KR20120115998A - Method of laser joining of aluminum alloy member and resin member - Google Patents

Abstract

By laser bonding using the thing which complicated the surface shape as an aluminum alloy member, the composite which raised the bonding strength with a resin member is obtained. After etching to the to-be-joined aluminum alloy member to form an unevenness | corrugation on the surface, one side of the said aluminum alloy member overlaps with a resin member, and after that, a laser beam is irradiated to the other surface of the said aluminum alloy member, The resin member in contact with the aluminum alloy member is softened to fill the irregularities with the resin. You may perform a blast process before an etching process.

Description

Laser joining method of aluminum alloy member and resin member {METHOD OF LASER JOINING OF ALUMINUM ALLOY MEMBER AND RESIN MEMBER}

The present invention relates to a laser bonding method showing high bonding strength between an aluminum alloy member and a resin member.

BACKGROUND ART An aluminum-resin composite material in which an aluminum member, which is a different material, and a synthetic resin are integrated is used in a wide range of fields such as automobiles, home appliances, and industrial equipment. Conventionally, as such an aluminum-resin composite material, one obtained by pressing an aluminum member and a resin member under an adhesive is used.

However, nowadays, a method of integrating high strength engineering resin without interposing an adhesive has been proposed. For example, in patent document 1, in the joining method of a metal material and a resin material, by using a laser light source, the joining part is heated to the temperature which produces a bubble in the resin material of a joining part in the state which joined the metal material and the resin material. A metal resin joining method to join is proposed.

The joining method is also a useful technique from the viewpoint of obtaining a composite material in which a metal material and a resin member are integrally bonded, but it is not sufficient to apply such a composite material to a mechanical structure requiring strong adhesion (sticking force) or rigidity. not.

Therefore, there is a demand for an aluminum-resin composite in which a resin having high strength is bonded with a strong adhesive force.

For example, in patent documents 2 and 3, the manufacturing method of the aluminum-resin composite which satisfy | filled the said request is proposed.

In patent document 2, the aluminum alloy component with which the surface was covered by the concave part of the number average internal diameters 10-80 nm by the electron microscope observation through the process immersed in one or more aqueous solution chosen from ammonia, a hydrazine, and a water-soluble amine compound, and the said aluminum alloy A metal resin composite composed of a thermoplastic synthetic resin composition component having a resin powder composition, which is adhered to the surface of a component by injection molding and whose main component is a polyamide resin and whose longitudinal component is an impact improving material, has been proposed.

This composite is intended to firmly adhere to the polyamide-based resin composition by forming the aluminum alloy component surface by covering with a very fine recess or hole.

In Patent Document 3, in the bonding of the thermoplastic resin material and the metal material, a thermoplastic film having compatibility with the thermoplastic resin material is interposed through the interface to be bonded, and the metal material is generated by heating the laser light to melt the film. The joining method of the thermoplastic resin material and a metal material characterized by welding by welding is proposed.

This bonding method is intended to maintain high bonding strength by interposing a thermoplastic film at an interface between the thermoplastic resin material and the metal material in advance to relieve stress generated during bonding.

WO2007 / 029440 publication Japanese Patent Publication No. 2007-182071 Japanese Patent Publication No. 2009-39987

However, the composite strength proposed by the said patent documents 2, 3 also does not exhibit the joint strength to the extent which can endure use as a mechanical structure.

SUMMARY OF THE INVENTION The present invention has been devised to solve such a problem, and provides an aluminum alloy member and a laser joining method of a resin member which have increased the bonding strength with the resin member by using a complexed surface shape as the aluminum alloy member. For the purpose of

In order to achieve the object, in the laser bonding method of the aluminum alloy member and the resin member of the present invention, one of the aluminum alloy members is formed after etching the bonded aluminum alloy member to form an uneven portion having irregularities on its surface. The surface and the resin member are superposed, and after that, the other side of the aluminum alloy member is irradiated with laser light to soften the resin member in contact with the aluminum alloy member, thereby filling the uneven portion with the resin.

It is preferable to perform a blast process on an aluminum alloy member before an etching process.

As the aluminum alloy member to be joined, it is preferable to use an aluminum alloy member having a plurality of concave portions resulting from the uneven portion obtained by the etching treatment or the blast treatment and the etching treatment, and the concave portion preferably has an opening width. It is good that it is 0.1 micrometer-30 micrometers in size, and depth is 0.1 micrometer-100 micrometers in size. Here, in the thickness direction cross section of the said aluminum alloy member, the said opening width is a half line between the top line which is orthogonal to this thickness direction, and passes through the highest part of the uneven part, and the bottom line which passes through the deepest part. It measured by scanning electron microscope observation.

