CN217167057U - Aluminum-based brazing composite material - Google Patents

Abstract

The utility model relates to an aluminum-based brazing composite material, which comprises a core layer and a brazing composite layer; the brazing composite layer comprises a nickel metal outer layer, a metal oxide layer and a filler alloy layer; the metal oxide layer is positioned between the filler alloy layer and the nickel metal outer layer; the filler alloy layer in the brazing composite layer is positioned on one surface facing the core layer; the metal oxide layer is a nickel oxide layer, a nickel-iron oxide layer, a nickel-cobalt oxide layer or a nickel-iron-cobalt oxide layer; the utility model discloses a cohesion of nickel metal skin and filler alloy layer reaches 3 grades and above, and aluminium base composite material of brazing is greater than or equal to 30mm when adopting T type model to braze.

Description

Aluminum-based brazing composite material

Technical Field

The utility model belongs to the technical field of aluminium brazing, a aluminium base composite material that brazes is related to.

Background

The aluminum brazing is to use aluminum and aluminum alloy with melting points lower than that of the base metal as brazing filler metal, the brazing filler metal is molten after heating, a weldment is not molten, the base metal is wetted by the liquid aluminum brazing filler metal, a joint gap is filled, the liquid aluminum brazing filler metal and the base metal are mutually diffused, and the weldment is tightly and firmly connected together. Aluminum heat exchangers have been replacing all-copper heat exchangers since the last 70 s for over 40 years, and in particular, in 1978, Alcan corporation developed NOCOLOK non-corrosive brazing flux which has been widely used up to now, taking up the trend of heat from conventional brazing methods such as vacuum brazing to Controlled Atmosphere Brazing (CAB) for automotive heat exchangers.

At present, the brazing method used by automobile heat exchanger manufacturers at home and abroad is mainly divided into VB and CAB. VB welding destroys the oxide film on the surface of aluminum by means of Mg evaporation in the brazing filler metal, and simultaneously leads the workpiece to be not oxidized when being heated and promotes the wettability of the molten brazing filler metal by means of the degassing function of Mg. The advantages of vacuum brazing (i.e., VB welding) are: firstly, no brazing flux is needed, no harmful gas is generated during heating, no cleaning after welding is needed, and no environmental pollution is caused; secondly, the problems of brazing flux residue and corrosion caused by salt are solved, and the service life of the product is long; and the welded surface is bright and the appearance effect is good. But also has the defects that the equipment cost is high, the efficiency is low, the maintenance is troublesome, and Mg evaporant adhered in the furnace wall is removed regularly, otherwise, the vacuum degree and the heating effect in the furnace are influenced. CAB welding has been developed as one of the main production methods for heat exchangers, using inert gases (mainly nitrogen) as the protective atmosphere and non-corrosive substances based on fluorides as brazing flux. CAB welding has the advantages that: the equipment has low cost and convenient maintenance; secondly, a larger joint clearance is allowed; thirdly, the brazing flux adhered to the surface of the brazing part has non-corrosiveness and non-hygroscopicity, so that the brazing part does not need to be cleaned, the processing procedure is simplified, and the processing cost is reduced. But has some disadvantages: firstly, the brazing flux is not dissolved in water, so that the coating of the brazing flux is troublesome, a special type heat exchanger still needs to be coated with the brazing flux manually for the second time, and then the brazing flux-coated product is dried; secondly, the fluoride brazing flux reacts with Mg, has strict requirements on the content of Mg in a base metal or brazing filler metal, and is generally controlled to be below 0.5 wt%, so that the application of Mg-containing aluminum alloys such as 5xxx series and 6xxx series is limited; thirdly, the operating temperature of the brazing flux is high (higher than 570 ℃), so that more than 50% of aluminum alloy is over-sintered and the method cannot be used; the use of the brazing flux improves the cost, reduces the production efficiency and worsens the working environment; the flux remains, which affects the surface quality and may cause local channel blockage, reducing the heat transfer efficiency. In view of the disadvantages of the two types of brazing methods described above, the development of heat transfer brazing aluminum materials which do not require flux application and can be brazed in a conventional CAB brazing furnace has been promoted.

U.S. patent No. 4,028,200 discloses a method of brazing aluminum parts wherein brazing occurs between two aluminum pieces or an aluminum piece and another metal piece, wherein the aluminum or aluminum alloy has a braze clad that is plated with an adhesion promoting alloy prior to brazing, or wherein an aluminum braze foil plated with a braze promoting alloy is substituted for the aluminum braze clad, the braze promoting alloy comprising nickel or cobalt with the addition of a small amount of lead such that nickel-lead or cobalt-lead can be used alone or in combination. The addition of lead is used to improve the wettability of the composite alloy during the brazing cycle. However, it is contemplated that components using lead-containing braze-promoting layer materials may be subject to environmental concerns during manufacture and use.

There is known art which discloses a brazing sheet product having a core material and a brazing filler material comprising an aluminium clad layer of an Al-Si alloy and a nickel layer thereon, the nickel layer being plated on the surface of the aluminium clad layer by means of electroplating. The addition of at least one of Bi, Pb, Li, Sb to the aluminum clad layer improves the wettability during brazing, eliminating the need to add lead to the layer comprising nickel while maintaining good brazeability in the brazed product and its components. It is believed that the coating of the brazing promoting layer on the surface of the brazed aluminum material by the electroplating method has certain disadvantages, such as low electroplating production rate, and the need of waste water treatment of nickel salt in the electroplating solution, which causes certain environmental protection problems.

