阅读说明：本技术 一种添加镍栅层的铜铝复合板带及其连续生产方法 (Copper-aluminum composite plate strip added with nickel grid layer and continuous production method thereof ) 是由 王日初 董翠鸽 吴天昊 罗森晖 杨益 唐超 于 2019-10-17 设计创作，主要内容包括：本发明公开了一种添加镍栅层的铜铝复合板带及其连续生产方法,该材料特征是：由三层金属组成,两外层分别是铜基材和铝覆材,中间层为电镀在铜基材表面的镍栅层。生产方法为先在铜基材表面电镀上相应厚度的镍栅层；然后将带有镍栅层的铜基材和铝覆材同时放入复合轧机中,通过单道次大变形完成复合；再将复合板带放入在线退火炉内进行热处理,制备得到复合强度高且表面质量优良的铜铝复合板带。本发明所述的产品具有成本低、机械性能好、结合强度高等突出优点,广泛应用于电力电子、汽车及通信等技术领域。(The invention discloses a copper-aluminum composite plate strip added with a nickel grid layer and a continuous production method thereof, and the material is characterized in that: the composite material consists of three layers of metal, wherein the two outer layers are a copper base material and an aluminum clad material respectively, and the middle layer is a nickel gate layer electroplated on the surface of the copper base material. The production method comprises the steps of firstly electroplating a nickel gate layer with a corresponding thickness on the surface of a copper substrate; then simultaneously putting the copper base material with the nickel grid layer and the aluminum clad material into a composite rolling mill, and completing the composite through single-pass large deformation; and then the composite plate strip is placed into an online annealing furnace for heat treatment, and the copper-aluminum composite plate strip with high composite strength and excellent surface quality is prepared. The product of the invention has the outstanding advantages of low cost, good mechanical property, high bonding strength and the like, and is widely applied to the technical fields of power electronics, automobiles, communication and the like.)

1. A continuous production method of a copper-aluminum composite plate strip added with a nickel grid layer is characterized by comprising the following steps: the method comprises the following steps of electroplating nickel on the surface of a copper substrate to obtain a nickel grid layer, overlapping the copper substrate containing the nickel grid layer and an aluminum clad material, and then carrying out single-pass rolling at room temperature to obtain the copper-aluminum rolled composite plate strip, wherein the deformation is controlled to be 55-70% in the rolling process; and then carrying out heat treatment on the copper-aluminum rolled composite plate strip to obtain the copper-aluminum composite plate strip.

2. The continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer as claimed in claim 1, which is characterized in that: the thickness of the copper base material is 4-6 mm, the width is 40-80 mm, and the thickness of the aluminum clad material is 0.3-0.5 mm, and the width is 8-20 mm.

3. The continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer as claimed in claim 1, which is characterized in that: the thickness of the nickel gate layer is 1-4 mu m.

4. The continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer as claimed in claim 1 or 3, which is characterized in that: when the nickel is electroplated, the electroplating solution is an aqueous solution containing the following components: 260-300 g/L of nickel sulfate, 35-45 g/L of nickel chloride and 40-50 g/L of boric acid.

5. The continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer as claimed in claim 1 or 3, which is characterized in that: when the nickel is electroplated, the technological parameters are as follows: the electroplating temperature is 50-60 ℃; the electroplating pH is 4-5; the current density is 2-6A/dm²(ii) a The electroplating time is 3-5 min.

6. The continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer as claimed in claim 1, which is characterized in that: in the rolling process, the rolling speed is 1-4 m/min.

7. The continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer as claimed in claim 1, which is characterized in that: in the rolling process, the rolling speed is 1.2-3.5 m/min.

8. The continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer as claimed in claim 1, which is characterized in that: the heat treatment is carried out in a protective atmosphere, and the heat preservation atmosphere is a mixed gas of nitrogen and hydrogen.

9. The continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer as claimed in claim 1, which is characterized in that: the heat treatment temperature is 450-540 ℃, and the treatment time is 2-5 min.

10. The copper-aluminum composite plate strip produced according to the claims 1 to 9, characterized in that: the obtained copper-aluminum composite plate strip consists of three layers of metals, wherein the two outer layers are respectively a copper base material and an aluminum clad material, and the middle layer is a nickel grid layer electroplated on the surface of the copper base material.

Technical Field

The invention belongs to the technical field of metal composite preparation, and particularly relates to a copper-aluminum composite plate strip added with a nickel grid layer and a continuous production method thereof.

Background

The rapid development of science and technology has made higher and higher demands on electronic components, and it is a key point that a great number of functions are increasingly performed in a very small space, which requires that power transmission be well performed at an interface and heat be rapidly and efficiently dissipated. The copper-aluminum composite plate strip material has the advantages of good thermal stability, excellent heat sink performance and high conductivity, can provide a single-metal welding system for electronic packaging and the like, can increase the circuit capacity and stably operate, thereby obtaining wide attention and research, and being expected to form a huge industry in the automobile field and the electronic component packaging field.

