CN116587600A - Multi-material 3D printer and printing method thereof - Google Patents

Abstract

The invention relates to a multi-material 3D printer and a printing method thereof, wherein the multi-material 3D printer comprises a forming device, a powder spreading and sucking device and a control device; the forming device comprises a forming chamber, a laser scanning head, a powder supply assembly, a forming cylinder body and a forming platform, wherein the forming cylinder body and the forming platform are positioned in the forming chamber; the powder spreading and sucking device comprises a powder spreading box body, a scraping plate, a powder distribution assembly, a powder sucking assembly and a translation assembly; the powder spreading box body is positioned above the top plane of the forming cylinder body and can controllably reciprocate along the X-axis direction of the top plane of the forming cylinder body; the translation assembly is arranged on the powder spreading box body, is arranged along the Y-axis direction of the top plane of the forming cylinder body, and is provided with a slidable mounting block; the powder distribution component and the powder suction component are arranged on the mounting block; the scraping plate is fixed at the bottom of the powder spreading box body corresponding to the powder distribution component. The multi-material 3D printer is matched with the powder paving box body and the translation assembly to move in the X-axis direction and the Y-axis direction respectively, so that accurate powder paving is realized according to a designated area, and the ineffective powder supply in the printing process is greatly reduced.

Description

A kind of multi-material 3D printer and printing method thereof

technical field

The invention relates to the technical field of 3D printing, in particular to a multi-material 3D printer and a printing method thereof.

Background technique

3D printing, also known as additive manufacturing, is based on digital model files, using powdered metal or filamentary plastics as molding materials, and constructing objects by layer-by-layer printing. The structural design of its parts is not limited by traditional processing techniques, and various complex-shaped surface features can be processed relatively quickly.

At present, the laser 3D printing technology based on the principle of powder bed fusion mainly includes selective laser melting technology (Selective Laser Melting, SLM), selective laser sintering technology (Selective Laser Sintering, SLS) and so on. This type of technology generally uses a scraper or roller to lay the powder layer by layer in the molding area, and then uses a laser beam to selectively melt or sinter the powder in the molding area to make it solidify, and then lay the next layer of powder and then solidify. , so that the cycle layer by layer accumulates into a three-dimensional entity. In the molding process, in addition to being used to form parts, the rest of the powder accumulated on the forming platform can also be used to fill the forming platform to provide powder support and even part support for the laying of the next layer of powder.

At present, when the multi-material laser selective melting 3D printing process prints a certain material area, the powder laying work basically needs to lay a whole layer of powder for printing and clean up the excess powder to re-lay the different powder; and in the process of cleaning the remaining powder It is often necessary to clean up almost all the powder in the current layer that has not undergone laser selective melting, including the powder that acts as a powder support, which will lead to an inflated amount of powder to be used during the printing process, and most of the powder is recycled to the powder collection chamber Instead of being used in the manufacture of parts, the powder utilization rate is low; and the powder recycling process cannot completely clean up the excess powder in some corners, causing these remaining powders to be mixed into the next laser selective melting of heterogeneous powders, affecting the molding of parts Accuracy reduces the molding quality.

Contents of the invention

Based on this, the object of the present invention is to provide a multi-material 3D printer and its printing method that can accurately spread powder according to a designated area, and realize additive manufacturing of heterogeneous materials in different layers and additive manufacturing of heterogeneous materials in the same layer.

