WO2020011027A1

WO2020011027A1 - Hydrogenation-roll compacting composite process for improving titanium alloy structure in additive manufacturing

Info

Publication number: WO2020011027A1
Application number: PCT/CN2019/093540
Authority: WO
Inventors: 孙中刚; 李永华; 陈小龙; 唐明亮; 张文书; 常辉
Original assignee: 南京尚吉增材制造研究院有限公司
Priority date: 2018-07-11
Filing date: 2019-06-28
Publication date: 2020-01-16
Also published as: CN108580884B; JP7020742B2; CN108580884A; JP2021523302A

Abstract

A hydrogenation-roll compacting composite process for improving a titanium alloy structure in additive manufacturing, comprising performing hydrogenation on titanium alloy powders, performing workpiece printing on the hydrogenated titanium alloy powders to form a titanium alloy metal deposition layer, rolling the titanium alloy metal deposition layer, repeating the printing and rolling steps until the workpiece finishes printing, subjecting the titanium alloy workpiece manufactured by means of additive manufacturing to a solid solution treatment, and subjecting the titanium alloy workpiece which has been subjected to solid solution treatment to annealing and dehydrogenation heat treatment. Said process uses hydrogen of the hydrogenated titanium alloy powder to promote elemental diffusion, reduce deformation resistance, promote dislocation movement to form deformation defects and promote non-spontaneous formation of nuclei, and uses roll compacting of the metal deposition layer by layer to cause deformation of the metal deposition layer and improve the density of printing workpieces.

Description

Hydrogen rolling composite process for improving titanium alloy structure in additive manufacturing

Technical field

The invention relates to the field of additive manufacturing, in particular to improvement treatment of titanium alloy structure, in particular to a hydrogenation + rolling process method for improving titanium alloy structure of additive manufacturing.

Background technique

The types of heat sources used in the additive manufacturing process include laser, arc, plasma, electron beam, etc., and in the extraordinary metallurgical environment where rapid heating and rapid cooling exist in the additive manufacturing process, the metallurgical quality of the additive manufacturing is poor and the organization is coarse. The material forms involved include powder and wire, but no matter how the light source and product form change, the metallurgical characteristics of the solidification process are basically the same: the metal micro-area is rapidly heated under the action of a concentrated heat source, quenched and rapidly solidified, and subsequently layer-by-layer After multiple cycles, variable cycles, severe heating and cooling, cyclic remelting and cooling occurred in adjacent layers or layers, and the grains of other deposited layers were cyclically micro-heat treated. Cyclic remelting and micro-heat treatment lead to a unique microstructure of additively fabricated metal components. During the additive manufacturing process of titanium alloy as raw material, grains such as laser selective melting and laser deposition forming grow perpendicular to the substrate interface to form coarse original beta grains and columnar grains, and only a small number of equiaxed or fine grains appear at the bottom and top. Grains, forming extremely heterogeneous microstructure features, this coarse structure has even developed into penetrating grains in higher energy density electron beam and arc additive processes. Nevertheless, the ultra-fast cooling also brings a fine special layer or acicular martensite microstructure inside the coarse grains, which is why the mechanical properties of the deposited state of the additive manufacturing titanium alloy structural parts are generally higher than those of the castings and even forgings. The main factor.

Around this issue, a lot of exploratory research has been carried out in the existing technology, from the additive manufacturing process itself, the addition of reinforced particles to refine the grains, and the use of magnetic fields, electric fields, ultrasound, lasers, micro-forging and other aspects to regulate the microstructure, Attempts to solve the problem of metallurgical organization in additive manufacturing:

1. The improvement of metallurgical structure can be achieved to some extent through the control of additive manufacturing process parameters. The prior art attempts to reduce the size of the columnar crystals through the process of controlling the process parameters of the forming process and the subsequent heat treatment process. For example, P.A. Kobryn et al. Studied the law of columnar crystals produced by laser cladding of Ti-6Al-4V alloy. The results show that high temperature gradients and large cooling rates are conducive to the growth of columnar crystals. High scanning speed can reduce the size of columnar crystals.

