CN105252002B - It is a kind of to apply the apparatus and method that continuous uniform malleation enters row metal increasing material manufacturing - Google Patents

Abstract

The invention belongs to metal material increasing field, and in particular to a kind of continuous uniform malleation that applies enters row metal increasing material manufacturing apparatus and method；The device provides the malleation of continuous uniform during metal increasing material manufacturing by high-pressure bottle, is optimized can the metallographic structure of metal increasing material manufacturing part, eliminates the defects such as micro-crack, deformation and pore.First before increasing material manufacturing is carried out, extract original air in high-pressure bottle out, make in container, to realize negative pressure；Noble gases are then passed to, is made high-pressure bottle interior while inert gas shielding is realized, is possessed the continuous uniform positive pressure environment higher than normal atmosphere；Then by the coordinated signals of heat power supply device, pay-off and location mobile device, realize increasing material manufacturing process；It is last successively to be scanned according to the CAD model section that the numerical control program compiled and edited or realization are generated, complete metal parts increasing material manufacturing.

Description

A device and method for metal additive manufacturing by applying continuous and uniform positive pressure

technical field

The invention belongs to the field of metal additive manufacturing, and in particular relates to a device and method for applying continuous and uniform positive pressure for metal additive manufacturing.

Background technique

As an important branch of additive manufacturing technology, metal additive manufacturing technology has achieved remarkable development in recent years. Its process methods include laser cladding, laser sintering, electron beam cladding, etc., and it has been able to prepare metal parts of a certain shape.

The basic principle of metal additive manufacturing is: melting metal raw materials (powder, silk, etc.) into a liquid state through a heat source, and stacking them layer by layer according to the pre-generated CAD slice path. Wherein, the heat source includes electron beams, laser beams, ion beams, electric arcs and the like. Due to the failure to effectively solve the problems of metallurgical defects and microstructure of metals in the process of additive manufacturing, metal parts processed by additive manufacturing have problems such as coarse grains, pores, microcracks, and a large number of residual stresses, resulting in the processing of parts. Defects such as deformation, cracking and insufficient strength make it difficult for metal additive manufacturing parts to be used in practical engineering applications.

A roller structure is disclosed in the patented technology "A Device for Controlling the Surface Quality of Metal Additive Forming" (Application No. 201410273921.5, Publication No. CN 104043832A). Due to the complete synchronous movement of the high-pressure roller and the additive manufacturing heat source of the device, when scanning the complex path, the actual position of the process processing equipment after turning will deviate from the original track required by the additive manufacturing parts, and it is difficult to reach the process processing equipment after turning. desired location.

Existing methods for optimizing defects in metal AM parts include in-process and post-processing methods. Wherein, the process treatment method includes applying ultrasonic field, electromagnetic field and rolling with high-pressure rollers; the post-treatment method includes shot peening, stress relief annealing, double annealing and hot isostatic pressing. Among them, the processing methods such as adding ultrasonic field, applying electromagnetic field, and adding high-pressure rollers for rolling, etc. need to add synchronous equipment such as ultrasonic generators, electromagnetic inductors or high-pressure rollers on the heat source of the printer. This method is likely to cause unstable equipment structure. And other factors. When the scanning path of the heat source is complex and small-angle turns are required, external equipment such as ultrasonic generators are prone to deviation and it is difficult to maintain synchronization. At the same time, the post-processing method also has certain limitations, such as: post-processing cannot solve the deformation or cracking of parts that have occurred during the additive manufacturing process.

In summary, it is urgent to propose a new defect optimization method for high-energy beam metal additive manufacturing parts, which can more effectively and fundamentally solve the defect problem of metal additive manufacturing parts.

Contents of the invention

In view of this, the present invention provides a device and method for applying continuous and uniform positive pressure for metal additive manufacturing. It can optimize the metallographic structure of metal additive manufacturing parts and eliminate defects such as microcracks, deformation and pores.

