-shape forming. While ensuring forming accuracy, it significantly improves material utilization and reduces manufacturing costs.

[0003] However, the extremely high cooling rate of the LPBF process easily leads to the formation of a large number of needle-like α′ martensite non-equilibrium structures with high dislocation density in near-α or α+β type titanium alloys. This non-equilibrium phase, along with the residual stress caused by the severe thermal gradient, degrades the overall performance of the material, limiting its engineering application in critical load-bearing components. Traditional isothermal post-heat treatment is an effective way to achieve martensite decomposition, microstructure optimization, and improved mechanical properties in LPBF-formed titanium alloys. However, martensite decomposition is relatively slow under isothermal conditions, resulting in long heat treatment cycles and high energy consumption. Although the decomposition process can be accelerated by increasing the post-heat treatment temperature, this often results in significant grain coarsening and Widmanstätten formation, leading to a decrease in strength and making it difficult to achieve the optimal balance between strength and plasticity. Therefore, developing an energy-efficient and effective post-treatment strategy to accelerate martensite decomposition while simultaneously improving microstructure and performance has become a critical issue that urgently needs to be addressed in the post-treatment field of additive manufacturing titanium alloys.

[0004] Pulsed current treatment, through its unique thermal effect (Joule heating) and non-thermal effect (electron wind and electromigration) coupling, can significantly promote atomic diffusion and the redistribution of β-stable elements, driving the rearrangement and annihilation of high-density tangled dislocations. This effectively releases residual stress in micro-regions, providing kinetic conditions for the rapid decomposition of α′ martensite at lower temperatures and within extremely short timeframes. Furthermore, the introduction of pulsed current helps weaken local metallic bonds, lowers diffusion activation energy and phase transformation barriers, and promotes the transformation of martensite to the equilibrium phase α+β at lower temperatures. However, the relatively short pulsed current treatment time can suppress excessive grain growth. In summary, LPBF-prepared titanium alloys achieve effective improvement in plasticity while maintaining high strength. Compared with traditional isothermal heat treatment, pulsed current treatment has advantages such as concentrated energy input, short treatment time, and low thermal inertia, providing a new technical direction for achieving instantaneous, precise, and controllable microstructure control in additive manufacturing of titanium alloys.

[0005] Developing an efficient and energy-saving post-processing technique to accelerate martensite decomposition, while simultaneously refining the microstructure and improving overall performance, is a core challenge in the field of additive manufacturing of titanium alloys. Although electrical pulse processing technology offers a potential pathway, existing research is largely limited to power frequency, conventional pulse modes, or low current densities, exhibiting significant limitations: its non-thermal effects are weak, and the control mechanism is still primarily based on macroscopic thermal effects; energy input fluctuates greatly and lacks stability; and thermal inertia remains a significant factor, easily leading to microstructure coarsening. These shortcomings often result in a dilemma between "insufficient decomposition" and "Widmanstätten microstructure coarsening," making it impossible to consistently obtain high-performance microstructures.

[0006] To address the aforementioned fundamental problems, this invention introduces a 1000 Hz pulsed current technology, outputting sharp waveforms and stable high-instantaneous pulses. This achieves a leap from a "heat-dominated" to a "thermoelectric synergy, non-thermal-dominated" mechanism, completely transforming the action mechanism from the traditional "heat-dominated long-term heat preservation" to a "pulsed electrical-thermal energy synergistic instantaneous impact." This leap changes the driving force of martensite decomposition from a single thermal diffusion to an electro-induced non-thermal effect, thereby achieving ultrafast phase transition and precise microstructure control. Specifically, the high-frequency, short-pulse-width Joule heating is generated at the microscale and within an extremely short time, forming a highly localized instantaneous high-temperature field. Simultaneously, it significantly enhances the "quasi-continuous" directional driving effect of non-thermal effects such as electron wind, thus efficiently driving atomic rearrangement and phase deformation nuclei at low temperatures. By synergistically controlling the current density, pulse width, and frequency, the energy density inside the input material can be precisely controlled, achieving control over the phase transition path. Furthermore, the microsecond-level energy injection overcomes thermal inertia and suppresses grain growth. Based on this, this study can drive the decomposition of α′ martensite and retain fine-grained structure in a very short period of time, according to different engineering needs, and finally achieve a reliable performance leap from "high strength and low plasticity" to "strength and plasticity synergy" in additive manufacturing of titanium alloys. Summary of the Invention

