CN106404795A - Infrared information-based metal additive manufacturing process control apparatus and method - Google Patents

Abstract

The invention discloses a metal additive manufacturing process control device based on infrared information, which includes: an additive manufacturing operation unit for manufacturing metal workpieces; an infrared image information acquisition unit, which includes an infrared acquisition device (1) for Real-time collection of infrared temperature field images of the melting pool of the metal workpiece and its surroundings, an image processing unit (9), which is connected with the infrared image information acquisition unit through a data bus (7), and is used to analyze the infrared temperature field The images are processed to generate feedback instructions, and a feedback control unit (10) is used to control the additive manufacturing operation unit, so as to adjust parameters to eliminate defects or alarm shutdown. The invention also discloses a control method using the device. The device of the present invention can realize real-time quality monitoring of the whole process of metal additive manufacturing, and can take timely measures to suppress the expansion of defects or stop operations in time to prevent product scrapping or repair after completion.

Description

A process control device and method for metal additive manufacturing based on infrared information

technical field

The invention belongs to the field of infrared detection and process control of metal additive manufacturing, and more particularly relates to a process control device and method for metal additive manufacturing based on infrared information.

Background technique

Metal additive manufacturing technology can process some products that are difficult to complete by conventional metal processing methods, and the production cycle is short and the efficiency is high. Nowadays, the field of metal additive manufacturing is more mature and applied in industrial production, mainly using laser or electron beam as heat source to melt and sinter metal powder or wire. Such as selective laser sintering (SLS), direct laser sintering (DMLS), laser surfacing (SLM) and electron beam melting (EMB). This type of metal additive manufacturing technology can quickly produce high-quality, high-precision products, and has begun to be used in industrial fields such as aerospace, automobile manufacturing, and medical equipment.

However, laser additive manufacturing and arc welding additive manufacturing inevitably have internal and external defects such as pores, cracks, lack of fusion, and forming deviations due to the influence of material properties or characteristic parameters during the manufacturing process. At present, the quality inspection of metal additive manufacturing products still belongs to the level of completion inspection, that is, the quality inspection after the product is completed. On the one hand, the dimension scanner is used to inspect the external dimensions of the components to find appearance defects and dimensional deviations; on the other hand, the X-ray flaw detector is used to detect the internal flaws of the components to detect internal defects. But completion inspection has inherent flaws—it is not real-time. Once a product is defective, it means that the product is scrapped or complicated to rework, resulting in huge cost waste. Especially for some additive manufacturing parts with large processing size, if the defects between the layers of additive manufacturing in the early stage, such as unfused, pores, etc., if not dealt with in time, will directly affect the quality of the interlayer of additive manufacturing in the later stage, and even lead to the failure of the entire product. qualified. Therefore, the industry urgently needs a device that can monitor the additive manufacturing process throughout the metal additive manufacturing process and optimize parameters in real time according to the additive manufacturing process. Shut down or adjust parameters in time after defects, to ensure the quality of metal additive manufacturing parts from the source and improve production efficiency.

At present, there are no literature records on the process monitoring method of laser metal additive manufacturing.

For the monitoring of metal melting and welding process, the infrared sensing method of melting channel/melting pool is focused on, because the infrared information of melting channel/melting pool includes temperature, size, shape and other parameters that are extremely related to quality. By analyzing and coupling these parameters, the welding quality can be effectively judged.

Patent document CN104741802A discloses a welding quality monitoring system and method. The system includes a welding torch, an infrared thermal imager, an image collector, etc., and the method is to use an infrared thermal imager to collect infrared information of a laser welding molten pool and use a computer to analyze it. Imaging data parameters to realize the evaluation of solder joint quality. However, the system and method disclosed in the patent document CN104741802A are mainly aimed at the process detection of laser welding, and the acquisition device used is an expensive thermal imager, and the function of the system is mainly biased towards monitoring, and the welding parameter feedback link is missing.

Contents of the invention

In view of the above defects or improvement needs of the prior art, the present invention provides a metal additive manufacturing process control device and method based on infrared information. Take measures in time to suppress the expansion of defects; when the defects exceed the set standard, stop the operation in time, so that it is convenient to take measures to rework to eliminate interlayer defects, and prevent product scrapping or repair after completion.