Implement the concrete technical scheme of the present invention as follows:

A device for applying continuous and uniform positive pressure for metal additive manufacturing, characterized in that the device includes: a host computer, a heat source device, a feeding device, a conveying pipeline, a metal additive manufacturing position moving device, a feeding head, a workbench, a high pressure Containers, inert gas tanks, booster valves, vacuum valves, inert gas boosters, vacuum pumps, vertical rotary pedestals and processing heads;

The metal additive manufacturing position moving device is mainly composed of a path scanning device, a vertical rotary table and a horizontal rotary table;

The conveying pipeline is mainly composed of an energy conveying pipeline and a material conveying pipeline;

The path scanning device adopts a multi-degree-of-freedom translation stage or a mechanical arm;

The inert gas tank is connected to the inert gas booster, the inert gas booster is connected to the high-pressure container through the booster valve, and the vacuum pump is connected to the high-pressure container through the vacuum valve; The continuous uniform positive pressure environment provided by the high-pressure container includes at least a working table and a feeding head, the horizontal rotary table is installed on the base of the high-pressure container, and the vertical rotary table is installed on the horizontal rotary table through a vertical rotary pedestal, The workbench is directly installed on the vertical rotary table; the heat source device and the feeding device are both connected to the delivery pipeline, the processing head is connected to the energy delivery pipeline, and the feeding head is connected to the feeding delivery pipeline; When the processing head is placed outside the high-pressure vessel, the path scanning device is a multi-degree-of-freedom translation stage, the processing head and the feeding head are fixed on the high-pressure vessel, and the multi-degree-of-freedom translation stage is placed under the horizontal rotating platform and connected to the high-pressure vessel ; When the processing head is placed inside the high-pressure container, the path scanning device is a mechanical arm or a multi-degree-of-freedom translation platform. When a mechanical arm is used, the processing head must be integrated with the feeding head, and the mechanical arm is fixedly connected. on the base of the high-pressure container; when a multi-degree-of-freedom translation stage is used, the mutual position connection relationship of the processing head, feeding head, high-pressure container, multi-degree-of-freedom translation stage and horizontal rotation table is the same as when the processing head is placed outside the high-pressure container ; The upper computer is respectively connected with the path scanning device, the vertical rotary table, the horizontal rotary table, the heat source device and the feeding device through a control cable.

Further, the energy source of the heat source device is electron beam, laser beam, ion beam or electric arc.

Further, if the heat source device generates a high-energy beam that can pass through a solid lens, it needs to be placed outside the high-pressure container, and if the heat source generated cannot pass through solids, it needs to be placed inside the high-pressure container.

Further, the delivery pipe includes an optical cable or an electric cable.

A method for applying continuous uniform positive pressure for metal additive manufacturing, the specific steps are as follows:

In the first step, before the additive manufacturing, the original air in the high-pressure container is pumped out through the vacuum pump, and after the negative pressure is realized in the high-pressure container, the vacuum pump is turned off;

In the second step, the inert gas in the inert gas tank is passed into the high-pressure container through the inert gas booster, so that the high-pressure container has a continuous and uniform positive pressure environment higher than the standard atmospheric pressure while realizing inert gas protection;

The third step is to turn on the heat source device and the feeding device, adjust the laser focus, raw material convergence point and target melting point irradiated by the feeding head, so that the laser focus, raw material convergence point and target melting point converge at one point to achieve focusing;

The fourth step is to realize the additive manufacturing process through the linkage control of the host computer on the heat source device, feeding device, path scanning device, vertical rotary table and horizontal rotary table; perform layer by layer according to the programmed NC program or pre-generated CAD model slices Scanning to complete the additive manufacturing of metal parts;

The fifth step, after completing the additive manufacturing process, release the positive pressure in the high-pressure container through the vacuum pump;

In the sixth step, the additive manufacturing part is removed to complete the manufacturing process.

Further, the optimization is carried out by the following methods: adjust the air pressure of the high-pressure container through the air pressure feedback loop, and adjust the power of the heat source device, the moving speed of the path scanning device, the feeding speed of the feeding head, and the distance between the feeding head and the workbench through temperature monitoring means. distance.

Further, the metal raw material delivery form of the feeding device is wire feeding or powder feeding.

