CN111974998B

CN111974998B - Additive manufacturing method for titanium alloy thin-wall part

Info

Publication number: CN111974998B
Application number: CN202010813323.8A
Authority: CN
Inventors: 楚瑞坤
Original assignee: Falcontech Co ltd
Current assignee: Falcontech Co ltd
Priority date: 2020-08-13
Filing date: 2020-08-13
Publication date: 2022-04-12
Anticipated expiration: 2040-08-13
Also published as: CN111974998A

Abstract

The invention provides an additive manufacturing method for a titanium alloy thin-wall part, which comprises the following steps: carrying out three-dimensional modeling according to the solid structure of the thin-wall part to obtain a solid model, adding an auxiliary support structure on the outer surface of the solid model to obtain an additive model, and carrying out slicing and layering on the additive model; (II) generating a scanning path according to the additive model manufacturing file, performing laser additive manufacturing on the part solid structure and the auxiliary supporting structure layer by layer on the substrate, and stacking layer by layer to form a part solid comprising the auxiliary structure; and (III) carrying out heat treatment on the parts with the substrate including the auxiliary structure. The additive manufacturing method provided by the invention effectively solves the problem of microcracks of the titanium alloy thin-wall part, improves the mechanical property of the thin-wall part, and maximally ensures that the dimensional precision of the thin-wall structure is controlled within a reasonable range, so that the prepared part meets the aerospace use requirements.

Description

Additive manufacturing method for titanium alloy thin-wall part

Technical Field

The invention belongs to the technical field of additive manufacturing, relates to an additive manufacturing method of a thin-wall part, and particularly relates to an additive manufacturing method for a titanium alloy thin-wall part.

Background

The additive manufacturing technology appears from the 90 s in the 20 th century, the development basis is the high-energy heat cladding technology and the rapid prototyping technology, compared with the traditional manufacturing technology, the method does not need to carry out cutting of various cutters and processing of various complicated procedures, greatly shortens the processing time, and simultaneously has higher processing process and manufacturing precision on parts with complex structures.

The additive manufacturing technology is mainly a technology for forming a three-dimensional CAD model of a part through computer generation, and stacking materials of the part layer by layer in an ink-jet mode according to size data of the model in a laser cladding mode to form a three-dimensional part. The material adding and manufacturing process is simple, the production cost is low, the application range is wide, the structure, the variety and the like of the manufactured part can be changed at any time according to different three-dimensional drawings of the part in the computer, and the method is particularly suitable for manufacturing metal parts with complex product structures, high material activity and high required purity.

The raw materials used by the additive manufacturing technology mainly comprise two types of metal and nonmetal, and other materials are added into the raw materials for sintering, curing and hot cladding. The additive manufacturing technology can be divided into the following steps according to different additive materials: rapid prototyping techniques and high performance metal component direct fabrication techniques.

Compared with the traditional cutting machining, the additive manufacturing technology can realize the one-step completion of the manufacturing process of the metal material part, the manufacturing process is carried out according to the three-dimensional CAD drawing of the part, so the size precision of the part is close to the actual requirement, the subsequent machining allowance is small, and the utilization rate and the production efficiency of the material are greatly improved. When the additive manufacturing technology is used, large-scale equipment is not needed, resources can be saved for production enterprises, meanwhile, the manufacturing time is short, and the additive manufacturing technology has high flexibility and can be changed at any time according to the structural change of products.

At present, titanium alloy products are applied in a plurality of fields, the products have complex structures, a plurality of varieties, small batch and high performance requirements, the traditional production and manufacturing technology cannot meet the requirements of the products, and the additive manufacturing technology can meet the manufacturing technology and the performance requirements of the titanium alloy products, so that the titanium alloy products are widely applied.

With the development of additive manufacturing technology, research on titanium alloy additive manufacturing technology is actively carried out in all countries of the world, and the titanium alloy additive manufacturing technology is expected to be applied in various aspects. According to research in recent years, the production processes currently applied to the processing of titanium alloy parts are a selective laser melting forming technology, an electron beam fuse forming technology, a laser three-dimensional forming technology and an electron beam selective melting forming technology.

CN108889946B discloses a laser three-dimensional forming method for an aluminum alloy thin-wall part, which relates to a laser additive manufacturing method for an aluminum alloy part. The invention aims to solve the technical problems of collapse and air holes of the existing aluminum alloy thin-wall part in the laser three-dimensional forming additive manufacturing process. The invention comprises the following steps: firstly, cleaning a substrate; secondly, drying the powder; and thirdly, laser additive manufacturing.

CN109396436A discloses a pure titanium 3D printing additive manufacturing method, which specifically comprises the following steps: three-dimensional modeling of the pure titanium thin-wall part; establishing support by layering curved surfaces; selecting a pure titanium original part material; printing a pure titanium thin-wall curved surface; carrying out heat treatment on the pure titanium thin-wall curved surface part; and (5) polishing the pure titanium thin-wall curved surface part.

