CN116571761A - Printing method of three-dimensional printing equipment - Google Patents

Abstract

The present invention relates to the technical field of three-dimensional printing methods, and provides a printing method for a three-dimensional printing device, including the following steps: S1: start the three-dimensional printing device, the three-dimensional printing device includes a print head; S2: input data with a target solid model into a memory model file; S3: Scan each layer: use the print head to scan each layer of the solid model data in a straight line to obtain a printed model; wherein, in S3, during the process of linear scanning for each layer , the number of scans for the same layer is at least two, and after one scan is completed, the print head is adapted to rotate at a certain angle before performing the next scan. The scanning angles of the two straight-line scans are different. After scanning the model of the same layer, pores will be generated, and then the next scan will be used to melt the metal and fill the pores to reduce the diameter of the pores. The effect of the small pores of the scanned model.

Description

A printing method of a three-dimensional printing device

technical field

The invention relates to the technical field of SLM printing, in particular to a printing method of a three-dimensional printing device.

Background technique

At present, metal 3D printing conformal waterway parts are widely used in the injection mold industry. Due to the characteristics of metal 3D printing, the existence of some pores cannot be avoided, so it cannot be used on molds with high polishing requirements. Both sizes have high requirements.

During the printing process, pores will be produced when laser high energy density melting powder molding and laser low energy density melting powder molding are used. The reason is that when printing with high energy density, the molten pool is deep and wide, and the size of the molten pool It will gradually increase with the increase of laser energy, and the gas generated by the evaporation of high-temperature metal liquid and the gas released after the pore powder in the original powder is not precipitated even if it is not precipitated, will form the situation that the pore parts are not dense; when printing with low energy density When printing with low energy density, the width of the molten pool becomes narrower, and the solidification time of the molten pool is short, resulting in pores not being filled in time, and the metal powder may not be completely melted during low energy density printing, which will affect the strength of the workpiece.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the prior art. During the printing process, pores will be generated when laser high energy density melting powder molding and laser low energy density melting powder molding are used. The reason is that when using high energy During density printing, the molten pool is deep and wide, and the size of the molten pool will gradually increase with the increase of laser energy, which will generate high-temperature molten metal evaporation to produce gas and the pores in the original powder. The gas released after the powder is melted will not be precipitated , will form the situation that the porous parts are not dense; when printing with low energy density, the width of the molten pool becomes narrower, and the solidification time of the molten pool is short, resulting in some pores not being filled in time to generate pores. And the metal powder may not be completely melted during low energy density printing, which will affect the strength of the workpiece, thereby providing a printing method for a three-dimensional printing device.

A printing method for a three-dimensional printing device, comprising the following steps: S1: start the three-dimensional printing device, and the three-dimensional printing device includes a printing head; S2: input a model file with target solid model data to the memory; S3: perform a process on each layer Scanning: use the print head to scan each layer of the solid model data sequentially in a straight line to obtain a printed model; wherein, in S3, during the linear scanning of each layer, the number of scans for the same layer is at least twice, After one scan is completed, the print head is adapted to rotate at a certain angle before performing the next scan.

Optionally, in the printing method of the above three-dimensional printing device, in S3, between two scans of each layer, the printing head is adapted to rotate by 10°-40°.

Optionally, in the printing method of the above three-dimensional printing device, in S3, the scanning laser power is between 180w-300w.

Optionally, in the printing method of the above-mentioned three-dimensional printing device, in S3, during each scanning process, the inclination angle of the printing head is between 45°-113°.

Optionally, in the printing method of the above-mentioned three-dimensional printing device, in S3, in each scan, the path offset pitch is 0.08-0.15 mm.

Optionally, in the printing method of the above-mentioned three-dimensional printing device, in S3, in each scan, the scanning width of the printing head is 8-12 mm.

Optionally, in the printing method of the above-mentioned three-dimensional printing device, in S3, in each scan, the scan overlap is 0.2-0.5 mm.

Optionally, in the printing method of the above three-dimensional printing device, in S3, the printing layer thickness of each layer is between 0.05mm-0.08mm.

Optionally, in the printing method of the above three-dimensional printing device, in S3, the printing speed is 750mm/s-1000mm/s.

Optionally, in the printing method of the above-mentioned three-dimensional printing device, in S3, after the linear scanning of the upper layer, the printing head is rotated by 45°-113°, and then the linear scanning of the next layer is performed, thereby completing the Linear scan of each layer.

