CN-121972762-A - Method and device for inhibiting manufacturing defects in any direction of magnetic control multi-pose arc additive

CN121972762ACN 121972762 ACN121972762 ACN 121972762ACN-121972762-A

Abstract

The invention provides a method and a device for inhibiting manufacturing defects in any direction of magnetic control multi-pose arc additive. According to the method, a composite magnetic field generating device and a camera assembly are integrated on a welding gun, a side image and a front image of a molten pool are obtained through a camera, the geometric dimension of the molten pool is calculated, and the equivalent gravity of the molten pool is obtained. And planning a forming path and a space pose according to the three-dimensional model of the member to be formed, and representing the pose inclination angle by an included angle between the positive direction of the axis of the welding gun and the gravity direction. And calculating transverse exciting current and longitudinal exciting current according to the pose inclination angle and equivalent gravity of the molten pool, and loading the exciting current to the transverse exciting channel and the longitudinal exciting channel to form a transverse and longitudinal composite magnetic field, wherein the transverse magnetic field and the arc current act to generate electromagnetic force to support and restrain the molten pool, and the longitudinal magnetic field is used for weakening arc deflection interference, so that the problems of sagging of the molten pool and falling of the molten pool caused by the action of gravity in the manufacturing process of the multi-pose arc additive in any direction are effectively solved.

Inventors

XIONG JUN
LIU HONGBO
PENG WENJING
ZHENG SENMU
CHEN HUI

Assignees

西南交通大学
四川航天长征装备制造有限公司

Dates

Publication Date: 20260505
Application Date: 20260331

Claims (7)