There is known art disclosing a method of manufacturing a brazing product comprising the step of coating a metal layer allowing fluxless brazing to a surface of the brazing product comprising an aluminium alloy core and a clad brazing layer on the aluminium alloy core, said surface being the surface clad brazing alloy, comprising the method of pre-treating said surface prior to the coating step, the metal layer comprising a material selected from the group consisting of nickel, nickel alloys, iron alloys, titanium alloys, cobalt and cobalt alloys, and applying the metal coating by physical vapour deposition or chemical vapour deposition and applying the metal coating to the clad brazing layer without an adhesive layer. The method using vapor deposition has two advantages over the conventional electroplating method: firstly, the treatment of waste water can be avoided, and secondly, the nickel layer can be made thinner, however, the method has the same problem with the traditional electroplating, namely, if elements such as Pb, Bi and the like for improving the wettability are not added, the adhesion between the metal nickel and the aluminum alloy material is poor, and the brazing performance is greatly reduced.

Therefore, the design of the aluminum-based brazing composite material containing the nickel metal layer, which does not need to add extra alloy elements such as Pb and the like for improving the wettability, can ensure the brazing performance of the nickel-plated aluminum brazing composite material, has a simple preparation process, is suitable for the existing plating technology, and has a good environment-friendly effect, has very important significance.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems existing in the prior art, the utility model aims to provide an aluminum-based brazing composite material, which comprises a core layer and a brazing composite layer; the brazing composite layer comprises a nickel metal outer layer, a metal oxide layer and a filler alloy layer, wherein the metal oxide layer is located between the filler alloy layer and the nickel metal outer layer and plays a role in improving the adhesion between the filler alloy layer and the nickel metal outer layer.

In order to achieve the above purpose, the utility model adopts the following scheme:

an aluminum-based brazing composite material comprises a core layer and a brazing composite layer; the brazing composite layer comprises a nickel metal outer layer, a metal oxide layer and a filler alloy layer;

the metal oxide layer is located between the filler alloy layer and the nickel metal outer layer; the filler alloy layer is located on a side of the brazing composite layer facing the core layer.

As a preferred technical scheme:

in the above aluminum-based brazing composite material, the metal oxide layer is a layer structure made of metal oxide, specifically: the metal oxide layer is a nickel oxide layer, a nickel-iron oxide layer (a mixture layer of nickel oxide and iron oxide), a nickel-cobalt oxide layer (a mixture layer of nickel oxide and cobalt oxide), or a nickel-iron-cobalt oxide layer (a mixture layer of nickel oxide, iron oxide, and cobalt oxide). Preferably: a nickel oxide layer, a nickel iron oxide layer (a mixture layer of nickel oxide and iron oxide having a nickel oxide content of 30 wt% or more), a nickel cobalt oxide layer (a mixture layer of nickel oxide and cobalt oxide having a nickel oxide content of 30 wt% or more), or a nickel iron cobalt oxide layer (a mixture layer of nickel oxide, iron oxide, and cobalt oxide having a nickel oxide content of 30 wt% or more).

According to the aluminum-based brazing composite material, the nickel metal outer layer is a pure nickel metal layer, and the nickel content is more than or equal to 99 wt%.

Through experimental comparison, the fact that the adhesion between the nickel metal outer layer and the surface of the filler alloy layer can be improved by introducing the layered structure of the metal oxide layer containing nickel oxide between the nickel metal outer layer and the filler alloy layer is beneficial to improving the brazing performance of the aluminum-based brazing composite material. When the content of nickel oxide in the metal oxide layer is more than 30 wt%, the effect of bonding the filler alloy layer and the nickel metal outer layer can be significantly improved, and too little nickel oxide does not play an ideal role, and therefore, nickel oxide is considered to be an effective substance for realizing the improvement of the bonding property. Because nickel is expensive, when the mass content of nickel oxide is sufficient, an oxide such as iron oxide can be used to reduce the cost, and the metal oxide layer is preferably a nickel oxide layer.

In the above aluminum-based brazing composite material, the core layer is a layer made of a 3xxx aluminum alloy with Mn as a main alloying element or a layer made of a 6xxx aluminum alloy with Mg and Si as main alloying elements, specifically an AA3003 aluminum alloy layer, a 6063 aluminum alloy layer, a 6060 aluminum alloy layer or a 3203 aluminum alloy layer;

the filler alloy layer is a layer made of 4xxx aluminum-silicon alloy, and specifically is an AA4045 aluminum alloy layer, a 4343 aluminum-silicon alloy layer, a 4043 aluminum alloy layer, a 4047 aluminum alloy layer or a4045 aluminum alloy layer.

An aluminium based brazing composite as described above, wherein the brazing composite is present on one or both sides of the core layer.

The total thickness of the aluminum-based brazing composite material is less than or equal to 6mm, and can be 0.04-6.0 mm, and more preferably 0.2-0.8 mm; in the aluminum-based brazing composite material, the thickness of each filler alloy layer is 2-30% (preferably 5-20%) of the total thickness of the aluminum-based brazing composite material; the composite ratio of the filler alloy layer (namely the thickness of the filler alloy layer accounts for the percentage of the total thickness) is not too small, otherwise, enough brazing filler metal cannot be met, and a weldment cannot be wetted in the brazing process; the composite ratio of the filler alloy layer should not be too large, which would result in a thicker composite overall and increased cost.

