CN-116135400-B - Low-pressure laser welding method applied to microstructure small-diameter closed weld joint

CN116135400BCN 116135400 BCN116135400 BCN 116135400BCN-116135400-B

Abstract

The invention relates to a low-pressure laser welding method applied to a microstructure small-diameter closed welding seam, which comprises the steps of positioning and fixing laser welding points after a fuel medium transmission part and an oxidant medium transmission part are assembled, selecting coordinate points along the circumferential direction of the welding seam by a laser probe, fitting a welding seam path by an interpolation calculation method, operating a laser emitter to enable the movement path of the laser points to coincide with the welding seam to determine a working path, rotating the laser emitter to an arcing point along the starting point of an arc receiving section by changing technological parameters to finish the welding of the closed welding seam, wherein in the welding seam welding process, the power P=300×Hd is set based on the penetration of a product, the arcing working distance H1 is delta 0+/-0.2 mm, and the working distance H2 of the arc receiving position is delta 0+5mm. The invention solves the problems that the conventional laser welding cannot ensure the penetration of a small-diameter closed welding line with a microstructure and has smaller welding deformation.

Inventors

ZHANG HUA
LI YIYAN
WANG XUEYUAN
ZHAO XIAOQING
XIE WEIWEI
XIA ZHIQIANG
YANG XUDONG

Assignees

西安航天发动机有限公司

Dates

Publication Date: 20260508
Application Date: 20230330

Claims (8)

1. The low-pressure laser welding method applied to the small-diameter closed welding line of the microstructure is characterized in that the closed welding line is formed by welding a fuel medium transmission part and an oxidant medium transmission part, the closed welding line is an end surface welding line positioned in an annular groove, micropores are arranged on the fuel medium transmission part and the oxidant medium transmission part, and the diameter of the micropores is not more than 0.4mm; Comprising the following steps: After the fuel medium transmission part and the oxidant medium transmission part are assembled, laser welding point positioning and fixing are carried out; Selecting a plurality of coordinate points along the circumferential direction of a welding seam by adopting a laser probe based on a working coordinate system of equipment, fitting a welding seam path by an interpolation calculation method, operating a laser transmitter to enable a movement path of the laser points to coincide with the welding seam, and determining a working path; The laser transmitter rotates to an arcing point along the starting point of the arc receiving section with variable process parameters to finish the welding of a closed welding line, wherein in the welding process of the welding line, the power P=300×Hd of the laser is set based on the penetration of the product, wherein P is the laser power, hd is the penetration of the product, the arcing working distance is that H1 is delta 0+/-0.2 mm, and the working distance H2 of the arc receiving position is delta 0+5mm, wherein delta 0 represents the focusing state of the laser focus on the front surface of the product; The environmental pressure in the welding process is less than or equal to 10Pa, and for titanium alloy and aluminum alloy, the environmental pressure in the welding process is less than or equal to 3Pa; In a low-voltage environment, the laser transmitter rotates to a starting point of an arc receiving section along an arc starting point of a working path, the process keeps the power Q, the working distance H1 and the angular speed omega unchanged, then the laser transmitter rotates to the starting point of the arc receiving section along the working path, the process keeps the power Q unchanged, the working distance is adjusted, the rotation process is uniformly adjusted to be uniformly decelerated, and when the laser transmitter rotates to the arc starting point, the working distance is increased from H1 to H2, and the angular speed is reduced from omega to 0.
2. The low-pressure laser welding method applied to the microstructure small-diameter closed weld joint, which is disclosed in claim 1, is characterized in that after the fuel medium transmission part and the oxidant medium transmission part are assembled, 4-8 welding positioning points are uniformly distributed along the circumferential direction, and the two parts are fixed.
3. The method for low-pressure laser welding of a small-diameter closed weld joint with a microstructure according to claim 1, wherein the weld joint path function expression is fitted by an interpolation calculation method, X 2 +Y 2 =R 2 and X, Y are coordinate values of a working coordinate system, and R is a fitted weld joint radius.
4. The method according to claim 1, wherein the welding is performed on the basis of no melting phenomenon at the center of a small-diameter end face round weld, and the angular velocity ω=v/R 1 , where V is a linear velocity, and R 1 is a weld radius, and the linear velocity is not less than 20mm/s when converted into the linear velocity V.
5. A low-pressure laser welding system applied to a microstructure small-diameter closed weld, for use in the low-pressure laser welding method applied to a microstructure small-diameter closed weld according to any one of claims 1 to 4, comprising: A laser transmitter working path determining module: After the fuel medium transmission part and the oxidant medium transmission part are assembled, laser welding point positioning and fixing are carried out; Selecting a plurality of coordinate points along the circumferential direction of a welding seam by adopting a laser probe based on a working coordinate system of equipment, fitting a welding seam path by an interpolation calculation method, operating a laser transmitter to enable a movement path of the laser points to coincide with the welding seam, and determining a working path; Closing the weld joint welding module: The laser transmitter rotates to an arcing point along the starting point of the arc receiving section with variable process parameters to finish the welding of a closed welding line, wherein in the welding process of the welding line, the power P=300×Hd of the laser is set based on the penetration of the product, wherein P is the laser power, hd is the penetration of the product, the arcing working distance is that H1 is delta 0+/-0.2 mm, and the working distance H2 of the arc receiving position is delta 0+5mm, wherein delta 0 represents the focusing state of the laser focus on the front surface of the product; The welding is performed by taking the fact that the melting phenomenon does not occur in the center of a small-diameter end face round welding line as a criterion, and the angular speed omega=V/R 1 , wherein V is the linear speed, R 1 is the radius of the welding line, and when the welding line is converted into the linear speed V, the linear speed is not less than 20mm/s; Micropores are arranged on the fuel medium transmission part and the oxidant medium transmission part, and the diameters of the micropores are not more than 0.4mm; the ambient pressure is less than or equal to 10Pa in the welding process; selecting 8-16 coordinate points along the welding seam circumference by using a laser probe based on a working coordinate system of equipment; In a low-voltage environment, the laser transmitter rotates to a starting point of an arc receiving section along an arc starting point of a working path, the process keeps the power Q, the working distance H1 and the angular speed omega unchanged, then the laser transmitter rotates to the starting point of the arc receiving section along the working path, the process keeps the power Q unchanged, the working distance is adjusted, the rotation process is uniformly adjusted to be uniformly decelerated, and when the laser transmitter rotates to the arc starting point, the working distance is increased from H1 to H2, and the angular speed is reduced from omega to 0.
6. The low pressure laser welding system for micro-structured small diameter closure welds of claim 5, wherein the closure welds are formed by welding a fuel medium transfer part with an oxidant medium transfer part, the closure welds being end welds located in the ring grooves.
7. The low-pressure laser welding system applied to the microstructure small-diameter closed weld joint, which is disclosed in claim 5, is characterized in that after the fuel medium transmission part and the oxidant medium transmission part are assembled, 4-8 welding positioning points are uniformly distributed along the circumferential direction, and the two parts are fixed.
8. The system of claim 5, wherein the algorithm is used to fit the weld path function expression by interpolation, X 2 +Y 2 =R 2 , X, Y are coordinate values of the working coordinate system, and R is the radius of the weld.