CN106513675A discloses a laser additive manufacturing and forming method for a titanium alloy thin-walled component, where the titanium alloy thin-walled component includes a supporting cylinder formed by combining three cylinders and a bottom bracket with a plate-shaped structure, and the method includes the steps of: (1) forming the bottom support by adopting a selective laser melting forming method, and obtaining the bottom support with a substrate and a support after the forming is finished; (2) forming a supporting cylinder by adopting a selective laser melting forming method, and obtaining the supporting cylinder with a substrate and a support after the forming is finished; (3) carrying out heat treatment on the bottom bracket with the substrate and the support obtained in the step (1) and the support cylinder with the substrate and the support obtained in the step (2) simultaneously; (4) performing linear cutting on the bottom support and the support cylinder subjected to the heat treatment in the step (3), and removing the substrate to obtain the bottom support and the support cylinder only with supports; (5) removing the supports of the bottom support and the support cylinder to obtain the bottom support and the support cylinder, and polishing and sandblasting the surfaces of the bottom support and the support cylinder; (6) and mechanically fixing the bottom support and the supporting cylinder by adopting a tool, connecting the bottom support and the supporting cylinder by adopting a laser cladding method, and removing the tool adopted during mechanical connection after the laser cladding is finished to obtain the titanium alloy integral component.

The TA15 alloy has good thermal conductivity, thermal strength, creep resistance, thermal stability and weldability, and has obvious application advantages in aerospace. The traditional TA15 part preparation process flow is complex, the preparation period is long, the material utilization rate is low, the preparation cost is high, the limitation of the material preparation process and the processing process is more in practical application, no good solution is provided for complex thin-wall parts, the use requirement cannot be met, a new part preparation solution is urgently needed to be provided, the appearance of an additive manufacturing process is an advantageous scheme for preparing the parts, the appearance of the additive manufacturing process is an advantageous scheme for preparing the parts, but the additive manufacturing of the TA15 thin-wall parts is easy to generate microcracks due to complex material components and poor material plasticity, and the parts are easy to deform if the heat input is uneven.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the additive manufacturing method for the titanium alloy thin-wall part, the additive manufacturing method provided by the invention effectively solves the problem of microcracks of the titanium alloy thin-wall part, improves the mechanical property of the thin-wall part, and furthest ensures that the dimensional precision of a thin-wall structure is controlled within a reasonable range, so that the prepared part meets the aerospace use requirements.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides an additive manufacturing method for a titanium alloy thin-walled part, the additive manufacturing method including the steps of:

performing three-dimensional modeling according to the solid structure of the thin-wall part to obtain a solid model, adding an auxiliary support structure on the outer surface of the solid model to obtain an additive model, slicing and layering the additive model, and introducing the additive model into additive manufacturing software;

(II) generating a scanning path according to the layering condition, taking titanium alloy powder as a raw material, performing laser additive manufacturing on a part solid structure and an auxiliary supporting structure layer by layer on a substrate, and stacking layer by layer to form a part solid comprising the auxiliary structure;

and (III) carrying out heat treatment on the parts with the substrate including the auxiliary structure.

The additive manufacturing method provided by the invention effectively solves the problem of microcracks of the titanium alloy thin-wall part, improves the mechanical property of the thin-wall part, and maximally ensures that the dimensional precision of the thin-wall structure is controlled within a reasonable range, so that the prepared part meets the aerospace use requirements.

As a preferred technical solution of the present invention, in step (i), the auxiliary supporting structure includes a rib or a lattice structure.

Preferably, holes are designed at the joints of the ribs and the solid model.

Preferably, the holes have a diameter of 1 to 4mm, and may be, for example, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm or 4.0mm, but not limited to the recited values, and other values not recited in the recited values are equally applicable within the range of values.

Preferably, the hole spacing between adjacent holes is 0.5 to 8mm, and may be, for example, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm or 8mm, but is not limited to the values recited, and other values not recited within this range are equally applicable.

Preferably, the thickness of the ribs is 1/3-1 times the thickness of the wall of the control area, such as 1/3 times, 2/3 times or 1 time, but not limited to the values listed, and other values not listed in the range are also applicable.

Preferably, the thickness of the deformation region to be controlled is 1.5-5 mm, such as 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5.0mm, but not limited to the values listed, and other values not listed in the range of values are equally applicable.

Preferably, the length of the rib is set to be equal to the length of the deformation area to be controlled.

Preferably, the equal-length insertion ribs are subjected to a separation process.

Preferably, the rod diameter of the lattice-structured unit cell is 0.4 to 1.8mm, and may be, for example, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 1.0mm, 1.1mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm, 1.8mm, which are limited to the enumerated values, and other values not enumerated within the range of values are also applicable.

In a preferred embodiment of the present invention, in step (i), the thickness of the additive model is 0.02 to 0.08mm, for example, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, or 0.08mm, but is not limited to the above-mentioned values, and other values not listed in the above-mentioned range are also applicable.