However, the control through the process is to control the tissue from the perspective of subcooling. Additive manufacturing lasers, electron beams and other high-energy heat sources heat, the solidification rate is 0.1ms-1 to 5ms-1, the temperature gradient is already at a very high level It is difficult to achieve fine grain strengthening through adjustment of process parameters;

2. Adding nucleating agents or alloying elements is a potential way to achieve the refinement of the structure of additive manufacturing. Banerjee and others in the United States have successfully prepared Ti-TiB and Ti6Al4V-TiB composite materials by using laser stereoforming technology. In the as-deposited alloy, the structure can be refined to some extent. The nucleating agent is added to increase the nucleation particles to improve the structure, but the addition of nucleating agent will affect the alloy composition, and it is not suitable for alloys with strict alloy composition requirements;

3. By improving the raw materials into the microstructure of additive manufacturing, such as the cyclic thermal hydrogen treatment process for improving the room temperature plasticity of TC4 titanium alloy proposed by Chinese patent CN201610032762.9, the TC4 titanium alloy is subjected to a second cycle hydrogen treatment, that is After the TC4 titanium alloy is subjected to hydrogen treatment for one time, the hydrogen is removed, then the hydrogen treatment is performed for the second time, and finally the solution quenching treatment is performed. The secondary hydrogen treatment method of the present invention improves the ratio of the α phase and the β phase in the TC4 titanium alloy, increases the content of the β phase with better plasticity, reduces the content of α ′ martensite, and refines the grains. Therefore, the plasticity at room temperature has been further improved; after the second cycle hot hydrogen treatment, the ultimate deformation rate of the improved TC4 titanium alloy is increased by 22.1%, the yield strength is reduced by 11.1%, and the yield ratio is reduced by 11.5%. However, its disadvantage is that it only uses the role of hydrogen to refine the grains in the subsequent heat treatment process of TC4 alloy, and cannot use hydrogen in the cyclic melting deposition process to promote element diffusion and increase the liquid / solid interface component undercooling; hydride formation and decomposition, and hydrogen storage. Reduce deformation resistance and promote dislocation movement to form deformation defects, promote non-spontaneous nucleation from multiple dimensions and multiple angles, and refine grains.

In addition, Zhao Jiaqi and others proposed in Chinese patent CN201110419193.0 a method of improving the microstructure of the cast Ti ₃ Al alloy by hydrogen-hot isostatic pressing, including: 1. hot isostatic pressing of the cast Ti ₃ Al alloy; The Ti ₃ Al alloy treated by the hot isostatic pressing process is subjected to hydrogen treatment; three, the Ti ₃ Al alloy treated with hydrogen is subjected to solution treatment and aging treatment; and finally, vacuum annealing treatment is performed. It is beneficial to the hot isostatic pressing process to repair defects such as pores in the cast Ti ₃ Al alloy and improve the density of the alloy. On the other hand, it uses the reversible alloying effect of hydrogen in the cast Ti ₃ Al alloy and various phase changes. Refine the microstructure of the cast Ti ₃ Al alloy to make up for the adverse effect of coarse grains on the properties of the alloy. However, the same drawback is that only the role of hydrogen in the subsequent heat treatment of Ti ₃ Al alloy is used to refine the grains, and hydrogen cannot be used to promote element diffusion and increase the liquid / solid interface component undercooling during the cyclic melting deposition process; Decomposition and placement of hydrogen reduce deformation resistance and promote dislocation movement to form deformation defects, promote non-spontaneous nucleation from multiple dimensions and multiple angles, and refine the role of grains.

Although the above three methods can improve the structure of additive manufacturing to a certain extent, all of them have corresponding problems and cannot effectively improve the structure of titanium alloy for additive manufacturing. Therefore, the process that can improve the texture of titanium alloy by additive manufacturing needs to be explored urgently.

Summary of the invention

1. Problems to be solved

The purpose of the present invention is to provide a hydrogenation rolling method for improving the titanium alloy structure of additive manufacturing. The purpose is to process the titanium alloy powder in the additive manufacturing process and combine it with the additive manufacturing process. The printed part is rolled layer by layer. Through the cycle process of printing-rolling-pressing-printing-rolling, a print with fine structure is prepared. Finally, the temporary alloying element hydrogen is removed by vacuum annealing to avoid the chemical composition of the final material. Changes in the microstructure of additive manufacturing titanium alloy.