Moreover, as the aluminum alloy member which performed the said etching process or the blasting process and the etching process, the concave part of the opening width which has a several convex part which consists of eutectic silicon crystal on the inner surface is 0.1 micrometer or more and 30 micrometers or less to a part or whole surface of a surface. It is preferable to use what has a plurality of Al-Si type aluminum alloy members, and the convex part which consists of said process silicon crystal has the size of 0.1 micrometer-10 micrometers in spherical equivalent particle diameter. That is, the joined aluminum alloy member is composed of an Al-Si-based aluminum alloy member, and has a convex portion made of the above-described process silicon crystal due to the uneven portion obtained by the etching treatment or the blast treatment and the etching treatment. It is preferable to use what recessed part was formed in multiple numbers in one part or whole surface of the to-be-joined aluminum alloy member. Here, the said opening width is a scanning electron in the half line between the top line which is orthogonal to this thickness direction in the thickness direction cross section of the said aluminum alloy member, and passes through the highest part of the uneven part, and the bottom line which passes through the deepest part. It was measured by microscope observation.

Projections made of a silicon crystal wherein the step portion, the concave portion at least 0.001g / m ² on the inner surface protruding in an amount of 1g / m ² or less? And is precipitated, and the opening having no convex part of the process the silicon crystal width 0.1㎛ It is preferable that a plurality of concave portions equal to or larger than 30 μm also exist at the same time.

 When etching to a to-be-joined aluminum alloy member, it is an acid aqueous solution of 0.1 weight%-80 weight% of acid concentration which contains a halogen ion concentration within the range of 0.1 g / L or more and 300 g / L or less as etching liquid, It is preferable to use what was manufactured by adding a water-soluble inorganic halogen compound in an acid aqueous solution.

Moreover, as a blasting process performed before an etching process, what is performed by an air nozzle system is preferable.

In addition, although the etching process performed before laser beam irradiation, or a blast process, and an etching process are sufficient from the viewpoint of obtaining the bonded body with high joint strength, only the joint surface with the resin member of a to-be-joined aluminum alloy member may be sufficient, but the whole surface may be sufficient. .

According to the method of this invention, the uneven | corrugated shape previously complicated by the aluminum alloy member used for manufacture of an aluminum resin composite material is given. For this reason, when the resin member is bonded to the surface by a laser joining method, for example, the complicated concave-convex shape effectively acts as an anchor effect, and an aluminum-resin composite having a high bonding strength is easily obtained.

In addition, in the method of the present invention, as an aluminum alloy material, not only can be used for general Al alloy materials, but also Al-Si casting alloys can be used, so that a composite having a high degree of freedom in shape can be manufactured at low cost. . In addition, the aluminum-resin composite thus prepared has extremely high adhesion strength and airtightness at the interface between the aluminum alloy member and the resin molded body (aluminum / resin interface), and can maintain excellent adhesion strength and airtightness even when exposed to harsh environments. It is possible to maintain high reliability over the long term.

Therefore, the aluminum-resin composite with high bonding strength obtained by the method of the present invention is widely used in a wide range of fields, including, for example, various sensor parts for automobiles, various switch parts for home appliances, and capacitor parts for various industrial devices. It can be suitably used for metal-resin integrally molded parts, and is suitably used for metal-resin integrally molded parts requiring high bonding strength.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram explaining the solidification structure of an Al-Si type alloy casting.
2 is a schematic diagram illustrating a cross-sectional structure after etching of an Al—Si alloy casting.
3 is a screen of the etching surface of the Al-Si-based alloy casting observed with a scanning electron microscope.
4 A diagram for describing a method for measuring the opening width of a recess formed in a surface of an aluminum alloy member.
Fig. 5 is a cross-sectional schematic view of a recess formed on the surface of the aluminum alloy member.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined about the cause and countermeasure which a sufficient bonding strength is not obtained by the manufacturing method of the aluminum-resin composite which employ | adopted the laser bonding method proposed by the said patent document 1 or 3.

In the process, assuming that the engagement between the softened resin member and the uneven portion of the aluminum surface is not sufficient, when producing an aluminum-resin composite, the improvement of the surface properties of the aluminum alloy member in order to increase the bonding property with the resin member to be compounded. Reviewed.

In order to improve the adhesiveness with a resin member, it is effective to form the uneven part with high anchor effect on the surface of an aluminum alloy member. However, for Al casting alloys having a wide metal composition range and complex metal structures, it is difficult to exert the anchor effect with a general etching treatment.