In a preferred embodiment of the present invention, in the step (ii), the titanium alloy powder is TA15 titanium alloy.

Preferably, the titanium alloy powder comprises titanium element, oxygen element, carbon element, silicon element and iron element.

Preferably, the oxygen content is 0.08 wt.% or less, and may be, for example, 0.01 wt.%, 0.02 wt.%, 0.03 wt.%, 0.04 wt.%, 0.05 wt.%, 0.06 wt.%, 0.07 wt.%, or 0.08 wt.%, but is not limited to the recited values, and other values not recited within the range of values are equally applicable.

Preferably, the carbon content is 0.03 wt.% or less, and may be, for example, 0.01 wt.%, 0.015 wt.%, 0.02 wt.%, 0.025 wt.%, or 0.03 wt.%, but is not limited to the recited values, and other values not recited within the range are equally applicable.

Preferably, the elemental silicon content is 0.05 wt.% or less, and can be, for example, 0.01 wt.%, 0.02 wt.%, 0.03 wt.%, 0.04 wt.%, or 0.05 wt.%, but is not limited to the recited values, and other values not recited within the range of values are equally applicable.

Preferably, the iron element is present in an amount of 0.1 wt.% or less, and may be, for example, 0.01 wt.%, 0.02 wt.%, 0.03 wt.%, 0.04 wt.%, 0.05 wt.%, 0.06 wt.%, 0.07 wt.%, 0.08 wt.%, 0.09 wt.%, or 0.1 wt.%, but is not limited to the recited values, and other non-recited values within this range are equally applicable.

In a preferred embodiment of the present invention, in step (ii), the titanium alloy powder is baked before laser additive manufacturing is started.

Preferably, the baking temperature is 100 to 150 ℃, for example, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, 145 ℃ or 150 ℃, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the heat preservation time of the powder baking process is 3 to 8 hours, for example, 3.0 hours, 3.5 hours, 4.0 hours, 4.5 hours, 5.0 hours, 5.5 hours, 6.0 hours, 6.5 hours, 7.0 hours, 7.8 hours or 8.0 hours, but not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.

As a preferred embodiment of the present invention, in step (ii), before the laser additive manufacturing is started, the substrate is preheated.

Preferably, the preheating temperature is 80 to 210 ℃, for example, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, 200 ℃ or 210 ℃, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

As a preferred technical solution of the present invention, in the step (ii), the laser process data required to be set in the process of performing laser additive manufacturing on the part solid structure includes laser power, spot diameter, scanning speed, powder layer thickness, and scanning pitch.

In the forming process of the thin-wall structure, the selection of laser process parameters is very important and is mainly influenced by factors in the aspects of laser power, scanning speed, powder layer thickness, scanning distance and the like. The main invention point of the invention lies in the special selection of the laser process parameters, and the problem of microcracks of the thin-wall part is effectively solved by limiting the optimal range of the laser process parameters, so that the mechanical property of the thin-wall part is greatly improved, the size precision of the thin-wall structure is controlled within a reasonable range to the maximum extent, and the prepared thin-wall part meets the use requirements of aerospace.

Preferably, the laser power is 170-300W, such as 170W, 180W, 190W, 200W, 210W, 220W, 230W, 240W, 250W, 260W, 270W, 280W, 290W or 300W, but not limited to the recited values, and other values not recited in the range of values are also applicable.

In the invention, for the thin-wall part additive manufacturing process of titanium alloy materials, if the set laser power is too low, titanium alloy powder cannot be sufficiently melted, and defects such as incomplete fusion and the like can occur inside a forming area, so that the flatness is not enough after the layer of powder is melted, the powder collides with a scraper in the powder laying process, and the part is easy to deform; if the power is too high, the convection of a molten pool is violent, the internal thermal stress of the formed thin-wall part is high, the surface of the formed thin-wall part has strip-shaped lines, and the product is easy to deform.

Preferably, the spot diameter is 0.05 to 0.2mm, and may be, for example, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, or 0.2mm, but is not limited to the values listed, and other values not listed in the range of values are equally applicable.

Preferably, the scanning speed is 700-1400 mm/s, such as 700mm/s, 800mm/s, 900mm/s, 1000mm/s, 1100mm/s, 1200mm/s, 1300mm/s or 1400mm/s, but not limited to the recited values, and other values not recited in the range of values are also applicable.

In the invention, aiming at the additive manufacturing process of the thin-wall part made of the titanium alloy material, when the scanning speed is lower, the spheroidization effect is easy to occur on the thin-wall part, and the thermal stress is large in the forming process, so that the part is easy to deform; too high a scanning speed may result in insufficient melting of the titanium alloy powder, increased internal porosity, and reduced surface quality.

Preferably, the powder layer has a thickness of 0.02-0.08 mm, such as 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm or 0.08mm, but not limited to the values listed, and other values not listed in this range are also applicable.

