WO2019019096A1

WO2019019096A1 - Low-temperature-resistant and salt-spray-proof welding process for welding radiator

Info

Publication number: WO2019019096A1
Application number: PCT/CN2017/094677
Authority: WO
Inventors: 陶振宇
Original assignee: 太仓陶氏电气有限公司
Priority date: 2017-07-27
Filing date: 2017-07-27
Publication date: 2019-01-31

Abstract

Disclosed is a low-temperature-resistant and salt-spray-proof welding process for welding a radiator, the welding process comprising the steps of preparation, casting, punching, polishing, coating, welding and gumming, wherein in the preparation step, a base (1) and a connection member (2) are made of H70 brass, and fins (3) are made of 6063 an aluminum alloy sheet; the base (1) and the connection member (2) are manufactured in a casting manner; the punching step is implemented by using a punching die to process the aluminum alloy sheet; a joining face of a base blank is polished; two layers of a coating are applied to surfaces of the fins (3); a combined welding of soldering and argon arc welding is then carried out; gumming is carried out after welding; and a desired radiator is obtained.

Description

Welding process of low temperature anti-salt mist welding radiator

Technical field

The invention relates to the field of thermal energy equipment, in particular to a welding process for a low temperature anti-salt mist welding radiator.

Background technique

Radiators, especially finned radiators, are widely used in electronics, computers, heaters, and auto parts. The existing fin design is various, but not precise enough. After using it for a long time, it will increase the overall thermal resistance. Thermal efficiency; the mating surface of the heating element and the heat sink is not tight enough, and the heat conduction is blocked, so that the heating element accumulates heat, causing local high temperature, which affects the service life and has potential safety hazards.

However, there are some defects in the preparation method of the heat sink. Although the pure casting method is simple and easy, the heat dissipation performance is not good, or the splicing after processing, the service life and the process stability may be problematic, and there are also rolling fins. Process, copper / aluminum / magnesium forging bonding process, and so on. For the radiator, different performance requirements are required in different occasions. For example, the machinery for offshore operations needs to have the function of preventing salt spray, otherwise it is easy to cause the electrochemical corrosion of the radiator to be damaged; and the radiator is sometimes also in the low temperature environment. Working underneath requires the ability to withstand long-term tolerance without compromising performance.

Summary of the invention

OBJECT OF THE INVENTION: The present invention provides a heat sink preparation process with simple process, fine structure, salt spray prevention and low temperature resistance, a heat sink produced by the process, and a heat dissipation adhesive coated on the heat sink fin to solve the prior art. There are problems in it.

SUMMARY OF THE INVENTION A welding process for a low temperature and salt spray resistant soldering radiator includes the following steps:

(1) Preparation: Prepare the basic material of the radiator, the base material of the base and the connecting piece is made of H70 brass, and the fin material is made of 6063 aluminum alloy piece with a thickness of 1.2-2mm to clean the raw materials;

(2) Casting: H70 brass is placed in the corresponding casting mold, cast into the required shape, processed at 825-850 ° C, and then fully low temperature heat treatment to release internal stress, low temperature heat treatment temperature 265-270 ° C, to obtain the base a blank and a connector blank, the base blank having a joint surface for engaging the heat generating workpiece, the base blank further having a joint groove for engaging the fin;

(3) stamping: the 6063 aluminum alloy sheet described in the step (1) is press-formed with a fin stamping die to form a fin blank;

(4) Polishing: After removing the burrs of the bottom surface of the base blank and the connector blank by the cutting tool, the joint faces of the base blanks are sequentially 200#, 500#, 1000#, 1500#, 3000#, 6000#. Grinding the sandpaper, and then polishing it with a polishing paste to obtain a base and a connecting member;

(5) Coating: The first coating and the second coating are formed by double-layer spraying on the surface of the fin blank, the first coating is sprayed with the magnesium-rich coating on the surface of the fin blank, and the second layer is coated with Teflon. The coating is sprayed on the surface of the first coating, and after the spraying, the roughness Ra is greater than 6.4 μm to obtain fins, and the magnesium-rich coating comprises the following components by weight:

(6) Welding: The base and the connecting piece are placed in a vacuum brazing furnace for brazing, the brazing temperature is 630-645 ° C, the degree of vacuum is (2-3) X10 ^-3 Pa, and the connecting piece is welded during welding. Corresponding position of the base; take out the integral part of the base and the connecting piece, and then weld the fin to the joint groove of the base by argon arc welding, the weld width is 5-12 mm, and the welded joint and the fin need to be joined Part of the weld width of 3-8mm;

(7) Gluing: uniformly apply the heat-dissipating glue in the space between each adjacent two fins to obtain the finished heat sink.