2. Technical solution

In order to solve the above problems, the present invention provides a hydrogenation rolling composite process for improving the titanium alloy structure of additive manufacturing, including the following steps:

Step 1. The titanium alloy powder is subjected to hydrogen treatment: the titanium alloy powder is placed in a tubular hydrogen treatment furnace, and the powder is layered, and the thickness of each layer is 2-8mm, and the vacuum is applied to 1.5 × 10 ^-3 Pa. Heat at a rate of 10-20 ° C / min to 700 ° C-800 ° C, hold for 10-30 minutes, fill in 0.1% -0.8% hydrogen according to the weight percentage of titanium alloy powder, hold for 1-4h, and then at 5-15 ° C / Cool to room temperature at the rate of min to obtain hydrogenated titanium alloy powder;

Step 2: The titanium alloy powder after hydrogenation is used for additive manufacturing, and the powder coating process or the powder feeding process is used to print the additive manufacturing workpiece to form a titanium alloy metal deposition layer;

Step 3: The control system is used to control the rolls to roll the titanium alloy metal deposition layer formed in step 2, and the rolling deformation is 10 to 50%;

Step 4. Repeat steps 2 and 3 to print and roll layer by layer until the workpiece is printed.

Step 5. The titanium alloy workpiece after the additive manufacturing is subjected to solution treatment, including: placing the titanium alloy workpiece in a heat treatment furnace, heating at a rate of 10-20 ° C / min to Tp ° C + 10 ° C, and maintaining the temperature for 20min to 40min. Then quenched, where Tp ° C is the phase transition temperature;

Step 6. Annealing + dehydrogenation heat treatment of the titanium alloy workpiece after solid solution, specifically: putting the titanium alloy into a vacuum heat treatment furnace, evacuating to 1.5 × 10 ^-3 Pa, at a speed of 10-20 ° C / min It is heated to 700 ℃ -800 ℃, the vacuum degree in the furnace is higher than 3 × 10 ^-3 Pa, the temperature is maintained for 2 hours to 4 hours, and then it is cooled to room temperature at 5-15 ° C / min.

Further, in the rolling process of step 4, it is required to control the rolling error to 0.01 mm at a rolling amount of 0.4 mm during rolling.

3. Beneficial effects

The hydrogen-rolling composite process for improving the titanium alloy structure of the additive manufacturing method of the present invention has a significant advantage in that hydrogen-solubility treatment is performed on the titanium alloy powder by utilizing the solubility of hydrogen in the titanium alloy. At the same time, in the process of additive manufacturing printing, on the one hand, the hydrogen of hydrogenated titanium alloy powder is used to promote the diffusion of elements and increase the liquid / solid interface component undercooling; cyclic hydride formation and decomposition during the cyclic melting deposition process, and the hydrogenation reduces the deformation resistance and promotes the position. Wrong movements then form deformation defects and promote non-spontaneous nucleation. On the other hand, the metal deposition layer is rolled layer by layer to cause deformation of the metal deposition layer and increase the density of the print. Dislocations and other defects will reduce the nucleation energy and increase the nucleation rate. In the tiny molten pool of the next printing process, the existence of dislocations and other defects can refine the print layer organization; through the interaction of the above factors, the Control of metallurgy and precise control of columnar / equiaxed crystal transformation.

It should be understood that all combinations of the foregoing ideas and additional ideas described in more detail below can be considered as part of the inventive subject matter of the present disclosure as long as such ideas do not contradict each other. In addition, all combinations of claimed subject matter are considered part of the inventive subject matter of the present disclosure.

The foregoing and other aspects, embodiments, and features of the teachings of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or benefits of exemplary embodiments, will be apparent from the following description, or be learned from practice of specific embodiments in accordance with the teachings of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a schematic flowchart of a hydrogenation rolling process for improving the titanium alloy structure of additive manufacturing according to the present invention.

detailed description

In order to better understand the technical content of the present invention, specific embodiments and the accompanying drawings are described as follows.

Aspects of the invention are described in this disclosure with reference to the accompanying drawings, in which many illustrated embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be understood that the various concepts and embodiments introduced above, as well as those concepts and embodiments described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed in the present invention are not Limited to any implementation. In addition, some aspects of the present disclosure may be used alone or in any suitable combination with other aspects of the present disclosure.