In the invention, for the thin-wall part additive manufacturing process of the titanium alloy material, when the powder spreading thickness is low, the printing period is long and the cost is high, and in addition, the low layer thickness can bring repeated input of heat, thus easily causing part deformation; when the powder spreading thickness is too high, the single-layer energy input is high, so that the forming surface roughness of the part is poor.

Preferably, the scanning pitch is 0.07 to 0.16mm, and may be, for example, 0.07mm, 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, or 0.16mm, but is not limited to the enumerated values, and other values not enumerated within the range are also applicable.

In the invention, aiming at the thin-wall part additive manufacturing process of the titanium alloy material, when the scanning distance is lower, the energy input is larger, and the part is easy to deform; when the scanning distance is too large, micro defects such as air holes, microcracks and the like are easy to generate after the part is formed.

Preferably, the oxygen content is controlled to be < 1000ppm, for example 100ppm, 200ppm, 300ppm, 400ppm, 500ppm, 600ppm, 700ppm, 800ppm or 900ppm, during laser additive manufacturing of the part body, but is not limited to the recited values, and other values not recited in the range of values are equally applicable.

As a preferable technical solution of the present invention, in the step (ii), the set laser process data in the process of performing laser additive manufacturing on the auxiliary support structure includes laser power, spot diameter, scanning speed, powder layer thickness, and scanning pitch.

Preferably, the laser power is 120-200W, such as 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W or 200W, but not limited to the values listed, and other values not listed in the range of values are also applicable.

Preferably, the scanning speed is 1000 to 2100mm/s, for example 1000mm/s, 1100mm/s, 1200mm/s, 1300mm/s, 1400mm/s, 1500mm/s, 1600mm/s, 1700mm/s, 1800mm/s, 1900mm/s, 2000mm/s or 2100mm/s, but is not limited to the values listed, and other values not listed in this range of values are equally applicable.

Preferably, the oxygen content is controlled to be < 1000ppm during laser additive manufacturing of the auxiliary support structure, for example 100ppm, 200ppm, 300ppm, 400ppm, 500ppm, 600ppm, 700ppm, 800ppm or 900ppm, but is not limited to the values recited, and other values not recited within the range of values are equally applicable.

As a preferable technical solution of the present invention, in the step (ii), after the laser additive manufacturing is finished, the substrate is cooled, and then the substrate is taken out and cleaned.

Preferably, the substrate is cooled to below 70 ℃, and the component entity and the auxiliary support structure with the substrate are taken out from the processing table of the additive manufacturing apparatus, for example, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃ or 70 ℃, but not limited to the recited values, and other values not recited in the range of values are also applicable.

As a preferred embodiment of the present invention, in step (iii), the heat treatment process includes: and carrying out annealing heat treatment on the part solid connecting substrate comprising the auxiliary structure together.

Preferably, the annealing heat treatment temperature is 750 to 850 ℃, for example, 750 ℃, 760 ℃, 770 ℃, 780 ℃, 790 ℃, 800 ℃, 810 ℃, 820 ℃, 830 ℃, 840 ℃ or 850 ℃, but not limited to the values listed, and other values not listed in the numerical range are also applicable.

Preferably, the heat-preserving time of the annealing heat treatment is 2 to 4 hours, for example, 2.0 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3.0 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours or 4.0 hours, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the part solid-attached substrate including the auxiliary structure is cooled after the heat preservation is finished.

Preferably, the cooling process is carried out in an inert gas.

The system refers to an equipment system, or a production equipment.

Compared with the prior art, the invention has the beneficial effects that:

the additive manufacturing method provided by the invention effectively solves the problem of microcracks of the titanium alloy thin-wall part, improves the mechanical property of the thin-wall part, furthest ensures that the dimensional accuracy of the thin-wall structure is controlled within a reasonable range, and simultaneously effectively solves the problem of microcracks of the thin-wall part by limiting the optimal range of laser process parameters, greatly improves the mechanical property of the thin-wall part, furthest controls the dimensional accuracy of the thin-wall structure within a reasonable range, so that the prepared thin-wall part meets the aerospace use requirements.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments.

Example 1

The embodiment provides an additive manufacturing method for manufacturing a thin-wall part of a control wing of an aerospace engine by adopting TA15 titanium alloy powder, wherein the content of each element component in the titanium alloy powder [ wt% ] is shown in the following table:

C

Al

Zr

Mo

V

Fe

Si

O

N

H

Ti

≤0.03

6.5

2

1.2

1.6

≤0.1

≤0.05

≤0.08

≤0.03

≤0.0125

balance of

The additive manufacturing method comprises the following steps:

(1) carrying out three-dimensional modeling according to the solid structure of the thin-wall part to obtain a solid model, adding ribs on the outer surface of the solid model to obtain a material increase model, designing holes with the thickness of 2mm at the connecting parts of the ribs and the solid model, wherein the hole distance between every two adjacent holes is 6mm, and slicing and layering the material increase model, wherein the slicing thickness is 0.04 mm;

