阅读说明：本技术 一种液态金属3d打印方法和液态金属3d打印铝合金材料 (Liquid metal 3D printing method and liquid metal 3D printing aluminum alloy material ) 是由 张佼 姜海涛 孙宝德 邢辉 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种液态金属3D打印方法和液态金属3D打印铝合金材料,涉及铝合金材料的制备技术领域。该液态金属3D打印方法包括将高温金属熔体在压力作用下经喷嘴冲击至至安装于三维运动平台上的冷却模具上堆积形成金属熔池,三维运动平台在冲击过程中按照扫描路径在水平面上运动,一次扫描结束后,利用耙平机构对金属熔池的上表面进行耙平,三维运动平台向下移动,继续扫描,重复多次直至完成打印。本申请通过在扫描打印结束后利用耙平机构施加耙平操作,耙平与扫描打印交替进行,可实现消除消除界面分层痕迹问题,提高界面结合力。制备获得的铝合金材料无冶金缺陷,材料组织细小、性能优异。(The invention discloses a liquid metal 3D printing method and a liquid metal 3D printing aluminum alloy material, and relates to the technical field of preparation of aluminum alloy materials. The liquid metal 3D printing method comprises the steps that high-temperature metal melt is impacted to a cooling die arranged on a three-dimensional motion platform through a nozzle under the action of pressure to be stacked to form a metal molten pool, the three-dimensional motion platform moves on a horizontal plane according to a scanning path in the impacting process, after one-time scanning is finished, a raking mechanism is used for raking the upper surface of the metal molten pool, the three-dimensional motion platform moves downwards, scanning is continued, and the steps are repeated for multiple times until printing is finished. According to the method and the device, the raking mechanism is utilized to apply the raking operation after the scanning and printing are finished, and the raking and the scanning and printing are alternately performed, so that the problem of interface layering traces can be eliminated, and the interface binding force is improved. The prepared aluminum alloy material has no metallurgical defect, fine material structure and excellent performance.)

1. A liquid metal 3D printing method is characterized by comprising the following steps:

impacting a high-temperature metal melt onto a cooling mould arranged on a three-dimensional motion platform through a nozzle under the action of pressure to form a metal molten pool in a stacking manner, wherein the three-dimensional motion platform moves on a horizontal plane according to a scanning path in the impacting process, after one-time scanning is finished, raking the upper surface of the metal molten pool by using a raking mechanism, moving the three-dimensional motion platform downwards, continuing scanning, and repeating for multiple times until printing is finished.

2. The liquid metal 3D printing method as recited in claim 1, wherein the leveling mechanism includes a rake bar and a plurality of tines uniformly mounted to a lower portion of the rake bar;

preferably, the rake teeth are of arc-shaped columnar structures, the bottom of each rake tooth is provided with a tip, the diameter of each rake tooth is 0.2-1mm, the distance between any two adjacent rake teeth is 1-3mm, and the height of each rake tooth is 10-30 mm;

preferably, the tines are molybdenum wire tines.

3. A liquid metal 3D printing method according to claim 2, wherein the tines comprise a plurality of first tines having arcuate opening directions opposite to arcuate opening directions of the second tines, the plurality of first tines and the plurality of second tines being arranged alternately.

4. The liquid metal 3D printing method of claim 2, wherein the molten metal impinges on the solidified molten metal pool on the cooling mold after a number of impacts greater than 1, the temperature of the molten metal causing the molten metal pool to partially melt to form a mushy zone having a first height H1, the molten metal building up on the cooling mold to form a liquid zone having a second height H2 per sweep;

the depth of the raking mechanism inserted into the molten metal bath at normal times is (1/3-1/2) H1+ H2.

5. The liquid metal 3D printing method of claim 1, wherein the raking mechanism is moved horizontally and up and down by a raking drive mechanism mounted between the nozzle and the cooling die;

preferably, the raking driving mechanism comprises a screw rod, a sliding block, a lifting driving member and a rotating driving member, the screw rod is mounted between the nozzle and the cooling die, the sliding block is slidably connected to the screw rod, the lifting driving member is connected with the lower surface of the sliding block, the screw rod is connected with the rotating driving member, and a telescopic rod of the lifting driving member is connected with the raking mechanism;

preferably, the downward movement speed of the raking mechanism is consistent with the downward speed of the three-dimensional movement platform, and both the downward speed and the downward speed are 3-5 mm/min.