Therefore, the present invention finds that even in an Al-Si casting alloy, by performing an effective etching treatment, irregularities having high anchor effect can be formed on the surface thereof.

The detail is demonstrated below.

First, the basic principle regarding the easy formation of complicated concavo-convex portions on the surface of the Al-Si-based alloy member will be described.

When the molten Al-Si alloy having a composition near the eutectic-process, which is practically used, is solidified in the mold, as shown in FIG. 1, a lamellar Al-Si process section is formed between the primary α-Al (1). (2) is embedded. And the Al-Si process part 2 becomes a form comprised from process (alpha) -Al (3) and process Si (4).

When the Al-Si alloy member having such a metal structure is chemically etched with an acid solution such as hydrochloric acid, the step α-Al (3) of the Al-Si process portion is selectively dissolved. This is because step α-Al has lower Al purity than primary α-Al (1).

As a result, only the process Si (4) remains in the lamellar process part which fills in between the primary α-Al (1), and the remaining Si remains in the void portion 5 between the primary α-Al which becomes the recess. It protrudes into the recess wall (see FIG. 2).

FIG. 3 shows the results of observing the surface of the sample used in Examples described later with a scanning electron microscope. It is understood that the Si crystal protrudes inside the concave portion formed between the primary α-Al to form a convex portion.

In the method of the present invention for the Al-Si-based Al alloy, the anchor Si at the time of joining the resin member by laser light irradiation to the concave portion in which the remaining Si between the primary α-Al protrudes on the wall surface. It is.

In order to express the anchor effect effectively, it is effective to make the concave portion to be formed fine, and to increase the fine and convex portions formed by the protruding Si crystals, and it is necessary to adjust the chemical etching conditions. Preferred etching conditions are described later.

In order to make fine and many convex parts which the Si crystal which protrudes in the Al casting alloy which is Al-Si type alloy especially become large, it is preferable to carry out a blast process as a pre-process before an etching process. Especially as a blast system, an air nozzle type blast is preferable. The following is mentioned as a reason to recommend the blasting process before an etching process. In an Al-Si-based Al casting alloy having a complicated metal structure, in some cases, uneven etching occurs and uniform etching treatment becomes difficult. In the blasting process, rapid heat and quenching are repeated on the outermost surface of the metal due to the collision of the shot media, and the surface structure is refined and uniformized. Therefore, the uniform treatment is possible by performing the etching treatment after the blast treatment.

Moreover, since the aluminum surface after a blasting process is roughened, the resin bonding property by a double roughening structure can be improved by performing the etching process which forms a recessed structure after that. As a blast treatment method, an air nozzle type is particularly preferable, and for example, the injection pressure of the media is higher than that of the shot type, and for example, the media is formed at a higher pressure than the shot blast of which the injection pressure is low. Since it is possible to impinge the surface on the surface, the surface structure suitable for a uniform etching process can be formed as a result. Moreover, the double roughening structure effective for resin bonding property can be formed by combining with an etching process.

On the other hand, when not blasting as a pretreatment, it is preferable to perform ultrasonication after an etching process. Like the substrate, etching irregularities occur, particularly in the initial etching behavior. In order to prevent this, it is necessary to increase the amount of dissolution by the etching treatment by increasing the bath temperature at the time of etching or by lengthening the immersion time. A problem arises that it accumulates in. Since the deposited layer of the step Si crystal has a porous structure, the resin is easily introduced, but on the other hand, it is difficult to obtain the bonding strength because the adhesion with the Al-Si-based Al alloy is very small. By the ultrasonic treatment after the etching treatment, it becomes possible to selectively remove the deposited process Si crystals present in the outermost layer and to leave only the process Si crystals in the surface recesses that contribute to the resin bonding property.

The size and distribution state of the convex portion which effectively exhibits the anchor function in the Al-Si alloy for Al casting will be described. When the surface structure of the aluminum alloy member was observed with a scanning electron microscope (FE-SEM made by Hitachi, in the form of S-4500), the size of the convex portion formed of the eutectic Si crystal was 0.1 µm or more and 10 µm or less with a spherical equivalent particle diameter. It is preferable. If the Si crystal size is less than 0.1 µm or less, the convex portion itself formed of the eutectic Si crystal is likely to be bent, so that the anchoring action may not be exhibited. On the other hand, even in the case where the Si crystal size is larger than 10 µm, the size may be too large to exhibit an anchoring action.