Beneficial effect:

(1) The present invention realizes the continuous and uniform positive pressure of the overall environment during the accumulation process of metal additive manufacturing through the positive pressure high-pressure container, without the need to introduce peripheral pressurization methods, making the structure more concise and reliable, and will not be affected by the scanning path of additive accumulation Complicated and impactful on stress application;

(2) The present invention provides a uniform positive pressure environment in the additive accumulation process to realize the repair of microcracks and internal pores of the metal additive manufacturing parts, and improve the strength of the manufactured parts;

(3) In the present invention, since the high-pressure roller must scan along the scanning path of the heat source of additive manufacturing, the rolling effect can be realized by keeping the speed gradient direction of the scanning path of the heat source of additive manufacturing at any time. The heat source of additive manufacturing moves completely synchronously. When scanning the complex path, the actual position of the process processing equipment after turning will deviate from the original track required by the additive manufacturing parts, and it is difficult to reach the required position of the process processing equipment after turning;

(4) The present invention realizes the optimization of the metallographic structure of metal additively manufactured parts by providing a uniform positive pressure environment during the additive stacking process, and improves the strength of the manufactured parts.

Description of drawings

Figure 1 is a schematic diagram of the structure I of a metal additive manufacturing device in a high-pressure vessel using a laser as a heat source.

Fig. 2 is a schematic diagram of the structure II of a metal additive manufacturing device in a high-pressure vessel using a laser as a heat source.

Figure 3 is a left view of the metal additive manufacturing device structure in a high-pressure vessel using a laser as a heat source.

Figure 4 is a partial enlarged view of the integration of the processing head and the feeding head.

Fig. 5 is a flowchart of the working principle of the present invention.

FIG. 6 is a schematic diagram of a moving effect a actually produced by applying the processing method of adding a high-pressure roller to a complex scanning path.

FIG. 7 is a schematic diagram of the moving effect b actually produced by applying the processing method of adding a high-pressure roller to a complex scanning path.

FIG. 8 is a schematic diagram of the moving effect a that needs to be generated when the processing method of adding a high-pressure roller is applied to a complex scanning path.

FIG. 9 is a schematic diagram of the moving effect b that needs to be generated when the processing method of adding a high-pressure roller is applied to a complex scanning path.

Among them, 1-host computer, 2-heat source device, 3-feeding device, 4-conveying pipeline, 5-path scanning device, 6-feeding head, 7-vertical rotary table, 8-working table, 9-horizontal rotary table, 10-High pressure container, 11-Inert gas tank, 12-Inert gas booster, 13-Vacuum pump, 14-Vertical rotating pedestal, 15-Processing head; 16-Additive manufacturing parts, 17-High pressure roller and other process processing equipment, 18-heat source for additive manufacturing, 19-actual position of process processing equipment after turning, 20-position of heat source for additive manufacturing after turning, 21-required position of process processing equipment after turning.

detailed description

The present invention will be described in detail below with reference to the accompanying drawings and examples.

A device for applying continuous and uniform positive pressure for metal additive manufacturing, as shown in Figure 1, the implementation device includes: a host computer 1, a heat source device 2, a feeding device 3, a conveying pipeline 4, and a path scanning device (in this example, a Mechanical arm) 5, feeding head 6, vertical rotary table 7, workbench 8, horizontal rotary table 9, high pressure container 10, inert gas tank 11, inert gas booster 12, vacuum pump 13, vertical rotary pedestal 14, processing head 15 The heat source device 2 is connected with the feeding head 6 (integrated with the processing head 15 of the laser) through the delivery pipeline 4, as shown in Figure 4; in addition, the processing head 15 can also be placed outside the high-pressure container 10 as shown in Figure 2 As shown; the feeding head 6 is connected to the mechanical arm, the feeding device 3 is connected to the delivery pipeline 4, the inert gas tank 11 is connected to the inert gas booster 12, and the vacuum valve of the vacuum pump 13 is connected to the The boost valves of the inert gas booster 12 are all connected to the high-pressure container 10, the horizontal rotary table 9 is connected to the vertical rotary table 7 through the vertical rotary platform 14, and the vertical rotary table 7 is connected to the workbench 8, as shown in the figure 3; the conveying pipeline 4, mechanical arm, feeding head 6, vertical rotary table 7, workbench 8 and horizontal rotary table 9 are placed in the high-pressure container 10, wherein the mechanical arm, vertical rotary table 7 and horizontal The rotating table 9 forms a metal additive manufacturing position moving device, which realizes metal melting and accumulation at any point and gradient within a certain space; the heat source device is installed outside or inside the high-pressure vessel 10, if the heat source generated cannot pass through the solid , needs to be placed inside the high-pressure container, and a lens needs to be installed on the top of the high-pressure container 10 or other high-energy beam entry directions; the feeding device 3 and the heat source device 2 are fixed on the same axis, and the heat source device described in this example adopts a laser. The feeding device 3 adopts a feeder, and the laser, powder feeder, mechanical arm, vertical rotary table 7 and horizontal rotary table 9 realize linkage control through the host computer 1; the mechanical arm can reach any coordinate point in space, so The vertical rotary table 7 and the horizontal rotary table 9 can always face the normal direction of the horizontal plane during the additive accumulation process, and the laser emits laser light through the feeding head 6 to irradiate the metal powder raw material transported by the powder feeder through the conveying pipeline 4 to realize metal material accumulation. molten accumulation.