(2) drying the TA15 titanium alloy powder at 100 ℃ for 8 h;

(3) the preheating temperature of a substrate is 80 ℃, a scanning path is generated according to a material increase model manufacturing file, TA15 titanium alloy powder is used as a raw material, laser material increase manufacturing of a part solid structure and an auxiliary supporting structure is carried out on the substrate layer by layer, and the part solid including the auxiliary structure is formed by layer stacking;

the laser process parameters set in the process of laser additive manufacturing of the solid structure of the part comprise: the laser power is 240W, the diameter of a light spot is 0.05mm, the thickness of the powder spreading layer is 0.04mm, and the scanning interval is 0.07 mm; controlling the oxygen content to be less than 1000ppm in the laser additive manufacturing process of the part entity;

the laser process parameters set in the laser additive manufacturing process of the auxiliary support structure comprise: the laser power is 120W, the diameter of a light spot is 0.05mm, the scanning speed is 1000mm, the thickness of a powder layer is 0.02mm, the scanning interval is 0.07mm, and the oxygen content is controlled to be less than 1000ppm in the laser additive manufacturing process of the auxiliary supporting structure;

(4) after the laser additive manufacturing is finished, waiting for the substrate to be cooled to below 70 ℃, and taking out the part entity and the auxiliary supporting structure on the substrate together with the substrate from a processing table of the additive manufacturing device;

(5) and carrying out annealing heat treatment on the part entity connecting substrate comprising the auxiliary structure together, wherein the annealing heat treatment temperature is 750 ℃, the heat preservation time is 4h, and after the heat preservation is finished, placing the part entity connecting substrate comprising the auxiliary structure in inert gas for cooling to obtain a finished product of the titanium alloy thin-wall part.

And (3) testing the comprehensive properties of the finished parts at room temperature, wherein the main tested comprehensive properties comprise yield strength, tensile strength, elongation and reduction of area, and the specific test results are shown in table 1.

Example 2

This example provides an additive manufacturing method for manufacturing cabin parts using TA15 titanium alloy powder, where the contents of each element component [% ] in the titanium alloy powder are shown in the following table:

C

Al

Zr

Mo

V

Fe

Si

O

N

H

Ti

≤0.03

7.2

1.5

1.3

≤0.1

≤0.05

≤0.08

≤0.03

≤0.0125

balance of

The additive manufacturing method comprises the following steps:

(1) carrying out three-dimensional modeling according to the solid structure of the thin-wall part to obtain a solid model, adding a lattice structure on the outer surface of the solid model to obtain an additive model, wherein the rod diameter of unit cells of the lattice structure is 0.4mm, and slicing and layering the additive model, wherein the slicing thickness is 0.05 mm;

(2) drying the TA15 titanium alloy powder at 120 ℃ for 6 h;

(3) the preheating temperature of a substrate is 112 ℃, a scanning path is generated according to a material increase model manufacturing file, TA15 titanium alloy powder is used as a raw material, laser material increase manufacturing of a part solid structure and an auxiliary supporting structure is carried out on the substrate layer by layer, and the part solid including the auxiliary structure is formed by layer stacking;

the laser process parameters set in the process of laser additive manufacturing of the solid structure of the part comprise: the laser power is 200W, the diameter of a light spot is 0.08mm, the thickness of a powder layer is 0.03mm, and the scanning interval is 0.09 mm; controlling the oxygen content to be less than 1000ppm in the laser additive manufacturing process of the part entity;

the laser process parameters set in the laser additive manufacturing process of the auxiliary support structure comprise: the laser power is 180W, the spot diameter is 0.08mm, the scanning speed is 1275mm, the powder layer thickness is 0.03mm, the scanning interval is 0.09mm, and the oxygen content is controlled to be less than 1000ppm in the laser additive manufacturing process of the auxiliary supporting structure;

(5) and carrying out annealing heat treatment on the part entity connecting substrate comprising the auxiliary structure together, wherein the annealing heat treatment temperature is 770 ℃, the heat preservation time is 3.5h, and after the heat preservation is finished, placing the part entity connecting substrate comprising the auxiliary structure in inert gas for cooling to obtain a finished product of the titanium alloy thin-wall part.

Example 3

This example provides an additive manufacturing method for manufacturing a thin-walled component of a connection joint using TA15 titanium alloy powder, wherein the contents of each element component [% ] in the titanium alloy powder are shown in the following table:

C

Al

Zr

Mo

V

Fe

Si

O

N

H

Ti

≤0.03

5.8

1.8

0.5

0.8

≤0.1

≤0.05

≤0.08

≤0.03

≤0.0125

balance of

The additive manufacturing method comprises the following steps:

(1) carrying out three-dimensional modeling according to the solid structure of the thin-wall part to obtain a solid model, adding ribs on the outer surface of the solid model to obtain a material increase model, designing holes with the thickness of 3mm at the connecting parts of the ribs and the solid model, wherein the hole distance between every two adjacent holes is 2mm, and slicing and layering the material increase model, wherein the slicing thickness is 0.06 mm;