Further, the concave portion in which the remaining Si protrudes from the wall surface is in the half line between the top line passing perpendicular to the thickness direction in the thickness direction cross section of the aluminum alloy member and passing through the top of the uneven portion and the bottom line passing through the deepest portion. WHEREIN: The aperture width measured by scanning electron microscope observation is 0.1 micrometer or more and 30 micrometers or less, Preferably they are 0.5 micrometer or more and 20 micrometers or less, More preferably, they are the sizes of 1 micrometer or more and 10 micrometers or less, and are top line to bottom line The depth up to 0.1 micrometer or more and 100 micrometers or less, Preferably it is 0.5 micrometer or more and 50 micrometers or less.

If the opening width of this concave portion is narrower than 0.1 micrometer, it will become difficult for molten resin to enter at the time of resin bonding, a micro void will generate | occur | produce in the interface of an aluminum alloy member and a resin member, and it will be hard to obtain the outstanding adhesive strength and airtightness. On the contrary, when it wants to make it wider than 30 micrometers, when the surface reaction (etching process) of an aluminum molded object progresses excessively, the problem of the lack of a material surface or the increase of the thickness reduction of a material arises. In addition, a product having insufficient material strength is generated, which causes a decrease in productivity. Also, when the depth is shallower than 0.1 µm, the immersion portion of a sufficient resin molded body may be difficult to be obtained. On the contrary, when it is intended to be deeper than 100 µm, the dissolution reaction proceeds excessively during the surface treatment (etching treatment) of the aluminum molded body. This may cause problems such as missing of the surface of the material or an increase in the reduction in sheet thickness of the material.

In the present invention, the density of the plurality of concave portions in which the remaining Si of the Al-Si-based Al alloy protrudes from the wall surface is in the range of 0.5 µm or more and 20 µm or less in the opening width per 0.1 mm and 0.5 µm or more and 20 µm or less in depth. It is good to exist in the range of 5 or more and about 200 or less of 1 type or 2 or more types of insides.

Further, when the surface structure of the Al-Si-based aluminum alloy member is analyzed by silicon and aluminum element analysis by mapping analysis of an energy dispersive X-ray analyzer (EMAX-7000 manufactured by Horiba Seisakusho Co., Ltd.), It is preferable to make the site | part which only Si which exists exists occupy 5% or more and 80% or less. If the Si distribution site is less than 5%, the effective anchor effect may not be expressed. On the contrary, if it exceeds 80%, the solubility of primary α-Al forming the concave wall surface cannot be ignored, and the wall surface dissolves and Si crystals are deposited in the concave portion, and the anchor effect acts on the resin component. You may not do it.

It is preferable that the protrusion amount of the convex part which consists of process Si crystals protrudes and precipitates in the quantity of 0.001 or more and 1 g / m <^2> or less on the inner surface of the said recessed part. If it is less than 0.001 g / m <^2> , an effective anchor effect may be hard to express. On the contrary, when it exceeds 1 g / m ² , the solubility of primary α-Al forming the concave wall surface cannot be ignored, and the wall surface dissolves, and Si crystals are deposited in the concave portion, and the anchor effect is applied to the resin component. May not work.

In addition, the protrusion amount of the convex part measured the crystal grains collected using the 0.1 micrometer PC membrane filter by the gravimetric method after shaving off the Si crystal formed on the surface of the Al-Si type aluminum alloy member using the brush. will be.

Here, the concave portion formed in the primary α-Al which effectively exhibits the anchor function together with the concave portion having the protruding portion of the step Si crystal formed by the selective dissolution of the step α-Al will be described. As shown in FIG. 4, the plurality of concave portions formed due to the uneven portion of the surface of the aluminum member are orthogonal to the thickness direction in the thickness direction cross section of the aluminum alloy member and pass through the top of the uneven portion. In the half line between the line and the bottom line passing through the deepest part, it is measured by scanning electron microscope observation. The opening width is 0.1 µm or more and 30 µm or less, preferably 0.5 µm or more and 20 µm or less, more preferably 1 µm or more and 10 µm or less, and the depth from the top line to the bottom line is 0.1 µm or more and 100 µm or less. Preferably, they are 0.5 micrometer-50 micrometers in size.