According to the aluminum-based brazing composite material, the thickness of the nickel metal outer layer in each brazing composite layer is 5-1000 nm (preferably 20-50 nm), and the thickness deviation is less than or equal to 10%; the nickel metal outer layer with too high thickness can cause cost increase, and the nickel metal outer layer with too low thickness causes poor brazing effect;

the thickness of the metal oxide layer in each brazing composite layer is 3-20 nm (preferably 10-20 nm), and the thickness deviation is less than or equal to 10%; a metal oxide layer having an excessively high thickness may rather hinder the brazing filler metal from being melted and wetted during brazing, and an excessively low metal oxide layer may be difficult to achieve in terms of processing.

According to the aluminum-based brazing composite material, the bonding force between the nickel metal outer layer and the filler alloy layer is 3-grade or above; the length of the welding seam of the aluminum-based brazing composite material is more than or equal to 30mm when the T-shaped sample model is adopted for brazing (under the same condition, the longer the welding seam is, the better the brazing performance is).

According to the preparation method of the aluminum-based brazing composite material, the metal oxide layer is firstly deposited on the surface of the filler alloy layer of the composite aluminum plate by adopting the ion beam vapor deposition method, and then the metal is continuously deposited by adopting the ion beam vapor deposition method to form the nickel metal outer layer;

the ion beam vapor deposition method is performed under vacuum conditions.

When the metal oxide layer is deposited by using a vapor deposition method, the effect is better compared with methods of arc evaporation and magnetron sputtering, because the layer is a high-energy unstable-state oxide layer formed under a vacuum condition, the oxide layer is easily converted to a low energy state when being heated, particularly at the brazing temperature of 600 ℃, metal oxide atoms migrate to two sides of the nickel metal outer layer and the filler alloy layer on the outermost layer respectively, and the interface bonding force between the nickel metal outer layer and the filler alloy layer is further improved.

In some existing researches, a nickel layer (equivalent to the nickel metal outer layer) is plated on the surface of the brazing filler metal by adopting a chemical nickel plating mode to improve the brazing performance of the aluminum brazing composite material, the thickness of the nickel layer obtained by the method is generally 1-2 μm, and in order to reduce the cost (nickel metal is expensive), a nano-scale nickel layer can be plated by adopting a chemical plating method, and the thickness deviation of the plating layer is often large when the size below 100nm is prepared.

In order to realize a nickel metal layer with a nano-scale thickness, such as a nickel layer with a thickness of 5-500 nm and a nickel layer with a thickness of 20-200 nm, compared with chemical plating, a metal oxide layer with a uniform thickness can be obtained by adopting methods such as vapor deposition, arc evaporation, magnetron sputtering and the like in the prior art.

The thin oxide film layer is attached between the metal layer and the filler alloy, so that the adhesion between the metal layer and the surface of the aluminum alloy can be improved, and the adhesion is favorable for improving the brazing performance of the aluminum-based brazing composite material. And it was found that the bonding effect was the best when a nickel metal layer of uniform thickness was deposited on the metal oxide layer of uniform thickness. Particularly, when the oxide film layer deposited by the vapor deposition method is used, the effect is better than that of the arc evaporation and magnetron sputtering methods, because the oxide film layer is a high-energy unstable-state oxide layer formed under the vacuum condition, the oxide layer is easily converted to a low-energy state by being heated especially at the brazing temperature (about 600 ℃), and atoms of the oxide film respectively migrate to two sides of the outermost nickel metal outer layer and the filler alloy layer, so that the interface bonding force of the nickel metal outer layer and the filler alloy layer is improved.

The process of the composite aluminum plate adopts a conventional process method, for example, the optional method is to respectively prepare the core layer and the filler alloy layer by using a traditional semi-continuous casting or continuous casting and rolling mode, sequentially stack the core layer and the filler alloy layer according to the thickness of the composite ratio, perform bonding rolling, and obtain the composite aluminum plate with target specification and performance through processes of hot rolling, cold rolling, annealing and the like; another optional method is to adopt a composite casting method to obtain a filler alloy layer and core layer composite ingot with a target composite ratio; and carrying out hot rolling, cold rolling, annealing and other processes on the composite ingot to obtain the composite aluminum plate with the target specification and performance.

And before the metal oxide layer is deposited, ion etching, magnetron sputtering etching or glow discharge etching is adopted to carry out pretreatment on the surface of the filler alloy layer of the composite aluminum plate.

The surface of the filler alloy layer of the composite aluminum plate is pretreated, so that the aluminum oxide layer influencing the brazing effect can be effectively removed, surface oil stain residues and heterogeneous particles are removed, the metal oxide layer or the metal layer deposited on the surface of the filler alloy layer of the composite aluminum plate is assisted, and the brazing without the brazing flux can be realized by forming a nickel metal layer on the surface of the filler alloy layer.

The technological parameters for depositing the metal oxide layer are as follows: the ion beam application time is 3-30 min (preferably 5-10 min), the beam current is not more than 80 muA (preferably 50-60 muA), and the voltage is 3-8 kV (preferably 5-7 kV);

the technological parameters for forming the nickel metal outer layer by depositing the metal are as follows: the ion beam application time is 8-1500 min (preferably 30-300 min), the beam current is not more than 80 muA (preferably 50-70 muA), and the voltage is 3-10 kV (preferably 6-8 kV).

The metal oxide layer is a metal oxide layer with nano-scale thickness and containing high-energy unstable nickel oxide.