The present invention is realized by following scheme:

A multi-material 3D printer comprising:

Forming device, powder spreading and suction device and control device;

The molding device includes a molding chamber, a laser scanning head, a powder supply assembly, a molding cylinder and a molding platform located in the molding chamber, the powder supply assembly communicates with the powder supply port on the top of the molding chamber, and the laser scanning head is located in the Right above the forming platform, the forming platform is liftably arranged inside the forming cylinder;

The powder spreading and suction device includes a powder spreading box, a scraper, a powder distribution assembly, a powder suction assembly and a translation assembly; the powder spreading box is located on the top plane of the molding cylinder, and can Controllable reciprocating movement in the X-axis direction; the translation assembly is arranged on the powder spreading box, the translation assembly includes a linear guide rail and a first drive source, and the linear guide rail is along the Y axis of the top plane of the molding cylinder direction arrangement, the linear guide rail is provided with a slidable mounting block, the first driving source is used to drive the mounting block; the powder distribution assembly and the powder suction assembly are arranged on the mounting block; the The powder distribution component is used to receive the powder of the powder supply component and discharge the powder; the powder suction component is used to absorb the powder; the scraper is fixed on the bottom of the powder spreading box corresponding to the powder distribution component;

The control device controls the work of the powder spreading and suction device and the molding device.

Further, the first driving source is a synchronous belt transmission drive assembly, and the installation block is fixed on the synchronous belt of the synchronous belt transmission drive assembly.

Further, the powder distributing assembly includes a powder distributing nozzle, a second driving source and a powder baffle, the powder distributing nozzle is installed on the mounting block, the top of the powder distributing nozzle is provided with a powder inlet, the The bottom of the powder distributing nozzle is provided with a powder distributing port, the bottom of the powder distributing nozzle is located above the top plane of the molding cylinder, the second driving source is arranged outside the powder distributing nozzle, and the powder baffle is arranged on the The inner cavity of the powder distribution nozzle is connected with the output end of the second driving source.

Further, a vibrating motor is provided on the outside of the top of the powder distribution nozzle.

Further, the top of the powder distribution nozzle is funnel-shaped.

Further, the powder suction assembly includes a powder suction nozzle, the powder suction nozzle is installed on the installation block, the powder distribution nozzle and the powder suction nozzle are arranged on opposite sides of the installation block, the The powder suction nozzle is located in front of the powder spreading box along the X-axis direction, the top of the powder suction nozzle is connected to the molding room through a pipeline, and connected to the external recycling device, and the bottom of the powder suction nozzle is located in the molding cylinder above the top plane.

Further, the powder supply assembly includes a plurality of powder supply funnels, a plurality of powder supply branch pipes and a powder supply main pipe, the plurality of powder supply funnels are connected to one end of the plurality of powder supply branch pipes, and the plurality of powder supply branch pipes are connected to each other. The other end of the powder feeding branch pipe is connected to one end of the powder feeding main pipe, and the other end of the powder feeding main pipe is connected to the powder supply port on the top of the molding chamber.

Further, a vibrating motor is arranged outside the powder feeding main pipe.

Further, a cleaning brush is provided on the wall plate of the molding chamber, and the cleaning brush is located at the terminal position of the moving path of the scraper.

The present invention also includes a printing method of a multi-material 3D printer, comprising the following steps:

S10: It is assumed that each ply of the multi-material part contains at least one material area. If there are multiple material areas, the material composition of each material area is different; the 3D printing process of the multi-material part is controlled by the control device; A variety of powder materials are placed in different powder supply funnels;

S20: The forming platform is lowered by a distance of one layer thickness;

S30: The control device moves the powder distributing component of the powder spreading and suction device directly below the powder supply port according to the type of material required in the current printing material area, and controls the powder material in the corresponding powder supply funnel to quantitatively fall into the powder distributing component ;

S40: The powder distributing component moves above the forming platform, and controls the movement of the translation component while advancing to the preset current material area, so that the powder is discharged to the current material area of the forming platform, and then the scraper spreads the powder onto the forming platform, The powder distributing component continues to move over the recycling box, and the excess powder will be dumped into the recycling box; the control device directs the laser beam through the laser scanning head to selectively melt or sinter the powder material according to the scanning data of the current printing material area;

S50: The control device executes the remaining powder removal procedure; the powder suction component starts to return above the recovery box, when the powder suction component returns to the current forming area, the powder suction component starts, and at the same time controls the movement of the translation component, so that the powder suction component will be printed in the next printing Movement in the material area, absorbing the remaining powder in the area;

S60: Determine whether the printing of the current layer is completed, if not, repeat steps S30-S60; if completed and the current layer is not the last layer, repeat steps S20-S60; if completed and the current layer is the last layer, complete the multi-material part of print.