When the opening width of the concave portion is smaller than 0.1 mu m, it is difficult for molten resin to enter during resin bonding, and micro voids are generated at the interface between the aluminum alloy member and the resin molded body, so that excellent adhesion strength and airtightness are difficult to be obtained. On the contrary, if it is intended to be wider than 30 µm, the dissolution reaction proceeds excessively during the surface treatment (etching treatment) of the aluminum molded body, resulting in a problem of missing the surface of the material or an increase in the plate thickness reduction of the material. Phosphorus product may arise and may cause productivity fall. Also, when the depth is shallower than 0.1 µm, the immersion portion of a sufficient resin molded body may be difficult to be obtained. On the contrary, when it is intended to be deeper than 30 µm, the dissolution reaction is excessive during the surface treatment (etching treatment) of the aluminum molded body. Proceeding, there may be a problem that there is a problem of missing the material surface or increasing the amount of sheet thickness reduction of the material.

In the present invention, the density of the plurality of concave portions formed due to the uneven portion of the surface of the aluminum alloy member is within the range of 0.5 µm or more and 20 µm or less in the opening width per 0.1 mm, and 0.5 µm or more and 20 µm or less in depth. One or two or more sizes are preferably present in the range of about 5 or more and 200 or less.

Moreover, as shown in FIG. 5, the some concave-shaped part of an aluminum alloy member has a concave-shaped part which has the protrusion part which protruded in the snow-covered shape toward the center of opening width direction from a part of opening edge part (refer FIG. 5 (a)). 2 may be a concave portion having a protrusion projecting in a snow-covered shape toward the center of the opening width direction from the entire opening edge portion (see FIG. 5B), but having a double concave portion structure in which a concave portion is further formed therein. It is preferable that it is a recessed part (refer FIG. 5 (c)), or a recessed part (refer FIG. 5 (d)) which has an internal uneven structure in which the internal protrusion part was formed in the inside wall surface. Moreover, these double concave structure and internal uneven structure may coexist. In some or all of the plurality of concave portions of the aluminum alloy member, such a double concave portion structure and an internal concave-convex structure exist, whereby the concave portion of the aluminum alloy member and the indentation portion of the resin molded body are more firmly bonded to each other, and aluminum More excellent adhesive strength and airtightness between the alloy member and the resin molded body are exhibited.

Next, the method of forming a desired uneven | corrugated part in the resin bonding surface of an aluminum alloy member is demonstrated.

Specifically, the aluminum alloy material is etched into an etching solution composed of an acid solution such as hydrochloric acid, phosphoric acid, sulfuric acid, acetic acid, oxalic acid, ascorbic acid, benzoic acid, butyric acid, citric acid, formic acid, lactic acid, isobutyl acid, malic acid, propionic acid, tartaric acid, and the like. The etching process method of immersing and forming a predetermined uneven | corrugated part on the surface of this aluminum alloy material is mentioned.

As an etching solution used for this purpose, it is set as an acid solution, The acid concentration is 0.1 weight% or more and 80 weight% or less, Preferably it is 10 weight% or more and 50 weight% or less hydrochloric acid solution, phosphoric acid solution, dilute acid solution, acetic acid solution, etc. And 0.1 wt% or more and 30 wt% or less of acid concentration, Preferably 10 wt% or more and 20 wt% or less of oxalic acid solution etc. are mentioned.

In addition, in the alloy for casting of Al, halides may be added to these acid solutions for the purpose of further promoting dissolution of the step α-Al. Examples of the halide include chlorides such as sodium chloride, potassium chloride, magnesium chloride and aluminum chloride, fluorides such as calcium fluoride, and bromide such as potassium bromide.

Preferably, it is a chloride in consideration of safety | security, etc., and halogen ion concentration in etching liquid is 0.1 g / liter (g / L) or more and 300 g / L or less, Preferably it is 1 g / L or more and 100 g / L or less. . If the amount is less than 0.1 g / L, since the effect of halogen ions is small, the dissolution of the process α-Al is less likely to occur, and there may be a problem that concave portions having protrusions of Si crystals are not formed, which exceeds 300 g / L. In this case, since the dissolution reaction proceeds rapidly during the surface treatment (etching treatment) of the aluminum molded body, there arises a problem that it becomes difficult to control the concave portion formed by the selective dissolution of the step α-Al and the protrusion of the Si crystal. There is a case.

In the present invention, an etching solution for forming a desired concave portion on the surface of an aluminum alloy member, which is a strong acid solution such as nitric acid or concentrated sulfuric acid at a concentration exceeding 80% by weight, alkali such as sodium hydroxide or potassium hydroxide. The solution is not suitable. A relatively strong oxidizing acid solution such as concentrated sulfuric acid has a film-forming ability with respect to the aluminum alloy, and rather forms a firm oxide film on the surface of the aluminum alloy member, making it difficult to dissolve the oxide film.