(2) drying the TA15 titanium alloy powder at 125 ℃ for 5 h;

(3) preheating a substrate at 145 ℃, generating a scanning path according to a material increase model manufacturing file, performing laser material increase manufacturing on a part solid structure and an auxiliary supporting structure on the substrate layer by taking TA15 titanium alloy powder as a raw material, and stacking layer by layer to form a part solid comprising the auxiliary structure;

the laser process parameters set in the process of laser additive manufacturing of the solid structure of the part comprise: the laser power is 300W, the diameter of a light spot is 0.1mm, the thickness of a powder layer is 0.06mm, and the scanning interval is 0.11 mm; controlling the oxygen content to be less than 1000ppm in the laser additive manufacturing process of the part entity;

the laser process parameters set in the laser additive manufacturing process of the auxiliary support structure comprise: the laser power is 300W, the diameter of a light spot is 0.1mm, the scanning speed is 1550mm, the powder layer thickness is 0.06mm, the scanning interval is 0.11mm, and the oxygen content is controlled to be less than 1000ppm in the laser additive manufacturing process of the auxiliary supporting structure;

(5) and carrying out annealing heat treatment on the part entity connecting substrate comprising the auxiliary structure together, wherein the annealing heat treatment temperature is 800 ℃, the heat preservation time is 3h, and after the heat preservation is finished, placing the part entity connecting substrate comprising the auxiliary structure in inert gas for cooling to obtain a finished product of the titanium alloy thin-wall part.

Example 4

This example provides an additive manufacturing method for making thin-walled shell parts using TA15 titanium alloy powder, where the contents of the elemental components [% ] in the titanium alloy powder are shown in the following table:

C

Al

Zr

Mo

V

Fe

Si

O

N

H

Ti

≤0.03

6.7

2.3

1.9

2.3

≤0.1

≤0.05

≤0.08

≤0.03

≤0.0125

balance of

The additive manufacturing method comprises the following steps:

(1) carrying out three-dimensional modeling according to the solid structure of the thin-wall part to obtain a solid model, adding a lattice structure on the outer surface of the solid model to obtain an additive model, wherein the rod diameter of unit cells of the lattice structure is 0.8mm, and slicing and layering the additive model, wherein the slicing thickness is 0.07 mm;

(2) drying the TA15 titanium alloy powder at 138 ℃ for 4 h;

(3) preheating a substrate to 176 ℃, generating a scanning path according to a material increase model manufacturing file, performing laser material increase manufacturing on a part solid structure and an auxiliary supporting structure on the substrate layer by taking TA15 titanium alloy powder as a raw material, and stacking layer by layer to form a part solid comprising the auxiliary structure;

the laser process parameters set in the process of laser additive manufacturing of the solid structure of the part comprise: the laser power is 320W, the diameter of a light spot is 0.15mm, the thickness of a powder layer is 0.07mm, and the scanning interval is 0.13 mm; controlling the oxygen content to be less than 1000ppm in the laser additive manufacturing process of the part entity;

the laser process parameters set in the laser additive manufacturing process of the auxiliary support structure comprise: the laser power is 320W, the diameter of a light spot is 0.15mm, the scanning speed is 1825mm, the thickness of a powder layer is 0.035mm, the scanning distance is 0.13mm, and the oxygen content is controlled to be less than 1000ppm in the laser additive manufacturing process of the auxiliary supporting structure;

(5) and carrying out annealing heat treatment on the part entity connecting substrate comprising the auxiliary structure together, wherein the annealing heat treatment temperature is 830 ℃, the heat preservation time is 2.5h, and after the heat preservation is finished, placing the part entity connecting substrate comprising the auxiliary structure in inert gas for cooling to obtain a finished product of the titanium alloy thin-wall part.

Example 5

This example provides an additive manufacturing method for preparing a blade-like thin-walled part using TA15 titanium alloy powder, where the contents of each element component [% ] in the titanium alloy powder are shown in the following table:

C

Al

Zr

Mo

V

Fe

Si

O

N

H

Ti

≤0.03

6.3

2.5

1.6

1.4

≤0.1

≤0.05

≤0.08

≤0.03

≤0.0125

balance of

The additive manufacturing method comprises the following steps:

(1) carrying out three-dimensional modeling according to the solid structure of the thin-wall part to obtain a solid model, adding ribs on the outer surface of the solid model to obtain a material increase model, designing holes with the thickness of 4mm at the connecting parts of the ribs and the solid model, wherein the hole distance between every two adjacent holes is 4mm, and slicing and layering the material increase model, wherein the slicing thickness is 0.08 mm;

(2) drying the TA15 titanium alloy powder at 150 ℃ for 3 h;