[0007] To address the aforementioned problems, the purpose of this invention is to provide a method for accelerating martensitic decomposition in additive titanium alloys using high-energy, short-time pulsed current, thereby solving the technical problems of slow martensitic decomposition, easy grain coarsening, and difficulty in synergistically improving strength and plasticity in traditional post-heat treatment processes. This method establishes a quantitative relationship between current density, application time, and microstructure evolution by designing pulsed current parameters. This effectively suppresses grain coarsening while efficiently driving the rapid decomposition of acicular martensite, ultimately breaking through the traditional constraints between strength and plasticity in additively manufactured titanium alloys and achieving significant optimization of their comprehensive mechanical properties. The technical solution adopted in this invention is as follows: A method for accelerating the martensitic decomposition of additive titanium alloys using high-energy short-time pulsed current includes: Step 1, Sample preparation; Step 2, Sample clamping and electrode connection: Connect the two sides of the sample to the two electrodes of the pulse power supply; Step 3, Pulse Current Processing: Set the experimental parameters for pulse current processing; Step 4, cooling and post-processing.

[0008] Further, step 1 includes: additively preparing α or α+β type titanium alloys using the LPBF method, then machining them into samples of a set size by wire cutting, mechanically grinding and polishing the sample surface, then ultrasonically cleaning and drying them with acetone and anhydrous ethanol, and finally spraying an anti-oxidation coating onto the sample surface.

[0009] Furthermore, in step 2, a pulse current processing device is used to clamp the sample and connect it to the electrode; the pulse current processing device includes a pulse power supply, an infrared imager, a copper block, and insulating material. The sample is held in place by copper blocks and insulating material on both sides. The two electrodes of the pulse power supply are connected to the copper blocks on both sides of the sample by wires. The infrared imager is used to monitor and record the sample temperature in real time.

[0010] Furthermore, in step 3, the experimental parameters for pulse current processing include: The pulse power supply operates at a frequency of 1000 Hz and outputs a DC pulse waveform. Pulse current density: 50-800 A / mm2; Single pulse processing time: 20-160 ms; Peak temperature for sample treatment: 600-900 ℃.

[0011] Furthermore, step 4 includes: cutting off the pulse power supply after the pulse current treatment is completed, and allowing the sample to cool naturally to room temperature in still air.

[0012] Furthermore, the chemical composition of the sample, by mass percentage, is as follows: Mo: 0.28%, Ni: 0.81%, Fe: 0.003%, C: 0.009%, O: 0.09%, H: 0.006%, with the balance being Ti and impurities.

[0013] Furthermore, α or α+β type titanium alloys prepared by additive manufacturing using the LPBF method include, but are not limited to, titanium alloys prepared by laser powder bed melting and laser directed energy deposition.

[0014] Furthermore, by adjusting the pulse current density or pulse duration, the energy density and spatiotemporal distribution input into the material can be controlled, thereby enabling targeted regulation and optimization of the material to meet different performance requirements.

[0015] The present invention has the following beneficial effects: (1) Rapid and precise control of microstructure and properties is achieved. This invention applies a high-density pulsed current to near-α or α+β type titanium alloys prepared by LPBF, utilizing the strong coupling effect of its thermal effect (Joule heating) and non-thermal effect (electron wind, etc.) to significantly promote atomic diffusion and redistribution of β-stable elements, and drive the rearrangement and annihilation of tangled dislocations with high dislocation density. This effectively releases microscopic residual stress within milliseconds to seconds, causing the rapid decomposition of acicular α′ martensite into refined lath-like α phase and dispersed β phase microstructure. This process is completed under conditions of low overall temperature and short pulse duration, suppressing excessive grain growth, and significantly improving the plasticity of the material while maintaining high strength, successfully breaking through the traditional trade-off between strength and ductility in additive manufacturing of titanium alloys.