Compared with the prior art, the beneficial effects of a multi-material 3D printer of the present invention are as follows:

1. In the multi-material 3D printer of the present invention, the powder spreading box and the translation component move in the X-axis and Y-axis directions respectively to realize precise powder spreading according to the designated area, which greatly reduces the powder invalidation in the printing process Supply, realize the additive manufacturing of heterogeneous materials in different layers and the additive manufacturing of heterogeneous materials in the same layer.

2. A multi-material 3D printer of the present invention, by setting the powder distributing nozzle and the powder suction nozzle on the opposite sides of the installation block, can accurately absorb powder in a designated area, realize regional powder spreading and powder suction, and greatly improve The work efficiency of the printer is improved, and at the same time, only one powder suction device is needed in the forming room, which reduces the overall volume of the printer and makes the structure more compact.

3. In the multi-material 3D printer of the present invention, after each material area is formed, the excess powder outside the material area can be cleaned up, avoiding the mixing of the printed materials in the next printing of heterogeneous materials.

Description of drawings

Fig. 1 is a schematic structural diagram of a multi-material 3D printer provided by the present invention;

Fig. 2 is the structural representation of the powder-spreading and suctioning device of Fig. 1;

Fig. 3 is the forward schematic diagram of Fig. 2;

Fig. 4 is a schematic structural view of the powder supply assembly of Fig. 1;

Fig. 5 is a schematic diagram of the receiving powder state of the powder suction device;

Fig. 6 is a schematic diagram of the state of laying powder of the powder suction device;

Fig. 7 is a schematic diagram of the state of the cleaning scraper of the powder suction device;

Fig. 8 is a schematic diagram of the suction powder state of the powder suction device;

Fig. 9 is a schematic diagram of the material distribution of a molded layer of the processed parts according to the embodiment of the present invention;

In the figure: 10. Forming chamber; 11. Laser scanning head; 12. Powder supply assembly; 121. Powder supply funnel; 122. Powder supply branch pipe; 123. Powder supply main pipe; Body; 132, scraper; 133, linear guide rail; 134, first drive source; 1341, synchronous belt; 135, powder distribution nozzle; 136, second drive source; 137, powder suction nozzle; 138, powder baffle plate; 139 14. Forming cylinder; 15. Forming platform; 16. Recovery box; 161. Cleaning brush; 21. Vibration motor; 22. First travel switch; 23. Second travel switch.

Detailed ways

The following are specific embodiments of the present invention and in conjunction with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", " The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner" and "outer" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and Simplified descriptions, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention.

It should be noted that when an element is referred to as being “fixed” to another element, it may be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present.

Aiming at the technical problems of low powder utilization rate and low powder laying efficiency due to the need to remove a large amount of first material powder and then lay second material powder in the secondary powder laying process in the background technology, the embodiment of the present invention provides a multi-material 3D The printer, as shown in Figures 1 and 2, in one embodiment, the multi-material 3D printer includes a molding device, a powder suction device 13 and a control device (not shown), and the control device controls the powder suction device 13 and the molding device. Work.

As shown in Figure 1, the molding device includes a molding chamber 10, a laser scanning head 11, a powder supply assembly 12, and a molding cylinder 14 and a molding platform 15 located in the molding chamber 10. The forming platform 15 is set up and down inside the forming cylinder 14, and the laser scanning head 11 is located directly above the forming platform 15, accepting the instructions of the control device, melting or sintering the powder on the forming platform 15 according to the graphic scanning data. .