6. The liquid metal 3D printing method according to any one of claims 1 to 5, wherein the cooling die is provided with a water inlet and a water outlet, and the water outlet has a water outlet temperature of 35-40 ℃.

7. A liquid metal 3D printing method according to any of claims 1-5, characterized in that the vibration is performed during scanning by a vibration mechanism mounted to the cooling mould;

preferably, the vibration mechanism is a pneumatic vibrator, and the vibration force of the vibration mechanism is 0.1-0.3 MPa.

8. A liquid metal 3D printing method according to any of claims 1-5, wherein the nozzles are arranged equidistantly in a single row, the number of the nozzles is 10-20, the distance between any two adjacent nozzles is 10-20mm, and the diameter of the nozzles is 2-4 mm;

preferably, the distance between the nozzle and the cooling die is 10-15 cm.

9. A liquid metal 3D printing method according to any of claims 1-5, characterized in that the printing is performed under vacuum pressure of 0.3-0.6 MPa;

preferably, the scanning path is of a straight reciprocating type.

10. A liquid metal 3D printing aluminum alloy material, characterized in that it is prepared by the liquid metal 3D printing method according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of preparation of aluminum alloy materials, in particular to a liquid metal 3D printing method and a liquid metal 3D printing aluminum alloy material.

Background

The 3D printing method can be used for preparing aluminum alloy cast ingots, aluminum alloy parts in different shapes can be prepared by the conventional 3D printing technology, but the limitation of 3D printing powder still exists, only limited alloy marks can be printed, and free design of components cannot be realized. The liquid metal 3D printing technology is a brand-new 3D printing method, aluminum alloy materials with any components can be prepared by a melt impact method, and the materials obtained by the method have the characteristics of tissue refinement, uniform components and the like. However, the technology also has an interface problem in the industrial application process, and the final performance of the material is influenced to a certain extent, so that the application value of the technology is reduced.

In view of this, the invention is particularly proposed.

Disclosure of Invention

The invention aims to provide a liquid metal 3D printing method and a liquid metal 3D printing aluminum alloy material, which can solve the problem of interface layering traces of a 3D printing material and realize a good metallurgical bonding interface.

The invention is realized by the following steps:

in a first aspect, the present invention provides a liquid metal 3D printing method, comprising:

impacting a high-temperature metal melt onto a cooling mould arranged on a three-dimensional motion platform through a nozzle under the action of pressure to form a metal molten pool in a stacking manner, wherein the three-dimensional motion platform moves on a horizontal plane according to a scanning path in the impacting process, after one-time scanning is finished, raking the upper surface of the metal molten pool by using a raking mechanism, moving the three-dimensional motion platform downwards, continuing scanning, and repeating for multiple times until printing is finished.

In an alternative embodiment, the raking mechanism comprises a rake bar and a plurality of tines which are uniformly mounted on the lower part of the rake bar;

preferably, the rake teeth are of arc-shaped columnar structures, the bottom of each rake tooth is provided with a tip, the diameter of each rake tooth is 0.2-1mm, the distance between any two adjacent rake teeth is 1-3mm, and the height of each rake tooth is 10-30 mm;

preferably, the tines are molybdenum wire tines.

In an alternative embodiment, the tines comprise a plurality of first tines having arcuate opening directions opposite to arcuate opening directions of the second tines, the plurality of first tines and the plurality of second tines being arranged alternately.

In an alternative embodiment, when the number of impacts is greater than 1, the molten metal impacts the solidified molten metal pool on the cooling mold, the temperature of the molten metal partially melts the molten metal pool to form a pasty zone with a first height H1, and the molten metal is accumulated on the cooling mold to form a liquid zone with a second height H2 during each scan;

the depth of the raking mechanism inserted into the molten metal bath at normal times is (1/3-1/2) H1+ H2.