According to the invention, a hydrogenation + rolling process method for improving the titanium alloy structure of additive manufacturing is disclosed. The hydrogenated titanium alloy powder is obtained after the hydrogenation treatment of the front titanium alloy powder, and the hydrogenated titanium alloy powder is used. After additive manufacturing + layer-by-layer rolling to obtain titanium alloy workpieces, the workpieces are subjected to solution treatment, and finally the solution-treated titanium alloy workpieces are subjected to dehydrogenation heat treatment and annealing to improve the titanium alloy microstructure of additive manufacturing.

The disclosed hydrogenation + rolling process method, on the one hand, utilizes the relatively high solubility of hydrogen in the β phase of the titanium alloy, and different proportions of hydrogen are built in this temperature range to obtain titanium alloy powders with different hydrogen contents. During the 3D printing process, the use of hydrogen to precipitate and decompose hydrides during the melting and solidification process promotes nucleation in the molten pool, and supercooling of the component promotes nucleation in many ways to refine the grains of the printed tissue; on the other hand, During the material manufacturing process, the metal deposition layer is rolled layer by layer, and the density of the rolling additive material is used. At the same time, the rolling will cause defects such as dislocations in the metal deposition layer to increase. Nuclear energy can improve the nucleation rate and further refine and improve the structure. Finally, the temporary alloying element hydrogen is removed through vacuum annealing to avoid the change of the chemical composition of the final material. At the same time, the hydrogen is refined in the process to improve the organization and Rolling reduces the nucleation energy and increases the nucleation rate by increasing defects such as dislocations. The interaction between the two achieves the purpose of improving the structure without changing the alloy composition.

With reference to FIG. 1, as an exemplary implementation of the present invention, the foregoing specific implementation process includes:

Step 1. The titanium alloy powder is subjected to hydrogen treatment. The titanium alloy powder is placed in a tubular hydrogen treatment furnace, and the powder is layered. The thickness of each layer is 2-8mm to ensure that the hydrogen composition is uniform. 10 ^-3 Pa, heating to 700 ° -800 ° C at a rate of 10-20 ° C / min, holding for 10-30 minutes, filling with 0.1% -0.8% hydrogen according to the weight percentage of titanium alloy powder, holding for 1-4h, and then Cooling to room temperature at 5 ～ 15 ℃ / min to obtain hydrogenated titanium alloy powder;

Step 2: The titanium alloy powder after hydrogenation is used for additive manufacturing to obtain a titanium alloy workpiece, and the powder spreading process and the powder feeding process can be used, for example:

Powder spreading process: powder spreading thickness is 20μm ～ 80μm, laser power is 200W ～ 500W; scanning speed is 1 ～ 15m / s.

Powder feeding process: powder feeding 0.2-5r / min, laser power 1500W ～ 8000W, scanning speed 1-30mm / s.

Step 3: The control system is used to control the roller to roll the titanium alloy metal deposited layer, and the rolling deformation is 10-50%;

Step 4. Repeat steps 2 and 3 until the print is finished printing. When rolling, it is required to control the rolling error to 0.01mm at a rolling amount of 0.4mm;

Step 5. The titanium alloy after the additive manufacturing is subjected to a solution treatment. The heat treatment process is: placing the titanium alloy workpiece in a heat treatment furnace and heating it to a temperature of Tp ° C (phase transition temperature) + 10 ° C at a rate of 10-20 ° C / min. , Keep for 20min ~ 40min, and then quench;

Step 6. Anneal the titanium alloy workpiece after solution treatment + hydrogen removal heat treatment; put the titanium alloy into a vacuum heat treatment furnace, evacuate to 1.5 × 10 ^-3 Pa, and heat it to 700 at a rate of 10-20 ° C / min. ℃ -800 ℃, the vacuum degree in the furnace is higher than 3 × 10 ^-3 Pa, holding for 2h ～ 4h, and then cooling to room temperature at 5 ～ 15 ℃ / min.

The specific process parameters of this embodiment can adopt corresponding processes according to different types of titanium alloys.

In order to facilitate better understanding, the present invention will be further described below in combination with specific examples. The metal powder is TC4 as an example, but the type of the titanium alloy powder is not limited thereto, and the content of the present invention is not limited thereto.

