CN112025022A

CN112025022A - Novel brazing technology based on ultrasonic atomization and injection

Info

Publication number: CN112025022A
Application number: CN202010283473.2A
Authority: CN
Inventors: 张彦振; 李德格; 孙强; 黄秉方; 曹毅; 郑超; 刘永红
Original assignee: China University of Petroleum East China
Current assignee: China University of Petroleum East China
Priority date: 2020-04-13
Filing date: 2020-04-13
Publication date: 2020-12-04

Abstract

The invention relates to a novel brazing technology based on ultrasonic atomization and spraying, and belongs to the field of welding and coating. The handheld ultrasonic atomization spray brazing device is internally provided with an annular piezoelectric ceramic ultrasonic generator, a stainless steel vibrating diaphragm, a temperature-adjustable heating ring and Al in sequence from bottom to top₂O₃The heat insulating layer, the feeding guide pipe and the like are externally provided with a supporting guide aiming device, so that a positioning reference can be provided for brazing. But temperature regulation's heating ring combines with ultrasonic vibration diaphragm to form semi-closed cavity, treats that the brazing material is heated to the molten state in the cavity, and under ultrasonic signal's excitation, the molten solder is sprayed to treating the position of brazing at a high speed, because the volume of molten solder is little, and is fast, can permeate fast and form the part that the effect of brazing is good in waiting to braze in the gap, closes ultrasonic drive signal and heating power supply and can terminate its work. The device can also be combined with a three-dimensional motion platform to realize precise partsThe fixed point accurate brazing. For the solder which is easy to oxidize, inert gas protection is needed during working.

Description

Novel brazing technology based on ultrasonic atomization and injection

Technical Field

The invention belongs to the field of welding, and relates to a novel brazing technology based on an ultrasonic atomization spraying technology, a piezoelectric technology and a brazing filler metal melting control technology.

Technical Field

Brazing technology has a long history and has developed rapidly after the 20 th century. Hard alloy cutters, drilling tools for oil field drilling, blades of steam turbines and the like in the field of mechanical manufacturing all need brazing technology; in addition, the electronic industry and the instrumentation field are also requiring the assistance of soldering technique, and the nine-generation core CPU of Intel also adopts soldering technique for obtaining better heat dissipation effect. Brazing is different from other welding techniques, and compared with fusion welding, brazing does not melt a matrix; compared with pressure welding, brazing has no external force effect. The same metal can be welded, and different metals can also be welded. With the continuous progress of scientific technology, various soldering techniques are gradually evolved, the most common is soldering iron soldering, which is commonly used for soldering electronic components in small circuit boards, and in addition, wave soldering, flame soldering, dip soldering, induction soldering, furnace soldering, vacuum soldering and the like are also adopted.

The main problems of the existing brazing are the fluidity and wettability of the molten brazing filler metal, on one hand, the performance of the material is improved by developing a new brazing filler metal, and on the other hand, the fluidity of the brazing filler metal is enhanced by improving a brazing process. The mainstream method is to introduce external force such as electromagnetic field, ultrasonic wave or electric field to improve the fluidity of the solder. The problems of insufficient magnetic stirring strength and unobvious effect exist in magnetic field assisted brazing; the introduction of the electric field in the electric field auxiliary brazing is beneficial to improving the material interface mass transfer effect, but the simple electrostatic field also has the problem of low medium flow promoting efficiency. The common ultrasonic auxiliary brazing mode is mainly that the ultrasonic is utilized to be connected with a workpiece to be brazed; or the ultrasonic part is connected with the brazing welding head, the generated high-frequency mechanical vibration is transmitted to the joint of the workpiece, the oxide film on the surface of the workpiece is removed, the fluidity of the brazing filler metal in a molten state is improved, and the flowing of the brazing filler metal in a welding seam is promoted. In addition, the ultrasonic vibration can also refine crystal grains and improve the mechanical property of the welding seam. However, the existing ultrasonic auxiliary brazing has large power loss, and the single ultrasonic auxiliary brazing also has the problems of poor temperature uniformity of heating environment, easy formation of a subcutaneous undercurrent layer and no contribution to improving the wettability of materials.

Disclosure of Invention

The invention aims to provide a novel brazing method based on an ultrasonic atomization spraying technology and a corresponding device aiming at the problems in brazing.

The principle of the invention is as follows: the handheld ultrasonic atomization spray brazing device is internally provided with an annular piezoelectric ceramic ultrasonic generator, a stainless steel vibrating diaphragm, a temperature-adjustable heating ring and Al in sequence from bottom to top₂O₃The heat insulating layer, the feeding guide pipe and the like are externally provided with a supporting guide aiming device, so that a positioning reference can be provided for brazing. The temperature-adjustable heating ring and a stainless steel vibrating diaphragm with a special small hole (the diameter of the small hole can be several micrometers to hundreds of micrometers) form a semi-closed liquid storage cavity, and Al is arranged outside the heating ring₂O₃The heat insulating layer is used for protecting, so that heat loss is prevented, and other parts of the handheld brazing device can be protected from being damaged by high temperature. The heating ring heats the fed brazing filler metal to a molten state, and at the moment, if an ultrasonic driving signal is not applied, the brazing filler metal cannot automatically drop due to the existence of the surface tension of the molten brazing filler metal. At the moment, an ultrasonic driving signal is applied, and the molten solder can be ejected out of the nozzle at a certain speed under the excitation action of the ultrasonic signal. Because the molten brazing filler metal sprayed by the device has certain kinetic energy, the size of the brazing filler metal is only in the micron level, the brazing filler metal can be sprayed into a welding seam very easily, and the brazing filler metal can impact a workpiece to be brazed under the action of the kinetic energy to effectively improve the problems of insufficient wettability and insufficient welding. For solder that is easily oxidized, work can be performed in a protective atmosphere. And stopping applying the ultrasonic signal, stopping spraying, and stopping working only by turning off the heating power supply and the ultrasonic driving signal.