In an alternative embodiment, the raking mechanism is moved horizontally and up and down by a raking drive mechanism mounted between the nozzle and the cooling die;

preferably, the raking driving mechanism comprises a screw rod, a sliding block, a lifting driving member and a rotating driving member, the screw rod is mounted between the nozzle and the cooling die, the sliding block is slidably connected to the screw rod, the lifting driving member is connected with the lower surface of the sliding block, the screw rod is connected with the rotating driving member, and a telescopic rod of the lifting driving member is connected with the raking mechanism;

preferably, the downward movement speed of the raking mechanism is consistent with the downward speed of the three-dimensional movement platform, and both the downward speed and the downward speed are 3-5 mm/min.

In an optional embodiment, the cooling mold is provided with a water inlet and a water outlet, and the water outlet has a water outlet temperature of 35-40 ℃.

In an alternative embodiment, the vibration is performed by a vibration mechanism mounted to the cooling mold during the scanning;

preferably, the vibration mechanism is a pneumatic vibrator, and the vibration force of the vibration mechanism is 0.1-0.3 MPa.

In an alternative embodiment, the nozzles are arranged in a single row at equal intervals, the number of the nozzles is 10-20, the distance between any two adjacent nozzles is 10-20mm, and the diameter of each nozzle is 2-4 mm;

preferably, the distance between the nozzle and the cooling die is 10-15 cm.

In an alternative embodiment, the printing is performed at a vacuum pressure of 0.3 to 0.6 MPa;

preferably, the scanning path is of a straight reciprocating type.

In a second aspect, the invention provides a liquid metal 3D printing aluminum alloy material, which is prepared by the liquid metal 3D printing method according to any one of the foregoing embodiments.

The invention has the following beneficial effects: according to the liquid metal 3D printing method, the raking mechanism is used for applying the raking operation after the scanning and printing are finished, and the raking and the scanning and printing are performed alternately, so that the problem of interface layering traces can be solved, and the effect of interface binding force is improved. The aluminum alloy material prepared by the liquid metal 3D printing method provided by the application has no metallurgical defect, small material structure and excellent performance.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a liquid metal 3D printing apparatus provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a leveling mechanism and a leveling driving mechanism of a liquid metal 3D printing apparatus according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a leveling mechanism of a liquid metal 3D printing apparatus according to an embodiment of the present application.

Icon: 100-liquid metal 3D printing device; 110-a smelting furnace; 111-a nozzle; 120-high voltage generating mechanism; 130-cooling the mold; 140-a three-dimensional motion platform; 150-raking mechanism; 151-rake bar; 152-rake teeth; 153-first tine; 154-second rake tine; 160-rake flat drive mechanism; 161-lead screw; 162-a slider; 163-lifting drive; 164-a rotary drive; 170-vibration mechanism.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The invention provides a liquid metal 3D printing method, a schematic structural diagram of a liquid metal 3D printing device for realizing the liquid metal 3D printing method is shown in figure 1, and the liquid metal 3D printing method comprises the following steps:

s1, impacting the high-temperature metal melt to a cooling mould 130 arranged on a three-dimensional moving platform 140 through a nozzle 111 under the action of pressure to form a metal molten pool in a stacking mode, wherein the three-dimensional moving platform 140 moves on a horizontal plane according to a scanning path in the impacting process.

In the application, a smelting furnace 110 is used for smelting required alloy to form liquid high-temperature metal melt, inert gas is introduced into the smelting furnace 110 to form high pressure (0.01-0.03MPa), and the high-temperature alloy melt is impacted to a cooling mold 130 through a nozzle 111 under the action of pressure. The cooling mold 130 is of a plate-shaped structure, the cooling mold 130 is provided with a water inlet (not shown) and a water outlet (not shown), and the water outlet temperature of the water outlet is 35-40 ℃. Realize cooling mould 130 through the temperature of control delivery port and carry out quick cooling solidification to the molten metal bath, smelting furnace 110 in this application is fixed motionless, and at the impact scanning in-process, three-dimensional motion platform 140 drives cooling mould 130 and moves on the horizontal plane according to the scanning path, realizes the panel that can print specific shape through the motion of three-dimensional motion platform 140, and particularly, the scanning path of this application is the straight line reciprocating type, realizes the panel of printing the cuboid shape.