In this invention, about the processing conditions at the time of etching the surface of an aluminum alloy member using the said etching liquid, the kind of etching liquid to be used, acid concentration, halogen ion concentration, etc., and the some which should be formed in an aluminum alloy member It also differs depending on the number and size of the concave portions. Usually, in the case of hydrochloric acid solution, the soaking time is 20 minutes or more and 80 degrees C or less, soaking time 1 minute or more and 40 minutes or less, and in the case of phosphoric acid solution, the soaking time is 20 minutes or more and 60 degrees C or less, soaking time 1 minute or more and 60 minutes or less, In the case of immersion time 1 minute or more and 50 minutes or less in bath temperature 20 degreeC or more and 70 degrees C or less, in the case of nitric acid aqueous solution, the bath temperature is 20 degreeC or more and 60 degreeC or less, soaking time 1 minute or more and 60 minutes or less, and in the case of oxalic acid solution, bath temperature 20 degreeC or more In the case of an acetic acid solution, it is preferable that it is the range of bath temperature 20 degreeC or more and 80 degreeC or less in immersion time for 1 minute or more and 30 minutes or less at 50 degreeC or less immersion time for 1 minute or more and 20 minutes or less. The higher the acid concentration and the bath temperature of the etching solution to be used, the more effective the etching treatment becomes and the shorter time treatment becomes possible. However, since the dissolution rate is slow at the bath temperature of less than 20 degrees, the productivity is poor and exceeds 80 ° C. At bath temperature, a dissolution reaction advances rapidly and becomes difficult to control. About immersion time, it is difficult to control melt | dissolution for less than 1 minute, and conversely, it becomes a cause of productivity fall at immersion time exceeding 60 minutes.

In the present invention, when etching the aluminum alloy material as described above to form an aluminum alloy member having a concave portion, if necessary, degreasing, surface adjustment, surface attachments on the surface of the aluminum alloy material before the etching treatment. For the purpose of removing contaminants and the like, a pretreatment consisting of an acid treatment with an acid solution and / or an alkali treatment with an alkaline solution may be performed.

Here, the acid solution used for this pretreatment may be, for example, one prepared with a commercially available acidic degreasing agent, inorganic acids such as sulfuric acid, nitric acid, hydrofluoric acid, phosphoric acid, organic acids such as acetic acid and citric acid, or mixed acids obtained by mixing these acids. What was manufactured using acid reagents, such as these, etc. can be used, Moreover, as an alkaline solution, what was manufactured, for example with the commercially available alkaline degreasing agent, what was manufactured with alkali reagents, such as caustic soda, or it mixed and manufactured these, Can be used.

About the operation method and processing conditions of the pretreatment performed using the said acid solution and / or alkaline solution, it may be the same as the operation method and processing conditions of the pretreatment currently performed using this kind of acid solution or alkaline solution, and the example For example, it can carry out by methods, such as an immersion method and a spray method.

After the pretreatment is performed on the surface of the aluminum alloy material or after the etching treatment for forming the concave portion, water washing may be performed as necessary. Industrial water, ground water, tap water, ion exchange water, or the like may be used for this washing process. It may be appropriately selected depending on the aluminum alloy member to be produced. In addition, the aluminum alloy material subjected to the pretreatment or the etching treatment is dried as necessary, but natural drying may also be performed at room temperature for this drying treatment, and is performed by using an air blow, a dryer, an oven, or the like. Drying is also good.

Example

Then, the case where the resin member was joined to the aluminum alloy member which surface-treated was actually introduced is introduced.

For the test, two kinds of aluminum alloy members were used: i) a JISADC12 alloy plate having a thickness of 2 mm, a width of 50 mm, and a length of 100 mm, and ii) an A5052 alloy plate having a thickness of 2 mm, a width of 50 mm and a length of 100 mm. PBT (polybutylene terephthalate) having a width of 50 mm and a length of 100 mm was used. JISADC12 alloy plate was produced by the die-cast method. In addition, the A5052 alloy plate is A5052-H34. In order to investigate the influence of the surface state on the joint strength, five types of test materials were prepared by changing the surface treatment method for each aluminum alloy member.

The manufacturing method of five types of test materials is mentioned later.

And about the test material which surface-treated, the surface state was observed with the method of mentioning later. The results are shown in Table 1 and Table 2.

The test materials (10 pieces in total) treated by each of the five types of methods for the two types of aluminum alloy members were superimposed on the PBT one by one, and irradiated with laser light from above the aluminum alloy test material, and the aluminum alloy test material and the PBT were applied. Spliced. At that time, as shown in Table 3, laser welding conditions were changed in various ways.