The principle of the utility model is that:

the utility model discloses an it can improve the adhesion between nickel metal skin and the filler alloy layer to attach the thin metal oxide layer that contains nickel oxide of one deck between nickel metal skin and the filler alloy layer, and this kind of adhesion is favorable to improving aluminium base composite material's of brazing performance.

By introducing a metal oxide layer (namely a nickel oxide layer or a nickel oxide and one or two oxide film layers of cobalt oxide and iron oxide) on the surface of the filler alloy layer and then depositing a nickel metal outer layer on the surface of the metal oxide layer, the brazing performance of the material is obviously improved. The introduction of the metal oxide layer containing nickel oxide is found to effectively improve the cohesiveness, and the improvement of the cohesiveness is found to be beneficial to improving the wettability of the brazing filler metal in subsequent brazing experiments, so the technical scheme of the invention can ensure the brazing performance of the nickel-plated aluminum brazing composite material without adding additional alloy elements such as Pb and the like for improving the wettability.

Advantageous effects

In the aluminum-based brazing composite material of the utility model, the bonding force between the nickel metal outer layer and the filler alloy layer is 3 grades or more; the length of the welding seam of the aluminum-based brazing composite material is more than or equal to 30mm when the T-shaped sample model is adopted for brazing.

Drawings

FIG. 1 is a schematic view of a T-shaped braze specimen model;

FIG. 2 is a transmission electron micrograph of an aluminum-based brazing composite obtained in example 1;

FIG. 3 is a metallographic image showing a cross section of a weld of a T-shaped specimen in example 1;

FIG. 4 is a schematic representation of an aluminum-based brazing composite material made in example 1;

FIG. 5 is a schematic representation of an aluminum-based brazing composite obtained in example 4;

FIG. 6 is a schematic representation of an aluminum-based brazing composite obtained in example 5;

FIG. 7 is a schematic representation of an aluminum-based brazing composite obtained in example 2;

the composite material comprises 1-a nickel metal outer layer, 2-a metal oxide layer, 3-a filler alloy layer, 4-a core layer, 5-a brazing composite layer, 6-a middle layer, 7-an anticorrosive layer, 8-a gasket I, 9-a welding line, 10-a test article, 11-a cushion rod and 12-a gasket II.

Detailed Description

The present invention will be further described with reference to the following detailed description. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes and modifications of the present invention may be made by those skilled in the art after reading the teachings of the present invention, and these equivalents also fall within the scope of the appended claims.

The utility model provides a test method that combined material adopted as follows:

1. the utility model grades the bonding force of the nickel metal outer layer and the filler alloy layer according to the GB/T9286-1998 grid test of colored paint and varnish-paint film, the result is totally 5 grades, and the larger the grade is, the smaller the bonding force of the film layer and the matrix is.

2. The brazing performance of the material is evaluated by adopting a T-shaped model, the schematic diagram of the T-shaped sample model is shown in figure 1, according to the assembly form of figure 1, an aluminum-based brazing composite material is cut into sample pieces with the size of 25mm multiplied by 60mm and is horizontally placed on a test bed, AA3003 alloy with the size of 25mm multiplied by 60mm is vertically placed on the aluminum-based brazing composite material, a nickel metal outer layer of the aluminum-based brazing composite material faces upwards and is assembled with the AA3003 alloy to form a T-shaped sample, wherein a gasket I8 is 50mm long (L1) and 1mm thick; the thickness of the test article 10 is 0.8 mm; the diameter of the backing rod 11 is 1mm, the length of the gasket II 12 is 60mm (L2), the width is 25mm (L3), and the thickness is 2mm, the T-shaped sample is placed into a quartz tube furnace with the caliber of 100mm for simulated brazing, and nitrogen protection is adopted in the quartz tube furnace. Simulating a brazing process: keeping the temperature for 3min after the temperature is raised by 600 ℃ at the heating rate of 30 ℃/min, taking out a sample, and air-cooling to room temperature to obtain the brazing sheet subjected to simulated brazing. And (5) counting the length of the T-shaped sample welding line 9 after brazing. The longer the length of the weld, the larger the cross-sectional area of the weld, indicating the better the fluidity of the molten filler metal and the better the brazing performance of the material.

3. Measuring the thickness and thickness deviation of the nickel metal outer layer and the metal oxide layer by adopting a transmission electron microscope, selecting two visual fields to measure the thickness of the nickel metal outer layer and the metal oxide layer, randomly selecting five different positions for measuring the thickness in each visual field, obtaining 10 sets of thickness values di of the nickel metal outer layer and the metal oxide layer respectively, and calculating the average value of the 10 sets of thickness values

The thickness deviation is the percentage of the maximum difference value of 10 groups of thickness values and the average value to the average value, and the formula is expressed as

Thickness variation indicates uniformity of thickness, and smaller variation indicates better uniformity of thickness.

