CN101607446A - A kind of manufacturing method of aluminum alloy and thermoplastic resin combination - Google Patents

Abstract

The invention provides a method for manufacturing a combination of an aluminum alloy and a thermoplastic resin, which at least comprises the following steps: providing an aluminum alloy sheet; carrying out pretreatment of removing a surface compact oxide layer on the aluminum alloy sheet; carrying out corrosion treatment at least comprising a plurality of two layers of micron-sized holes on the surface of the aluminum alloy sheet; placing the aluminum alloy sheet in a mold; injecting molten thermoplastic resin into the mold to form a combination of the aluminum alloy and the thermoplastic resin; since the thermoplastic resin and the aluminum alloy are not easily peeled off, the resin composition has both the advantages of a metal case and the advantages of a thermoplastic resin structure, is high in productivity and mass-producible, and can be freely designed in shape and structure in electronic devices and household electric appliances.

Description

A kind of manufacturing method of aluminum alloy and thermoplastic resin combination

technical field

The invention provides a method for manufacturing an aluminum alloy and thermoplastic resin combination. More specifically, the invention relates to a composition of aluminum alloy shapes and thermoplastic resin produced by various mechanical processing methods to form a structure with high bonding strength , It can be used in the production method of aluminum alloy and resin combination used in various electronic products for portable use, home appliances, other structural parts or exterior decoration parts.

Background technique

Technology for firmly integrating metals and resins is required in a wide range of fields such as consumer electronics and home electrical products, and many adhesives (adhesives) have been developed, and many very good adhesives have been proposed. . Adhesives that volatilize at room temperature or by heating are used to integrally bond metal and synthetic resin, and this method is now a commonly used technique.

There is another technology, such as the publication number CN 1717323A application published in China on January 4, 2006 by Japan's Dacheng Plus Co., Ltd., the title of the invention is "composite body of aluminum alloy and resin composition and manufacturing method", the The case was applied for PCT on November 7, 2003 and made international public on May 21, 2004. Its technology is to sandblast the aluminum alloy first, then pickle it or pre-treat it with an alkaline solution, and then carry out the treatment of the aluminum alloy and thermoplastic resin with polybutylene terephthalate resin or polyphenylene sulfide as the main component. Complex. When a specific thermoplastic resin is in contact with polybutylene terephthalate resin or polyphenylene sulfide thermoplastic resin on the surface of the aluminum alloy, an exothermic reaction occurs without rapid cooling and solidification, and it will immerse into the aluminum alloy surface In the fine recesses, it will be fixed next. However, in this way, the surface of the aluminum alloy is a single layer of microscopic holes, which is easy to peel off under the different expansion coefficients of the aluminum alloy and the thermoplastic resin, so it needs to be sandblasted first, and then a coating film is formed.

However, those skilled in the art believe that whether the resin is formed first, and then the formed resin is adhered to the surface of the aluminum alloy with an adhesive, or a layer of specific resin is first attached to the surface of the aluminum alloy, and then the specific resin is directly applied to the surface of the aluminum alloy. There will always be a more reasonable joint method, which can omit the adhesive, and does not need to attach a layer of specific resin on the surface of the aluminum alloy. Thermoplastic resin can be directly formed on the surface of the aluminum alloy, and has a comparable effect with the aluminum alloy. Bond strength.

Contents of the invention

In order to overcome various defects existing in the prior art, the present invention has developed a method for manufacturing an aluminum alloy and thermoplastic resin combination after a long period of research and development, which can make the bonding interface of the aluminum alloy and thermoplastic resin have a relatively high strength and is not easy to peel off.

The object of the present invention is to provide a method for manufacturing a combination of aluminum alloy and thermoplastic resin. This manufacturing method is convenient for producing structural parts or components combined with aluminum alloy and thermoplastic resin. Thermoplastic components of various shapes can be combined on aluminum alloy mechanical components. Resin structural parts, and the bonding interface between aluminum alloy and thermoplastic resin is not easy to peel off.

The invention provides a method for manufacturing an aluminum alloy and thermoplastic resin combination, the method at least includes the following steps:

providing an aluminum alloy sheet;

Carrying out the pretreatment of removing the dense oxide layer on the surface of the aluminum alloy sheet;

Performing corrosion treatment on the surface of the aluminum alloy sheet containing at least two layers of micron-scale holes;

Put the aluminum alloy sheet in the mould;

Molten thermoplastic resin is injected into the mold to form a combined body of aluminum alloy and thermoplastic resin.

The combination of aluminum alloy and thermoplastic resin of the present invention can also be referred to as a thermoplastic composite workpiece containing aluminum alloy, therefore, the subject matter of the present invention can also be a combination method and manufacturing method of a composite workpiece containing aluminum alloy and thermoplastic resin .