In the embodiment, the nozzles 111 are arranged in a single row at equal intervals, the number of the nozzles is 10-20, the distance between any two adjacent nozzles 111 is 10-20mm, and the diameter of each nozzle 111 is 2-4 mm; the distance between the nozzle 111 and the cooling die 130 is 10-15 cm; the distance between the nozzle 111 and the cooling mold 130 described herein is a distance between the nozzle 111 and the upper surface of the cooling mold 130, and therefore, when a molten metal pool is deposited on the surface of the cooling mold 130, it is necessary to move down by the three-dimensional moving platform 140 to maintain the distance between the nozzle 111 and the upper surface of the molten metal pool deposited on the cooling mold 130 to be 10 to 15 cm.

Printing under the condition that the vacuum pressure is 0.3-0.6 MPa; the vacuum condition can effectively reduce the oxidation of the metal melt in the printing process.

Further, in the present embodiment, the vibration is performed by the vibration mechanism 170 installed at the bottom of the cooling mold 130 during the scanning; preferably, the vibration mechanism 170 is a pneumatic vibrator, and the vibration force of the vibration mechanism 170 is 0.1-0.3 MPa.

S2, after the first scanning is finished, the leveling mechanism 150 is used to level the upper surface of the molten metal bath.

In the present application, by adding the leveling operation after the scanning is finished, referring to fig. 2 and 3, the leveling mechanism 150 includes a rake rod 151 and a plurality of rake teeth 152, and the rake teeth 152 are uniformly installed at the lower part of the rake rod 151; preferably, the rake teeth 152 are arc-shaped cylindrical structures, the bottom of the rake teeth 152 is provided with a tip, the diameter of the rake teeth 152 is 0.2-1mm, the distance between any two adjacent rake teeth 152 is 1-3mm, and the height of the rake teeth 152 is 10-30 mm.

The rabble blade 152 is inserted into the molten metal bath for movement during raking, and specifically, when the number of impacts is greater than 1, the molten metal impacts the solidified molten metal bath on the cooling mold 130, and the temperature of the molten metal partially melts the molten metal bath to form a mushy zone having a first height H1, which is the interface between the lower cooled molten metal bath and the upper newly injected high temperature molten metal bath. A liquid region with a second height H2, wherein the metal melt is accumulated on the cooling mold 130 during each scanning; in the actual printing process, H1 may be 3-5mm, and H2 may be 5-8 mm. The depth of the metal molten bath inserted when the raking mechanism 150 rakes is (1/3-1/2) H1+ H2. The raking mechanism 150 can effectively improve the interface problem between layers by inserting a newly sprayed liquid region and extending into a pasty region, in addition, the raking mechanism 150 can rake and remove the oxide skin on the surface of a molten metal pool by raking the molten metal pool impacting onto the cooling die 130, the air holes in the molten metal pool are broken, and when the molten metal pool is scanned again subsequently, the molten metal pool is contacted with fresh molten metal, so that the binding force is better, the interface defects are fewer, the problems of air holes and interface layering marks can be eliminated, and the interface binding force is improved. It is noted that, when first impacted, no stratification interface is formed, since there is only one layer of molten metal bath, and therefore, no raking operation, or only raking operations less than or equal to the height of H2, may be applied.

