阅读说明：本技术 一种激光选区熔化成形铝合金微小飞行器零件的工艺方法 (Process method for melting and forming aluminum alloy micro aircraft parts in selective laser area ) 是由 沈理达 李军 柏华文 吕非 谢德巧 张寒旭 于 2021-06-03 设计创作，主要内容包括：本发明提供一种激光选区熔化成形铝合金微小飞行器零件的工艺方法,属于金属增材制造和微小飞行器设计领域,实现微小飞行器的铝合金零部件能够一次性整体成形、快速成形的目的,使微小飞行器的零部件精度高、生产周期短,满足实际工况的需要。本发明包括以下步骤：将所设计的微小飞行器具体零部件建模并且完成切片处理；将烘干的铝合金粉末添加到激光选区熔化设备中并导入切片完成的模型；选择合适的基板固定在成形缸平台上,对基板进行预热、对舱室进行洗气处理,通入惰性气体并打开通风；打印样件并从基板上分离。该工艺方法实现铝合金微小飞行器复杂零部件的快速高精度一次性整体成形。(The invention provides a process method for melting and forming aluminum alloy micro aircraft parts in a selective laser area, belongs to the field of metal additive manufacturing and micro aircraft design, and aims to realize one-time integral forming and rapid forming of aluminum alloy parts of micro aircraft, so that the parts of the micro aircraft have high precision and short production period, and meet the requirements of actual working conditions. The invention comprises the following steps: modeling the designed specific parts of the micro aircraft and finishing slicing processing; adding the dried aluminum alloy powder into selective laser melting equipment and guiding the aluminum alloy powder into a sliced model; selecting a proper substrate to be fixed on a forming cylinder platform, preheating the substrate, carrying out gas washing treatment on a cabin, introducing inert gas and opening for ventilation; the swatches are printed and separated from the substrate. The process method realizes the rapid high-precision one-step integral forming of the complex parts of the aluminum alloy micro aircraft.)

1. A process method for melting and forming aluminum alloy micro aircraft parts in a selective laser area is characterized by comprising the following steps:

step 1, establishing a model: designing and establishing a corresponding three-dimensional model by using modeling software according to the specific part requirements of the micro aircraft, and storing the three-dimensional model into an STL format file;

step 2, slicing treatment: carrying out layered slicing on the model file obtained in the step 1 according to the thickness of the powder spreading layer, and setting technological parameters of selective laser melting forming;

step 3, material preparation: taking raw material aluminum alloy powder and drying;

step 4, preparation for forming: adding the aluminum alloy powder dried in the step (3) into a material cylinder of selective laser melting equipment, selecting a substrate to be fixed on a forming cylinder platform capable of ascending and descending, washing the cabin of the selective laser melting equipment and flushing inert gas, and simultaneously opening a heating system and a ventilation system;

step 5, sample printing: scanning the mixed powder paved on the platform of the forming cylinder by using fiber laser and deflecting laser beams through a galvanometer, then ascending the material cylinder, descending the forming cylinder, paving powder from the material cylinder to the forming cylinder by using a powder paving rod, repeating the action, and piling up the geometric shape of the sample piece layer by layer;

and 6, placing the formed sample piece obtained in the step 5 into a forming cylinder of selective laser melting equipment, cooling to room temperature, taking out, and separating from the substrate.

2. The process method for selective laser melting forming of the aluminum alloy micro aircraft parts according to claim 1, wherein the specific parts of the micro aircraft in the step 1 comprise micro gears and micro brackets.

3. The process method for selective laser melting forming of the aluminum alloy micro aircraft parts according to claim 1, wherein in the step 2, selective laser melting is performed in a single-layer powder laying mode and two laser scanning modes.

4. The process method for selective laser melting forming of aluminum alloy micro aircraft parts according to claim 3, wherein in the step 2, the first scanning power of selective laser melting laser is 180W-220W, and the scanning speed is 1500 mm/s-1800 mm/s; the second scanning power of the laser is 350W-400W, and the scanning speed is 1700 mm/s-2200 mm/s; the scanning distance is 50-80 μm, the powder spreading layer is 30-50 μm thick, and the scanning strategy is as follows: the initial angle was scanned at 57 deg. and deflected at an angle of 67 deg..

5. The process for selective laser melting forming of aluminum alloy micro aircraft parts as claimed in claim 3, wherein the aluminum alloy powder in step 3 is AlSi10Mg powder with particle size of 15 μm to 53 μm, wherein D10 is 15 μm to 25 μm, D50 is 30 μm to 45 μm, and D90 is 50 μm to 65 μm.