In order to achieve the above object, according to one aspect of the present invention, a process control device for metal additive manufacturing based on infrared information is provided, the device includes:

Additive manufacturing operating unit, one end of which is mounted on the workbench and the other end is linked to a welding torch or nozzle for the manufacture of metal workpieces;

Infrared image information collection unit, which is installed at one end of the additive manufacturing operation unit close to the welding torch or nozzle, the infrared image information collection unit includes infrared collection equipment for real-time collection of the molten pool of the metal workpiece and its surroundings Infrared temperature field image;

An image processing unit, which is connected to the infrared image information acquisition unit through a data bus, and is used to process the infrared temperature field image and generate a feedback instruction; and

A feedback control unit, which is connected to the image processing unit at one end of the data bus, and connected to the additive manufacturing operation unit at the other end, and is used to control the additive manufacturing operating unit according to the feedback instruction, thereby adjusting parameters To eliminate defects or alarm shutdown.

Further, the infrared collection device is an infrared camera, an infrared charge-coupled device, an infrared sensor or an infrared thermal imager.

Further, the parameters and configuration of the infrared acquisition device can be adjusted and replaced according to the material selected for additive manufacturing and the temperature field of the molten pool and the surrounding area, so as to meet the needs of different temperature ranges and different additive manufacturing speed ranges. Precise infrared images.

Further, the infrared image information collection unit also includes a radiator, which is used to reduce the high temperature generated by welding arc radiation, so as to ensure the normal operation of the infrared image information collection unit.

Further, the infrared image information acquisition unit further includes an image acquisition card for converting the collected infrared temperature field image information into a visible digital signal.

Further, the infrared image information acquisition unit also includes a protective shell, which is used to integrate and install the infrared acquisition device, radiator and image acquisition card in it, so as to protect the infrared acquisition device, radiator and image acquisition card It is not damaged by splashing when the heat source is working, and at the same time, it can filter part of the arc light to reduce the interference to the imaging of infrared acquisition equipment.

Further, the image processing unit includes an expert database and a processor, which are used to compare the infrared temperature field image with the infrared image of the standard steady-state temperature field, so as to intuitively reflect the size defects in the infrared image In terms of shape, it is also used to indirectly represent internal defects as the depth and light color and distribution characteristics of the infrared temperature field, so as to identify the size defects and internal defects, and generate the feedback instruction.

Further, the internal defects include one or more of pores, cracks, overheating or lack of fusion.

According to another aspect of the present invention, there is provided a control method for applying the infrared information-based metal additive manufacturing process control device, the method includes the following steps:

S1: Install the metal additive manufacturing process control device based on infrared information on the workbench and adjust its position;

S2: Set the parameters of additive manufacturing, and perform additive manufacturing of metal workpieces;

S3: The metal additive manufacturing process control device based on infrared information starts to work, and the infrared acquisition device collects the infrared temperature field image of the molten pool of the metal workpiece and the surrounding area in real time, and simultaneously detects the temperature difference between layers;

S41: The image processing system compares the image of the infrared temperature field with the infrared image of the standard steady-state temperature field, and detects and identifies possible defects such as weld bumps, incomplete penetration, and overheating. After the processing system has identified said defect, it evaluates the level of the defect;

S411: If the defect exceeds the set standard value, immediately end the additive manufacturing operation, take remedial measures for the defect, and proceed to the next layer of manufacturing after the defect is eliminated;

S412: If the defect does not exceed the set standard value, adjust the parameters of the additive manufacturing operation unit through the feedback control unit to repair the defect, thereby eliminating the defect and proceed to the next layer of manufacturing ;

S42: The image processing system compares the temperature difference between layers with a set label value;

S421: If the interlayer temperature difference is within a reasonable range, adjust the parameters of the additive manufacturing unit through the feedback control unit, so as to realize the stability of the subsequent temperature difference;

S422: If the interlayer temperature difference exceeds a reasonable range, end the additive manufacturing operation and take processing measures.

Further, the infrared temperature field image includes the surface topography, forming size, forming defects and temperature difference between layers of the metal workpiece.

Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

(1) The device of the present invention can realize the real-time quality monitoring of the whole process of metal additive manufacturing, and can take measures in time to suppress the expansion of defects after defects occur; stop the operation in time when the defects exceed the set standard, and it is convenient to take measures to rework and eliminate layers Interim defects prevent product scrapping or repair after completion, forming a complete monitoring, feedback, and adjustment process.