And the tensile shear strength was measured about the joined body of each aluminum alloy test material and PBT. Moreover, the measuring method of tensile shear strength is also mentioned later.

Table 4 shows the measurement results of the tensile shear strength (N / mm) of the bonding material.

In the aluminum alloy plate (test material 5) which does not perform the air nozzle type blasting process or the etching process which is a comparative example, it did not join with PBT on all the laser welding conditions. Moreover, in the air nozzle type blasting material, the joining strength of what is joined is low. On the other hand, as for the etching process material of this invention, the high bonding strength is obtained compared with the comparative example. Moreover, the highest joining strength was obtained by combining the air nozzle type blasting process and the etching process.

[Adjustment Method of Test]

About the two types of aluminum alloy plates of the said JISADC12 alloy plate and A5052 alloy plate, the test materials 1-5 of the following conditions were prepared, respectively.

(Test Material 1)

After adjusting the surface roughness to Rz: 40 micrometers by the air nozzle type blasting process of an aluminum alloy plate, 90 g / L (chloride ion concentration: 61 g / L) aluminum chloride hexahydrate is added to 1.2 wt% hydrochloric acid solution, After immersing in manufactured etching liquid at 40 degreeC for 1 minute, and performing the etching process to wash with water, it dried for 5 minutes by hot air of 120 degreeC, and it was set as aluminum alloy test material 1.

(Test Material 2)

The aluminum alloy plate was prepared by adjusting the surface roughness to Rz: 40 by air nozzle blasting, and then adding 90 g / L (chloride ion concentration: 61 g / L) of aluminum chloride hexahydrate in 1.2 wt% hydrochloric acid solution. After immersing in one etching liquid at 40 degreeC for 4 minutes, and performing the water-washing etching process, it dried for 5 minutes by 120 degreeC hot air, and it was set as the aluminum casting alloy test material 2.

(Test Material 3)

The aluminum alloy plate was washed with water after adjusting the surface roughness to Rz: 40 by an air nozzle type blasting treatment, and then dried for 5 minutes by hot air at 120 ° C to obtain aluminum alloy test material 3.

(Test Material 4)

The aluminum alloy plate was immersed at 40 ° C. for 4 minutes in an etching solution prepared by adding 90 g / L (chloride ion concentration: 61 g / L) of aluminum chloride hexahydrate in a 1.2 wt% hydrochloric acid solution without performing a blast treatment. After the etching process performed with water washing, it dried for 5 minutes by 120 degreeC hot air, and used as the aluminum alloy test material 4.

(Test Material 5)

The aluminum alloy plate was washed with water without performing a blast treatment or an etching treatment, and dried for 5 minutes by hot air at 120 ° C after that to obtain an aluminum alloy test material 5.

[Surface Observation Method of Each Test Material]

The surface of each aluminum alloy test material obtained by treating the JISADC12 alloy plate was observed using a scanning electron microscope (FE-SEM made by Hitachi, S-4500 form), the size of the silicon crystal was observed, and the amount of precipitation It measured by the gravimetric method. In addition, the amount of precipitation measured the silicon crystal formed on the surface of Al alloy test piece using the brush, and measured the collected crystal particle by the gravimetric method using a 0.1 micrometer PC membrane filter.

In addition, about each aluminum alloy test material obtained with the two types of aluminum alloy plates, the cross section of the area | region of the thickness direction cross section was 1000 magnification using a scanning electron microscope (FE-SEM made by Hitachi, S-4500 form). It observed by the ship and measured as follows based on the obtained cross-sectional observation photograph (measured field of view 3).

First, in the thickness direction cross section of an aluminum alloy test material, the top line TL orthogonal to this thickness direction and passing through the highest part of an uneven part is determined, and similarly to the above, orthogonal to the thickness direction of an aluminum alloy test material, Also, the bottom line passing through the innermost part of the uneven portion is determined, and a line segment is drawn in the vertical direction from the top line TL to the bottom line BL, and passes through the middle portion of the line segment, and also the top line TL or The aluminum alloy test piece on the half line HL drawn in parallel with the bottom line BL and the distance between the gaps present between the aluminum alloy test piece are defined as the opening width d of the concave portion (see FIG. 4). The shape and size (opening width) of the concave portion formed due to the uneven portion of the surface of the test material were observed. Observation was similarly performed about the 2 views of the same aluminum alloy test material, and the value divided by the total measurement score with respect to all the opening widths observed from the system 3 views was measured as the average opening width. On the other hand, the depth of the concave portion defined by the distance from the top line TL to the bottom line BL was similarly observed and the average depth was measured. In addition, about the density of a recessed part, element mapping analysis is performed by EDX at 1000 times magnification, and compared with the untreated case, the area | region where the fluorescent X-ray intensity of an aluminum element is low is defined as a recessed part, and it measures to the measured mapping photograph. The density of the concave portion was measured using image processing software (ImageJ).