Example 1

A preparation method of an aluminum-based brazing composite material comprises the following specific steps:

(1) obtaining a filler alloy layer and core layer composite ingot with a target composite ratio by adopting a composite casting method; carrying out hot rolling, cold rolling and annealing processes on the composite ingot to obtain a composite aluminum plate with target specification and performance;

wherein, the core layer is an AA3003 aluminum alloy layer taking Mn as a main alloy element;

the filler alloy layer is an AA4045 aluminum alloy layer taking Si as a main alloy element;

(2) performing pretreatment on the surface of the filler alloy layer of the composite aluminum plate prepared in the step (1) by adopting ion etching to remove an aluminum oxide layer influencing the brazing effect and simultaneously removing oil stain residues and heterogeneous particles on the surface;

(3) at a pressure of 5X 10 ^－5 Depositing a metal oxide layer made of a mixture of 70 wt% of nickel oxide and 30 wt% of iron oxide on the surface of the filler alloy layer of the pretreated composite aluminum plate by adopting an ion beam vapor deposition method under the vacuum condition of Pa; the thickness of the metal oxide layer is 3nm, and the thickness deviation is 10%;

the process parameters for depositing the metal oxide layer by the ion beam vapor deposition method are as follows: the ion beam application time is 5min, the beam current is 50 muA, and the voltage is 5 kV;

(4) at a pressure of 5X 10 ^－5 Continuously depositing metal on the surface of the metal oxide layer prepared in the step (3) by adopting an ion beam vapor deposition method under the vacuum condition of Pa to form a nickel metal outer layer with the thickness of 200nm and the thickness deviation of 0.50 percent, thereby preparing the aluminum-based brazing composite material; the nickel content in the nickel metal outer layer is 99 wt%;

the technological parameters of the ion beam vapor deposition method for depositing metal to form the nickel metal outer layer are as follows: the ion beam application time is 30min, the beam current is 50 muA, and the voltage is 6 kV.

As shown in fig. 2 and 4, the aluminum-based brazing composite material with the total thickness of 0.8mm is prepared, and comprises a core layer 4 and a brazing composite layer 5; the brazing composite layer 5 comprises a nickel metal outer layer 1, a metal oxide layer 2 and a filler alloy layer 3 (the thickness is 20 percent of the total thickness of the aluminum-based brazing composite material); the bonding force between the nickel metal outer layer 1 and the filler alloy layer 3 is 2 level; as shown in FIG. 3, the aluminum-based brazing composite material has a weld length of 35mm when brazed using a T-pattern die.

Comparative example 1

A method for preparing an aluminum-based brazing composite material, which is basically the same as that in example 1, except that the treatment in step (3) is not performed, and a nickel metal outer layer is formed by directly depositing metal on the surface of a filler alloy layer of a pretreated composite aluminum plate by an ion beam vapor deposition method, so as to prepare the aluminum-based brazing composite material.

The bonding force between the nickel metal outer layer and the filler alloy layer of the aluminum-based brazing composite material is 4-level; the length of the welding seam of the aluminum-based brazing composite material is 22mm when the T-shaped sample model is adopted for brazing.

The bonding force and the length of the weld of comparative example 1 are smaller than those of example 1, compared to example 1, because when the metal oxide layer including the nickel oxide layer is not provided, excellent bonding force cannot be obtained, thereby further affecting the brazing effect.

Comparative example 2

A method of producing an aluminium-based brazing composite material, substantially as described in example 1, except that in step (3) a metal oxide layer is deposited which is a mixture of 20 wt% nickel oxide and 80 wt% iron oxide.

The bonding force between the nickel metal outer layer and the filler alloy layer of the prepared aluminum-based brazing composite material is 4-level; the length of the welding seam of the aluminum-based brazing composite material is 25mm when the T-shaped sample model is adopted for brazing.

The bonding force and the length of the weld of comparative example 2 are less than those of example 1, compared to example 1, because the effect of improving the bonding force of the nickel metal outer layer and the filler alloy layer is not outstanding and the increase in the length of the weld is insignificant when the content of nickel oxide in the metal oxide layer is less than 30 wt%.

Comparative example 3

A method of producing an aluminum-based brazing composite material, substantially as in example 1, except that in step (4), a pure iron metal outer layer (iron content of 99 wt%) is formed by continuing to deposit metal on the surface of the metal oxide layer by ion beam vapor deposition.

The binding force between the pure iron metal outer layer and the filler alloy layer of the prepared aluminum-based brazing composite material is 3 grades; the length of the welding seam of the aluminum-based brazing composite material is 21mm when the T-shaped sample model is adopted for brazing.

The bonding force and the length of the weld of comparative example 3 are smaller than those of example 1, compared to example 1, because the same effect as that of pure nickel cannot be obtained by changing the metal outer layer to pure iron, and the use of pure nickel for the outer layer cannot be substituted.

Comparative example 4

A method of producing an aluminium-based brazing composite material, substantially as in example 1, except that in step (4), a pure cobalt metal outer layer (with a cobalt content of 99 wt%) is formed by continuing to deposit metal on the surface of the metal oxide layer by ion beam vapour deposition.

The binding force between the pure cobalt metal outer layer and the filler alloy layer of the prepared aluminum-based brazing composite material is 3 grades; the length of the welding seam of the aluminum-based brazing composite material is 19mm when the T-shaped sample model is adopted for brazing.

The bonding force and the length of the weld of comparative example 4 are smaller than those of example 1, compared to example 1, because the same effect as that of pure nickel cannot be obtained by changing the metal outer layer to pure cobalt, and the use of pure nickel for the outer layer cannot be substituted.