(3) the preheating temperature of a substrate is 210 ℃, a scanning path is generated according to a material increase model manufacturing file, TA15 titanium alloy powder is used as a raw material, laser material increase manufacturing of a part solid structure and an auxiliary supporting structure is carried out on the substrate layer by layer, and the part solid including the auxiliary structure is formed by layer stacking;

the laser process parameters set in the process of laser additive manufacturing of the solid structure of the part comprise: the laser power is 340W, the diameter of a light spot is 0.2mm, the thickness of a powder layer is 0.08mm, and the scanning interval is 0.16 mm; controlling the oxygen content to be less than 1000ppm in the laser additive manufacturing process of the part entity;

the laser process parameters set in the laser additive manufacturing process of the auxiliary support structure comprise: the laser power is 340W, the diameter of a light spot is 0.2mm, the scanning speed is 2100mm, the thickness of a powder layer is 0.08mm, the scanning interval is 0.16mm, and the oxygen content is controlled to be less than 1000ppm in the laser additive manufacturing process of the auxiliary supporting structure;

(5) and carrying out annealing heat treatment on the part entity connecting substrate comprising the auxiliary structure together, wherein the annealing heat treatment temperature is 850 ℃, the heat preservation time is 2 hours, and after the heat preservation is finished, placing the part entity connecting substrate comprising the auxiliary structure in inert gas for cooling to obtain a finished product of the titanium alloy thin-wall part.

Comparative example 1

The difference between the comparative example and the example 1 is that in the step (3), the laser power set in the laser additive manufacturing process of the solid structure of the part is 150W, and other laser process parameters and operation steps are completely the same as those in the example 1.

Comparative example 2

The difference between the comparative example and the example 1 is that in the step (3), the laser power set in the laser additive manufacturing process of the solid structure of the part is 310W, and other laser process parameters and operation steps are completely the same as those in the example 1.

Comparative example 3

The difference between the comparative example and the example 1 is that in the step (3), the scanning speed set in the laser additive manufacturing process of the part solid structure is 600mm/s, and other laser process parameters and operation steps are completely the same as those in the example 1.

Comparative example 4

The difference between the comparative example and the example 1 is that in the step (3), the scanning speed set in the laser additive manufacturing process of the part solid structure is 1500mm/s, and other laser process parameters and operation steps are completely the same as those in the example 1.

Comparative example 5

The difference between the comparative example and the example 1 is that in the step (3), the powder layer thickness set in the laser additive manufacturing process of the solid structure of the part is 0.01mm, and other laser process parameters and operation steps are completely the same as those in the example 1.

Comparative example 6

The difference between the comparative example and the example 1 is that in the step (3), the powder layer thickness set in the laser additive manufacturing process of the solid structure of the part is 0.05mm, and other laser process parameters and operation steps are completely the same as those in the example 1.

Comparative example 7

The difference between the comparative example and the example 1 is that in the step (3), the scanning interval set in the laser additive manufacturing process of the part solid structure is 0.06mm, and other laser process parameters and operation steps are completely the same as those in the example 1.

Comparative example 8

The difference between the comparative example and the example 1 is that in the step (3), the scanning interval set in the laser additive manufacturing process of the part solid structure is 0.17mm, and other laser process parameters and operation steps are completely the same as those in the example 1.

TABLE 1

As can be seen from the data in Table 1, the overall performance of the finished parts prepared in the examples is better than that of the comparative examples, specifically:

it can be seen from the test data of the embodiment 3 and the comparative examples 1 and 2 that if the set laser power is too low, the titanium alloy powder cannot be sufficiently melted, and defects such as incomplete fusion and the like occur inside a forming region, so that the flatness is not sufficient after the layer of powder is melted, the powder collides with a scraper in the powder spreading process, and the part is easily deformed, and in addition, the surface roughness problem of the formed thin-wall part can be caused due to too low energy density; if the power is too high, the convection of a molten pool is violent, the internal thermal stress of the formed thin-wall part is high, the surface of the formed thin-wall part has strip-shaped lines, and the product is easy to deform.

As can be seen from the test data of the embodiment 3 and the comparative examples 3 and 4, when the scanning speed is lower, the spheroidization effect is easy to occur on the thin-wall part, and the part is easy to deform due to large thermal stress in the forming process; too high a scanning speed may result in insufficient melting of the titanium alloy powder, increased internal porosity, and reduced surface quality.

It can be seen from the test data of example 3 and comparative examples 5 and 6 that when the powder spreading thickness is low, the printing cycle is long, the cost is high, and in addition, the heat is repeatedly input due to the low layer thickness, so that the part is easy to deform; when the powder spreading thickness is too high, the single-layer energy input is high, so that the forming surface roughness of the part is poor.