[0016] (2) It overcomes the technical limitations of traditional heat treatment and conventional electric pulse treatment. Compared with traditional isothermal heat treatment, the method of this invention has the advantages of concentrated energy input, extremely short action time, and low thermal inertia. It can realize instantaneous, local and controllable regulation of the structure and avoid grain coarsening and performance degradation caused by long-term high temperature holding. Compared with the power frequency, conventional pulse mode or low current density pulse current treatment technology commonly used in existing research - its non-thermal effect is weak, still mainly thermal effect, and the thermal inertia has a significant impact, which easily causes the structure to coarsen - this invention adopts medium frequency inverter high frequency pulse current technology, which has the characteristics of precise, stable and digitally controllable energy output. The high frequency and short pulse width make Joule heating occur in a very short time and at a microscopic scale, forming a highly localized instantaneous high temperature zone. At the same time, it significantly enhances non-thermal effects such as electron wind, realizes "electric-thermal" synergistic driving, and thus efficiently promotes atomic rearrangement, dislocation untangling and phase deformation nuclei, and achieves rapid decomposition of martensite at a temperature much lower than that of traditional heat treatment. In addition, millisecond-level energy injection and intermittent mechanisms effectively suppress thermal diffusion, completely overcome thermal inertia, and help preserve fine-grained structures while avoiding coarsening.

[0017] (3) It possesses clear process adjustability and engineering applicability. By establishing the correspondence between "current density-processing time-microstructure", the material properties can be directionally controlled within a wide process window (pulse current density, processing time, and corresponding temperature). This method has a short process, low energy consumption, and is environmentally friendly, providing a reliable new technology approach with good prospects for the efficient and energy-saving post-processing of additively manufactured titanium alloy components. Attached Figure Description

[0018] Figure 1 Microstructure of additively manufactured titanium alloy after treatment with 2500 A and 100 ms pulsed current; Figure 2 Tensile stress-strain curves of additively manufactured titanium alloys after pulsed current treatment; Figure 3 Microstructure of untreated additively manufactured titanium alloy; Figure 4 Tensile stress-strain curves of titanium alloys for additive manufacturing; Figure 5 Microstructure of additively manufactured titanium alloy after heat treatment at 750 °C for 3 min; Figure 6 The tensile stress-strain curve is shown after holding at 750 ℃ ​​for 3 min. Figure 7 This is a schematic diagram of a pulse current processing device. Detailed Implementation

[0019] The following will be described in conjunction with embodiments of the present invention. Figures 1-7 The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0020] This invention targets near-α or α+β type titanium alloys produced through additive manufacturing. By applying a pulsed current with high instantaneous energy and short duration, it achieves rapid and controllable decomposition of acicular α′ martensite, thereby significantly improving the strength-ductility balance of the material. This method precisely controls the energy density and distribution input into the material through precise adjustment of the pulsed current parameters, enabling targeted optimization of the microstructure for different performance requirements. After treatment with this method, the original coarse acicular α′ martensite in the additively manufactured titanium alloy is rapidly decomposed into a multiphase microstructure composed of fine lath-like α phase and dispersed β phase, effectively coordinating the improvement of strength and ductility while refining the microstructure.

[0021] This invention proposes a method for additive manufacturing driven by a high-energy short-time pulsed current, comprising: Step 1, Sample preparation; Step 2, Sample clamping and electrode connection: Connect the two sides of the sample to the two electrodes of the pulse power supply; Step 3, Pulse Current Processing: Set the experimental parameters for pulse current processing; Step 4, cooling and post-processing.

[0022] Further, step 1 includes: additively preparing α or α+β type titanium alloys using the LPBF method, then machining them into samples of a set size via wire cutting, mechanically grinding and polishing the sample surface, followed by ultrasonic cleaning with acetone and anhydrous ethanol and drying to thoroughly remove the oxide layer and surface contaminants. Afterwards, an anti-oxidation coating is sprayed onto the sample surface to prevent surface oxidation during subsequent pulsed current treatment.

[0023] Furthermore, in step 2, a pulse current processing device is used to clamp the sample and connect it to the electrode. The pulse current processing device includes a pulse power supply, an infrared imager, a copper block, and insulating material. The prepared sample is installed between the two electrodes of the self-made pulse current processing device to ensure a tight and stable surface contact between the sample and the electrode, so as to minimize the contact resistance and ensure that the current is uniformly and efficiently introduced into the entire sample.

[0024] The sample is held in place by copper blocks and insulating material on both sides. The two electrodes of the pulse power supply are connected to the copper blocks on both sides of the sample via wires. An infrared imager is used to monitor and record the sample temperature in real time. During the pulse current processing, an infrared thermal imager or thermocouple is used to monitor and control the sample temperature in real time to ensure that its peak temperature is always within the set process window.

[0025] Furthermore, in step 3, the experimental parameters for pulse current processing include: The pulse power supply operates at a frequency of 1000 Hz and outputs a DC pulse waveform. Pulse current density: 50-800 A / mm2; Single pulse processing time: 20-160 ms; Peak temperature for sample treatment: 600-900 ℃.