Example 2

A preparation method of an aluminum-based brazing composite material comprises the following specific steps:

(1) obtaining a composite ingot with a target composite ratio, which is made of a filler alloy layer, a core layer and an anticorrosive layer, by adopting a composite casting method, wherein the filler alloy layer and the anticorrosive layer are respectively positioned on two sides of the core layer; carrying out hot rolling, cold rolling and annealing processes on the composite ingot to obtain a composite aluminum plate with target specification and performance;

wherein, the core layer is 6063 aluminum alloy taking Mg and Si as main alloy elements;

the filler alloy layer is 4343 aluminum-silicon alloy with Si as a main alloy element;

the anticorrosive layer is 7072 aluminum-zinc alloy with Zn as main alloy element;

(2) performing pretreatment on the surface of the filler alloy layer of the composite aluminum plate prepared in the step (1) by adopting magnetron sputtering etching to remove an aluminum oxide layer influencing the brazing effect and remove surface oil stain residues and heterogeneous particles;

(3) at a pressure of 5X 10 ^－5 Depositing a metal oxide layer made of a mixture of 32 wt% of nickel oxide, 60 wt% of iron oxide and 8 wt% of cobalt oxide on the surface of the filler alloy layer of the pretreated composite aluminum plate by adopting an ion beam vapor deposition method under the vacuum condition of Pa; the thickness of the metal oxide layer is 5nm, and the thickness deviation is 1%;

the process parameters for depositing the metal oxide layer are as follows: the ion beam application time is 10min, the beam current is 56 muA, and the voltage is 6 kV;

(4) at a pressure of 5X 10 ^－5 Continuously depositing metal on the surface of the metal oxide layer prepared in the step (3) by adopting an ion beam vapor deposition method under the vacuum condition of Pa to form a nickel metal outer layer with the thickness of 400nm and the thickness deviation of 0.20%; the nickel content in the nickel metal outer layer is 99.1 wt%;

the technological parameters for forming the nickel metal outer layer by depositing metal are as follows: the ion beam application time is 150min, the beam current is 56 muA, and the voltage is 7 kV;

as shown in fig. 7, the aluminum-based brazing composite material with the total thickness of 0.04mm is prepared, and comprises a core layer 4, an anticorrosive layer 7 (the thickness is 8% of the total thickness of the aluminum-based brazing composite material) and a brazing composite layer 5; the brazing composite layer 5 comprises a nickel metal outer layer 1, a metal oxide layer 2 and a filler alloy layer 3 (the thickness is 10 percent of the total thickness of the aluminum-based brazing composite material); the bonding force between the nickel metal outer layer 1 and the filler alloy layer 3 is 3 grades; the length of the welding seam of the aluminum-based brazing composite material is 31mm when the T-shaped sample model is adopted for brazing.

Example 3

A preparation method of an aluminum-based brazing composite material comprises the following specific steps:

(1) respectively preparing a core layer and two filler alloy layers by using a traditional semi-continuous casting mode;

wherein, the core layer is 6060 aluminum alloy taking Mg and Si as main alloy elements;

the filler alloy layer is 4043 aluminum alloy with Si as a main alloy element;

(2) sequentially stacking the filler alloy layer, the core layer and the filler alloy layer, performing bonding rolling, and performing hot rolling, cold rolling and annealing processes to obtain a composite aluminum plate with target specification and performance;

(3) performing pretreatment on the surface of one filler alloy layer of the composite aluminum plate by adopting ion etching to remove an aluminum oxide layer influencing the brazing effect and simultaneously removing oil stain residues and heterogeneous particles on the surface;

(4) at a pressure of 5X 10 ^－5 Under the vacuum condition of Pa, adopting an ion beam vapor deposition method to carry out surface treatment on the filler alloy layer of the pretreated composite aluminum plateDepositing a metal oxide layer made of a mixture of 60 wt% nickel oxide and 40 wt% iron oxide; the thickness of the metal oxide layer is 9nm, and the thickness deviation is 2%;

the technological parameters of the ion beam vapor deposition method for depositing the metal oxide layer are as follows: the ion beam application time is 25min, the beam current is 60 muA, and the voltage is 8 kV;

(5) at a pressure of 5X 10 ^－5 Continuously depositing metal on the surface of the metal oxide layer prepared in the step (4) by adopting an ion beam vapor deposition method under the vacuum condition of Pa to form a nickel metal outer layer with the thickness of 5nm and the thickness deviation of 10%, thereby preparing the aluminum-based brazing composite material; the nickel content in the nickel metal outer layer is 99.3 wt%;

the technological parameters of the ion beam vapor deposition method for depositing metal to form the nickel metal outer layer are as follows: the ion beam application time is 8min, the beam current is 60 muA, and the voltage is 3 kV.

The prepared aluminum-based brazing composite material with the total thickness of 0.1mm comprises a filler alloy layer, a core layer and a brazing composite layer; the brazing composite layer comprises a nickel metal outer layer, a metal oxide layer and a filler alloy layer (the thickness is 30 percent of the total thickness of the aluminum-based brazing composite material); the bonding force between the nickel metal outer layer and the filler alloy layer is 2 grade; the length of the welding seam of the aluminum-based brazing composite material is 35mm when the T-shaped sample model is adopted for brazing.

Example 4

A preparation method of an aluminum-based brazing composite material comprises the following specific steps:

(1) respectively preparing a core layer and two filler alloy layers by using a traditional continuous casting mode;

wherein, the core layer is 3203 aluminum alloy taking Mn as a main alloy element;

the prepared filler alloy layer is 4047 aluminum alloy with Si as a main alloy element;

(2) sequentially stacking the filler alloy layer, the core layer and the filler alloy layer, performing bonding rolling, and performing hot rolling, cold rolling and annealing processes to obtain a composite aluminum plate with target specification and performance;

(3) performing pretreatment on the surface of one filler alloy layer of the composite aluminum plate by adopting magnetron sputtering etching to remove an aluminum oxide layer influencing the brazing effect and simultaneously removing oil stain residues and heterogeneous particles on the surface;