1. The method for inhibiting the manufacturing defects in any direction of the magnetic control multi-pose arc additive is characterized by comprising the following steps of: The method comprises the steps of installing a composite magnetic field generating device and a camera assembly on a welding gun, wherein the composite magnetic field generating device comprises a transverse magnetic field generating assembly and a longitudinal magnetic field generating assembly and is electrically connected with an excitation power supply, the excitation power supply comprises a transverse excitation channel and a longitudinal excitation channel which are mutually independent, the transverse excitation channel is electrically connected with the transverse magnetic field generating assembly so as to form a transverse magnetic field perpendicular to the axis direction of the welding gun when the welding gun is electrified, and the longitudinal excitation channel is electrically connected with the longitudinal magnetic field generating assembly so as to form a longitudinal magnetic field along the axis direction of the welding gun when the welding gun is electrified; Step two, slicing in layers according to the three-dimensional model of the member to be formed, planning the forming path and the space pose of each layer, and executing according to the following criteria: (1) The axis of the welding gun is always parallel to the normal vector of the surface to be formed, and the positive direction of the axis of the welding gun is regulated to be pointed to a molten pool by the welding gun; (2) Defining an included angle between the positive direction of the axis of the welding gun and the gravity direction as a pose inclination angle theta, wherein theta=0 DEG and theta=180 DEG are end point poses, and 0 DEG < theta <180 DEG is a transition pose; Thirdly, a welding gun starts an arc and moves along a forming path of a current layer, a molten pool image is acquired through the first camera and the second camera, and the molten pool length L, the molten pool height H and the molten pool width W are calculated based on calibration conversion; Determining transverse exciting current I T according to the pose inclination angle theta and the equivalent gravity G m of the molten pool so as to inhibit forming defects: (1) If 0 DEG < theta <180 DEG, calculating the transverse exciting current according to the formula I T =μ 1 Gm/(K 1 sin theta; (2) If θ=0° or θ=180°, calculating a lateral excitation current according to formula I T =μ 2 Gm/K 2 ; wherein mu 1 、μ 2 is a transverse excitation proportional coefficient, and K 1 、K 2 is a calibration coefficient; Calculating longitudinal exciting current I L according to a formula I L =ηI T , wherein eta is a longitudinal exciting proportionality coefficient; Loading exciting currents to the transverse exciting channel and the longitudinal exciting channel according to the obtained I T and I L respectively to form a composite magnetic field, wherein the transverse magnetic field is used for inhibiting sagging of a molten pool and falling off of the molten pool, and the longitudinal magnetic field is used for weakening arc deflection interference; and step seven, after the formation of the current layer is finished, lifting the welding gun by one layering slice height, and repeating the steps three to six to finish the stacking formation of the residual layer.
2. The method according to claim 1, wherein the composite magnetic field generating device comprises a transverse magnetic field generating assembly and a longitudinal magnetic field generating assembly, the transverse magnetic field generating assembly comprises two groups of strip electromagnets with rectangular cross sections, wherein the two groups of magnetic cores are symmetrically arranged on two sides of a welding gun, the magnetic pole directions of the strip electromagnets are perpendicular to the axis direction of the welding gun so as to form transverse magnetic fields distributed along the direction perpendicular to the axis direction of the welding gun in a deposition area, the longitudinal magnetic field generating assembly is a hollow cylindrical electromagnet arranged along the axis direction of the welding gun, the central axis of the longitudinal magnetic field generating assembly is coaxial with the axis of the welding gun, and the welding gun penetrates through an axial hollow through hole of the longitudinal magnetic field generating assembly so as to form a longitudinal magnetic field distributed along the axis direction of the welding gun in the deposition area.
3. The method of claim 1, wherein the magnetic induction intensity of the transverse magnetic field and the longitudinal magnetic field takes a position of 10-30 mm of the end part of the welding gun along the positive direction of the axis of the welding gun as a calibration position, the magnetic induction intensity of the transverse magnetic field is 0-80 mT, the magnetic induction intensity of the longitudinal magnetic field is 0-30 mT, the transverse magnetic field generating assembly and the longitudinal magnetic field generating assembly are respectively connected with a transverse exciting channel and a longitudinal exciting channel of the same exciting power supply, and the output exciting current range of the two channels is 0-20A.
4. The method of claim 1 wherein the first camera is positioned in a direction perpendicular to a plane formed by the direction of the weld gun axis and the direction of the forming path for acquiring a side image of the weld pool and the second camera is positioned orthogonal to the first camera and along the direction of the forming path for acquiring a front image of the weld pool.
5. The method of claim 4 wherein the first camera and the second camera are calibrated for pixel size and the pixel size of the weld pool profile is converted to a weld pool length L, a weld pool height H and a weld pool width W, wherein L is the weld pool length along the forming path, H is the weld pool height along the weld gun axis, and W is the weld pool transverse width perpendicular to both the forming path and the weld gun axis.
6. The method of claim 1, wherein the calibration coefficients K 1 and K 2 , the transverse excitation scaling coefficients μ 1 and μ 2 , and the longitudinal excitation scaling coefficient η are all determined by pre-experimental calibration, where K 1 and K 2 are 0.01-100, μ 1 and μ 2 are 0.1-10, and η is 0.01-2.0.
7. The magnetic control multi-pose arc additive manufacturing defect suppression device in any direction is suitable for the method of any one of claims 1 to 6 and is characterized by comprising a protection gas cylinder (1), a heat source (2), a welding gun (3), a longitudinal magnetic field generation assembly (4), a transverse magnetic field generation assembly (5), a first camera (6), a second camera (7), a computer (8) and an excitation power supply (9), wherein the heat source (2) is electrically connected with the welding gun (3), the protection gas cylinder (1) is communicated with the welding gun (3), the welding gun (3) is used for carrying out multi-pose deposition movement, the longitudinal magnetic field generation assembly (4) and the transverse magnetic field generation assembly (5) form a composite magnetic field generation device, the excitation power supply (9) comprises a transverse excitation channel and a longitudinal excitation channel which are mutually independent, the transverse magnetic field generation assembly (5) is electrically connected, the longitudinal excitation channel and the longitudinal magnetic field generation assembly (4) are electrically connected to form a composite magnetic field when the welding gun (3), and the first camera (6) and the second camera (7) are connected with the computer (8) to obtain a geometric molten pool image for extracting geometric parameters.