(2) The device of the present invention makes it possible for machine inspection to replace manual or traditional technology inspection in metal additive manufacturing, and the entire inspection process in manufacturing is real-time and traceable.

(3) The modular integration of the device of the present invention can make the system have good portability and adaptability. By adjusting certain configurations and parameters, it is possible to apply it to different metal additive manufacturing equipment, and it can be widely used in the industrial production of metal additive manufacturing.

(4) Compared with methods such as using sensors to obtain the temperature of the molten pool and its surroundings, the device of the present invention uses infrared cameras and other infrared acquisition equipment to photograph the molten pool and its surrounding infrared temperature field, which can truly, accurately and intuitively reflect the molten pool and its surroundings Geometric shape and temperature field distribution of the region.

(5) The method adopted by the method of the present invention is scientific and effective in reducing the internal stress of the metal additive manufacturing part by regulating the temperature difference between the additive manufacturing layers.

Description of drawings

1 is a schematic diagram of an infrared information-based metal additive manufacturing process control device according to an embodiment of the present invention;

Fig. 2 is a logic flow chart of an infrared information-based metal additive manufacturing process control method according to an embodiment of the present invention.

In Fig. 1, the same reference numerals represent the same components, wherein: 1-infrared acquisition device, 2-protective shell, 3-radiator, 4-auxiliary power supply, 5-image acquisition card, 6-fixing mechanism, 7 -data bus, 8-display, 9-image processing unit, 10-feedback control unit, 11-nozzle or welding torch, 12-workpiece, 13-precision workbench.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

Fig. 1 is a schematic diagram of an infrared information-based metal additive manufacturing process control device according to an embodiment of the present invention. As shown in Figure 1, the system includes: infrared acquisition device 1, protective case 2, radiator 3, auxiliary power supply 4, image acquisition card 5, fixing mechanism 6, data bus 7, display 8, image processing unit 9, feedback Control unit 10 , nozzle or torch 11 , workpiece 12 and precision table 13 .

As shown in FIG. 1 , an infrared acquisition device 1 is integrated with a heat dissipation system 3 , an auxiliary power supply 4 , and an image acquisition card 5 and is installed in a protective shell 2 . The infrared acquisition device 1 is used to collect the infrared temperature field images of the molten pool and its surroundings in real time; the heat dissipation system 3 is used to reduce the high temperature caused by arc radiation and ensure the normal operation of other components; the auxiliary power supply 4 is used to maintain the camera and other components under special conditions. The components work normally; the image acquisition card 5 is used to convert the collected infrared temperature field image information into a visible digital signal; the protective shell 2 is used to protect the camera lens and other components from splash damage when the heat source is working, and can filter Partial arc light reduces interference to infrared camera imaging.

In a preferred embodiment of the present invention, the infrared acquisition device 1 shown is an infrared camera, an infrared charge-coupled device, an infrared thermal imager, or an infrared sensor.

As shown in FIG. 1 , the data bus 7 connects the collected infrared temperature field image acquisition card 5 and the image processing unit 9 . The data bus 7 is used to transmit digital signals; the image processing unit 9 is used to compare the collected infrared temperature field image with the infrared image of the standard steady-state temperature field, and the size defects such as molding deviation can be intuitively reflected on the shape of the infrared image , such as bending and discontinuity in the temperature field; internal defects such as pores, cracks, and lack of fusion can be judged indirectly by the color depth and distribution characteristics of the infrared temperature field. Based on the recognition of defects by the image processing system 9 , corresponding feedback instructions are given, and timely alarms are issued to shut down or parameters are adjusted to eliminate defects.

In a preferred embodiment of the present invention, the internal defects include one or more of pores, cracks, overheating or lack of fusion.

As shown in FIG. 1 , the image processing system 9 is connected to a feedback control unit 11 through a data bus 7 . An instruction issued by the image processing system 9 after analyzing the defect; the feedback control unit 11 controls and operates the additive manufacturing operation unit, so as to adjust the parameters to eliminate the defect or give an alarm to shut down.