As shown in FIG. 2 , the powder spreading and suction device 13 includes a powder spreading box 131 , a scraper 132 , a powder distribution assembly, a powder suction assembly and a translation assembly. The powder spreading box 131 is located above the forming cylinder 14, and can controllably move back and forth along the X-axis direction of a horizontal plane; the translation component is arranged on the powder spreading box 131, and the translation component includes a linear guide rail 133 and a first driving source 134, the linear guide rail 133 is arranged along the Y-axis direction of the horizontal plane, the linear guide rail 133 is provided with a slidable mounting block 139, the first driving source 134 is used to drive the mounting block 139 to move; the powder distributing component and the powder suction component are arranged on the mounting block 139 Above, the powder distribution component is used to receive and discharge powder from the powder supply component 12, and the powder suction component is used to absorb powder; the scraper 132 is fixed on the bottom of the powder spreading box 131 corresponding to the powder distribution component, and is used to scrape the forming platform 15 and the excess powder is sent to recovery box 16.

The end of one side of the linear guide rail is also provided with a first travel switch 22. The first travel switch 22 is electrically connected to the control device. The first travel switch 22 can sense the in-position signal of the installation block 139. During the 3D printing process, the control device adopts the first A travel switch 22 serves as a position zero point, combined with the first driving source 134 , to realize precise control of the position of the mounting block 139 on the linear guide rail 133 .

During the working process, the powder spreading and absorbing device 13 cooperates with the powder spreading box body 131 and the translation assembly to move in the X-axis and Y-axis directions respectively, so as to realize precise powder spreading according to the designated area, which greatly reduces the invalid supply of powder in the printing process , without providing a large amount of powder to complete the printing. At the same time, regionalized powder spreading and powder suction greatly improve the working efficiency of the printer, and at the same time, only one powder spreading and suction device 13 needs to be installed in the molding chamber 10 so that the overall volume of the printer will not be too large and the structure will be more compact.

Preferably, the first driving source 134 is a synchronous belt transmission drive assembly, and the synchronous belt transmission drive assembly is driven by a stepper motor controlled by a control device via a synchronous pulley to pull the synchronous belt 1341 to realize the transmission function. The mounting block 139 is fixed on the synchronous belt 1341 of the synchronous belt transmission drive assembly. When the synchronous belt 1341 moves, it drives the powder distributing assembly and the powder suction assembly on the mounting block 139 to move along the Y-axis direction of the horizontal plane.

In one of the embodiments, as shown in Figures 1, 2 and 5, the powder distribution assembly includes a powder distribution nozzle 135, a second driving source 136 and a powder baffle 138, and the powder distribution nozzle 135 is installed on a mounting block 139, and the powder distribution nozzle The top of the mouth 135 is provided with a powder receiving port, the bottom of the powder distribution nozzle 135 is provided with a powder distribution port, the bottom of the powder distribution nozzle 135 is located 0.3 mm to 1 mm above the top plane of the molding cylinder 14, and the second driving source 136 is arranged on the cloth Outside the powder nozzle 135 , a powder baffle plate 138 is disposed in the inner cavity of the powder distribution nozzle 135 and connected to the output end of the second driving source 136 . The rotational position of the powder baffle 138 is controlled by the control device. When the powder baffle 138 is in a fully closed state, the powder baffle 138 blocks the inner cavity channel of the powder dispensing nozzle 135, and the top of the powder baffle 138 is used to hold the powder temporarily. To print the required powder, the control device controls the rotation of the powder baffle 138 to control when the powder falls onto the forming platform 15 . In this embodiment, the top of the powder distributing nozzle 135 is in the shape of a funnel, and the funnel shape is more conducive to receiving powder under the powder supply port on the top of the molding chamber 10 to facilitate the falling of the powder.