(4) at a pressure of 5X 10 ^－5 Depositing a metal oxide layer made of a mixture of 78 wt% of nickel oxide and 22 wt% of iron oxide on the surface of the filler alloy layer of the pretreated composite aluminum plate by adopting an ion beam vapor deposition method under the vacuum condition of Pa; the thickness of the metal oxide layer was 12nm, and the thickness deviation was 1.5%;

the technological parameters of the ion beam vapor deposition method for depositing the metal oxide layer are as follows: the ion beam application time is 3min, the beam current is 70 muA, and the voltage is 3 kV;

(5) at a pressure of 5X 10 ^－5 Under the vacuum condition of Pa, continuously depositing metal on the surface of the metal oxide layer obtained in the step (4) by adopting an ion beam vapor deposition method to form a nickel metal outer layer with the thickness of 50nm and the thickness deviation of 2%; the nickel content in the nickel metal outer layer is 99.4 wt%;

the technological parameters of the ion beam vapor deposition method for depositing metal to form the nickel metal outer layer are as follows: the ion beam application time is 1500min, the beam current is 70 muA, and the voltage is 4 kV;

(6) and (6) repeating the steps (3) to (5) on the surface of the other filler alloy layer of the composite aluminum plate obtained in the step (5) to obtain the aluminum-based brazing composite material.

As shown in FIG. 5, the aluminum-based brazing composite material with the total thickness of 2mm is prepared, and comprises a core layer 4 and two brazing composite layers 5; each brazing composite layer 5 comprises a nickel metal outer layer 1, a metal oxide layer 2 and a filler alloy layer 3 (the thickness of each filler alloy layer is 8% of the total thickness of the aluminum-based brazing composite); the bonding force between the nickel metal outer layer 1 and the filler alloy layer 3 is 2 level; the length of the welding seam of the aluminum-based brazing composite material is 38mm when the T-shaped sample model is adopted for brazing.

Example 5

A preparation method of an aluminum-based brazing composite material comprises the following specific steps:

(1) respectively preparing a core layer, a filler alloy layer, an intermediate layer and an anticorrosive layer by using a traditional continuous casting and rolling mode;

wherein, the core layer is 6063 aluminum alloy taking Mg and Si as main alloy elements;

the intermediate layer is 1050 aluminum alloy;

the filler alloy layer is 4045 aluminum alloy with Si as a main alloy element;

the anticorrosive layer is 7072 aluminum alloy with Zn as a main alloy element;

(2) sequentially stacking the anticorrosive layer, the core layer, the intermediate layer and the filler alloy layer, performing bonding rolling, and performing hot rolling, cold rolling and annealing processes to obtain a composite aluminum plate with target specification and performance;

(3) pretreating the surface of the filler alloy layer of the composite aluminum plate prepared in the step (2) by adopting glow discharge etching to remove an aluminum oxide layer influencing the brazing effect, and simultaneously removing oil stain residues and heterogeneous particles on the surface;

(4) at a pressure of 5X 10 ^－5 Depositing a metal oxide layer made of a mixture of 36 wt% of nickel oxide and 64 wt% of cobalt oxide on the surface of a filler alloy layer of the composite aluminum plate by adopting an ion beam vapor deposition method under the vacuum condition of Pa; the thickness of the metal oxide layer is 18nm, and the thickness deviation is 0.9%;

the technological parameters of the ion beam vapor deposition method for depositing the metal oxide layer are as follows: the ion beam application time is 30min, the beam current is 80 muA, and the voltage is 4 kV;

(5) at a pressure of 5X 10 ^－5 Under the Pa vacuum condition, continuously depositing metal on the surface of the metal oxide layer by adopting an ion beam vapor deposition method to form a nickel metal outer layer with the thickness of 1000m and the thickness deviation of 0.10 percent, thereby preparing the aluminum-based brazing composite material; the nickel content in the nickel metal outer layer is 99.9 wt%;

the technological parameters of the ion beam vapor deposition method for depositing metal to form the nickel metal outer layer are as follows: the ion beam application time is 750min, the beam current is 80 muA, and the voltage is 10 kV.

As shown in fig. 6, the prepared aluminum-based brazing composite material with the total thickness of 6mm comprises an anticorrosive layer 7 (the thickness is 5% of the total thickness of the aluminum-based brazing composite material), a core layer 4, an intermediate layer 6 (the thickness is 5% of the total thickness of the aluminum-based brazing composite material) and a brazing composite layer; the brazing composite layer comprises a nickel metal outer layer 1, a metal oxide layer 2 and a filler alloy layer 3 (the thickness is 2 percent of the total thickness of the aluminum-based brazing composite material); the bonding force between the nickel metal outer layer 1 and the filler alloy layer 3 is 3 grades; the length of the welding seam of the aluminum-based brazing composite material is 32mm when the T-shaped sample model is adopted for brazing.

Example 6

A method of producing an aluminum-based brazing composite material, substantially as in example 1, except that the deposition in step (3) is carried out, and that the metal oxide layer produced in the final step (3) has a layer structure of nickel oxide, the metal oxide layer having a thickness of 3nm and a thickness deviation of 10%.

The bonding force between the nickel metal outer layer and the filler alloy layer of the prepared aluminum-based brazing composite material is grade 1; the length of the welding seam of the aluminum-based brazing composite material is 41mm when the T-shaped sample model is adopted for brazing.