The infrared information-based metal additive manufacturing process control device of the present invention realizes real-time monitoring of surface topography, forming dimensions, and forming defects in the additive manufacturing process, real-time detection and adjustment of temperature differences between layers, and real-time identification of additive manufacturing. Manufacturing defects are alerted, and the additive manufacturing process can be recorded throughout the process for product traceability. In addition, the device of the present invention can be applied to the quality control process of metal additive manufacturing of various lasers and metal additive manufacturing of molten and non-melted electrodes visible in the molten pool, which solves the problem that cannot be controlled in existing additive manufacturing. The problem of controlling the whole process of metal additive manufacturing.

An embodiment of an infrared information-based metal additive manufacturing process control method of the present invention is performed by the above-mentioned infrared information-based metal additive manufacturing process control device. Fig. 2 is a logic flow chart of an infrared information-based metal additive manufacturing process control method according to an embodiment of the present invention. As shown in Figure 2, the method includes the following steps:

(1) Preparatory work before additive manufacturing, including installation and fixation of the device.

(2) After the preparation is completed, set the parameters of additive manufacturing and perform additive manufacturing.

(3) At the same time, the metal additive manufacturing process control device based on infrared information starts to work. At this time, the infrared camera 1 collects the morphology and infrared temperature field information of the molten pool and surrounding areas in real time.

(4) The monitoring is divided into two parallel processes: the detection of the molten pool and its surrounding area and the detection of the temperature difference between layers.

(41) The molten pool inspection process is responsible for judging whether the temperature field distribution in the molten pool and its surrounding areas is normal, mainly based on the analysis of morphology characteristics, temperature field detection, standard temperature field comparison, etc. Defects such as overheating are detected and identified; after the system detects the defect, the system will evaluate the level of the defect. If the defect exceeds the standard, the manufacturing process will be terminated immediately, and measures will be taken to ensure that the defect is eliminated before proceeding to the next layer of manufacturing; if the defect does not exceed the standard , the parameters of the additive manufacturing equipment will be adjusted according to the cause of the defect;

(42) The interlayer temperature difference process is responsible for detecting whether the temperature difference between adjacent additive manufacturing layers is normal. If it is not normal, it will also judge whether it is reasonable according to the standard; if the temperature difference between layers is within a reasonable range, adjust the additive manufacturing parameters to achieve the stability of the subsequent temperature difference; if the temperature difference exceeds the standard range, end the additive manufacturing, Take measures.

In a preferred embodiment of the present invention, the parameters of the additive manufacturing include one or more of current, voltage, speed, powder/wire feeding amount or shielding gas.

In a preferred embodiment of the present invention, the infrared temperature field image includes the surface topography, forming dimensions, forming defects, and temperature difference between layers of the metal workpiece.

In the technical solution of the present invention, the infrared acquisition device with better effect is given in the embodiment, but the present invention is not limited to the infrared camera provided in the embodiment, and the infrared acquisition device includes an infrared camera, an infrared charge-coupled element, an infrared sensor or Infrared thermal imager, the specific infrared acquisition equipment is determined according to the actual situation.

The invention is based on the infrared information-based metal additive manufacturing process control method, and proposes a control method for metal additive manufacturing real-time parameter adjustment, which reduces the defective product rate of additive manufacturing products and the workload of post-processing, and improves production efficiency. .

Those skilled in the art can easily understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (10)

1. a kind of metal increasing material manufacturing process control equipment based on infrared information it is characterised in that：This device includes：

Increasing material manufacturing operating unit, its one end is installed on the table, and the other end is linked with welding gun or nozzle (11), for manufacturing Metal works；

Infrared Image Information collecting unit, it is installed on described increasing material manufacturing operating unit near one end of welding gun or nozzle, institute State Infrared Image Information collecting unit and include infrared collecting equipment (1), the molten bath for metal works described in Real-time Collection and its The infrared temperature field picture of periphery；

Graphics processing unit (9), it is connected with described Infrared Image Information collecting unit, for institute by data/address bus (7) State infrared temperature field picture to be processed and generated feedback command；And

Feedback control unit (10), it is connected with described image processing unit (9) by data/address bus (7) one end, the other end with Described increasing material manufacturing operating unit connects, for described increasing material manufacturing operating unit is controlled according to described feedback command, thus right Parameter is adjusted to eliminate defect or shutdown of reporting to the police.