The numerical value shown in Table 1 has shown these measured values.

[Measurement method of tensile shear strength]

An aluminum alloy test material having a thickness of 2 mm, a width of 50 mm, and a length of 100 mm, and a PBT (polybutylene terephthalate) resin plate having a thickness of 10 mm, a width of 50 mm, and a length of 100 mm treated by the above five kinds of methods are overlapped by 15 mm in the longitudinal direction. It set so that it might irradiate a laser beam from the upper direction of the aluminum alloy test material, and laser-welded in the width direction. After laser welding, three tensile test pieces cut | disconnected by the width 10mm were taken at the position of 30 mm from the edge part of the test piece of width 100mm, and the tension test piece was tested with the tensile tester, and the load (N) obtained was tested. The value divided by the width of was taken as the tensile shear strength. In addition, the tensile velocity was 8x10 <^-3> m / sec.

Claims (7)

After etching to the bonded aluminum alloy member to form an uneven portion having irregularities on the surface, one side of the aluminum alloy member and the resin member are superimposed, and thereafter, laser light is applied to the other surface of the aluminum alloy member. The resin bonding method which softens the resin member which contact | connects an aluminum alloy member, and fills the said uneven part with the said resin, The laser bonding method of an aluminum alloy member and a resin member characterized by the above-mentioned. The laser bonding method of the aluminum alloy member and the resin member according to claim 1, wherein the aluminum alloy member is blasted prior to the etching treatment. The aluminum alloy member according to claim 1 or 2, wherein an aluminum alloy member having a plurality of concave portions formed by the uneven portion obtained by the etching treatment or the blast treatment and the etching treatment is used as the joined aluminum alloy member. The shape portion has an opening width of 0.1 µm or more and 30 µm or less, and a depth of 0.1 µm or more and 100 µm or less, and the opening width is perpendicular to the thickness direction in the thickness direction cross section of the aluminum alloy member. And a half line between the top line passing through the highest part of the uneven portion and the bottom line passing through the deepest part, which is measured by scanning electron microscope observation, wherein the laser of the aluminum alloy member and the resin member is measured. Bonding method. The concave-shaped portion according to claim 1 or 2, wherein the joined aluminum alloy member is made of an Al-Si-based aluminum alloy member, and a plurality of concave portions are formed due to the uneven portion obtained by the etching treatment or the blast treatment and the etching treatment. It is formed in part or the whole surface of the surface, The said recessed part has the opening width of 0.1 micrometer or more and 30 micrometers or less, and has a some convex part which consists of process silicon crystal on the inner surface, The said opening width is the said aluminum alloy In the thickness direction cross section of a member, it measured by scanning electron microscope observation in the half line between the top line which is orthogonal to this thickness direction, and passes through the highest part of the uneven part, and the bottom line which passes through the deepest part. A convex portion made of the eutectic silicon crystal has a size of 0.1 µm or more and 10 µm or less in terms of a sphere equivalent particle diameter. Laser bonding method of minyum alloy member and the resin member. In claim 4, wherein the step portion formed of the convex silicon crystals, the recessed portion on the inner surface 0.001g / m ² at least 1g / m ² or less in an amount of protrusion? Precipitation and, and also having a convex part of the process the silicon crystal A laser bonding method of an aluminum alloy member and a resin member, wherein a plurality of concave portions having an opening width of 0.1 μm or more and 30 μm or less exist simultaneously at the same time. The acid according to any one of claims 1 to 5, wherein when the etching treatment is performed on the aluminum alloy member to be bonded, an acid containing a halogen ion concentration within a range of 0.1 g / L or more and 300 g / L or less as an etching solution. A laser bonding method of an aluminum alloy member and a resin member using an acid aqueous solution having a concentration of 0.1% by weight or more and 80% by weight or less and using one prepared by adding a water-soluble inorganic halogen compound to the acid aqueous solution. The laser bonding method of the aluminum alloy member and resin member in any one of Claims 2-6 with which the blasting process performed before an etching process is performed by the air nozzle system.

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