Description

Method and device for inhibiting manufacturing defects in any direction of magnetic control multi-pose arc additive Technical Field The invention belongs to the technical field of arc additive manufacturing, and particularly relates to a method and a device for inhibiting manufacturing defects in any direction of magnetic control multi-pose arc additive manufacturing. Background Metal additive manufacturing is a type of advanced manufacturing technology that uses an arc, laser, or electron beam as a heat source to continuously melt and build up layers of wire or powder. The arc additive manufacturing takes the arc as a heat source and the wire as a filling material, has the advantages of high deposition efficiency, relatively low equipment cost, suitability for manufacturing and repairing medium and large components and the like, and has wide application prospect in the field of industrial manufacturing. With the rise of the integrated manufacturing requirement of complex components, the arc additive manufacturing needs to realize deposition in any direction so as to meet the in-situ continuous forming requirement of complex structures. The prior art mainly realizes the deposition in any direction by supporting the support structure or turning the positioner. However, the support structure increases the post-treatment process and reduces the efficiency, and the position changer is difficult to turn over and clamp the large-size component, so that the in-situ continuous deposition is difficult to realize. Therefore, there is a need to develop a new method of arc additive manufacturing in any direction that does not require support structures and displacers. The multi-pose arc additive manufacturing method can realize in-situ deposition forming of complex components in any direction only by regulating and controlling the spatial pose of a heat source, as shown in figure 1. However, in the multi-pose random-direction deposition process, the relative relation between the deposition direction and the gravity direction is continuously changed, and the molten pool is easy to be unstable under the action of gravity, so that the sagging defect of the molten pool and the falling defect of the molten pool are generated, the forming quality is reduced, and the subsequent stacking process is possibly interrupted. The defect is shown in fig. 2, wherein the molten pool sagging defect is represented by a downward shift of the liquid metal and uneven solidification, and the molten pool sagging defect is represented by a partial or total separation of the liquid metal from the formed layer. The magnetic field is used as a non-contact execution means and can act on the electric arc conducting channel and the molten pool current to generate controllable electromagnetic force, so that the molten drop transition and the molten pool flow are regulated, and the influence of gravity on the stability of the molten pool is weakened to a certain extent. In the prior art, the 'manufacturing device and method based on constant magnetic control laser arc composite additive' of Chinese patent application publication No. CN118287831A applies a constant transverse magnetic field in the process of laser arc composite additive so as to improve the flow of a molten pool and inhibit humps. The Chinese patent application publication No. CN119035720A discloses a follow-up magnetic field auxiliary arc fuse material-increasing repairing device and a method, and the matching of the magnetic field direction and the path direction is realized through a follow-up mechanism. The Chinese patent application publication No. CN119549837A discloses a curved surface shape-following material-increasing molten pool magnetic field control system and a method, which inhibit molten pool flowing and improve curved surface forming precision through an external constant magnetic field. However, the current magnetic field assisted arc additive solution is mostly aimed at a single pose or specific application scenario, and its design objective is mainly to improve local forming quality, not to achieve in-situ deposition in any direction. In the deposition process in any direction, the posture of a heat source is continuously changed, so that the components of gravity in a molten pool and the action effect thereof are obviously changed, the integral instability of the molten pool, particularly the serious defects of sagging of the molten pool, falling of the molten pool and the like are easily caused, and the existing scheme can not provide an effective defect inhibition means under the working condition. In addition, the existing magnetic field auxiliary method mostly adopts a single transverse magnetic field, which is easy to induce arc deflection, and causes unstable molten drop transition. Therefore, in order to realize in-situ stable deposition forming in any direction under the multi-pose condition, it is highly desirable to provide a multi-pose arc additive manuf