[0026] By precisely controlling the pulse current density or pulse duration, the energy density and spatiotemporal distribution input into the material can be controlled, thereby enabling targeted regulation and optimization of the material structure to meet different performance requirements.

[0027] After being treated with pulsed current, the original coarse needle-like α′ martensite in the additively manufactured titanium alloy is rapidly decomposed and transformed into a two-phase structure consisting of fine lath-like α phase and diffusely distributed β phase. This achieves microstructure refinement while effectively coordinating the synergistic improvement of strength and plasticity.

[0028] During pulsed current treatment, the peak temperature of the sample caused by the Joule heating effect is controlled within a temperature range of no more than 50 °C in and below the α+β phase region. For the LPBF-prepared TA10 alloy, the preferred range for the peak temperature of the pulsed current treatment is 600-900 °C. Experimental verification shows that when the peak temperature induced by the pulsed current treatment is within 50 °C in and below the α+β phase region of the TA10 alloy, the material achieves optimal strength-ductility matching. Within this temperature window, the thermal activation energy provided by Joule heating drives the decomposition of α' metastable martensite while avoiding grain coarsening caused by excessively high temperatures. Therefore, the microstructure exhibits uniform and refined α-lamellae, thus maintaining high strength while improving ductility. Conversely, if the temperature is too low (e.g., below 600 ℃), the thermal driving force is insufficient, and the α' phase decomposition and dislocation recombination processes are incomplete, resulting in limited microstructure evolution and performance improvement. If the temperature is too high (e.g., above 900 ℃ or even entering the single-phase β region), significant grain growth and lath coarsening will occur, and unfavorable Widmanstätten structures or continuous grain boundary α phases may form during cooling, leading to a significant deterioration in material plasticity. Therefore, the selected temperature range, i.e., the α+β phase region and below, not exceeding 50 ℃, approximately 600-900 ℃, is essentially an optimized process window that balances phase transformation driving force and microstructure stability.

[0029] Furthermore, step 4 includes: cutting off the pulse power supply after the pulse current treatment is completed, and allowing the sample to cool naturally to room temperature in still air.

[0030] Furthermore, the method of the present invention is applicable to additive manufacturing of near-α or α+β type titanium alloys with a primary microstructure dominated by metastable α′ martensite; including TA10 alloy, whose chemical composition by mass percentage is: Mo: 0.28%, Ni: 0.81%, Fe: 0.003%, C: 0.009%, O: 0.09%, H: 0.006%, with the balance being Ti and unavoidable impurities.

[0031] This invention employs a medium-frequency inverter power supply as the core for energy input and regulation. By outputting a pulsed current with a millisecond-level pulse width, and utilizing the synergistic coupling effect of the instantaneous Joule heating and electroinduced non-thermal effects (such as electron wind and electromigration), the atomic diffusion energy barrier and the activation energy for phase transition nucleation are significantly reduced, thereby efficiently driving the rapid decomposition of metastable needle-like α′ martensite. Through the synergistic regulation of pulsed current density and energizing duration, this method can achieve precise control of the energy input per unit volume into the material. This mechanism based on instantaneous high energy density can effectively capture and stabilize the non-equilibrium intermediate state during martensite decomposition, achieving fine-grained control of the phase transition path.

[0032] Most importantly, thanks to the extremely short millisecond-level processing cycle, this method effectively suppresses grain coarsening caused by excessively long heat exposure time while promoting the decomposition of martensite and its transformation into fine lath structure. This ensures that while improving the plasticity of the material, it can still maintain the fine-grain strengthening effect inherent in the additive manufacturing state, thus successfully overcoming the inherent contradiction between strength and plasticity in traditional heat treatment.

[0033] In summary, this invention utilizes the electro-thermal multi-field coupling effect of pulsed current to achieve the microstructural evolution that traditional heat treatment requires long-term heat treatment in a very short time, significantly reducing energy consumption and time costs. It successfully promotes the performance leap of additive manufacturing near-α or α+β type titanium alloys from "high strength and low plasticity" to "excellent strength and plasticity", providing an efficient, energy-saving and performance-designable short-process post-processing solution for engineering components.

[0034] The present invention provides the following embodiments: The sample was prepared using LPBF technology with TA10 titanium alloy. The forming process parameters were uniformly set as follows: laser power 125 W, scanning rate 1400 mm / s, scanning spacing 0.06 mm, and powder layer thickness 0.02 mm.