In the above-mentioned production method, the pretreatment step is carried out in an alkaline solution with a concentration of 1-10 moles or an acidic solution with a concentration of 1-10 moles.

The step of etching the micron-sized holes of the two layers is carried out in an etching tank with an alkaline solution of 1-10 molar concentration or an acidic solution of 1-10 molar concentration for 1 to 10 minutes.

The steps of the above-mentioned etching treatment include a chemical etching step and an electrochemical etching step. When it is a chemical etching step, the chemical etching step is to form a plurality of two-layer micron-scale holes, and the size of the multiple two-layer micron-scale holes is at least 1 μm above, and the depth of the hole is at least 1 μm.

When it is an electrochemical corrosion step, the corrosion treatment step is carried out through an electrochemical corrosion step in the form of alternating current. Electrochemical corrosion step of alternating current mode The electrochemical corrosion is carried out by passing alternating current on the two graphite electrodes, and the aluminum alloy test piece is placed parallel to the two graphite electrodes. That is, the electrochemical corrosion step of the above-mentioned alternating current mode carries out electrochemical corrosion to include a graphite electrode, and the aluminum alloy test piece is carried out as another electrode; that is to say, preferably, the above-mentioned corrosion treatment step is carried out by The electrochemical corrosion step is carried out in a direct current mode, and the electrochemical corrosion step includes a graphite electrode as a cathode, and the aluminum alloy test piece as an anode.

"Multiple" in the present invention means two or more.

In the manufacturing method of the present invention, the method of injecting molten thermoplastic resin into the mold includes any method selected from the group consisting of injection molding, injection molding, co-extrusion molding or thermocompression molding, and rolling extrusion method. A sort of.

After the corrosion treatment step of the present invention and before placing the aluminum alloy sheet in a mold, a step of cleaning chemical products is preferably included.

In the present invention, the aluminum alloy is soaked in the solution and subjected to chemical treatment or electrochemical treatment, so that holes with a size of more than 1 μm and a depth of at least 1 μm are formed on the surface of the aluminum alloy. on the alloy. When the molten thermoplastic resin is coated on the surface of the aluminum alloy, the molten thermoplastic resin is poured into these multi-layer interlaced micron-sized holes, and the molten thermoplastic resin is cooled and solidified, and the aluminum alloy and thermoplastic resin use these multi-layer interlaced micron-sized holes to tighten Tightly buckle each other, and due to the interlaced characteristics of the holes, the aluminum alloy and the thermoplastic resin will not be peeled off due to the difference in thermal expansion coefficient, resulting in a combination of aluminum alloy and thermoplastic resin with high bonding strength. The combination method and manufacturing method facilitate the production of structural parts or components combined with aluminum alloy and thermoplastic resin, that is, on the aluminum alloy mechanical components, thermoplastic resin structural parts of various shapes are combined.

Description of drawings

Figure 1a: Schematic diagram of the present invention when performing pretreatment and chemical etching.

Figure 1b: Schematic diagram of the present invention performing electrochemical corrosion with alternating current, the aluminum alloy can be energized or not.

Figure 1c: Another schematic diagram of the present invention when electrochemical corrosion is carried out with alternating current, the aluminum alloy can be electrified or not electrified.

Figure 1d: A schematic diagram of the present invention when performing electrochemical corrosion with direct current.

Various production environments for the production of aluminum alloys with multiple layers of interlaced micron-scale pores on the surface:

Figure 2: Schematic diagram of the production process of the aluminum alloy test piece with multi-layered interlaced micron-scale holes on the surface of the present invention.

Fig. 3a: Aluminum alloy sheet with multi-layered interlaced micron-scale holes on the surface of the present invention.

Fig. 3b: The combination of aluminum alloy and thermoplastic resin with multi-layered interlaced micron-scale pores on the surface of the present invention.

Figure number:

5——tank body 10——aluminum alloy 11——thermoplastic resin

12——a combination of aluminum alloy and thermoplastic resin 15——multilayer interlaced micron-scale holes

30——electrode 40——pretreatment step 50——chemical corrosion step

50——Electrochemical corrosion step 60——Chemical cleaning

65——chemical conversion treatment 70——steps of aluminum alloy test piece with multilayer staggered micron-scale holes

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings, but the implementation scope of the present invention is not limited.

Please refer to FIG. 1 a , which is a schematic diagram of pretreatment according to a preferred embodiment of the present invention. First of all, the 1xxx to 7xxx series aluminum alloys are first sliced for 10 minutes, and then soaked at 20°C to 60°C for 10 seconds to 3 minutes in a solution containing NaOH, KOH, Na ₂ CO ₃ , etc. Grease, dust and dense oxides on the aluminum alloy surface.