Preferably, the second driving source 136 adopts a stepping motor controlled by a control device, combined with the second travel switch 23 and an induction iron (not shown in the figure) to realize the rotational position control of the powder baffle plate 138 . The second travel switch 23 is installed outside the coaxial center of the stepping motor shaft, and an induction iron is installed on the stepping motor shaft, and the second travel switch 23 can sense the rotation in place signal of the induction iron, thereby realizing the powder baffle plate 138 Rotary position control.

Preferably, as shown in Figures 2 and 3, in this embodiment, in order to facilitate the disassembly and assembly of the powder baffle plate 138, the powder distribution nozzle 135 is designed as an upper part and a lower part, which are connected into one body by screws.

Preferably, a vibrating motor 21 is also provided on the outside of the top of the powder distribution nozzle 135 . The vibrating motors 21 are distributed on both sides of the top of the powder distributing nozzle 135. During the powder supply process, the two vibrating motors 21 maintain a vibrating state to vibrate and slide the powder remaining on the top of the powder distributing nozzle 135 to avoid laying heterogeneous materials next time. Materials cause a mixture of different materials.

In one of the embodiments, as shown in Figures 2 and 3, the powder suction assembly includes a powder suction nozzle 137, the powder suction nozzle 137 is installed on the mounting block 139, and the bottom of the powder suction nozzle 137 is located above the top plane of the molding cylinder 14 0.3mm to 1mm, the powder distribution nozzle 135 and the powder suction nozzle 137 are arranged on opposite sides of the installation block 139, the powder suction nozzle 137 is located in front of the powder spreading box body 131 along the X-axis direction, and the top of the powder suction nozzle 137 is connected by a pipe Out of the molding chamber 10, it is connected with an external recovery device.

The powder suction nozzle 137 is arranged in front of the powder spreading box body 131 to ensure higher working efficiency of the powder suction nozzle 137 .

In one of the embodiments, as shown in Figures 1 and 4, the powder supply assembly 12 includes a plurality of powder supply funnels 121, a plurality of powder supply branch pipes 122 and a powder delivery main pipe 123, and a plurality of powder supply funnels 121 correspond to a plurality of One end of the powder feeding branch pipe 122 is connected, and the other end of a plurality of powder feeding branch pipes 122 is connected with one end of the powder feeding main pipe 123 , and the other end of the powder feeding main pipe 123 communicates with the powder supply port on the top of the molding chamber 10 . When any powder is needed, the corresponding powder supply funnel 121 is opened, and the powder is sent into the molding chamber 10 through the powder feeding branch pipe 122 and the powder feeding main pipe 123 .

Preferably, a vibrating motor 21 is also installed on the outside of the powder feeding main pipe 123 . When the powder is sent out from the powder feeding main pipe 123, the vibrating motor 21 keeps vibrating to prevent the powder from remaining on the powder feeding main pipe 123 and the powder feeding branch pipe 122, so as to avoid powder contamination caused by mixing of different materials when laying heterogeneous materials next time.

In one embodiment, as shown in FIG. 7 , a cleaning brush 161 is installed on the wall plate of the molding chamber 10 on the right side of the molding platform 15 , and the cleaning brush 161 is located at the terminal position of the moving path of the scraper 132 . When the scraper 132 sends excess powder to the recovery box 16, the cleaning brush 161 and the bottom of the scraper 132 rub against each other, and the cleaning brush 161 cleans up the remaining powder particles at the bottom of the scraper 132 to prevent the existence of various powder particles on the scraper 132 resulting in powder contamination.

The present invention also provides a printing method of a multi-material 3D printer, comprising the following steps:

S10: It is assumed that each layer of the multi-material part contains at least one material region, as shown in Figure 9, if there are multiple material regions, the material composition of each material region is different; the 3D printing process of the multi-material part is all controlled by The control device controls the operation; various powder materials are respectively placed in different powder supply funnels 121;

S20: the forming platform 15 is lowered by a layer thickness;

S30: The control device moves the powder distributing component of the powder suction device 13 to the right below the powder supply port according to the material type required by the current printing material area, such as the material area A shown in Figure 9, and controls the corresponding powder supply funnel The powder material inside falls into the powder distribution component quantitatively;

