FEEDSTOCK FOR 3D PRINTING, PREPARATION METHOD AND APPLICATION THEREOF

Abstract

The present invention relates to a feedstock for 3D printing, a preparation method and an application thereof. The feedstock is polymer binder-coated metal powder, being in a linear shape. After being printed into a green body with a preset shape via a 3D printer, the linear feedstock is sequentially degreased and sintered, so that a metal product with a complex structure and high accuracy can be obtained. Compared with the prior art, the linear feedstock is applied to 3D printing, so that waste of raw materials can be avoided; the accuracy of a product surface is controlled and the quality of products is improved by selecting different wire diameters of the feedstock and controlling the heating temperature; and melting treatment can be performed by a simple thermocouple without need for complex and dear laser heating equipment, so that production cost is reduced. The powder injection molding technology and 3D printing technology are combined, so that complex products can be quickly printed and manufactured, development flow is shortened, and mass production popularization is realized. The feedstock has good economic benefits and wide application prospect.

Claims

1. A feedstock for 3D printing, wherein the feedstock is polymer binder-coated metal powder, being in a linear shape.

2. The feedstock according to claim 1, wherein the feedstock consists of the following components by volume percentage: 15-75% of metal powder; 25-85% of polymer binder.

3. The feedstock according to claim 2, wherein the linear feedstock has a diameter of 0.1-5 mm.

4. The feedstock according to claim 3, wherein the linear feedstock has a diameter of 1-3 mm.

5. The feedstock according to claim 1, wherein the metal powder is any one of titanium and/or titanium alloy powder, copper and/or copper alloy powder, aluminum and/or aluminum alloy powder, iron and/or iron alloy powder, neodymium and/or neodymium alloy powder.

6. A preparation method of the feedstock for 3D printing according to claim 1, wherein the method comprises the following steps: (1) mixing formula amounts of metal powder and polymer binder, such that the polymer binder is coated on the surface of the metal powder; (2) extruding and molding the polymer binder-coated metal powder obtained in step (1) into a linear shape, and cooling to obtain the feedstock for 3D printing.

7. The method according to claim 6, wherein the mixing in step (1) is performed at a temperature of 165-200 C.

8. The method according to claim 6, wherein the linear feedstock obtained in step (2) is wound into a disk shape for use.

9. An application of the feedstock according to claim 1, wherein the feedstock is applied in 3D printing.

10. The application according to claim 9, wherein the application includes the following steps: (1) using the linear feedstock as a raw material to print a green body with a preset shape via a 3D printer; (2) degreasing the green body obtained in step (1) to obtain a brown body; (3) sintering the brown body obtained in step (3) to obtain a sintered part; (4) optionally, post-processing the sintered part obtained in step (3).

11. The application according to claim 10, wherein based on the total amount, the amount of polymer binder which is removed from the brown body is 8-12%.

12. The application according to claim 10, wherein the sintering in step (3) is performed at a temperature of 1200-1450 C.

13. The feedstock according to claim 1, wherein the metal powder is titanium and/or titanium alloy powder.

14. The feedstock according to claim 1, wherein the polymer binder is plastic-based binder or wax-based binder.

15. The method according to claim 6, wherein the mixing in step (1) is performed for 0.5-2 h.

16. The application according to claim 10, wherein the method of degreasing in step (2) is any one of thermal degreasing, water degreasing, acid degreasing, and organic solvent degreasing.

17. The application according to claim 16, wherein the medium for acid degreasing is nitric acid or oxalic acid.

18. The application according to claim 10, wherein the sintering in step (3) is performed for 2-3 h.

Description

DESCRIPTION OF THE DRAWINGS

[0045] FIG. 1 is a process flow diagram of preparation and application of the feedstock provided by a specific embodiment of the present application.

[0046] The embodiments of the present invention will be further described in detail as following. However, the following embodiments are merely illustrative examples of the present application and do not represent or limit the protection scope of the present application. The protection scope of the present application is subject to the claims.

DETAILED DESCRIPTION

[0047] The technical solutions of the present application will be further described below with reference to the accompanying drawings and by specific embodiments.

[0048] As shown in FIG. 1, the process for preparation and application of the feedstock provided by a specific embodiment of the present application can be: a metal powder and a polymer binder are mixed to prepare a linear feedstock, and the obtained feedstock is printed and molded by using 3D printing to obtain a green body, and the obtained green body is successively subjected to degreasing, sintering and post-processing to obtain a finished product.

[0049] In order to better illustrate the present application and facilitate understanding of the technical solutions of the present application, typical but non-limiting examples of the present application are as follows:

Example 1

[0050] A preparation method of a feedstock for 3D printing is as follows:

[0051] (1) 60 vol % of titanium metal powder was mixed with 40 vol % of polymer binder, the polymer binder including: 85 wt % of polyoxymethylene, 14 wt % of polypropylene, and 1 wt % of stearic acid; the raw materials were added into an internal mixer and mixed at 170 C. for 1 h;

[0052] (2) The material obtained after mixing in the step (1) was extruded into a linear material with a diameter of 2 mm by using an extruder, cooled to obtain a feedstock for 3D printing, and the linear feedstock was wound into a disk shape for use.