[0035] Step 1, Specimen Preparation: The TA10 titanium alloy block formed by LPBF is wire-cut into flat specimens that meet the tensile test standard, wherein the cross section of the deformed section of the specimen is 6×1 mm. 2 The sample surface was mechanically ground and polished, and then ultrasonically cleaned in acetone and anhydrous ethanol in sequence. After drying, a high-temperature anti-oxidation coating was sprayed on to prevent surface oxidation during the treatment process.

[0036] Step 2, clamping and connecting the sample to the electrodes: install the prepared sample between the two electrodes of the self-made high-energy pulse current processing device to ensure a tight and stable surface contact between the sample and the electrodes, so as to minimize the contact resistance and ensure that the current is uniformly and efficiently introduced into the entire sample.

[0037] Step 3, Pulse Current Processing: Set the experimental parameters for pulse current processing, where the pulse current density is 2500 A / mm². 2 The processing time is 100 ms. The pulse current processing power supply is activated, and a single pulse current is applied to the sample according to the preset process parameters. During the pulse current processing, a non-contact infrared thermal imager is used to monitor and record the sample temperature in real time; the maximum peak temperature is approximately 750 ℃.

[0038] Step 4, Cooling and Post-treatment: Immediately after the pulsed current treatment is completed, the power supply is cut off, and the sample is allowed to cool naturally to room temperature in still air.

[0039] Step 5, Microstructure and Property Analysis. After pulsed current treatment, the microstructure of the TA10 alloy prepared by LPBF is as follows... Figure 1 As shown, the original coarse acicular α′ martensite rapidly decomposes within an extremely short time (100 ms), transforming into fine, short-plate-like α phases. The microstructure becomes significantly refined and homogenized, evolving towards a basketweave structure. This process is accompanied by lattice distortion relaxation, a significant decrease in dislocation density, and a tendency towards uniform crystal orientation. Room temperature tensile properties are shown in the figure. Figure 2 As shown, the tensile strength of the treated specimen was 853.62 MPa, and the elongation after fracture was 23.82%. Compared with the specimen before treatment (see Comparative Example 1), the plasticity was significantly improved while maintaining a high level of strength, achieving a good synergy between strength and plasticity.

[0040] This embodiment demonstrates that the proposed high-energy short-time pulsed current processing method can efficiently drive the decomposition of non-equilibrium α′ martensite within milliseconds through the electro-thermal coupling effect, completing the microstructure transformation that traditional heat treatment requires a long time to achieve, and successfully achieving the target of regulating the synergistic properties of strength and plasticity. The entire process, from power-on to cooling completion, takes no more than 2 minutes, demonstrating extremely high processing efficiency.

[0041] Comparative Example 1: This comparative sample consisted of TA10 titanium alloy from the same batch of LPBF that had not undergone any post-treatment after forming. After being cut, ground, and ultrasonically cleaned using the same process, its mechanical properties and microstructure were directly tested. Its microstructure was as follows: Figure 3 As shown, the structure consists entirely of coarse, needle-like, non-equilibrium α′ martensite formed by rapid laser solidification. The melt pool boundary and columnar crystal morphology are clearly visible. This non-equilibrium structure is the direct cause of the high strength but low plasticity. Room temperature tensile property test results are as follows... Figure 4 As shown, its tensile strength is 1065.56 MPa and its elongation after fracture is 13.59%, exhibiting typical characteristics of high strength and low plasticity.

[0042] Comparative Example 2: To investigate the effect of pure thermal effects over a very short time, this comparative example used conventional heat treatment to control the same batch of samples. The samples used in this comparative example were prepared in the same way as those treated with the pulsed current in Example 1. To prevent surface oxidation during heat treatment, a high-temperature anti-oxidation coating was sprayed onto the sample surface. The prepared samples were then placed in a box furnace preheated to 750 °C, held at that temperature for 3 minutes, and then air-cooled. The heat exposure time (3 min) was significantly longer than the pulse treatment time (100 ms) in Example 1. Figure 5 The microstructure results shown indicate that after this heat treatment, the acicular martensite in the LPBF-prepared TA10 sample did not undergo significant decomposition and showed no essential difference compared to the original microstructure. Furthermore, Figure 6The room temperature tensile mechanical properties shown indicate that after holding at 750 ℃ ​​for 3 min, the elongation of the sample only increased slightly, while the tensile strength decreased to some extent. Neither of these properties changed significantly, and the overall mechanical properties were basically the same as those in the original printed state, without any significant optimization.

