SYSTEM AND METHOD FOR DETECTING AND REGULATING MICROSTRUCTURE ONLINE WITH ELECTROMAGNETIC ASSISTANCE

Abstract

A system and a method are disclosed for detecting and regulating a microstructure online with an electromagnetic assistance. The system comprises a substrate, and a forming device, a detecting device and a regulating device located above the substrate, the detecting device is connected with the regulating device comprising an electromagnetic shock regulating unit and an electromagnetic stirring regulating unit; a workpiece may be formed layer by layer on the substrate through the forming device, the detecting device performs a real-time detection for the microstructure in a formed area, and transmits a detection result to the regulating device, and according to the detection result, the electromagnetic shock regulating unit may perform the electromagnetic shock on a newly formed fused micro area, or the electromagnetic stirring regulating unit may perform the electromagnetic stirring on a molten pool to regulate the microstructure of the workpiece.

Claims

1. A system for detecting and regulating a microstructure online with an electromagnetic assistance, wherein the system comprises a forming device, a detecting device, a regulating device and a substrate; wherein, the forming device, the detecting device and the regulating device are located above the substrate; the detecting device is connected with the regulating device, and the regulating device comprises an electromagnetic shock regulating unit and an electromagnetic stirring regulating unit; in operation, a workpiece may be formed layer by layer on the substrate through the forming device; the detecting device and the regulating device may be moved synchronously with the forming device; the detecting device performs a real time detection for the microstructure in a formed area, and transmits a detection result to the regulating device; and then according to the detection result, the electromagnetic shock regulating unit may be used to perform the electromagnetic shock on a newly formed fused micro area, or the electromagnetic stirring regulating unit may be used to perform the electromagnetic stirring on a molten pool, to regulate the microstructure of the workpiece and complete the detection and the regulation for the microstructure.

2. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 1, wherein the detecting device is an electromagnetic eddying detecting device.

3. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 1, wherein an axis of the detecting device is perpendicular to the substrate.

4. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 1, wherein each of the electromagnetic shock regulating unit and the electromagnetic stirring regulating unit comprises an excitation coil and a magnetic core; the excitation coil winds the magnetic core; and the magnetic core is installed on the forming device through an adjustable support.

5. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 4, wherein a water cooling channel is provided on the magnetic core.

6. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 1, wherein the forming device is an arc forming device, a laser forming device or an electron beam forming device.

7. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 2, wherein the forming device is an arc forming device, a laser forming device or an electron beam forming device.

8. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 3, wherein the forming device is an arc forming device, a laser forming device or an electron beam forming device.

9. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 4, wherein the forming device is an arc forming device, a laser forming device or an electron beam forming device.

10. The system for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 5, wherein the forming device is an arc forming device, a laser forming device or an electron beam forming device.

11. A method for detecting and regulating a microstructure online with an electromagnetic assistance implemented by a system, wherein, the system comprises a forming device, a detecting device, a regulating device and a substrate; wherein, the forming device, the detecting device and the regulating device are located above the substrate; the detecting device is connected with the regulating device, and the regulating device comprises an electromagnetic shock regulating unit and an electromagnetic stirring regulating unit; in operation, a workpiece may be formed layer by layer on the substrate through the forming device; the detecting device and the regulating device may be moved synchronously with the forming device; the detecting device performs a real time detection for the microstructure in a formed area, and transmits a detection result to the regulating device; and then according to the detection result, the electromagnetic shock regulating unit may be used to perform the electromagnetic shock on a newly formed fused micro area, or the electromagnetic stirring regulating unit may be used to perform the electromagnetic stirring on a molten pool, to regulate the microstructure of the workpiece and complete the detection and the regulation for the microstructure; the method comprises: (S1) a forming device forming a workpiece layer by layer on a substrate according to a predetermined forming path, a detecting device and a regulating device moving synchronously with the forming device, and the detecting device detecting a microstructure of the workpiece in a formed area in real time; (S2) under a condition that a detection result is normal, repeating S1; under a condition that an abnormal microstructure is detected, transmitting the detection result to the regulating device, the regulating device using an electromagnetic shock regulating unit to perform the electromagnetic shock on a newly formed fused micro area according to the detection result, in order to produce a plastic ductile deformation of the fused micro area; or the regulating device using an electromagnetic stirring regulating unit to perform the electromagnetic stirring on a molten pool according to the detection result to homogenize a temperature of the molten pool and generate convection, so as to regulate the microstructure; and (S3): repeating S1 and S2 until the workpiece is formed, to realize an online detection and regulation for the microstructure during a forming process of the workpiece.

12. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 11, wherein the detecting device performs an electromagnetic eddying non destructive detection on the formed area of the workpiece, and then realizes the detection of the microstructure in the formed area according to a detected electromagnetic signal and a database with a relationship between a predetermined electromagnetic signal and the microstructure.

13. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 12, wherein magnetic field applied to the detecting device, the electromagnetic shock regulating unit and the electromagnetic stirring regulating unit is any one or more of a stable magnetic field, an alternating magnetic field and a pulsed magnetic field.

14. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 11, wherein an axis of the detecting device is perpendicular to the substrate.

15. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 14, wherein the detecting device performs an electromagnetic eddying non destructive detection on the formed area of the workpiece, and then realizes the detection of the microstructure in the formed area according to a detected electromagnetic signal and a database with a relationship between a predetermined electromagnetic signal and the microstructure.

16. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 15, wherein magnetic field applied to the detecting device, the electromagnetic shock regulating unit and the electromagnetic stirring regulating unit is any one or more of a stable magnetic field, an alternating magnetic field and a pulsed magnetic field.

17. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 11, wherein each of the electromagnetic shock regulating unit and the electromagnetic stirring regulating unit comprises an excitation coil and a magnetic core; the excitation coil winds the magnetic core; and the magnetic core is installed on the forming device through an adjustable support.

18. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 17, wherein the detecting device performs an electromagnetic eddying non destructive detection on the formed area of the workpiece, and then realizes the detection of the microstructure in the formed area according to a detected electromagnetic signal and a database with a relationship between a predetermined electromagnetic signal and the microstructure.

19. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 18, wherein magnetic field applied to the detecting device, the electromagnetic shock regulating unit and the electromagnetic stirring regulating unit is any one or more of a stable magnetic field, an alternating magnetic field and a pulsed magnetic field.

20. The method for detecting and regulating the microstructure online with the electromagnetic assistance according to claim 17, wherein a water cooling channel is provided on the magnetic core.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a schematic structure diagram of a system for detecting and regulating a microstructure online with an electromagnetic assistance according to an embodiment of the present disclosure.

[0026] FIG. 2 is a flowchart of a method for detecting and regulating a microstructure online with an electromagnetic assistance according to an embodiment of the present disclosure.

[0027] Throughout all the drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1—a detecting device, 2—a fused micro area, 3—an electromagnetic shock regulating unit, 4—a forming device, 5—an electromagnetic stirring regulating unit, 6—a molten pool, and 7—a formed area.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] For a better understanding of intentions, technical solutions and advantages of the present disclosure, the disclosure will be further described in details by reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, not to limit the disclosure. In addition, the technical features involved in the various embodiments of the present disclosure described below can be combined with each other as long as they do not conflict with each other.

[0029] A system for detecting and regulating a microstructure online with an electromagnetic assistance is provided by an embodiment of the present disclosure. As shown in FIG. 1, the system comprises a forming device 4, a detecting device 1, a regulating device and a substrate, wherein:

[0030] the forming device 4, the detecting device 1 and the regulating device are located above the substrate; specifically, the forming device 4 is an arc forming device, a laser forming device or an electron beam forming device.

[0031] The detecting device 1 is connected with the regulating device and located behind the forming device 4. The detecting device 1 may be moved synchronously with the forming device 4. And an axis of the detecting device 1 is perpendicular to the substrate. In a further embodiment, the detecting device 1 is an electromagnetic eddying detecting device, which detects the microstructures based on electromagnetic signals. The electromagnetic eddying detecting device shares an electromagnetic generator with the regulating device.

[0032] The regulating device is located around the forming device 4, which comprises an electromagnetic shock regulating unit 3 and an electromagnetic stirring regulating unit 5, which may change a magnitude of a magnetic field, a type of the magnetic field and a distribution of the magnetic field of an electromagnetic field generator in a molten pool area by changing a magnitude and a type of an exciting current of an electromagnetic field generator or by changing a position and a tilt angle of the electromagnetic field generator relative to the forming device 4, in order to change a magnitude, a type and a direction of an external magnetic field such that a process of grain growth, a convection in the molten pool and a heat and mass transfer may be controlled through the external magnetic field.

[0033] Specifically, each of the electromagnetic shock regulating unit 3 and the electromagnetic stirring regulating unit 5 comprises an excitation coil and a magnetic core, the excitation coil winds the magnetic core, and the magnetic core is installed on the forming device 4 through an adjustable support. A relative position and a posture of the magnetic core and the molten pool may be changed by the adjustable support to adjust the distribution of the magnetic field. A water cooling channel is provided on the magnetic core.