Because the rake teeth 152 of the present application need to be deep into the molten metal bath for leveling, and at first need to satisfy the characteristic that the molten metal cannot be melted at high temperature, conventional metal wires such as iron wires, copper wires, and the like cannot be used as a preparation material of the rake teeth 152 of the present application, and meanwhile, the rake teeth 152 need to have certain hardness to realize the function of supporting leveling, but the hardness cannot be too large, and the excessively hard rake teeth 152 easily hang a metal molten bath out of a stamp, so the molybdenum wires are selected as the material of the rake teeth 152 in the present application, and the molybdenum wires can well play a role of leveling without damaging the metal molten bath. The raking of the molten metal bath by the raking mechanism 150 rakes impurities such as oxide scales in the molten metal bath and fresh molten metal on the surface of the molten metal bath, and the raked impurities are brought to the outer side of the molten metal bath by the raking mechanism 150, and part of the raked impurities may remain on the side wall of the molten metal bath or drip on the cooling mold 130, so that after the printing is completed, the outer side wall of the formed ingot needs to be processed to ensure the quality of the ingot.

Since the scanning path of the three-dimensional moving platform 140 is a linear reciprocating type in the present application, the present application implements one raking operation in accordance with the scanning direction of the three-dimensional moving platform 140 after the scanning is completed by setting the specific shape of the rake 152, specifically, the rake 152 in the present application includes a plurality of first rake teeth 153 and second rake teeth 154, the direction of the arc-shaped opening of the first rake teeth 153 is opposite to the direction of the arc-shaped opening of the second rake teeth 154, the method of the arc-shaped opening of the first rake teeth 153 and the second rake teeth 154 is opposite, when the rake teeth 152 move forward or backward, the tips of the first rake teeth 153 or the second rake teeth 154 can be directly utilized to puncture the molten metal pool, so as to puncture the air holes in the molten metal, which is beneficial to reducing the porosity, meanwhile, the tip of the first rake teeth 153 or the second rake teeth 154 directly acts on the surface of the molten metal bath, and the raking effect is better. In the present application, the plurality of first tines 153 and the plurality of second tines 154 are alternately arranged. In the application, the first rake teeth 153 and the second rake teeth 154 in two directions are alternately arranged, so that the rake teeth 152 correspondingly move after the three-dimensional motion platform 140 moves according to the scanning path. It should be noted that, during the process of moving the rake face by the rake teeth 152, the nozzle 111 should pause spraying, the three-dimensional moving platform 140 also pauses scanning, after the rake face operation is finished, the nozzle 111 sprays again, and the three-dimensional moving platform 140 moves down to a proper position and then performs the next scanning according to the scanning path. The pause of the nozzle 111 and the three-dimensional moving platform 140 in this application can be performed by setting a scan waiting program, and the scan waiting time of the nozzle 111 and the three-dimensional moving platform 140 is controlled to be consistent with the raking time of the raking mechanism 150.

In the present application, referring to fig. 2 and 3, the leveling mechanism 150 performs horizontal movement and up-and-down movement by the leveling driving mechanism 160 installed between the nozzle 111 and the cooling mold 130; the rake drive mechanism 160 may be configured in a variety of ways, as long as it is capable of achieving both horizontal and up-and-down movement of the rake mechanism 150. The present embodiment provides a typical but non-limiting example, the raking driving mechanism 160 includes a lead screw 161, a slider 162, a lifting driving member 163, and a rotating driving member 164, the lead screw 161 is installed between the nozzle 111 and the cooling mold 130, the slider 162 is slidably connected to the lead screw 161, the lifting driving member 163 is connected to a lower surface of the slider 162, the lead screw 161 is connected to the rotating driving member 164, and a telescopic rod of the lifting driving member 163 is connected to the raking mechanism 150. In this application, the screw 161 is driven to rotate by the rotation driving member 164, the screw 161 drives the slider 162 to perform linear reciprocating motion along the screw 161, and then the lifting driving member 163 connected with the slider 162 and the raking mechanism 150 are driven to perform linear reciprocating motion. When the three-dimensional motion platform 140 moves downward, the lifting driving member 163 may drive the leveling mechanism 150 to move downward, thereby ensuring the subsequent insertion depth. Preferably, the downward movement speed of the raking mechanism 150 is consistent with the downward speed of the three-dimensional movement platform 140, and is 3-5 mm/min.