Preferably, the polishing paste is a mixture of nano-alumina and nano-aluminum hydroxide having a particle size of less than 500 nm. The polishing paste is finer for polishing nano materials, improving the uniformity and efficiency of polishing.

Preferably, in the step (5), the hydrophilic coating in the magnesium-rich coating composition is an aqueous epoxy resin coating. Waterborne epoxy coatings have good adhesion, hydrophilicity and reactivity, and are suitable as carrier coatings for metal coatings.

A heat sink in a welding process of a low temperature anti-salt spray soldering heat sink, comprising a base, a connecting piece and a fin, the base has a joint surface at one end, and a set of connecting members are mounted on the front and rear sides, the fin a set of fins on each side of the base is a fin set by welding the fin grooves located in the base and covering the upper and lower sides of the base;

The fin is undulating as a whole, has a plurality of undulations, the undulations have a width of 2 to 10 mm, the fins are provided with heat dissipation holes, and the surface of the fins is coated with a first coating from the inside to the outside. And a second coating, the first coating being a magnesium-rich coating and the second coating being a Teflon coating.

Preferably, the joint surface has a surface roughness Ra of less than 0.4 μm. The joint surface needs to be joined to the heat-generating workpiece, so the smoothness is required to be high, so that the heat transfer efficiency in the initial stage is critical.

Preferably, the connecting member has two sheets on the front and rear sides of the base, and the two connecting members on the same side are symmetrically connected to the upper and lower fin groups. The structural design of the connecting member not only makes the fin connection more stable, but also makes the heat transfer guidance of the whole system smoother and more efficient.

A heat dissipating glue in a welding process of a low temperature anti-salt mist welding radiator, comprising the following components by weight:

Preferably, the spherical alumina component has a particle size of less than 25 μm and the graphene component has a particle diameter of less than 500 nm. Small particle size spherical alumina facilitates uniform coating heat dissipation, and small particle nanographene has extremely high heat transfer efficiency.

Compared with the prior art, the invention has the beneficial effects that the welding process of the low temperature anti-salt mist welding radiator of the invention is simple in operation, anti-freeze and anti-salt mist, and superior in performance. The base and the connecting piece are cast and the fins are mutually distinguished and related by stamping. The materials selected by the two are excellent in frost resistance; the shape of the fin is designed to have a large surface area, which greatly enhances the heat dissipation area and is effective. Heat dissipation area; the first coating and the second coating, the magnesium-rich coating and the Teflon coating have good anti-corrosion effect, the former is resistant to salt spray corrosion, the latter is resistant to acid and alkali corrosion and anti-freeze; The technical improvement has excellent heat dissipation performance at both normal temperature and lower temperature. The process, product and formulation of the present invention form an organic whole, especially the design of the two-layer coating and the shape and structure design of the heat sink, with outstanding salt spray and anti-freeze properties.

DRAWINGS

1 is a schematic view of a process flow of an embodiment of the present invention, and FIG. 2 is a schematic structural view of a heat sink according to an embodiment of the present invention.

In the figure: 1-base, 10-joint surface, 11-fin groove, 2-connector, 3-fin, 30-fin group, 31-undulation, 4-heat vent.

Detailed ways

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and the drawings in the following description are only the present application. Some of the embodiments described herein can be obtained by those of ordinary skill in the art in view of the drawings without departing from the scope of the invention.

As shown in FIG. 1, a welding process for a low temperature anti-salt mist welding radiator includes the following steps:

(4) Polishing: After removing the burrs of the bottom surface of the base blank and the connector blank by the cutting tool, the joint faces of the base blanks are sequentially 200#, 500#, 1000#, 1500#, 3000#, 6000#. Grinding the sandpaper and then mechanically polishing with a polishing paste to obtain a susceptor and a connecting member, the polishing paste being a mixture of nano alumina and nano aluminum hydroxide having a particle diameter of less than 500 nm;

2, a heat sink in a welding process of a low temperature anti-salt spray soldering heat sink, comprising a base 1, a connecting member 2, and a fin 3, the base 1 having an engaging surface 10 at one end and front and rear sides mounted a set of connecting members 2, the fins 3 being welded by the fin slots 11 of the base 1 and covering the upper and lower sides of the base 1, and a set of fins 3 on each side of the base 1 is a fin set 30, Each of the sets of fins 30 has a number of fins of 8 to 12; the connecting member 2 has two pieces on the front and rear sides of the base 1, and the connecting member 2 has a "U" shape, and two connecting pieces on the same side. 2 symmetrically connecting the upper and lower fin groups 30;

The fins 3 are undulating as a whole, have a plurality of undulations 31, the undulations 31 have a width of 2 to 10 mm, and the fins 3 are arranged in a matrix form with heat dissipation holes 4, the surfaces of the fins 3 being inner The outer coating is coated with a first coating and a second coating, the first coating is a magnesium-rich coating, and the second coating is a Teflon coating;

The surface roughness Ra of the joint surface 10 is less than 0.2 μm, and the joined heat-generating workpiece is also polished to the surface roughness Ra of less than 0.2 μm in accordance with the welding process step (4).