6. The process method for selective laser melting forming of the aluminum alloy micro aircraft parts according to claim 5, wherein the AlSi10Mg powder in the step 3 comprises the following components in percentage by mass: mg: 0.20% -0.45%, Ti: less than or equal to 0.05 percent, Fe: less than or equal to 0.55 percent, Pb: less than or equal to 0.05 percent, Zn: less than or equal to 0.10 percent, Ni: less than or equal to 0.05 percent, Sn: less than or equal to 0.05 percent, O: less than or equal to 0.08 percent, N: less than or equal to 0.05 percent, Cu: less than or equal to 0.05 percent, Mn: less than or equal to 0.45 percent, less than or equal to 9.50 to 10.50 percent of Si, and the balance of Al.

7. The process method for selective laser melting forming of aluminum alloy micro aircraft parts according to claim 1, wherein the drying process in step 3 is as follows: drying for 6-8 h at 40-80 ℃.

8. The process method for selective laser melting forming of aluminum alloy micro aircraft parts according to claim 1, wherein the substrate material selected in step 4 is AlSi10Mg, and the temperature of the heating system is set to 80-130 ℃; the inert gas introduced into the selective laser melting and forming cabin is argon, the oxygen content of the cabin is controlled to be below 500ppm in the selective laser melting and forming process, and the ventilation frequency of the ventilation system is 14 Hz-16 Hz.

9. The process method for selective laser melting forming of aluminum alloy micro aircraft parts according to claim 1, wherein in the step 6, the sample piece is separated from the substrate by cutting and separating by using a high-speed wire-cut electrical discharge machine.

10. The process method for selective laser melting forming of aluminum alloy micro aircraft parts according to claim 1, wherein in the high-speed wire-moving electric spark wire cutting, the electrode wire is a molybdenum wire with a diameter of 0.18 mm.

Technical Field

The invention belongs to the field of aluminum alloy laser additive manufacturing technology and micro aircraft manufacturing, and particularly relates to a process method for forming an aluminum alloy micro aircraft part by selective laser melting.

Background

The aluminum alloy material has low density and high strength, and is lighter compared with steel with the same strength; the surface of the aluminum alloy part can form aluminum oxide due to oxidation and the like so as to play a role in protection, and the corrosion resistance of the part is improved; the aluminum alloy has good electric and heat conducting properties, which are second to silver, copper and gold; the aluminum alloy has high plasticity and can be applied to the preparation of various section bars. Therefore, aluminum alloys are widely used in the fields of home appliances, automobiles, ships, and aerospace. The traditional aluminum alloy processing method is difficult to form parts on the micro aircraft, the material waste is large, the processing period is long, and the manufacturing efficiency of the aircraft can be reduced. The selective laser melting technology can solve the problems and realize the manufacturing of high-efficiency, high-precision and controllable tiny aircraft parts.

The selective laser melting technology is that according to the shape information of a model in a control system, a laser beam sweeps a partial area of thin metal powder paved on a layer of metal plate; the area irradiated by the laser beam is melted and then rapidly solidified to form a layer of solid, and then the steps are repeated to form the whole solid of the part. The formed part melted in the laser selective area has short production period and high density, can be manufactured into a complex shape, and greatly saves time and cost.

Disclosure of Invention

The invention aims to provide a process method for melting and forming aluminum alloy micro aircraft parts in a selective laser area, which realizes the aim that the aluminum alloy parts of the micro aircraft can be integrally formed and quickly formed at one time, so that the parts of the micro aircraft have high precision and short production period, and the requirements of actual working conditions are met.

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

a process method for melting and forming aluminum alloy micro aircraft parts in a selective laser area comprises the following steps:

step 1, establishing a model: designing and establishing a corresponding three-dimensional model by using modeling software according to the specific part requirements of the micro aircraft, and storing the three-dimensional model into an STL format file;

step 2, slicing treatment: carrying out layered slicing on the model file obtained in the step 1 according to the thickness, and setting technological parameters of selective laser melting forming;

step 3, material preparation: taking raw material aluminum alloy powder and drying;

step 4, preparation for forming: adding the aluminum alloy powder dried in the step (3) into a material cylinder of selective laser melting equipment, selecting a substrate to be fixed on a forming cylinder platform capable of ascending and descending, washing the cabin of the selective laser melting equipment and flushing inert gas, and simultaneously opening a heating system and a ventilation system;

step 5, sample printing: scanning the mixed powder paved on the platform of the forming cylinder by using fiber laser and deflecting laser beams through a galvanometer, then ascending the material cylinder, descending the forming cylinder, paving powder from the material cylinder to the forming cylinder by using a powder paving rod, repeating the action, and piling up the geometric shape of the sample piece layer by layer;

and 6, placing the formed sample piece obtained in the step 5 into a forming cylinder of selective laser melting equipment, cooling to room temperature, taking out, and separating from the substrate.