S40: As shown in Figures 6 and 7, the powder distributing component moves above the forming platform 15, and controls the movement of the translation component while advancing to the preset current material area, so that the powder is discharged to the current material area of the forming platform 15, and the scraper 132 spread the powder onto the forming platform 15, and the powder distributing assembly continues to translate to the top of the recovery box 16, and the excess powder will be dumped into the recovery box 16; the control device directs the laser beam to scan according to the current printing material area through the laser scanning head 11 Data for selective melting or sintering of powdered materials;

S50: As shown in Figure 8, the control device executes the remaining powder removal procedure; the powder suction component starts to return above the recovery box 16, and when the powder suction component returns to the current molding area, the powder suction component starts, and at the same time controls the movement of the translation component, Make the powder suction component move in the next printing material area, and absorb the remaining powder in this area;

S60: Determine whether the printing of the current layer is completed. If not, repeat steps S30-S60; if it is completed and the current layer is not the last layer, repeat steps S20-S60 to complete the processing of the subsequent B material area or C material area; if completed and If the current layer is the last layer, the multi-material part is printed.

Compared with the prior art, the beneficial effects of a multi-material 3D printer according to the embodiment of the present invention are as follows:

1. A multi-material 3D printer according to the embodiment of the present invention, through the cooperating movement of the powder spreading box and the translation component in the X-axis and Y-axis directions respectively, realizes precise powder spreading according to the designated area, greatly reducing the time spent in the printing process. Ineffective supply of powder enables additive manufacturing of heterogeneous materials in different layers and additive manufacturing of heterogeneous materials in the same layer.

2. A multi-material 3D printer according to the embodiment of the present invention, by setting the powder distributing nozzle and the powder suction nozzle on opposite sides of the installation block, it can accurately absorb powder in a designated area, and realize regional powder spreading and powder suction. The working efficiency of the printer is greatly improved, and at the same time, only one powder suction device is needed in the forming room, which reduces the overall volume of the printer and makes the structure more compact.

3. In the multi-material 3D printer of the embodiment of the present invention, after each material area is formed, the excess powder outside the material area can be cleaned up, so as to avoid mixing the printed material in the next printing of heterogeneous materials.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims (10)

1. A multi-material 3D printer, comprising:

the device comprises a forming device, a powder spreading and sucking device and a control device;

the forming device comprises a forming chamber, a laser scanning head, a powder supply assembly, a forming cylinder body and a forming platform, wherein the forming cylinder body and the forming platform are positioned in the forming chamber, the powder supply assembly is communicated with a powder supply port at the top of the forming chamber, the laser scanning head is positioned right above the forming platform, and the forming platform is arranged in the forming cylinder body in a lifting manner;

the powder spreading and sucking device comprises a powder spreading box body, a scraping plate, a powder distribution assembly, a powder sucking assembly and a translation assembly; the powder spreading box body is positioned on the top plane of the forming cylinder body and can controllably reciprocate along the X-axis direction of the top plane of the forming cylinder body; the translation assembly is arranged on the powder paving box body and comprises a linear guide rail and a first driving source, the linear guide rail is arranged along the Y-axis direction of the top plane of the forming cylinder body, the linear guide rail is provided with a slidable mounting block, and the first driving source is used for driving the mounting block; the powder distribution component and the powder suction component are arranged on the mounting block; the powder distribution assembly is used for receiving powder of the powder supply assembly and discharging the powder; the powder sucking component is used for sucking powder; the scraping plate is fixed at the bottom of the powder spreading box body corresponding to the powder distribution assembly;

the control device controls the work of the powder spreading and sucking device and the forming device.

2. A multi-material 3D printer according to claim 1, wherein:

the first driving source is a synchronous belt conveying driving assembly, and the mounting block is fixed on a synchronous belt of the synchronous belt conveying driving assembly.