At present, the research on the preparation of the copper-aluminum bimetal composite plate strip is more, and the preparation methods are also various. The method is divided according to the process attributes of the common bimetal compounding process, and comprises a fusion casting compounding method, an explosion compounding method, a welding compounding method, a rolling compounding method and the like. But copper and aluminum are easily oxidized in the fusion casting compounding process, so that the interface bonding strength is low; the problems of poor plate type, complex process and high cost exist in explosive cladding; solder lamination is not suitable because of the large difference in physical and chemical properties of copper and aluminum; the hot rolling composite bonding strength in the rolling composite is good, but the size precision is low, particularly the positioning precision in the local composite; the cold rolling compounding is the most potential processing method for producing the local copper-aluminum composite plate strip on a large scale with simple operation, easy automation, precise size and high efficiency.

But in copper-aluminum complexThe combination of copper and aluminum on the interface in the process of rolling the plywood strip is only physical combination and does not reach the metallurgical combination degree, and meanwhile, due to the uneven deformation of the two materials, serious residual stress can be generated on a substrate, and the performance after compounding is greatly influenced. Therefore, in order to improve the comprehensive properties of the copper-aluminum composite plate strip, such as the interface strength and the like, the copper-aluminum cold-rolled composite plate strip needs to be subjected to heat treatment. However, during the heat treatment process, copper and aluminum are easy to diffuse and react with each other, and CuAl are formed at the interface₂、Cu₄Al₉And the brittle phases are equal, and the bonding strength of the composite plate strip is reduced due to the brittle phases, so that the use performance of the material is influenced.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a copper-aluminum composite plate strip added with a nickel grid layer and a continuous production method thereof, wherein the nickel grid layer is introduced, so that on one hand, direct contact between copper and aluminum is prevented by nickel, and the formation of a copper-aluminum brittle intermediate phase is avoided; on the other hand, copper and nickel can form a copper-nickel solid solution, so that the interface bonding strength is enhanced, and finally, the copper-aluminum composite plate belt material with high interface bonding strength, stable performance and long service life is obtained.

In order to achieve the purpose, the invention is realized by the following technical scheme:

the invention relates to a continuous production method of a copper-aluminum composite plate strip added with a nickel grid layer, which comprises the following steps: electroplating nickel on the surface of a copper substrate to obtain a nickel grid layer, overlapping the copper substrate containing the nickel grid layer and an aluminum clad material, and then carrying out single-pass rolling at room temperature to obtain a copper-aluminum rolling composite plate strip, wherein the deformation is controlled to be 55-70% in the rolling process; and then carrying out heat treatment on the copper-aluminum rolled composite plate strip to obtain the copper-aluminum composite plate strip.

In the actual operation process, when the copper base material containing the nickel gate layer is superposed with the aluminum clad material, the aluminum clad material is ensured to be placed at the position of the copper base material with the nickel gate layer, and the aluminum clad material is contacted with the nickel gate layer.

When the copper-aluminum composite plate strip is prepared, the nickel grid layer is electroplated on the surface of copper, and the copper-aluminum composite plate strip which is high in bonding strength, good in mechanical property and convenient to deep drawing and bending processing is obtained through single-pass large-deformation rolling and finally low-temperature heat treatment.

According to the industrial continuous production method provided by the invention, in the actual operation process of the method, the nickel electroplating on the surface of the copper substrate adopts on-line continuous electroplating, so that the method has the characteristics of simple operation and stable and controllable process, if the nickel is electroplated on the surface of the aluminum clad material, the operation is not facilitated, and the obtained nickel-plated aluminum belt has poor bending resistance and influences subsequent processing.

In the actual operation process, the copper plate and the aluminum strip with the sizes meeting the requirements are selected according to the requirements of finished products.

In the preferred scheme, the thickness of the copper base material is 4-6 mm, the width of the copper base material is 40-80 mm, and the thickness of the aluminum clad material is 0.3-0.5 mm, and the width of the aluminum clad material is 8-20 mm.

In a preferable scheme, the thickness of the nickel gate layer is 1-4 μm.

In the invention, the thickness of the nickel gate layer has certain influence on the performance of the material, and the control within the scope of the invention can ensure the smooth proceeding of the processing technology and obtain excellent composite effect, while if the electroplated nickel gate layer is too thick, the plating layer is easy to peel off, and if the nickel gate layer is too thin, the nickel gate layer is seriously crushed in the composite rolling process, and the complete transition layer can not be maintained at the copper-aluminum composite interface.

Before electroplating, the copper plate is degreased, an oxide layer is removed, the copper plate is cleaned and dried, and then a special non-adhesive protective film is attached to a non-composite area on the surface of the copper plate for protection.