[0053] The application of the feedstock for 3D printing obtained in this example includes the following steps:

[0054] (1) The linear feedstock was used as a raw material to print a green body with a preset shape via a 3D printer;

[0055] (2) The green body obtained in step (1) was degreased at 110 C. for 4 h using nitric acid as a medium, 10% of polymer binder was removed to obtain a brown body;

[0056] (3) The brown body obtained in step (2) was placed in a vacuum furnace, sintered at 1250 C. for 3 h, and cooled to obtain a titanium-based product.

Example 2

[0057] A preparation method of a feedstock for 3D printing is as follows:

[0058] (1) 50 vol % of titanium alloy powder was mixed with 50 vol % of polymer binder, the polymer binder including: 80 wt % of paraffin wax, 19.5 wt % of polyethylene and 0.5 wt % of stearic acid; the raw materials were added into an internal mixer and mixed at 200 C. for 0.5 h;

[0059] (2) The material obtained after mixing in the step (1) was extruded into a linear material with a diameter of 3 mm by using an extruder, cooled to obtain a feedstock for 3D printing, and the linear feedstock was wound into a disk shape for use.

[0060] The application of the feedstock for 3D printing obtained in this example includes the following steps:

[0061] (1) The linear feedstock was used as a raw material to print a green body with a preset shape via a 3D printer;

[0062] (2) The green body obtained in step (1) was soaked at 80 C. for 6 h using heptane as a medium, 12% of polymer binder was removed to obtain a brown body;

[0063] (3) The brown body obtained in step (2) was placed in a vacuum furnace, sintered at 1260 C. for 2.5 h, and cooled to obtain a titanium alloy-based product.

[0064] (4) The titanium alloy-based product obtained in step (3) was post-processed according to customer requirements.

Example 3

[0065] A preparation method of a feedstock for 3D printing is as follows:

[0066] (1) 70 vol % of copper powder was mixed with 30 vol % of polymer binder, the polymer binder including: 84 wt % of paraffin wax, 14 wt % of polypropylene and 2 wt % of stearic acid; the raw materials were added into an internal mixer and mixed at 165 C. for 2 h;

[0067] (2) The material obtained after mixing in the step (1) was extruded into a linear material with a diameter of 5 mm by using an extruder, cooled to obtain a feedstock for 3D printing, and the linear feedstock was wound into a disk shape for use.

[0068] The application of the feedstock for 3D printing obtained in this example includes the following steps:

[0069] (1) The linear feedstock was used as a raw material to print a green body with a preset shape via a 3D printer;

[0070] (2) The green body obtained in step (1) was soaked at 60 C. for 8 h using heptane as a medium, 11% of polymer binder was removed to obtain a brown body;

[0071] (3) The brown body obtained in step (2) was placed in a vacuum furnace, sintered at 1030 C. for 2 h, and cooled to obtain a copper-based product.

Example 4

[0072] A preparation method of a feedstock for 3D printing is as follows:

[0073] (1) 50 vol % of titanium metal powder was mixed with 50 vol % of polymer binder, the polymer binder including: 70 wt % of polyoxymethylene, 27.5 wt % of polypropylene, and 2.5 wt % of stearic acid; the raw materials were added into an internal mixer and mixed at 185 C. for 1 h;

[0074] (2) The material obtained after mixing in the step (1) was extruded into a linear material with a diameter of 1.5 mm by using an extruder, cooled to obtain a feedstock for 3D printing, and the linear feedstock was wound into a disk shape for use.

[0075] The application of the feedstock for 3D printing obtained in this example includes the following steps:

[0076] (1) The linear feedstock was used as a raw material to print a green body with a preset shape via a 3D printer;

[0077] (2) The green body obtained in step (1) was soaked at 120 C. for 3 h using nitric acid as a medium, 8% of polymer binder was removed to obtain a brown body;

[0078] (3) The brown body obtained in step (2) was placed in a vacuum furnace, sintered at 1250 C. for 3 h, and cooled to obtain a titanium-based product.

Example 5

[0079] A preparation method of a feedstock for 3D printing is as follows:

[0080] (1) 60 vol % of stainless steel powder was mixed with 40 vol % of polymer binder, the polymer binder including: 70 wt % of polyoxymethylene, 28 wt % of polypropylene, and 2.0 wt % of stearic acid; the raw materials were added into an internal mixer and mixed at 185 C. for 1 h;

[0081] (2) The material obtained after mixing in the step (1) was extruded into a linear material with a diameter of 1.75 mm by using an extruder, cooled to obtain a feedstock for 3D printing, and the linear feedstock was wound into a disk shape for use.

[0082] The application of the feedstock for 3D printing obtained in this example includes the following steps:

[0083] (1) The linear feedstock was used as a raw material to print a green body with a preset shape via a 3D printer;

[0084] (2) The green body obtained in step (1) was soaked at 120 C. for 3 h using nitric acid as a medium, 8% of polymer binder was removed to obtain a brown body;

[0085] (3) The brown body obtained in step (2) was placed in a vacuum furnace, sintered at 1360 C. for 3 h, and cooled to obtain a stainless steel-based product.

[0086] The preferred embodiments of the present application have been described in detail above. However, the present application is not limited to the specific details in the above embodiments. Various simple variations of the technical solutions of the present application may be made within the technical concept of the present application, and all these simple variations belong to the protection scope of the present application.

[0087] In addition, it should be noted that the specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary duplication, various possible combinations will not be further explained in the present application.

[0088] In addition, any combination may also be made between various different embodiments of the present application as long as it does not violate the idea of the present application, which should also be regarded as disclosure of the present application.