It can be seen from the test data of example 3 and comparative examples 7 and 8 that when the scan pitch is low, the energy input is large, which easily causes part deformation; when the scanning distance is too large, micro defects such as air holes, microcracks and the like are easy to generate after the part is formed.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims

1. A TA15 titanium alloy aerospace engine rudder wing thin-wall part additive manufacturing method is characterized by comprising the following steps:

(II) generating a scanning path according to the layering condition, taking TA15 titanium alloy powder as a raw material, performing laser additive manufacturing on a part solid structure and an auxiliary supporting structure layer by layer on a substrate, and stacking layer by layer to form a part solid comprising the auxiliary structure;

(III) carrying out heat treatment on the part solid connecting substrate comprising the auxiliary structure;

in the step (II), laser process data required to be set in the process of laser additive manufacturing of the part entity structure comprise laser power, spot diameter, scanning speed, powder spreading layer thickness and scanning interval, wherein the laser power is 170-300W, the spot diameter is 0.05-0.2 mm, the scanning speed is 700-1400 mm/s, the powder spreading layer thickness is 0.02-0.08 mm, the scanning interval is 0.07-0.16 mm, and the oxygen content is controlled to be less than 1000ppm in the laser additive manufacturing process of the part entity;

the auxiliary supporting structure is a rib, holes are designed at the joint of the rib and the solid model, the diameter of each hole is 1-2 mm, and in the step (I), the hole distance between every two adjacent holes is 0.5-8 mm.

2. The additive manufacturing method according to claim 1, wherein in the step (I), the thickness of the ribs is set to be 1/3-1 times of the wall thickness of the deformation region to be controlled.

3. The additive manufacturing method according to claim 2, wherein in the step (I), the thickness of the wall of the deformation region to be controlled is 1.5-5 mm.

4. The additive manufacturing method according to claim 2, wherein in step (i), the length of the rib is set to be equal to the length of the deformation region to be controlled.

5. The additive manufacturing method according to claim 1, wherein in the step (i), the ribs that are put in the equal length are subjected to a separation process.

6. The additive manufacturing method according to claim 1, wherein in step (I), the thickness of the slice of the additive model is 0.02-0.08 mm.

7. The additive manufacturing method according to claim 1, wherein the titanium alloy powder comprises titanium, oxygen, carbon, silicon, and iron.

8. The additive manufacturing method according to claim 7, wherein the oxygen element content is less than or equal to 0.08 wt%.

9. The additive manufacturing method according to claim 7, wherein the carbon element content is less than or equal to 0.03 wt%.

10. The additive manufacturing method according to claim 7, wherein the elemental silicon content is less than or equal to 0.05 wt%.

11. The additive manufacturing method according to claim 7, wherein the content of the iron element is less than or equal to 0.1 wt%.

12. The additive manufacturing method according to claim 1, wherein in the step (II), the titanium alloy powder is subjected to powder baking before laser additive manufacturing is started.

13. The additive manufacturing method according to claim 12, wherein the powder baking temperature is 100-150 ℃.

14. The additive manufacturing method according to claim 12, wherein the heat preservation time of the powder baking process is 3-8 hours.

15. The additive manufacturing method according to claim 1, wherein in step (ii), the substrate is preheated before the laser additive manufacturing is started.

16. The additive manufacturing method according to claim 15, wherein the preheating temperature is 80-210 ℃.

17. The additive manufacturing method according to claim 1, wherein in the step (ii), the laser process data set in the laser additive manufacturing process for the auxiliary support structure comprises laser power, spot diameter, scanning speed, powder layer thickness and scanning interval.

18. The additive manufacturing method according to claim 17, wherein the laser power is 120-200W.

19. The additive manufacturing method according to claim 17, wherein the spot diameter is 0.05-0.2 mm.

20. The additive manufacturing method according to claim 17, wherein the scanning speed is 1000 to 2100 mm.

21. The additive manufacturing method according to claim 17, wherein the powder coating layer has a thickness of 0.02 to 0.08 mm.

22. The additive manufacturing method according to claim 17, wherein the scan pitch is 0.07 to 0.16 mm.

23. The additive manufacturing method according to claim 17, wherein the oxygen content is controlled to be < 1000ppm during laser additive manufacturing of the auxiliary support structure.

24. The additive manufacturing method according to claim 1, wherein in the step (II), after the laser additive manufacturing is finished, the substrate is cooled, and then the substrate is taken out and cleaned.

25. The additive manufacturing method according to claim 24, wherein the substrate is cooled to below 70 ℃ and the part entity and the auxiliary support structure carried by the substrate are removed from the processing table of the additive manufacturing apparatus.

26. The additive manufacturing method according to claim 1, wherein in step (iii), the heat treatment process comprises: and carrying out annealing heat treatment on the part solid connecting substrate comprising the auxiliary structure together.

27. The additive manufacturing method according to claim 26, wherein the annealing heat treatment is performed at a temperature of 750 to 850 ℃.

28. The additive manufacturing method according to claim 26, wherein the annealing heat treatment is performed for a holding time of 2 to 4 hours.

29. The additive manufacturing method according to claim 26, wherein the part solid-link substrate including the auxiliary structure is cooled after the heat preservation is finished.

30. The additive manufacturing method of claim 29, wherein the cooling is performed in an inert gas.