[Implementation 1]

Step 1, the alloy powder is set to a hydrogen treatment, the titanium alloy powder As the hydrogenation heat treatment furnace tube, layered powder spreading, dusting each to ensure uniform thickness of 3mm hydrogen component set, was evacuated to 1.5 × 10 ^{- 3} Pa, heating to 700 ° C-800 ° C at a rate of 10-20 ° C / min, holding for 10-30 minutes, filling 0.2% hydrogen according to the weight percentage of the titanium alloy powder, holding for 2h, and then cooling to 10 ° C / min At room temperature, titanium alloy powder is obtained;

Step 2: The titanium alloy powder after hydrogen deposition is used for additive manufacturing to obtain a titanium alloy workpiece with a powder thickness of 40 μm, a laser power of 300 W, and a scanning speed of 5 m / s.

Step 3: The control system is used to control the rolls to roll the titanium alloy metal deposition layer, and the rolling deformation is 15%;

[Implementation 2]

Step 1, the alloy powder is set to a hydrogen treatment, the titanium alloy powder As the hydrogenation heat treatment furnace tube, layered powder spreading, dusting each to ensure uniform thickness of 4mm hydrogen component set, was evacuated to 1.5 × 10 ^{- 3} Pa, heating to 700 ° C-800 ° C at a rate of 10-20 ° C / min, holding for 10-30 minutes, filling with 0.3% hydrogen according to the weight percentage of the titanium alloy powder, holding for 3 hours, and then cooling to 10 ° C / min At room temperature, titanium alloy powder is obtained;

Step 2. Step 2. The titanium alloy powder after hydrogen is used for additive manufacturing to obtain a titanium alloy workpiece with a powder thickness of 50 μm, a laser power of 350 W, and a scanning speed of 5 m / s.

Step 3: The control system is used to control the rolls to roll the titanium alloy metal deposited layer, and the rolling deformation is 20%;

[Implementation 3]

Step 1, the alloy powder is set to a hydrogen treatment, the titanium alloy powder As the hydrogenation heat treatment furnace tube, layered powder spreading, dusting each to ensure uniform thickness of 4mm hydrogen component set, was evacuated to 1.5 × 10 ^{- 3} Pa, heating to 700 ° C-800 ° C at a rate of 10-20 ° C / min, holding for 10-30 minutes, filling with 0.5% hydrogen according to the weight percentage of the titanium alloy powder, holding for 3.5 hours, and then cooling at 15 ° C / min To room temperature, titanium hydrogen alloy powder is obtained;

Step 2. The titanium alloy powder after hydrogenation is used for additive manufacturing to obtain a titanium alloy workpiece with a powder thickness of 60 μm, a laser power of 400 W, and a scanning speed of 8 m / s.

Step 3: The control system is used to control the rolls to roll the titanium alloy metal deposited layer, and the rolling deformation is 35%;

[Implementation 4]

Step 1, the alloy powder is set to a hydrogen treatment, the titanium alloy powder As the hydrogenation heat treatment furnace tube, powder-layered, the thickness of each layer of powder spreading 5mm to ensure uniformity of hydrogenation component, evacuated to 1.5 × 10 ^{- 3} Pa, heating to 700 ° C-800 ° C at a rate of 10-20 ° C / min, holding for 10-30 minutes, filling 0.6% hydrogen according to the weight percentage of the titanium alloy powder, holding for 4h, and then cooling to 10 ° C / min At room temperature, titanium alloy powder is obtained;

Step 2: The titanium alloy powder after hydrogenation is used for additive manufacturing to obtain a titanium alloy workpiece, the powder feeding speed is 3r / min, the laser power is 1600W, and the scanning speed is 15mm / s.

Step 3: The control system is used to control the roller to roll the titanium alloy metal deposition layer, and the rolling deformation is 45%;

The test results of mechanical properties are shown in Table 1;

Table 1 Comparison of mechanical properties

In the field of additive manufacturing, the formation of columnar grains and coarse primary grains is due to the thermodynamic dynamics of the metallurgical process. The abnormal metallurgical conditions and cyclic deposition in the micro-melt bath of the additive manufacturing process cause insufficient temperature and composition undercooling, and are not spontaneous. The reduction of nucleation particles is the core issue. The above method utilizes the solubility of hydrogen in the titanium alloy to treat the titanium alloy powder with hydrogen. In the 3D printing process, on the one hand, the use of hydrogen to promote the diffusion of elements and increase the liquid / solid interface component undercooling; the formation and decomposition of hydrides during the cyclic melt deposition process; the hydrogen to reduce the deformation resistance and promote the dislocation movement to form deformation defects, and promote Non-spontaneous nucleation; on the other hand, the rolling of the metal deposition layer by layer will cause the deformation of the metal deposition layer and increase the density of the print. At the same time, the rolling will introduce defects such as dislocations in the deposition layer, which will reduce Nucleation energy, improve the nucleation rate, in the tiny molten pool of the next layer printing process, the existence of defects such as dislocations can refine the print layer organization; through the interaction of the above two factors, to achieve metallurgy of the additive manufacturing organization Control and precise control of columnar / equiaxed crystal transitions.