The specific operation steps (see Figure 5) are as follows:

In the first step, before performing additive manufacturing, the original air in the high-pressure container 10 is extracted by the vacuum pump 13, and after negative pressure is realized in the high-pressure container 10, the vacuum pump 13 is turned off;

In the second step, the inert gas in the inert gas tank 11 is passed into the high-pressure container 10, so that the high-pressure container 10 has a continuous and uniform positive pressure environment higher than the standard atmospheric pressure while realizing inert gas protection;

The third step is to turn on the laser and the powder feeder, and adjust the laser focus, raw material convergence point and target melting point irradiated by the feeding head 6, so that the laser focus, raw material convergence point and target melting point converge at one point to achieve focusing;

In the fourth step, the additive manufacturing process is realized through the linkage control of the host computer 1 on the laser, the powder feeder, the mechanical arm, the vertical rotary table 7 and the horizontal rotary table 9 . Scanning layer by layer according to the programmed NC program or pre-generated CAD model slices to complete the additive manufacturing of metal parts.

In the fifth step, after the additive manufacturing process is completed, the positive pressure in the high-pressure container 10 is released through the vacuum pump 13 .

In the sixth step, the additive manufacturing part is removed to complete the manufacturing process.

FIG. 6 and FIG. 7 are schematic diagrams of the actual movement effect produced by applying the processing method of adding high-pressure rollers to the complex scanning path. FIG. 8 and FIG. 9 are schematic diagrams of the moving effect to be produced when the processing method of adding a high-pressure roller is applied to a complex scanning path. The process processing method of adding high-pressure rollers is applied to the moving effect generated in the complex scanning path. Since the high-pressure roller 17 must follow the scanning path of the additive manufacturing heat source 18 for scanning, it must be kept in the scanning path of the additive manufacturing heat source 18 at any time. The rolling effect can only be realized in the direction of the speed gradient. This device avoids the patent name "a device for controlling the surface quality of metal additive molding". Since the high-pressure roller 17 and the additive manufacturing heat source 18 move completely synchronously, complex During path scanning, the actual position 19 in the process processing equipment will deviate from the original track required by the additively manufactured parts 16 after turning, and it is difficult to reach the required position 21 of the process processing equipment after turning.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. it is a kind of to apply the device that continuous uniform malleation enters row metal increasing material manufacturing, it is characterised in that the device includes：Host computer (1), heat power supply device (2), pay-off (3), conveyance conduit (4), metal increasing material manufacturing location mobile device, feed point (6), work Make platform (8), high-pressure bottle (10), noble gases tank (11), pressure charging valve, vacuum valve, noble gases supercharger (12), vacuum pump (13), vertical rotary pedestal (14) and processing head (15)；

The metal increasing material manufacturing location mobile device is mainly by path scanning means (5), vertical rotary platform (7) and horizontal rotation Platform (9) is constituted；

The conveyance conduit (4) is mainly made up of energy conveying pipeline and material conveying pipe；

Path scanning means (5) is using multiple degrees of freedom displacement platform or mechanical arm；