When the dense oxide on the surface of the aluminum alloy 10 is removed, it is different from soaking in a solution containing amine or amine derivatives in the prior art to form a chemical substance attached to the surface of the aluminum alloy. The method of the present invention is to make the surface of the aluminum alloy 10 larger Staggered corrosion holes between 1 μm and 100 μm and depth between 1 μm and 50 μm. The formation method of corrosion holes can be chemical corrosion or electrochemical corrosion.

The method of chemical corrosion is similar to the method of pretreatment. In the device shown in Figure 1a, the chemical corrosion tank 5 is built with an acidic or alkaline solution, and the aluminum alloy 10 is placed in the chemical corrosion tank 5 and then corroded at 20°C to 60°C for 1-10 minutes to achieve the corrosion on the aluminum alloy. 10 The surface produces staggered corrosion holes 15 with a size between 1 μm and 100 μm and a depth between 1 μm and 50 μm (please also refer to Figure 3a An aluminum alloy sheet with multiple layers of interlaced micron-sized holes on the surface. Using an optical microscope or a scanning electron microscope, it can be seen that after the corrosion hole is soaked in the corrosion solution for the second time, there are two or more layers of composite interlaced micron-scale holes 15 in many places. At this point, the surface has approximately 10% to 90% of the surface area, producing multiple layers of interlaced micron-sized holes.

With electrochemical corrosion, for example, an alternating current of about ±1V to ±10V can accelerate the formation of composite corrosion holes. As shown in FIG. 1 b , the corroded aluminum alloy sheet 10 is not energized, and graphite is used for the two electrodes 30 of alternating current, and the aluminum alloy sheet 10 is placed between the two energized graphite electrodes 30 . Or as shown in FIG. 1 c , the aluminum alloy sheet 10 is one electrode of the alternating current, and the two graphites are the other electrodes 30 of the alternating current. Of course, if only one surface of the aluminum alloy sheet 10 is to be corroded, only one graphite electrode 30 is required. In addition, the other side of the aluminum alloy sheet 10 is covered with anti-corrosion ink or plastic protective film.

Another electrochemical corrosion is to use the aluminum alloy sheet 10 as an anode, and a graphite sheet 30 as a cathode. Referring to Fig. 1d, a DC voltage of 1V to 10V is applied. Generally speaking, electrochemical corrosion can accelerate the formation of composite interlaced micron-sized holes 15 . The etching time is shorter, and the density of interlaced micron-sized holes 15 is higher than that of ordinary chemical etching. And the generation time is shortened. At this point, the surface has approximately 10% to 90% of the surface area, producing multiple layers of interlaced micron-sized holes.

In another embodiment, in addition to pure chemical etching or electrochemical etching, chemical etching and electrochemical etching can also be used alternately in a predetermined schedule to produce the required interleaved micron-scale holes 15 .

FIG. 2 is a schematic diagram of the steps of producing an aluminum alloy with multiple layers of interlaced micron-scale pores on the surface. It includes pretreatment 40 , chemical corrosion treatment 50 , or electrochemical corrosion treatment 55 , and chemical cleaning 60 to remove corrosion products 60 in the corrosion holes, and final chemical conversion treatment 65 . The chemical conversion treatment 65 is similar to the aluminum alloy anode treatment step. The aluminum alloy sheet 10 itself is used as the anode, graphite is used as the cathode, and the electrolyte uses different coloring solutions according to the desired coloring. For example, the electrolyte solution of tin salt can produce bronze or black, while the electrolyte solution containing silver salt is golden yellow or yellow-green.

Subsequently, for complex-shaped electronic parts, the aluminum alloy sheet 10 of the present invention can provide strength, and the parts that require complex processing are replaced by stamped plastic or thermoplastic resin 11, and the multi-layer interlaced micron Grade hole 15 aluminum gold would be a good choice. First, the aluminum alloy sheet 10 that has been punched and formed with multi-layered interlaced micron-scale holes 15 is placed in a mold, and then injection molding, injection molding, co-extrusion molding or thermocompression molding and rolling extrusion are used. The first method is to directly mold the resin on the aluminum alloy sheet 10 with multi-layered interlaced micron-scale holes 15, which can firmly combine the aluminum alloy parts and the resin parts 12. This production step is compared with the production of adhesives. steps, not only greatly shorten the production time, but also simplify the production process. In addition, because the surface of the aluminum alloy sheet 10 still retains a considerable proportion of the metal surface, the ratio of the metal surface to the plastic surface varies depending on the generation of multi-layer interlaced micron-scale holes as mentioned above. Therefore, when it is colored by chemical conversion and then molded into parts by plastic stamping, another kind of aesthetics can be added.

Referring to Fig. 3a is the aluminum alloy sheet with multi-layered interlaced micron-scale holes on the surface of the present invention; Fig. 3b is the combination of aluminum alloy and thermoplastic resin with multi-layer interlaced micron-sized holes on the surface of the present invention.