Description

Low-pressure laser welding method applied to microstructure small-diameter closed weld joint Technical Field The invention relates to a low-pressure laser welding method applied to a small-diameter closed weld joint with a microstructure, and belongs to the technical field of metal fusion welding. Background The power of the dual-component low-thrust attitude control thrust chamber is provided by the mutual reaction of the impact and atomization of two working mediums of oxidant and fuel. The angle of impact and the atomization effect after impact are entirely determined by the structure of the core, which is closely related to the welding method of the core. The core component is formed by welding parts with two fine structures, the two parts are provided with a plurality of micro holes, the deformation of the two parts in the welding process is controlled, and the impact angle and atomization effect of two working mediums flowing out of a welded product are directly influenced. Meanwhile, the reliability of the welding seam structure can ensure that two working media are not contacted in advance in the product, and the risk of product deflagration caused by severe reaction of the working media in the product is eliminated. The traditional laser welding method is only suitable for welding products with large diameter and high penetration depth, the welding deformation has almost no influence on the products with large size, and aiming at the small-diameter closed welding line with a microstructure, the welding penetration depth and the welding deformation cannot be simultaneously considered by adopting the traditional laser welding process. Disclosure of Invention The invention solves the technical problems of overcoming the defects of the prior art, providing a low-pressure laser welding method applied to a small-diameter closed welding line of a microstructure, and solving the problems that the penetration and the small welding deformation of the small-diameter closed welding line of the microstructure cannot be ensured by the traditional laser welding. The solution of the invention is as follows: a low-pressure laser welding method for small-diameter closed weld joints of fine structures is formed by welding fuel medium transmission parts and oxidant medium transmission parts to form closed weld joints, wherein the closed weld joints are end face weld joints positioned in ring grooves, micropores are arranged on the fuel medium transmission parts and the oxidant medium transmission parts, the diameters of the micropores are not more than 0.4mm, Comprising the following steps: After the fuel medium transmission part and the oxidant medium transmission part are assembled, laser welding point positioning and fixing are carried out; Selecting 8-16 coordinate points along the circumferential direction of a welding seam by adopting a laser probe based on a working coordinate system of equipment, fitting a welding seam path by an interpolation calculation method, operating a laser transmitter, enabling a laser point movement path to coincide with the welding seam, and determining a working path; The laser emitter rotates to an arcing point along the starting point of the arc receiving section with variable technological parameters to finish the welding of the closed weld joint, wherein in the welding process of the weld joint, the power P=300×Hd of the laser is set based on the penetration of the product, wherein P is the laser power, hd is the penetration of the product, the arcing working distance H1 is delta 0+/-0.2 mm, and the working distance H2 of the arc receiving position is delta 0+5mm, wherein delta 0 represents the focusing state of the laser focus on the front surface of the product. Further, after the fuel medium transmission part and the oxidant medium transmission part are assembled, 4-8 welding positioning points are uniformly distributed along the circumferential direction, and the two parts are fixed. Further, a weld path function expression is fitted through an interpolation calculation method, wherein X 2+Y2＝R2 and X, Y are coordinate values of a working coordinate system, and R is the radius of the fitted weld. Furthermore, the ambient pressure in the welding process is less than or equal to 10Pa. Furthermore, the welding is based on the criterion that the center of the small-diameter end face round welding line does not have melting phenomenon, and the angular velocity omega=v/R, wherein V is the linear velocity, R is the welding line radius, and when the welding is converted into the linear velocity V, the linear velocity is not less than 20mm/s. A low pressure laser welding system for a microstructure small diameter closed weld, comprising: A laser transmitter working path determining module: After the fuel medium transmission part and the oxidant medium transmission part are assembled, laser welding point positioning and fixing are carried out; Selecting 8-16 coordinate points along th