The noble gases tank (11) is connected with the noble gases supercharger (12), and the noble gases supercharger (12) passes through The pressure charging valve is connected with the high-pressure bottle (10), and the vacuum pump (13) is by the vacuum valve and the high-pressure bottle (10) connect；The continuous uniform positive pressure environment that the high-pressure bottle (10) provides includes at least workbench (8) and feed point (6), , on the base of the high-pressure bottle (10), vertical rotary platform (7) is by vertical rotary pedestal for the horizontal rotating table (9) (14) on the horizontal rotating table (9), the workbench (8) is directly installed on vertical rotary platform (7)；The thermal source Device (2) and the pay-off (3) are connected with the conveyance conduit (4), the processing head (15) and energy conveying pipeline Connection, the feed point (6) are connected with feeding conveyance conduit；When processing head (15) is placed in high-pressure bottle (10) outside, path Scanning means (5) is multiple degrees of freedom displacement platform, and the processing head (15) and feed point (6) are each attached on high-pressure bottle, more certainly It is placed in below horizontal rotating table (9) by degree displacement platform, and is connected with high-pressure bottle (10)；When processing head is placed in high-pressure bottle (10) When internal, path scanning means (5) is mechanical arm or multiple degrees of freedom displacement platform, and when using mechanical arm, processing head (15) must be with Feed point (6) is integrated, and is connected with mechanical arm, and mechanical arm is fixed on the base of high-pressure bottle (10)；When using how free During degree displacement platform, the processing head (15), feed point (6), high-pressure bottle (10), multiple degrees of freedom displacement platform and horizontal rotating table (9) mutual alignment annexation is identical when being placed in outside high-pressure bottle (10) with processing head (15)；The host computer (1) passes through Control cable respectively with the path scanning means (5), vertical rotary platform (7), horizontal rotating table (9), heat power supply device (2) and give Material device (3) connection.

2. a kind of applying continuous uniform malleation as claimed in claim 1 enters the device of row metal increasing material manufacturing, it is characterised in that The energy source of the heat power supply device (2) is electron beam, laser beam, ion beam or electric arc.

3. a kind of applying continuous uniform malleation as claimed in claim 1 enters the device of row metal increasing material manufacturing, it is characterised in that The heat power supply device (2), if producing the high energy beam that can pass through solid lens, need to be placed in the outside of the high-pressure bottle (10), if The thermal source of generation can not pass through solid, need to be placed in the inside of high-pressure bottle.

4. a kind of applying continuous uniform malleation as claimed in claim 1 enters the device of row metal increasing material manufacturing, it is characterised in that The conveyance conduit (4) is including optical cable or cable.

5. it is a kind of to apply the method that continuous uniform malleation enters row metal increasing material manufacturing, it is characterised in that to comprise the following steps that：

The first step, before increasing material manufacturing is carried out, extracts original air in high-pressure bottle (10) out by vacuum pump (13), makes described After negative pressure is realized in high-pressure bottle (10), vacuum pump (13) is closed；

Noble gases in noble gases tank (11) are passed through the high-pressure bottle by noble gases supercharger (12) by second step (10), in, while making high-pressure bottle (10) inherence realize inert gas shielding, also possess continuing higher than normal atmosphere Even positive pressure environment；

3rd step, opens heat power supply device (2) and pay-off (3), adjusts laser spot, raw material remittance that feed point (6) is irradiated Accumulation and target melting point, are made laser spot, raw material convergent point are compiled in a bit with target melting point, realize focusing；

4th step, by host computer (1) to heat power supply device (2), pay-off (3), path scanning means (5), vertical rotary platform And the coordinated signals of horizontal rotating table (9) realize increasing material manufacturing process (7)；According to the numerical control program compiled and edited or previously generate CAD model section is successively scanned, and completes metal parts increasing material manufacturing；

5th step, after completing increasing material manufacturing process, discharges the normal pressure in high-pressure bottle (10) by vacuum pump (13)；

6th step, takes out increasing material manufacturing part, completes manufacture process.

6. the method that a kind of applying continuous uniform malleation as claimed in claim 5 enters row metal increasing material manufacturing, it is characterised in that It is optimized by the following method：The air pressure of high-pressure bottle (10) is adjusted by air pressure feedback circuit, by monitoring temperature means The power of feedback regulation heat power supply device (2), the translational speed of path scanning means (5), the feeding speed of feed point (6), feeding The distance between head and workbench (8).

7. the method that a kind of applying continuous uniform malleation as claimed in claim 5 enters row metal increasing material manufacturing, it is characterised in that The raw metal transporting pattern of the pay-off (3) is wire feed or powder feeding.