Example 7

A method of producing an aluminium-based brazing composite material, substantially as in example 1, except that in the deposition step (3), the metal oxide layer produced in the final step (3) is a metal oxide layer made of a mixture of 70 wt% nickel oxide and 30 wt% iron oxide, the metal oxide layer having a thickness of 50nm and a thickness variation of 0.1%.

The bonding force between the nickel metal outer layer and the filler alloy layer of the prepared aluminum-based brazing composite material is 2-level; the length of the welding seam of the aluminum-based brazing composite material is 30mm when the T-shaped sample model is adopted for brazing.

Example 8

A method of producing an aluminium-based brazing composite material, substantially as described in example 1, except that in the deposition step (3), the metal oxide layer produced in the final step (3) is a metal oxide layer made of a mixture of 70 wt% nickel oxide and 30 wt% iron oxide, the metal oxide layer having a thickness of 22nm and a thickness variation of 0.5%.

The bonding force between the nickel metal outer layer and the filler alloy layer of the prepared aluminum-based brazing composite material is 2-level; the length of the welding seam of the aluminum-based brazing composite material is 32mm when the T-shaped sample model is adopted for brazing.

Example 9

A method of producing an aluminium-based brazing composite material, substantially as in example 1, except that in the deposition step (3), the metal oxide layer produced in the final step (3) is a metal oxide layer made of a mixture of 70 wt% nickel oxide and 30 wt% iron oxide, the metal oxide layer having a thickness of 20nm and a thickness variation of 0.5%.

The bonding force between the nickel metal outer layer and the filler alloy layer of the prepared aluminum-based brazing composite material is 2-level; the length of the welding seam of the aluminum-based brazing composite material is 38mm when the T-shaped sample model is adopted for brazing.

Example 10

A method of producing an aluminium-based brazing composite material, substantially as described in example 1, except that in the deposition step (3), the metal oxide layer produced in the final step (3) is a metal oxide layer made of a mixture of 70 wt% nickel oxide and 30 wt% iron oxide, the metal oxide layer having a thickness of 10nm and a thickness variation of 2%.

In the prepared aluminum-based brazing composite material, the bonding force between the nickel metal outer layer and the filler alloy layer is 2 level; the length of the welding seam of the aluminum-based brazing composite material is 39mm when the T-shaped sample model is adopted for brazing.

In examples 1 and 7 to 10, in order to prepare metal oxide layers with different thicknesses, the evaluation results show that the excellent weld joint length is more suitable to be obtained at the thickness of 3 to 20nm, more preferably 10 to 20nm, and the metal oxide layer with the excessively high thickness can cause a barrier to the melting and wetting of the brazing filler metal during brazing.

Example 11

A method for preparing an aluminum-based brazing composite material, which is basically the same as that in the example 1, and is different in that in the step (4), nickel plating is adopted to form a nickel metal outer layer.

In the prepared aluminum-based brazing composite material, the thickness of the nickel metal outer layer is 5nm, the thickness deviation is 120%, and the bonding force between the nickel metal outer layer and the filler alloy layer is 3 grades; the length of a welding seam of the aluminum-based brazing composite material is 30mm when the T-shaped sample model is adopted for brazing; compared with a vapor deposition method, the thickness deviation of the nickel metal outer layer is difficult to control very small by an electroplating method, and when the thickness of the nickel metal outer layer reaches the same level as that of the metal oxide layer, the thickness uniformity difference is too large, so that the cohesiveness of the nickel metal outer layer and the metal oxide layer is too poor, and the length of a welding seam is further influenced.

Claims (10)

1. An aluminum-based brazing composite material is characterized in that: comprises a core layer (4) and a brazing composite layer (5); the brazing composite layer (5) comprises a nickel metal outer layer (1), a metal oxide layer (2) and a filler alloy layer (3);

the metal oxide layer (2) is located between the filler alloy layer (3) and the nickel metal outer layer (1); the filler alloy layer (3) is located on the side of the brazing composite layer (5) facing the core layer (4).

2. The aluminum-based brazing composite according to claim 1, wherein the metal oxide layer is a nickel oxide layer, a nickel-iron oxide layer, a nickel-cobalt oxide layer or a nickel-iron-cobalt oxide layer.

3. An aluminium-based brazing composite according to claim 1, characterized in that said nickel metal outer layer (1) is a pure nickel metal layer.

4. An aluminium based brazing composite according to claim 1, characterized in that said core layer (4) is an AA3003 aluminium alloy layer, a 6063 aluminium alloy layer, a 6060 aluminium alloy layer or a 3203 aluminium alloy layer.

5. An aluminium-based brazing composite according to claim 1, characterized in that said filler alloy layer (3) is a 4xxx series aluminium-silicon alloy layer.

6. An aluminium-based brazing composite material according to claim 1, characterized in that said brazing composite layer (5) is present on one or both sides of said core layer (4) of said aluminium-based brazing composite material.

7. The aluminum-based brazing composite according to claim 1, wherein the total thickness of the aluminum-based brazing composite is less than or equal to 6 mm.

8. The aluminum-based brazing composite according to claim 7, wherein each of said filler alloy layers (3) has a thickness comprised between 2 and 30% of the total thickness of said aluminum-based brazing composite.

9. The aluminum-based brazing composite material as claimed in claim 6, wherein the thickness of the nickel metal outer layer (1) in each brazing composite layer (5) is 5-1000 nm, and the thickness deviation is less than or equal to 10%.

10. The aluminum-based brazing composite material according to claim 6, wherein the metal oxide layer (2) in each brazing composite layer (5) has a thickness of 3-20 nm and a thickness deviation of 10% or less.

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