Preferably, in the nickel electroplating, the electroplating solution is an aqueous solution containing the following components: 260-300 g/L of nickel sulfate, 35-45 g/L of nickel chloride and 40-50 g/L of boric acid.

In a preferred scheme, when the nickel is electroplated, the process parameters are as follows: the electroplating temperature is 50-60 ℃; the electroplating pH is 4-5; the current density is 2-6A/dm²(ii) a The electroplating time is 3-5 min. The thickness of the nickel gate layer can be controlled within a desired range under the above process parameters.

Before rolling, cleaning the copper base material and the aluminum clad material electroplated with the nickel gate layer by using alcohol, and drying for later use by using cold air; and putting the cleaned and dried copper base material and the aluminum clad material into a four-high mill for rolling and compounding.

In the preferable scheme, the rolling speed is 1-4 m/min in the rolling process.

Further preferably, in the rolling process, the rolling speed is 1.2-3.5 m/min.

In the invention, single-pass and large-deformation rolling is adopted, so that the process is greatly simplified, the continuous production is simple and convenient, the rolling oil can not be added for lubrication and cooling in the rolling process, the composite material and the roller are effectively prevented from being overheated by adopting the rolling speed, and the composite effect and the smooth operation of the rolling process are ensured. If the rolling speed is too high, the materials and the roller can generate heat seriously, and further, aluminum can be adhered to the surface of the roller in the rolling process, so that the composite effect and the rolling process are influenced.

Preferably, the heat treatment is performed in a protective atmosphere, and the protective atmosphere is a mixed gas of nitrogen and hydrogen. That is, in the present invention, the heat treatment is an in-line heat treatment performed in an in-line annealing furnace protected by a mixed gas of nitrogen and hydrogen.

In a preferred scheme, the heat treatment temperature is 450-540 ℃, and the treatment time is 2-5 min.

More preferably, the heat treatment temperature is 450-480 ℃ and the treatment time is 3-4 min.

In the invention, ① annealing softens the copper-aluminum material to eliminate the internal stress generated in the composite rolling process, ② promotes the diffusion among copper, nickel and aluminum to form metallurgical bonding and increase the bonding strength.

The invention also provides the copper-aluminum composite strip prepared by the preparation method, and the obtained copper-aluminum composite strip added with the nickel grid layer consists of three layers of metals, wherein the two outer layers are respectively a copper base material and an aluminum clad material, and the middle layer is the nickel grid layer electroplated on the surface of the copper base material.

The copper-aluminum composite plate strip obtained by the invention is used for detecting the bonding strength of a finished product through a bending experiment, and a scanning electron microscope is used for carrying out microscopic structure analysis on a bonding interface; through detection, after the product is bent for 3-5 times at 90 ℃, the phenomena of interface cracking, aluminum coating peeling, cracking and the like do not exist, and the combination is good; the bonding interface has a diffusion layer with the thickness of 1.5-2.4 μm, but no copper-aluminum brittle phase is generated.

Has the advantages that:

the copper-aluminum composite plate belt produced by the invention has high bonding strength, good mechanical property, convenient deep drawing and bending processing and wide application range. By introducing the nickel grid layer, the bonding interface structure of the copper-aluminum composite plate strip is improved, and Al is prevented₂The generation of copper-aluminum brittle intermediate phases such as Cu and CuAl replaces an AlNi and Ni-Cu solid solution diffusion layer, so that the bonding strength of a copper-aluminum interface is high. The prepared copper-aluminum composite plate strip material has excellent copper-aluminum combination, can provide a wide homogeneous welding work area for aluminum welding on the basis of excellent performances of high heat conductivity, high electric conductivity and the like of a copper substrate, and is widely applied to the technical fields of electronics, automobiles, communication and the like. The advantages are that:

1. the copper-aluminum composite plate strip added with the nickel grid layer has high interface bonding strength, does not crack in the subsequent processing processes of stamping, bending and the like, and does not separate and crack an aluminum layer;

2. compared with the prior art, the continuous production method of the copper-aluminum composite plate strip added with the nickel grid layer has the advantages that the processing and heat treatment processes are greatly simplified, namely, the copper-aluminum composite plate strip which is high in bonding strength, good in mechanical property and convenient for deep drawing and bending processing is obtained by carrying out low-temperature heat treatment once through single-pass and large-deformation rolling, so that the operation is simple, the cost is low, and the large-scale industrial continuous production is facilitated.

Drawings

FIG. 1 is a flow chart of the preparation of the copper-aluminum composite plate strip added with a nickel grid layer;

FIG. 2 is a partial schematic view of a composite part of a copper-aluminum composite plate with a nickel gate layer added before composite rolling;

fig. 3 is an interface microstructure photograph of the copper-aluminum composite strip with the nickel grid layer added prepared in example 1.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.