Optionally, in the printing method of the above-mentioned three-dimensional printing device, in S3 and S2, it further includes S0: layering the model file of the target entity model data.

The technical solution of the present invention has the following advantages:

1. The printing method of a kind of three-dimensional printing equipment provided by the present invention comprises the following steps: S1: start three-dimensional printing equipment, and described three-dimensional printing equipment comprises printing head; S2: input the model file that has target entity model data to memory; S3 : Scan each layer: Use the print head to scan each layer of the solid model data in a straight line to obtain the printed model; wherein, in S3, during the process of scanning each layer in a straight line, the scanning of the same layer The number of times is at least two, and after one scan is completed, the print head is adapted to rotate at a certain angle before performing the next scan.

In this printing method, during the scanning process, when scanning each layer, at least two linear scans are used, and after one scan is completed, the print head rotates at a certain angle, and then the next scan is performed, thus making the two The scanning angle of the secondary linear scan is different. After scanning the model of the same layer once, pores will be generated, and then the next scan will be used to melt the metal, and the pores can be filled to reduce the diameter of the pores and realize the scanning. The finished model has small pores, which improves the overall density of the model, reduces the porosity of the parts, meets the high polishing requirements of the mold, and overcomes the use of laser high energy density melting in the printing process in the prior art Both powder molding and laser low energy density melting powder molding will produce pores. The reason is that when printing with high energy density, the molten pool is deep and wide, and the size of the molten pool will gradually increase with the increase of laser energy. The gas generated by the evaporation of the high-temperature metal liquid and the gas released after the pore powder in the original powder is not precipitated will cause the porous parts to be not dense; when printing with low energy density, the width of the molten pool becomes narrower, and the solidification of the molten pool The time is short, resulting in some pores not being filled in time to produce pores, and the metal powder may not be completely melted during low energy density printing, which will affect the strength of the workpiece.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

Fig. 1 is the surface pore metallographic diagram of the mold insert prepared in the embodiment 1 of the present application;

Fig. 2 is the surface pore metallographic diagram of the mold insert prepared in Example 2 of the present application;

Fig. 3 is the product metallographic diagram of the mold insert of comparative example 1;

Fig. 4 is the product metallographic diagram of the mold insert of comparative example 2;

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are part of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, or in a specific orientation. construction and operation, therefore, should not be construed as limiting the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

It should be noted that after the scanning is completed, the product needs to be heat treated.

Example 1

This implementation records a printing method for a three-dimensional printing device, including the following steps: S1: start the three-dimensional printing device, and the three-dimensional printing device includes a print head; S2: input a model file with target entity model data into the memory; S3: Scan each layer: Use the print head to scan each layer of the solid model data sequentially in a straight line to obtain the printed model; wherein, in S3, in the process of linear scanning for each layer, the number of scans of the same layer is at least For two times, after one scan is completed, the print head is rotated at a certain angle, and then the next scan is performed.

In actual use, the light beam emitted by the laser generator is reflected on the printing layer via the galvanometer for printing, wherein the inclination angle of the print head is controlled by the inclination angle of the galvanometer. Specifically, the change of the inclination angle of the galvanometer can be Adjust the angle of incidence between the laser beam emitted by the laser generator and the vibrating mirror, and then the angle of reflection will also change, so as to realize the tilt angle of the printing head.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the printing head is adapted to rotate by 10° between two scans of each layer, that is, during the scanning process of the same layer by the printing head , when the print head scans for the first time, the inclination angle is 45°. Before the second scan, the print head is rotated by 10°. 55°, thus completing the scanning of the same layer.

In S3, the scanning laser power is set to 180w. Using lower laser energy to seal can avoid the air holes caused by the gas generated when the metal melts at high temperature. The second rotation angle scanning can melt and fill the remaining air holes in the first scanning. Reduced pore diameter size.

In the printing method of the three-dimensional printing device in this embodiment, in S3, during each scanning process, the inclination angle of the printing head is between 45°-113°, for example, when scanning the same layer, the first time Scanning, the inclination angle of the print head is 45°, the second inclination angle is 55°, and when scanning the next layer, adjust the inclination angle of the print head to the inclination angle of the first scan of the previous layer , which is 45°, after the first scan is completed, the inclination angle of the second scan is 55°.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the path offset pitch is 0.08mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the scanning width of the printing head is 12mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the scans overlap by 0.2 mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the printing layer thickness of each layer is set to 0.08 mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the printing speed is 1000 mm/s.