Because the relationship between the strength of the alloy material and the grain size conforms to the Hall-Petch relationship, the finer the grains, the higher the strength of the alloy; and only when the grains are refined can the strength and plasticity of the material be improved at the same time. In the foregoing embodiments of the present invention, the placement of hydrogen and the layer-by-layer rolling treatment can very effectively refine the grains during the printing process, improve the structure, and improve the material properties; and the titanium is not changed by the final hydrogen removal treatment. Composition of the alloy.

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined by the claims.

Claims

A hydrogen rolling composite process for improving the titanium alloy structure of additive manufacturing is characterized in that it includes the following steps:

Step 1. The titanium alloy powder is subjected to hydrogen treatment: the titanium alloy powder is placed in a tube type hydrogen treatment furnace, and the powder is layered, and the thickness of each layer is 2-8mm, and the vacuum is applied to 1.5 × 10 -3 Pa. Heat at a rate of 10-20 ° C / min to 700 ° C-800 ° C, hold for 10-30 minutes, fill in 0.1% -0.8% hydrogen according to the weight percentage of titanium alloy powder, hold for 1-4h, and then at 5-15 ° C / Cool to room temperature at the rate of min to obtain hydrogenated titanium alloy powder;

Step 2: The titanium alloy powder after hydrogen is used for additive manufacturing to print a workpiece to form a titanium alloy metal deposition layer;

Step 3: The control system is used to control the rolls to roll the titanium alloy metal deposition layer formed in step 2;

Step 4. Repeat steps 2 and 3 to print and roll layer by layer until the workpiece is printed.

Step 5. The titanium alloy workpiece after the additive manufacturing is subjected to solution treatment, including: placing the titanium alloy workpiece in a heat treatment furnace, heating at a rate of 10-20 ° C / min to Tp ° C + 10 ° C, and maintaining the temperature for 20min to 40min. Then quenched, where Tp ° C is the phase transition temperature;

Step 6. Annealing + dehydrogenation heat treatment of the titanium alloy workpiece after solid solution, specifically: putting the titanium alloy workpiece into a vacuum heat treatment furnace, evacuating to 1.5 × 10 -3 Pa, at a temperature of 10-20 ° C / min. The speed is heated to 700 ° C-800 ° C, then after the vacuum degree in the furnace reaches the set value, the temperature is maintained for a certain time, and finally cooled to room temperature.
The hydrogenation rolling composite process for improving the titanium alloy structure of additive manufacturing according to claim 1, characterized in that, in step 6, when the vacuum degree in the furnace is higher than 3 × 10 -3 Pa, the heat is maintained for 2 hours. ～ 4h, and then cooled to room temperature at 5 ～ 15 ℃ / min.
The hydrogen rolling composite process for improving the titanium alloy structure of additive manufacturing according to claim 1 or 2, characterized in that in the rolling process of step 4, a rolling amount of 0.4 mm is required during rolling The lower rolling error is controlled at 0.01mm.
The hydrogen-containing rolling composite process for improving the titanium alloy structure of additive manufacturing according to claim 1, characterized in that, in step 2, a powder-laying process or a powder-feeding process is used to print an additive manufacturing workpiece.
The hydrogenation rolling composite process for improving the titanium alloy structure of additive manufacturing according to claim 1, characterized in that, in the rolling process of step 3, the rolling deformation is controlled to be 10-50%.
The hydrogen-containing rolling composite process for improving the titanium alloy structure of additive manufacturing according to claim 1, characterized in that the additive manufacturing printing process in step 2 is selected from the following powder spreading process or powder feeding process Kind of:

Powder spreading process: powder spreading thickness is 20μm ～ 80μm, laser power is 200W ～ 500W; scanning speed is 1 ～ 15m / s;

Powder feeding process: powder feeding speed 0.2-5r / min, laser power 1500W ～ 8000W, scanning speed 1-30mm / s.