3. A multi-material 3D printer according to claim 1, wherein:

the powder distribution assembly comprises a powder distribution nozzle, a second driving source and a powder baffle, wherein the powder distribution nozzle is arranged on the installation block, a powder receiving opening is formed in the top of the powder distribution nozzle, a powder distribution opening is formed in the bottom of the powder distribution nozzle, the bottom of the powder distribution nozzle is located on the plane of the top of the forming cylinder body, the second driving source is arranged on the outer side of the powder distribution nozzle, and the powder baffle is arranged in an inner cavity of the powder distribution nozzle and is connected with the output end of the second driving source.

4. A multi-material 3D printer according to claim 3, wherein:

and a vibrating motor is arranged at the outer side of the top of the powder distribution nozzle.

5. The multi-material 3D printer of claim 4, wherein:

the top of the powder distribution nozzle is funnel-shaped.

6. A multi-material 3D printer according to claim 1, wherein:

the powder suction assembly comprises a powder suction nozzle, the powder suction nozzle is arranged on the installation block, the powder distribution nozzle and the powder suction nozzle are arranged on two opposite sides of the installation block, the powder suction nozzle is positioned in front of the powder paving box body along the X-axis direction, the top of the powder suction nozzle is connected to the outside of the forming chamber through a pipeline and is connected with an external recovery device, and the bottom of the powder suction nozzle is positioned on the plane of the top of the forming cylinder body.

7. A multi-material 3D printer according to claim 1, wherein:

the powder feeding assembly comprises a plurality of powder feeding funnels, a plurality of powder feeding branch pipes and a powder feeding main pipe, wherein a plurality of powder feeding funnels are correspondingly connected with one ends of the powder feeding branch pipes, the other ends of the powder feeding branch pipes are connected with one ends of the powder feeding main pipe, and the other ends of the powder feeding main pipe are communicated with a powder feeding port at the top of the forming chamber.

8. A multi-material 3D printer according to claim 7, wherein:

and a vibrating motor is arranged on the outer side of the powder feeding main pipe.

9. A multi-material 3D printer according to claim 1, wherein:

the wall plate of the forming chamber is provided with a cleaning brush, and the cleaning brush is positioned at the end position of the scraper moving path.

10. A printing method of a multi-material 3D printer using the 3D printer according to any one of claims 1 to 9, comprising the steps of:

s10: providing a multi-material part, wherein each layer sheet comprises at least one material area, and if a plurality of material areas exist, the material compositions of the material areas are different; the 3D printing process of the multi-material part is controlled by a control device to run; respectively placing a plurality of powder materials into different powder supply hoppers;

s20: lowering the forming platform by a layer thickness distance;

s30: the control device enables the powder distribution component of the powder spreading and sucking device to move to the position right below the powder supply port according to the type of the material required by the current material printing area, and controls the powder material in the corresponding powder supply funnel to quantitatively fall into the powder distribution component;

s40: the powder distribution assembly moves to the upper part of the forming platform, and the translation assembly is controlled to move when the powder distribution assembly advances to a preset current material area, so that powder leaks to the current material area of the forming platform, the scraper plates flatten the powder on the forming platform, the powder distribution assembly continues to translate to the upper part of the recovery box, and redundant powder is dumped into the recovery box; the control device directs the laser beam to selectively melt or sinter the powder material according to the scanning data of the current printing material area through the laser scanning head;

s50: the control device executes a residual powder removing program; the powder sucking component starts to return above the recovery box, when the powder sucking component returns to the secondary forming area, the powder sucking component is started, and meanwhile, the translation component is controlled to move, so that the powder sucking component moves in the next printing material area and sucks residual powder in the area;

s60: judging whether the current layer is printed, if not, repeating the steps S30-S60; if the current layer is finished and is not the last layer, repeating the steps S20 to S60; if the printing is finished and the current layer is the last layer, the printing of the multi-material part is finished.