In the printing method of the three-dimensional printing device in this embodiment, in S3, after the linear scanning of the upper layer, the printing head is rotated by 113°, and then the linear scanning of the next layer is performed, thereby completing the scanning of each layer. linear scan.

In the printing method of the three-dimensional printing device in this embodiment, in S3 and S2, it further includes S0: layering the model file of the target solid model data.

In this embodiment, printing each layer requires two straight line scans and fills. When the first scan line fills with a rotation angle of 0, the second line fills with an angle of 10-40 degrees based on the first line fill rotation angle. Scanning and filling, after scanning, the forming cylinder reduces the layer thickness by 0.05-0.08 to enter the next layer for powder spreading, and then rotate 45-113° on the basis of the linear scanning and filling of the previous layer for linear filling and scanning.

The scanning angle between two linear scanning fillings of the same layer is 10-40°, and the rotation angle of linear scanning filling between each layer after the layer thickness changes is 45-113°.

Through metal 3D printing equipment, the oxygen content of the molding cylinder is below 500ppm, the protective gas in the molding cylinder is argon, the particle size of the powder is 15-75um, and the heating temperature of the substrate is 100-150°C, using the set parameters in this embodiment. Print and shape.

The invention uses lower energy density to print multiple filling methods, which reduces the problem of large pores in the printing process and the parts are not dense, improves the density of the parts, and reduces the porosity of the parts to 0.002-0.01%, which meets the high mold requirements. Polishing requirements.

Example 2:

This embodiment records a printing method of a three-dimensional printing device, including the following steps: S1: start the three-dimensional printing device, and the three-dimensional printing device includes a print head; S2: input a model file with target entity model data to the memory; S3: Scan each layer: use the print head to scan each layer of the solid model data sequentially in a straight line to obtain the printed model; where, in S3, the number of scans of the same layer during the linear scan of each layer At least twice, after completing one scan, the print head is adapted to rotate at a certain angle before performing the next scan.

Different from Embodiment 1, in the printing method of the 3D printing device in this embodiment, in S3, the printing head is adapted to rotate by 40° between two scans of each layer.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the scanning laser power is set to 300w.

In the printing method of the three-dimensional printing device in this embodiment, in S3, during each scanning process, the inclination angle of the printing head is set to 45°.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the path offset pitch is 0.15mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the scanning width of the printing head is 8mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the scan overlap is 0.5mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the printing layer thickness of each layer is set to 0.05mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the printing speed is 750 mm/s.

In the printing method of the three-dimensional printing device in this embodiment, in S3, after the linear scanning of the upper layer, the printing head is rotated by 45°, and then the linear scanning of the next layer is performed, thereby completing the scanning of each layer. linear scan.

In the printing method of the three-dimensional printing device in this embodiment, in S3 and S2, it further includes S0: layering the model file of the target solid model data.

Example 3:

This implementation records a printing method for a three-dimensional printing device, including the following steps: S1: start the three-dimensional printing device, and the three-dimensional printing device includes a print head; S2: input a model file with target entity model data into the memory; S3: Scan each layer: Use the print head to scan each layer of the solid model data sequentially in a straight line to obtain the printed model; wherein, in S3, in the process of linear scanning for each layer, the number of scans of the same layer is at least For two times, after one scan is completed, the print head is rotated by a certain angle under the action of an external force, and then the next scan is performed.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the printing head is adapted to rotate by 25° between two scans of each layer, that is, during the scanning process of the same layer by the printing head , when the print head scans for the first time, its inclination angle is 25°. Before the second scan, the print head is rotated by 20°. 65°, thus completing the scanning of the same layer.

In S3, the scanning laser power is set to 240w. Using lower laser energy to seal can avoid the air holes caused by the gas generated when the metal melts at high temperature. The second rotation angle scanning can melt and fill the remaining air holes in the first scanning. Reduced pore diameter size.

In the printing method of the three-dimensional printing device in this embodiment, in S3, during each scanning process, the inclination angle of the printing head is between 45°-113°, for example, when scanning the same layer, the first time Scanning, the inclination angle of the print head is 60°, the second inclination angle is 45°, and when scanning the next layer, adjust the inclination angle of the print head to the inclination angle of the first scan of the previous layer , which is 45°, after the first scan is completed, the inclination angle of the second scan is 65°.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the path offset pitch is 0.12mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the scanning width of the printing head is 10 mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, in each scan, the scan overlap is 0.35mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the printing layer thickness of each layer is set to 0.06mm.