The invention has the following characteristics:

1. the novel ultrasonic atomization spray brazing method is based on the principle of ultrasonic atomization spray, molten metal brazing filler metal has certain kinetic energy under the action of ultrasonic waves and is sprayed into a gap to be brazed at a certain speed, and a workpiece with a specific welding area can be obtained by controlling the relative motion of a spray head and the workpiece.

2. The handheld ultrasonic atomization spray brazing device is small in size and convenient to carry and operate.

3. The handheld ultrasonic atomization spray brazing device is low in cost, and a high-power ultrasonic generator and a variable amplitude transmission device are not needed.

4. The invention works under the drive of ultrasonic signals, has high spraying efficiency and can quickly finish various brazing tasks.

5. The diameter of the ultrasonic spray hole of the handheld ultrasonic atomization spray brazing device can be several micrometers to hundreds of micrometers, metal liquid drops at the micrometer level can be obtained, and the metal liquid drops can be accurately sprayed to a position to be brazed with the aid of the aiming device, so that a good brazing effect is obtained.

6. The handheld ultrasonic atomization spray brazing device can also be combined with a three-dimensional automatic motion device, and can perform fixed-point brazing on tiny precise parts with complex structures.

Drawings

FIG. 1 is a schematic diagram of a hand-held ultrasonic atomizing jet brazing apparatus;

FIG. 2 is a schematic diagram of the operation of the ultrasonic atomizing and spraying brazing device.

Detailed Description

See fig. 1. The invention relates to a novel efficient brazing method based on an ultrasonic atomization and injection technology, wherein a semi-open type temperature-adjustable liquid storage cavity is formed by an annular temperature-adjustable heating cavity and a piezoelectric ceramic ultrasonic vibration film. The brazing filler metal is heated to a molten state in the heating chamber after entering the heater through the guide pipe, and the ultrasonic vibration film is provided with small holes, but when an ultrasonic driving signal is not applied, the molten metal brazing filler metal can be stably kept in the liquid storage chamber under the action of surface tension, and the phenomenon of self-dropping or leakage from the ultrasonic atomization spray holes can be avoided. The support aiming device of the ultrasonic brazing device is aligned to the position to be brazed, then an ultrasonic driving signal is started, the brazing filler metal in a molten state is sprayed to a gap to be brazed at a high initial speed under the driving of a high-frequency ultrasonic signal, and the fine molten brazing filler metal impacts a welding seam to obtain a good spreading effect. For the solder which is easy to oxidize, the operation is carried out in an inert gas environment to ensure the soldering quality. In addition, the handheld ultrasonic brazing device can be combined with a three-dimensional motion platform, automatic control of brazing is achieved, and fixed-point accurate brazing of precise parts can be completed, as shown in the attached drawing 2.

The ultrasonic atomization spray brazing device is high in flexibility, can be applied to various occasions, and can be used for brazing parts in various shapes.

Claims

1. A new brazing technology based on an ultrasonic atomization spraying technology is characterized in that: the handheld ultrasonic atomization spray brazing device is internally provided with an annular piezoelectric ceramic ultrasonic generator, a stainless steel vibrating diaphragm, a temperature-adjustable heating ring and Al in sequence from bottom to top₂O₃The heat insulating layer, the feeding guide pipe and the like are externally provided with a supporting guide aiming device, so that a positioning reference can be provided for brazing. The temperature-adjustable heating ring and the stainless steel vibrating membrane form a semi-closed cavity, and Al is arranged outside the heating ring₂O₃The heat insulation layer is used for protection.

2. The new brazing technique based on ultrasonic atomized spray technology as claimed in claim 1, wherein the annular piezoelectric ceramic ultrasonic generator can be other type of ultrasonic generator with proper power, and the energy is not too large or too small, so as to overcome the surface tension of the molten metal and realize high-efficiency spraying.

3. The new brazing technique based on the ultrasonic atomizing and spraying technology as claimed in claim 1, wherein the ultrasonic vibration membrane can be made of stainless steel or other high temperature resistant materials.

4. The new brazing technique based on the ultrasonic atomized spray technology as claimed in claim 1, wherein the brazing filler metal can be various common brazing materials.

5. The new brazing technique based on the ultrasonic atomizing spray technology as claimed in claim 1, wherein the heating device can be a high temperature resistant heating ceramic ring or other heating devices.

6. The new brazing technique based on the ultrasonic atomization spraying technology as claimed in claim 1, wherein the hand-held device can be combined with a three-dimensional motion platform to realize the fixed-point precise brazing of precise parts.