2. a kind of metal increasing material manufacturing process control equipment based on infrared information according to claim 1, its feature exists In：Described infrared collecting equipment (1) is infrared camera, infrared charge coupling element, infrared sensor or thermal infrared imager.

3. a kind of metal increasing material manufacturing process control equipment based on infrared information according to claim 1 and 2, its feature It is：The parameter of described infrared collecting equipment (1) and configuration can be according to increasing material manufacturing selected materials and molten bath and neighboring area temperature Degree field is accordingly adjusted and is changed, and is obtained more accurate in different temperatures scope, different increasing material manufacturing velocity interval with satisfaction Infrared image.

4. a kind of metal increasing material manufacturing process control dress based on infrared information according to any one of claim 1-3 Put it is characterised in that：Described Infrared Image Information collecting unit also includes radiator (3), for reducing due to welding arc light spoke Penetrate the high temperature of generation it is ensured that described Infrared Image Information collecting unit normal operation.

5. a kind of metal increasing material manufacturing process control dress based on infrared information according to any one of claim 1-4 Put it is characterised in that：Described Infrared Image Information collecting unit also includes image pick-up card (5), for the infrared temperature that will gather Degree field picture information is converted into visual data signal.

6. a kind of metal increasing material manufacturing process control dress based on infrared information according to any one of claim 1-5 Put it is characterised in that：Described Infrared Image Information collecting unit also includes protecting valve jacket (2), for setting described infrared collecting For (1), radiator (3) and image pick-up card (5) integrated installation in wherein, thus protecting described infrared collecting equipment (1), radiating What device (3) and image pick-up card (5) splashed when not worked by thermal source damages, simultaneously can filtration fraction arc light, reduce to infrared The interference of collecting device imaging.

7. a kind of metal increasing material manufacturing process control equipment based on infrared information according to claim 1, its feature exists In：Described image processing unit (9) includes expert database and processor, for will be steady with standard for described infrared temperature field picture The infrared image in state temperature field is compared, thus dimensional defects are intuitively reflected in described infrared image in shape, with When for internal flaw is indirectly indicative depth color and distribution characteristics for described infrared temperature field, thus to described size Defect and internal flaw are identified, and generate described feedback command.

8. a kind of metal increasing material manufacturing process control equipment based on infrared information according to claim 7, its feature exists In：Described internal flaw includes one or more of pore, crackle, overheated or incomplete fusion.

9. the metal increasing material manufacturing process control equipment based on infrared information any one of a kind of application claim 1-8 Control method it is characterised in that：The method comprises the steps：

S1：Metal increasing material manufacturing process control equipment based on infrared information is installed on the table, adjusts its position；

S2：The parameter of setting increasing material manufacturing, carries out the increasing material manufacturing of metal works；

S3：Started working based on the metal increasing material manufacturing process control equipment of infrared information, described infrared collecting equipment (1) is in real time Gather the molten bath of described metal works and the infrared temperature field picture of neighboring area, and detect interlayer temperature difference simultaneously；

S41：Described image processing system (9) is according to described infrared temperature field picture, the infrared image with standard Steady-State Thermal Field Compare, the defect being likely to occur is carried out with detection identification, after described image processing system (9) identifies described defect, right The rank of defect is evaluated；

S411：If described defect exceedes the standard value of setting, it is immediately finished described increasing material manufacturing operation, described defect is taken Remedial measure, carries out next layer after described defect expressivity and manufactures；

S412：If described defect, not less than the standard value setting, is grasped to increasing material manufacturing by described feedback control unit (10) The parameter making unit is regulated and controled, and described defect is repaired, thus eliminating described defect, carrying out next layer and manufacturing；

S42：Described image processing system (9) is poor according to described interlayer temperature, compares with setting mark value；

S421：If described interlayer temperature difference is in rational scope, is adjusted by described feedback control unit (10) and increase material system Make the parameter of unit, thus realizing stablizing of following temperature difference；

S422：If described interlayer temperature difference is beyond rational scope, terminates increasing material manufacturing operation, take treatment measures.

10. a kind of metal increasing material manufacturing process control equipment based on infrared information according to claim 9, its feature exists In：Described infrared temperature field picture includes temperature difference between surface topography, forming dimension, forming defects and the layering of metal works.