In order to reduce the installation space of the leveling mechanism 150 and the leveling driving mechanism 160 between the nozzle 111 and the cooling mold 130 as much as possible, in the present application, the leveling driving mechanism 160 is installed outside the corresponding section of the nozzle 111 and the cooling mold 130, so that the leveling driving mechanism 160 does not occupy the space between the nozzle 111 and the cooling mold 130, and the leveling rod 151 of the leveling mechanism 150 is configured as two vertical rods and a cross rod connected between the two vertical rods, and the free ends of the two vertical rods face oppositely, so that the leveling rod 151 is shaped as shown in fig. 3, so that only part of the leveling rod 151 and the rake teeth 152 are installed between the nozzle 111 and the cooling mold 130, and the space utilization is more reasonable.

And S3, after finishing raking, moving the three-dimensional motion platform 140 downwards, continuing scanning, and repeating for multiple times until printing is finished.

In this application, move down through three-dimensional motion platform 140 in order to guarantee the interval between nozzle 111 and the cooling mould 130 upper surface to guarantee the best impact force, after three-dimensional motion platform 140 moved down, three-dimensional motion platform 140 carried out sharp reciprocating type motion according to the scanning route again, and nozzle 111 sprays high temperature metal melt, carries out the raking operation of step S2 again after the scanning, repeats many times until accomplishing the printing.

The liquid metal 3D printing aluminum alloy material is prepared by the liquid metal 3D printing method, the problem of interface layering traces can be solved, and the interface bonding force is improved. The liquid metal 3D printing aluminum alloy material prepared by the method has no metallurgical defect, small material structure and excellent performance.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

Referring to fig. 1-3, the present embodiment provides a liquid metal 3D printing apparatus 100, which includes a melting furnace 110, a high pressure generating mechanism 120, a cooling mold 130, a three-dimensional moving platform 140, a leveling mechanism 150, a leveling driving mechanism 160, and a vibrating mechanism 170.

The smelting furnace 110 is used for smelting metal components (for example, 7075 aluminum alloy) to obtain metal melt, nozzles 111 are arranged at the bottom of the smelting furnace 110, the number of the nozzles 111 is 15, the distance between any two adjacent nozzles 111 is 15mm, and the diameter of each nozzle 111 is 3mm, wherein the nozzles 111 are arranged in a single row at equal intervals.

The high pressure generating mechanism 120 is communicated with the top of the smelting furnace 110 and is used for introducing inert gas into the smelting furnace 110 to make the metal melt spout out under the action of pressure.

The cooling mold 130 is mounted on the three-dimensional moving platform 140 and can move along with the three-dimensional moving platform 140. In this embodiment, the cooling mold 130 is composed of a bottom wall and a peripheral side wall, and the bottom wall and the side wall are both provided with a water inlet and a water outlet. The vibration mechanism 170 is mounted on the side wall of the cooling mold 130.

The raking mechanism 150 comprises a rake rod 151 and a plurality of rake teeth 152, wherein the rake teeth 152 are uniformly arranged at the lower part of the rake rod 151; the rake teeth 152 are arc-shaped columnar structures, the bottom of the rake teeth 152 is provided with a tip, the diameter of the rake teeth 152 is 0.5mm, the distance between any two adjacent rake teeth 152 is 2mm, and the height of the rake teeth 152 is 20 mm. In the present application, the rake teeth 152 include a plurality of first rake teeth 153 and a plurality of second rake teeth 154, the arc opening direction of the first rake teeth 153 is opposite to the arc opening direction of the second rake teeth 154, and the plurality of first rake teeth 153 and the plurality of second rake teeth 154 are alternately arranged.

The raking driving mechanism 160 includes a screw 161, a slider 162, a lifting driving member 163 and a rotating driving member 164, the screw 161 is installed between the nozzle 111 and the cooling mold 130, the slider 162 is slidably connected to the screw 161, the lifting driving member 163 is connected to a lower surface of the slider 162, the screw 161 is connected to the rotating driving member 164, and an expansion rod of the lifting driving member 163 is connected to the raking mechanism 150.

Example 2

The present embodiment provides a liquid metal 3D printing method, which is performed using the liquid metal 3D printing apparatus 100 as described in embodiment 1.