[0043] Conclusion: This result directly proves that the ultra-rapid decomposition of martensite in Example 1 was not caused by simple short-term high-temperature heat exposure. The significant difference in the microstructure evolution results at similar peak temperatures highlights the decisive role of the non-thermal effects unique to pulsed current (such as electron wind and electromigration) in driving the rapid decomposition of martensite. As shown in Table 1, at similar peak temperatures, compared to heat treatment at 750 °C for 3 min, the strength decreased slightly, the plasticity increased slightly, and the performance changes were limited. The 2500 A, 100 ms pulsed current treatment sacrificed some strength but achieved a significant increase in plasticity. This indicates that under the same short-term high-temperature exposure, the traditional thermal diffusion-dominated phase transformation or recovery process is insufficient, while pulsed current treatment can drive a more efficient and more intense microstructure transformation process. The unique non-thermal effects of pulsed current (such as electron wind and electromigration) play a decisive role in regulating tissue and performance, thus powerfully verifying that the uniqueness and advancement of the method of this invention originate from the synergistic regulation of electro-thermal multi-physics fields, rather than a single thermal effect.

[0044] Table 1: Comparison of tensile strength and elongation of samples under different treatment conditions

[0045] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, alterations, alterations, or substitutions made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for accelerating the martensitic decomposition of additive titanium alloys using high-energy short-time pulsed current, characterized in that, include: Step 1, Sample preparation; Step 2, Sample clamping and electrode connection: Connect the two sides of the sample to the two electrodes of the pulse power supply; Step 3, Pulse Current Processing: Set the experimental parameters for pulse current processing; Step 4, cooling and post-processing.

2. The method for accelerating the martensitic decomposition of additive titanium alloys with high-energy short-time pulsed current according to claim 1, characterized in that, Step 1 includes: additively preparing α or α+β type titanium alloys using the LPBF method, then machining them into samples of a set size by wire cutting, mechanically grinding and polishing the sample surface, then ultrasonically cleaning with acetone and anhydrous ethanol and drying, and finally spraying an anti-oxidation coating onto the sample surface.

3. The method for accelerating the martensitic decomposition of additive titanium alloys with high-energy short-time pulsed current according to claim 1, characterized in that, In step 2, a pulse current processing device is used to clamp the sample and connect it to the electrode; the pulse current processing device includes a pulse power supply, an infrared imager, a copper block, and insulating material. The sample is held in place by copper blocks and insulating material on both sides. The two electrodes of the pulse power supply are connected to the copper blocks on both sides of the sample by wires. The infrared imager is used to monitor and record the sample temperature in real time.

4. The method for accelerating the martensitic decomposition of additive titanium alloys with high-energy short-time pulsed current according to claim 1, characterized in that, In step 3, the experimental parameters for pulse current processing include: The pulse power supply operates at a frequency of 1000 Hz and outputs a DC pulse waveform. Pulse current density: 50-800 A / mm2; Single pulse processing time: 20-160 ms; Peak temperature for sample treatment: 600-900 ℃.

5. The method for accelerating the martensitic decomposition of additive titanium alloys with high-energy short-time pulsed current according to claim 1, characterized in that, Step 4 includes: after the pulse current treatment is completed, the pulse power supply is cut off, and the sample is allowed to cool naturally to room temperature in still air.

6. A method for accelerating the martensitic decomposition of additive titanium alloys using high-energy short-time pulsed current according to any one of claims 1-5, characterized in that, The chemical composition of the sample, by mass percentage, is as follows: Mo: 0.28%, Ni: 0.81%, Fe: 0.003%, C: 0.009%, O: 0.09%, H: 0.006%, with the balance being Ti and impurities.

7. A method for accelerating the martensitic decomposition of additive titanium alloys using high-energy short-time pulsed current according to any one of claims 1-6, characterized in that, α or α+β type titanium alloys prepared by additive manufacturing using the LPBF method include, but are not limited to, titanium alloys prepared by laser powder bed melting and laser directed energy deposition.

8. A method for accelerating the martensitic decomposition of additive titanium alloys using high-energy short-time pulsed current according to any one of claims 1-7, characterized in that, By adjusting the pulse current density or pulse duration, the energy density and spatiotemporal distribution input into the material can be controlled, thereby enabling targeted regulation and optimization of the material structure to meet different performance requirements.

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