In the above steps, the specific parts of the micro aircraft in step 1 include a micro gear, a micro bracket, and the like;

the technological parameters required by the selective laser melting equipment in the step 2 are as follows: adopting a single-layer powder spreading and two-time laser scanning mode, wherein the first-time laser scanning power is 180W-220W, and the scanning speed is 1500 mm/s-1800 mm/s; the second scanning power of the laser is 350W-400W, and the scanning speed is 1700 mm/s-2200 mm/s; the scanning distance is 50-80 μm, the powder spreading layer is 30-50 μm thick, and the scanning strategy is as follows: scanning an initial angle of 57 ° and deflecting at an angle of 67 °;

the aluminum alloy powder in the step 3 is AlSi10Mg powder with the granularity of 15-53 mu m, wherein D10 is 15-25 mu m, D50 is 30-45 mu m, and D90 is 50-65 mu m;

the AlSi10Mg powder in the step 3 comprises the following components in percentage by mass: mg: 0.20% -0.45%, Ti: less than or equal to 0.05 percent, Fe: less than or equal to 0.55 percent, Pb: less than or equal to 0.05 percent, Zn: less than or equal to 0.10 percent, Ni: less than or equal to 0.05 percent, Sn: less than or equal to 0.05 percent, O: less than or equal to 0.08 percent, N: less than or equal to 0.05 percent, Cu: less than or equal to 0.05 percent, Mn: less than or equal to 0.45 percent, less than or equal to 9.50 to 10.50 percent of Si, and the balance of Al;

the drying process in the step 3 is as follows: drying for 6-8 h at 40-80 ℃;

the substrate material selected in the step 4 is AlSi10Mg, and the temperature of a heating system is set to be 80-130 ℃;

in the step 4, the inert gas introduced into the selective laser melting forming cabin is argon, the oxygen content of the cabin is controlled to be below 500ppm in the selective laser melting forming process, and the ventilation frequency of a ventilation system is 14 Hz-16 Hz;

and 6, separating the sample piece from the substrate by using a high-speed wire-moving electric spark wire cutting machine for cutting and separating, wherein the electrode wire is a molybdenum wire and has the diameter of 0.18 mm.

Has the advantages that: the invention provides a process method for melting and forming aluminum alloy micro aircraft parts in a selective laser area, which has the following advantages compared with the prior art:

the selective laser melting forming process adopts a single-layer powder laying mode and two-time laser scanning mode, and the two-time scanning parameters are different, so that the alloy surface solidified by the first-time laser scanning can be melted again, unfused powder, cavities and cracks in a formed part are reduced, and the fatigue resistance of the part is improved;

according to the invention, the aluminum alloy powder is melted layer by the optical fiber laser beam, so that the rapid forming of the tiny aircraft part is realized, and the problems of difficult processing, long processing period and low processing precision are solved;

the invention adopts the selective laser melting technology to directly form parts, the precision of the formed parts is high, and the microhardness, the corrosion resistance and the fatigue resistance are all improved.

The invention has short production period, no mould, part cost saving, free part design, light part weight and high forming quality.

Drawings

FIG. 1 is a flow chart of a process for selective laser melting forming of aluminum alloy micro aircraft parts in an embodiment of the invention;

FIG. 2 is a scanning electron micrograph of AlSi10Mg powder according to an example of the present invention;

FIG. 3 is a schematic view of a gear of a micro aircraft obtained by the process of the embodiment of the invention;

FIG. 4 is a schematic view of a small aircraft support obtained by the process of the embodiment of the invention.

Detailed Description

The invention provides a process method for melting and forming aluminum alloy micro aircraft parts in a selective laser area. For ease of understanding, the following further description is provided in terms of specific embodiments and the accompanying drawings:

example 1

Preparation of micro aircraft gear

The embodiment provides a process method for forming an aluminum alloy micro aircraft gear by selective laser melting, which specifically comprises the following steps:

(1) establishing a model: designing a three-dimensional model by using SolidWorks software according to the requirements of the micro aircraft gear, and storing the three-dimensional model into an STL format file for later use;

(2) and (3) slicing treatment: and (3) carrying out layered slicing on the model file of the micro aircraft gear obtained in the step (1) in the AutoFab software according to the thickness of the powder layer, and setting technological parameters of selective laser melting: the first scanning power of the laser is 195W, the scanning speed is 1600mm/s, the second scanning power of the laser is 390W, and the scanning speed is 2000 mm/s; the scanning distance is 50 μm, the powder layer thickness is 30 μm, and the scanning strategy is: scanning an initial angle of 57 ° and deflecting at an angle of 67 °;