The liquid metal 3D printing method provided by the embodiment includes the following steps:

s1, impacting the high-temperature metal melt (7075 aluminum alloy) to a cooling mould 130 arranged on the three-dimensional moving platform 140 through a nozzle 111 under the action of pressure to form a metal molten pool liquid region with a second height H2 (about 6mm) in a stacking mode, wherein the three-dimensional moving platform 140 moves on a horizontal plane according to a scanning path in the impacting process. During the scanning and printing process, the vibration mechanism 170 continuously applies vibration, and the temperature of the water outlet of the cooling mold 130 is controlled to be 35 ℃.

S2, after the first scanning, the leveling mechanism 150 levels the upper surface of the molten metal bath, and the insertion depth of the leveling mechanism 150 is H2 (the puddle is not present at the time of the first scanning).

S3, after finishing raking, the three-dimensional motion platform 140 moves downwards to continue scanning, the molten metal impacts the solidified molten metal pool on the cooling mould 130, the temperature of the molten metal enables the molten metal pool to be partially melted to form a pasty zone with a first height H1 (about 4mm), after scanning is finished, the raking mechanism 150 is used for raking the upper surface of the molten metal pool, and the insertion depth of the raking mechanism 150 is 1/2H1+ H2.

And repeating for multiple times until printing is finished.

Example 3

This embodiment is substantially the same as embodiment 2 except that the vibrating operation of the vibrating mechanism 170 in embodiment 2 is omitted.

Example 4

This embodiment is substantially the same as embodiment 2 except that the insertion depth of the raking mechanism 150 is changed, and the insertion depth of the raking mechanism 150 in step S3 in this embodiment is H2.

Example 5

This embodiment is substantially the same as embodiment 2 except that the insertion depth of the raking mechanism 150 is changed, and the insertion depth of the raking mechanism 150 in step S3 in this embodiment is H1+ H2.

Example 6

This embodiment is substantially the same as embodiment 2, except that the rake teeth 152 of the raking mechanism 150 in this embodiment are made of steel wire.

Example 7

This embodiment is substantially the same as embodiment 2 except that the raking mechanism 150 in this embodiment has only the first rake teeth 153 in the same direction.

Comparative example 1

The raking operation of the raking mechanism 150 in embodiment 2 is omitted.

The liquid metal 3D printing aluminum alloy materials obtained in the above examples 2-7 and the comparative example 1 are subjected to performance detection, and the detection method comprises the following steps: carrying out metallographic microscopic analysis and mechanical property test on the cast ingot, wherein the detection results are as follows:

as can be seen from the above table, the ingot prepared by the method has good mechanical properties, which fully shows that the material has good internal structure and no interface problem. In addition, the microstructure of the material has fine grains. When the vibration operation is omitted, the crystal grain size is significantly increased, while the insertion depth of the raking mechanism 150 is changed in examples 4 and 5, when the insertion depth is not deep into the boundary of the interface, the interface problem still exists, and when the insertion depth is too large, the original coagulated tissue is destroyed again, resulting in poorer internal tissue effect, while the hardness of the steel wire is greater than that of the molybdenum wire, which is easy to scratch the internal tissue during raking, thereby affecting the product performance, and as can be seen from example 7, when the first rake teeth 153 are only arranged unidirectionally, the raking effect is not good enough. When the raking operation is completely omitted, the interface problem increases significantly.

In summary, the liquid metal 3D printing method provided by the application utilizes the leveling mechanism 150 to perform leveling operation after scanning and printing are finished, and leveling and scanning and printing are performed alternately, so that the problem of interface layering marks can be solved, and the interface binding force can be improved. Meanwhile, the vibration mechanism 170 is used for applying vibration operation in the scanning process, so that the uniformity of the metal melt can be improved, meanwhile, the overflow of bubbles is easier to puncture by the raking mechanism 150, and further, the porosity is reduced. The aluminum alloy material prepared by the liquid metal 3D printing method provided by the application has no metallurgical defect, small material structure and excellent performance.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.