[0034] The above system is adopted to perform an online detection and regulation for a microstructure, as shown in FIG. 2, which specifically comprises following steps:

[0035] S1: A forming device 4 forms a workpiece layer by layer on a substrate according to a predetermined forming path, a detecting device 1 and a regulating device move synchronously with the forming device 4. In a detection module 210, at a step 202, the detecting device 1 performs an electromagnetic eddying non-destructive detection on a formed area 7 of the workpiece, and then performs a realtime detection of the microstructure in the formed area 7 according to a detected electromagnetic signal and a default relational database between a predetermined electromagnetic signal and the microstructure.

[0036] S2: At a step 204, it is determined whether the microstructure is normal. Under a condition that a detection result is normal, S1 is repeated; under a condition that an abnormal microstructure is detected, the detecting device 1 transmits the detection result to the regulating device, so that in a control module 220, at a step 206, the regulating device uses a electromagnetic shock regulating unit 3 to perform the electromagnetic shock on a newly formed fused micro area 2, or uses the electromagnetic stirring regulating unit 5 to perform the electromagnetic stirring on a molten pool 6 according to the detection result, determined at a step 208, so as to change a whole forming process from a solidification and crystallization, solid-state phase transformation of the molten pool to a recrystallization of the molten pool and the regulation of the microstructure to improve performances of the workpiece.

[0037] S3: S1 and S2 are repeated until the workpiece is formed to realize the online detection and regulation for the microstructure during the forming process of the workpiece.

[0038] The above overall detection-regulation is realtime, online and closed-loop during additive forming. Specifically, the detection-regulation performs data transmission and determination in a short time, in order to avoide excessively long regulating blind zone caused by a detection-regulation interval to affect final forming quality. As for a hysteresis of the regulating device relative to the detecting device, position parameters to be regulated may be stored, the regulation of the electromagnetic shock may be performed during forming a next layer.

[0039] Specifically, a database for forming materials needs to be established before the additive forming, and comprises a database with a relationship between the electromagnetic signal and the microstructure and a database with a relationship between the microstructure and regulating parameters of the magnetic field. More specifically, a database with microstructure—initial permeability or resistivity—electromagnetic signal may be established through finite element micro and macro models to obtain a relationship between the electromagnetic signals (frequency over zero) and the microstructures such that the microstructure of the workpiece may be predicted according to the detected electromagnetic signal and the microstructure in a solidified formed area may be monitored in real time. The microstructure of the workpiece comprises compositions of the microstructure (grain size) and defects of the microstructure (pores/incomplete fusion). The database with the relationship between the microstructure and the regulating parameters of the magnetic field comprises a database with a relationship between the size of the grain and stirring parameters of the magnetic field in the molten pool/shock parameters of the magnetic field in the molten pool and a database with a relationship between the defects of pores/incomplete fusion and stirring parameters of the magnetic field in the molten pool/shock parameters of the magnetic field in the molten pool.

[0040] More specifically, the electromagnetic shock regulating unit 3 performs an AC electromagnetic shock on the newly formed fused micro area 2, i.e. an electromagnetic force is applied to a solidified area with a higher temperature and a higher plasticity in a rear of the molten pool through an AC electromagnetic field, to produce a plastic ductile deformation, achieve effects of grain refinement, uniform distribution, residual stress reduction, and reduction of defects such as pores and incomplete fusion. The electromagnetic stirring regulating unit 5 performs an AC electromagnetic stirring on the molten pool 6 to control a flow of the molten pool 6, i.e. on the one hand, an external magnetic field is used to apply an external electromagnetic force on a molten pool of molten liquid metal to induce forced convection in the molten pool, thereby stirring the molten pool and refining the grains, changing the forming structure, and suppressing metallurgical defects such as pores, segregation, inclusions; on the other hand, flow of the molten pool may accelerate a homogenization of a temperature of the molten pool, slow down a superheat of a central liquid pool, slow down a temperature gradient near a solid-liquid interface, increase a supercooling in a two-phase region, and provide conditions for an endogenous nucleation, thereby increasing a nucleation rate and refining the grains.

[0041] Optionally, the magnetic field applied to the detecting device 1, the electromagnetic shock regulating unit 3 and the electromagnetic stirring regulating unit 5 is any one of a stable magnetic field, an alternating magnetic field and a pulsed magnetic field or a comprehensive magnetic field mixed with several magnetic fields. A forming mode of the forming device 4 includes, but is not limited to, laser, electron beam or electric arc of base materials such as metal powder/wire and composite additive manufacturing forming thereof.

[0042] Those skilled in the art may easily understand that the above descriptions are only preferred embodiments of the present disclosure and are not intended to limit the disclosure. Any modification, equivalent replacement and improvement made within the spirit and principle of the present disclosure shall be included in the claimed scope of the disclosure.