(3) preparing materials: taking raw material AlSi10Mg powder, wherein the particle size is 15-53 μm, D10 is 22.58 μm, D50 is 37.51 μm, D90 is 58.73 μm, the microstructure is shown in figure 2, and the AlSi10Mg powder comprises the following components in percentage by mass: mg: 0.41%, Ti: 0.0084%, Fe: 0.1%, Pb: 0.01%, Zn: < 0.005%, Ni: < 0.005%, Sn: < 0.01%, O: 0.029%, N: < 0.001%, Cu: < 0.05%, Mn: 0.03%, Si: 9.53 percent, and the balance of Al;

(4) and (3) drying treatment: drying the aluminum alloy powder at 40 ℃ for 8 h;

(5) preparation of molding: adding aluminum alloy powder into a material cylinder of selective laser melting equipment, fixing a substrate made of AlSi10Mg on a forming cylinder platform capable of lifting, leveling the forming platform, performing gas washing treatment on the selective laser melting equipment, and introducing argon to control the oxygen content to be 500ppm, and simultaneously opening a heating system and a ventilation system to heat the substrate to 80 ℃ and ensure that the ventilation frequency is 16 Hz;

(6) printing a sample piece: using fiber laser, deflecting laser beams through a galvanometer, scanning the aluminum alloy powder paved on the platform of the forming cylinder twice according to different process parameters, then ascending the material cylinder, descending the forming cylinder, paving the aluminum alloy powder from the material cylinder to the forming cylinder by a powder paving roller, repeating the action, and piling up the geometric shapes of the micro aircraft gear layer by layer;

(7) and (3) placing the formed sample piece of the gear of the micro aircraft in a forming cylinder of selective laser melting equipment, cooling to room temperature, taking out, and separating the formed sample piece from the substrate by using a high-speed wire-moving electric spark wire cutting machine with a molybdenum wire diameter of 0.18mm to obtain the formed piece shown in figure 3.

Example 2

Preparation of micro aircraft bracket

The embodiment provides a process method for forming an aluminum alloy micro aircraft support through selective laser melting, which specifically comprises the following steps:

(1) establishing a model: designing a three-dimensional model by using SolidWorks software according to the requirements of the micro aircraft bracket, and storing the three-dimensional model into an STL format file for later use;

(2) and (3) slicing treatment: and (3) carrying out layered slicing on the model file of the micro aircraft support obtained in the step (1) in the AutoFab software according to the thickness of the powder layer, and setting technological parameters of selective laser melting: the first scanning power of the laser is 200W, the scanning speed is 1600mm/s, the second scanning power of the laser is 390W, and the scanning speed is 2000 mm/s. The scanning distance is 60 μm, the powder layer thickness is 30 μm, and the scanning strategy is: scanning an initial angle of 57 ° and deflecting at an angle of 67 °;

(3) preparing materials: taking raw material AlSi10Mg powder, wherein the particle size is 15-53 μm, D10 is 22.58 μm, D50 is 37.51 μm, D90 is 58.73 μm, the microstructure is shown in figure 2, and the AlSi10Mg powder comprises the following components in percentage by mass: mg: 0.41%, Ti: 0.0084%, Fe: 0.1%, Pb: 0.01%, Zn: < 0.005%, Ni: < 0.005%, Sn: < 0.01%, O: 0.029%, N: < 0.001%, Cu: < 0.05%, Mn: 0.03%, Si: 9.53 percent, and the balance of Al;

(4) and (3) drying treatment: drying the aluminum alloy powder at 60 ℃ for 6 h;

(5) preparation of molding: adding aluminum alloy powder into a material cylinder of selective laser melting equipment, fixing a substrate made of AlSi10Mg on a forming cylinder platform capable of lifting, leveling the forming platform, performing gas washing treatment on the selective laser melting equipment, and introducing argon to control the oxygen content to be 500ppm, and simultaneously opening a heating system and a ventilation system to heat the substrate to 100 ℃ and ensure that the ventilation frequency is 16 Hz;

(6) printing a sample piece: using fiber laser, deflecting laser beams through a galvanometer, scanning the aluminum alloy powder paved on the platform of the forming cylinder twice according to different process parameters, then ascending the material cylinder, descending the forming cylinder, paving the aluminum alloy powder from the material cylinder to the forming cylinder by a powder paving roller, repeating the action, and piling up the geometric shape of the micro aircraft support layer by layer;

(7) and (3) placing the formed sample piece of the micro aircraft bracket in a forming cylinder of selective laser melting equipment, cooling to room temperature, taking out, and separating the formed sample piece from the substrate by using a high-speed wire-moving electric spark wire cutting machine with a molybdenum wire diameter of 0.18mm to obtain the formed piece shown in figure 4.

The invention relates to a process method for forming an aluminum alloy micro aircraft part by selective laser melting.

The following description is only exemplary of the present invention, and the detailed description is not intended to limit the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.