In the printing method of the three-dimensional printing device in this embodiment, in S3, the printing speed is 850 mm/s.

In the printing method of the three-dimensional printing device in this embodiment, in S3, after the linear scanning of the upper layer, the printing head is rotated by 113°, and then the linear scanning of the next layer is performed, thereby completing the scanning of each layer. linear scan.

In the printing method of the three-dimensional printing device in this embodiment, in S3 and S2, it further includes S0: layering the model file of the target solid model data.

Comparative example 1:

The difference between Comparative Example 1 and Example 1 is that in S3, the 3D printing process parameters are adjusted, the laser power is 500w, the laser scanning speed is 750mm/s, each layer is scanned once, the inclination angle is 20°, and the other parameters are the same. Higher porosity.

Comparative example 2:

The difference between Comparative Example 2 and Example 1 is that each layer is scanned twice, the scanning angle of the printing head is set to be the same, other parameters are the same, and the porosity of the obtained product is higher.

performance test

Detection method/test method: The porosity of the obtained product is detected by metallographic microscope detection method.

data analysis

Table 1 is the test parameter of embodiment 1-3 and comparative example 1,2

Example 1 Example 2 Example 3 Comparative example 1 Comparative example 2 Porosity 0.002% 0.009% 0.005% 0.11% 0.15% Polishing grade A1 A0 A2 A4 A4

In combination with Examples 1-4 and Comparative Examples 1-2 and in conjunction with Table 1 and Fig. 1-Fig. 4, it can be seen that the pore diameter in Fig. 1 is 12 μm, one of the pore diameters in Fig. 2 is 9 μm, and the other is 27 μm. There are many pores in the metallographic diagram of the model in 3, and the pore diameters are 30 μm, 39 μm, 56 μm, 38 μm and 48 μm respectively. The pores of the mold insert prepared by the preparation process in Example 1 and Example 2 The ratio is obviously lower than the porosity of the mold inserts in Comparative Example 1 and Comparative Example 2, and the porosity of the mold inserts obtained by the preparation process of this application can be reduced to 0.002%-0.009%, and the polishing grade can reach A0-A1 , can prepare mold inserts with low porosity and excellent polishing.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (11)

1. A printing method of a three-dimensional printing apparatus, comprising the steps of:

s1, starting three-dimensional printing equipment, wherein the three-dimensional printing equipment comprises a printing head;

s2: inputting a model file with target solid model data into a memory;

s3: scanning each layer: using a printing head to sequentially perform linear scanning on each layer of the entity model data so as to obtain a printing model;

in the step S3, in the process of performing the linear scanning on each layer, the number of scanning times of the same layer is at least two, and after the scanning is completed once, the print head is suitable for rotating a certain angle, and then performing the next scanning.

2. A method of printing a three-dimensional printing device according to claim 1, characterized in that in S3 the print head is adapted to be rotated by 10 ° -40 ° between two scans of each layer.

3. The printing method of a three-dimensional printing apparatus according to claim 1 or 2, wherein in S3, the scanned laser power is between 180w and 300w.

4. A method of printing a three-dimensional printing device according to any one of claims 1-3, characterized in that in S3 the inclination angle of the print head is between 45 ° -113 ° during each scan.

5. The printing method of the three-dimensional printing apparatus according to any one of claims 1 to 4, wherein in S3, the path shift pitch is 0.08 to 0.15mm in each scan.

6. The printing method of the three-dimensional printing apparatus according to any one of claims 1 to 5, wherein in S3, a scanning width of the print head is 8 to 12mm in each scanning.

7. The printing method of three-dimensional printing apparatus according to any one of claims 1 to 6, wherein in S3, the scan overlap is 0.2 to 0.5mm in each scan.

8. The printing method of the three-dimensional printing apparatus according to any one of claims 1 to 7, wherein in S3, the thickness of the printing layer of each layer is between 0.05mm and 0.08mm.

9. The printing method of the three-dimensional printing apparatus according to any one of claims 1 to 8, wherein in S3, the printing speed is 750mm/S to 1000mm/S.

10. The printing method of a three-dimensional printing apparatus according to any one of claims 1 to 9, wherein,

in S3, after the linear scanning of the previous layer, the printing head is rotated by 45 ° -113 °, and then the linear scanning of the next layer is performed, thereby completing the linear scanning of each layer.

11. The printing method of the three-dimensional printing apparatus according to any one of claims 1 to 10, further comprising S0 in S3 and S2; and layering the model files of the target entity model data.