The spherical alumina component has a particle diameter of less than 25 μm, and the graphene component has a particle diameter of less than 500 nm.

The above embodiments are only for explaining the preferred technical solutions of the present invention, and it should be noted that It will be apparent to those skilled in the art that <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt;

Claims

A welding process for a low temperature anti-salt mist welding radiator, characterized in that the method comprises the following steps:

(1) Preparation: Prepare the basic material of the radiator, the base material of the base and the connecting piece is made of H70 brass, and the fin material is made of 6063 aluminum alloy piece with a thickness of 1.2-2mm to clean the raw materials;

(2) Casting: H70 brass is placed in the corresponding casting mold, cast into the required shape, processed at 825-850 ° C, and then fully low temperature heat treatment to release internal stress, low temperature heat treatment temperature 265-270 ° C, to obtain the base a blank and a connector blank, the base blank having a joint surface for engaging the heat generating workpiece, the base blank further having a joint groove for engaging the fin;

(3) stamping: the 6063 aluminum alloy sheet described in the step (1) is press-formed with a fin stamping die to form a fin blank;

(4) Polishing: After removing the burrs of the bottom surface of the base blank and the connector blank by the cutting tool, the joint faces of the base blanks are sequentially 200#, 500#, 1000#, 1500#, 3000#, 6000#. Grinding the sandpaper, and then polishing it with a polishing paste to obtain a base and a connecting member;

(5) Coating: The first coating and the second coating are formed by double-layer spraying on the surface of the fin blank, the first coating is sprayed with the magnesium-rich coating on the surface of the fin blank, and the second layer is coated with Teflon. The coating is sprayed on the surface of the first coating, and after the spraying, the roughness Ra is greater than 6.4 μm to obtain fins, and the magnesium-rich coating comprises the following components by weight:

(6) Welding: The base and the connecting piece are placed in a vacuum brazing furnace for brazing, the brazing temperature is 630-645 ° C, the vacuum degree is 2-3 X10-3 Pa, and the connecting piece is welded to the base during welding. Corresponding position of the seat; take out the integral part of the base and the connecting piece, and then weld the fin to the joint groove of the base by argon arc welding, the weld width is 5-12 mm, and then the welded joint and the fin need to be joined Part, the weld width is 3-8mm;

(7) Gluing: uniformly apply the heat-dissipating glue in the space between each adjacent two fins to obtain the finished heat sink.
The soldering process for a low temperature anti-salt spray soldering heat sink according to claim 1, wherein the polishing paste is a mixture of nano alumina and nano aluminum hydroxide having a particle diameter of less than 500 nm.
The soldering process for a low-temperature anti-salt spray soldering heat sink according to claim 1, wherein in the step (5), the hydrophilic coating in the magnesium-rich coating composition is a water-based epoxy resin coating .
A heat sink in a welding process of a low temperature anti-salt spray soldering heat sink according to any one of claims 1 to 3, comprising a base, a connecting member and a fin, the base One end has a joint surface, a pair of connecting members are mounted on the front and rear sides, the fins are welded through the fin groove and covered on the upper and lower sides of the base, and a set of fins on each side of the base is a fin group;

The fins are undulating as a whole, have a plurality of undulating segments, the undulating segments have a width of 2 to 10 mm, and the fins are covered with a heat dissipation hole in a matrix form, and the surface of the fins is coated from the inside to the outside. A coating and a second coating, the first coating being a magnesium rich coating and the second coating being a Teflon coating.
A heat sink according to claim 4, wherein said joint surface has a surface roughness Ra of less than 0.4 μm.
The heat sink according to claim 4, wherein the connecting member has two pieces on the front and rear sides of the base, and the two pieces on the same side are symmetrically connected to the upper and lower fin groups. .
A heat dissipating glue in a welding process of a low temperature anti-salt spray soldering radiator according to any one of claims 1 to 3, characterized in that it comprises the following components by weight:
A heat-dissipating gel according to claim 7, wherein said spherical alumina component has a particle diameter of less than 25 μm, and said graphene component has a particle diameter of less than 500 nm.