Compared with the traditional way of firmly integrating aluminum alloy parts and resin parts, it is necessary to apply the adhesive to the aluminum alloy parts, and then stick the injection-molded resin parts to the existing adhesive method. Many consumer electronic products, household electrical products and other components are manufactured on aluminum alloys. In terms of production, the present invention can omit many steps.

The multi-layer aluminum alloy sheet 10 with interlaced micron-scale holes of the present invention can also be used in another way besides the above-mentioned direct and one-time production of parts to be injection molded. For example, the molten thermoplastic resin 11 is extruded into the multi-layer interlaced micron-scale holes 15 with a roller, so that the aluminum alloy sheet 10 presents two types of interfaces. One is a thermoplastic interface, which can provide users with structural parts that can be bonded to other plastic materials. . The other is an interface where metals and metallic properties combine. Because the surface of the aluminum alloy sheet still retains a considerable proportion of the surface area of the metal surface, not only can it be colored by chemical conversion treatment as mentioned above to increase the aesthetics, users can also combine the aluminum alloy sheet of the present invention with structural parts of the same metal nature.

The aluminum alloy sheet of the present invention has the following advantages:

(1) First of all, even though the thermal expansion coefficients of the thermoplastic resin and the aluminum alloy are different, the aluminum alloy and the thermoplastic resin are deeply interlocked due to the staggered holes, so they will not be peeled off due to the difference in thermal expansion coefficient, so that a high bond can be produced Combination of strong aluminum alloy and thermoplastic resin.

(2) The combination method of aluminum alloy and thermoplastic resin of the present invention is very suitable for producing thermoplastic structural parts directly by injection molding. It is only necessary to put the aluminum alloy that has been stamped and formed with multi-layered interlaced micron-scale holes into the injection molding mold, and directly inject the resin The parts are molded on the aluminum alloy with multi-layer staggered micron-scale holes, so that the aluminum alloy parts and the resin parts can be firmly combined.

(3) Because the surface of the aluminum alloy sheet still retains a metal surface with a considerable proportion of surface area, it can not only be colored, but also increase the aesthetics, and it can also provide users with one more choice. The user can also combine the aluminum alloy sheet of the present invention. Structural parts of the same metal nature.

Claims (10)

1. A method for manufacturing an aluminum alloy and thermoplastic resin combination, at least comprising the following steps: providing an aluminum alloy sheet; Carrying out the pretreatment of removing the dense oxide layer on the surface of the aluminum alloy sheet; Performing corrosion treatment on the surface of the aluminum alloy sheet containing at least two layers of micron-sized holes; Put the aluminum alloy sheet in the mould; Molten thermoplastic resin is injected into the mold to form the composite workpiece. 2. The manufacturing method according to claim 1, wherein the above-mentioned pretreatment step is carried out in an alkaline solution with a concentration of 1-10 molar or an acidic solution with a concentration of 1-10 molar. 3. The manufacturing method as claimed in claim 1, wherein the step of the etching treatment of the above-mentioned two-layer micron-scale hole is to carry out 1 to 1 in an etching tank with 1-10 molar concentration of alkaline solution or 1-10 molar concentration of acidic solution. 10 minutes. 4. The manufacturing method as claimed in claim 1, wherein the step of the above-mentioned etching treatment is a chemical etching step to form the above-mentioned multiple two-layer micron-scale holes, the size of the multiple two-layer micron-scale holes is at least 1 μm, and the holes to a depth of at least 1 μm. 5. The manufacturing method as claimed in claim 1, wherein the above-mentioned etching treatment step is performed by an electrochemical etching step by means of alternating current. 6. The manufacturing method as claimed in claim 5, wherein the electrochemical corrosion step of the above-mentioned alternating current mode carries out electrochemical corrosion by passing through alternating current on two graphite electrodes, and the aluminum alloy test piece is parallel to the two graphite electrodes. The graphite electrode is placed and carried out. 7. The manufacturing method as claimed in claim 5, wherein the electrochemical corrosion in the step of electrochemical corrosion with alternating current includes a graphite electrode, and the aluminum alloy test piece is performed with another electrode. 8. The manufacturing method as claimed in claim 1, wherein the step of above-mentioned corrosion treatment is carried out by an electrochemical corrosion step in a direct current mode, and the electrochemical corrosion step comprises a graphite electrode as a cathode, and the aluminum alloy test piece is Anode is performed. 9. The manufacturing method as claimed in claim 1, wherein the above-mentioned method of injecting molten thermoplastic resin into the mold comprises injection molding, injection molding, co-extrusion molding or thermocompression molding and rolling extrusion method. any of the groups. 10. The manufacturing method according to claim 1, wherein after the step of etching and before placing the aluminum alloy sheet in a mold, a step of cleaning chemical products is further included.

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