JP5381687B2 - Aluminum alloy member excellent in resin bondability and manufacturing method thereof - Google Patents

Description

  The present invention relates to an aluminum alloy member excellent in resin bondability for producing a structure integrated with a high-strength thermoplastic resin composition and a method for producing the same.

An aluminum-resin composite material obtained by integrating an aluminum member and a synthetic resin, which are different materials, is used in a wide range of fields such as automobiles, home appliances, and industrial equipment. Conventionally, as such an aluminum-resin composite material, an aluminum member and a resin member, which are pressure-bonded with an adhesive interposed, has been used.
However, recently, a method for integrating a high-strength engineering resin without the intervention of an adhesive has been proposed. For example, Patent Document 1 discloses a method of manufacturing an aluminum-resin composite in which a resin layer is formed on at least one surface of an aluminum thin plate by an injection molding method, and an etching method is previously applied to the surface of the aluminum thin plate on the side on which the resin layer is formed Then, a fine rough surface layer was provided, and then the aluminum thin plate was set in a movable mold of the mold, and the rough surface layer was pressed against the fixed mold side and closely clamped, and pressed against the rough surface layer. There has been proposed the manufacturing method characterized in that a resin layer is formed on at least one surface of an aluminum thin plate by injecting resin into a cavity formed by a fixed mold.

The above manufacturing method is also a useful technique from the viewpoint of obtaining a composite material in which an aluminum member and a resin member are integrally joined. However, such a composite material has a strong adhesive force (adhesion force) and rigidity. Is not enough to apply to the required mechanical structure.
Therefore, there is a demand for an aluminum-resin composite in which a high strength resin member is bonded with a strong adhesive force.
For example, Patent Documents 2 and 3 propose a method for producing an aluminum-resin composite that satisfies the above-mentioned demand.

JP 2000-176962 A WO2004 / 041533 JP 2007-182071 A

For example, in Patent Document 3, the surface is covered with a recess having a number average inner diameter of 10 to 80 nm by electron microscope observation through a step of immersing in one or more aqueous solutions selected from ammonia, hydrazine, and a water-soluble amine compound. A metal comprising an aluminum alloy part and a thermoplastic synthetic resin composition part having a resin component composition which is fixed to the surface of the aluminum alloy part by injection molding and whose main component is a polyamide resin and whose subcomponent is an impact resistance improving material. Resin composites have been proposed.
This composite is intended to firmly bond the polyamide resin composition by forming the surface of the aluminum alloy part so as to be covered with ultrafine recesses and hole openings.

However, the composites proposed in Patent Documents 2 and 3 have not been able to exhibit a strong adhesive force that can withstand use as a mechanical structure.
The present invention has been devised in order to solve such a problem, and uses a specific alloy-based aluminum alloy part and makes the surface properties complicated, thereby joining the resin member to be compounded. An object of the present invention is to provide an aluminum alloy part having improved properties.

  In order to achieve the object, the aluminum alloy member excellent in resin bondability of the present invention has Al-Si having a plurality of concave portions having a plurality of convex portions made of eutectic silicon crystals on the inner surface or a part of the surface. This is an aluminum alloy member, and the convex part made of the eutectic silicon crystal has a sphere equivalent particle size of 0.1 μm or more and 10 μm or less, and silicon element and aluminum element analysis is performed by fluorescent X-ray mapping analysis The region where only silicon present in the eutectic portion is distributed occupies 5% or more and 80% or less.

  Further, on the surface of the aluminum alloy member excellent in resin bondability of the present invention, a concave portion having an average opening width of 0.1 μm or more and 30 μm or less having a plurality of convex portions made of the eutectic silicon crystal is formed, In addition to these concave portions, the primary α-Al portion passes through the top line and the deepest portion that are orthogonal to the thickness direction in the cross section in the thickness direction of the aluminum alloy member and pass through the highest portion of the uneven portion. In the half line between the bottom line, the average aperture width measured by scanning electron microscope observation is 0.1 μm or more and 30 μm or less, and the depth is 0.1 μm or more and 30 μm or less. A plurality of concave portions are formed.

The convex portion made of the eutectic silicon crystal preferably protrudes and precipitates on the inner surface of the concave portion in an amount of 0.001 g / m ² or more and 1 g / m ² or less.
As an aluminum alloy constituting the aluminum alloy member having excellent resin bondability, Si: 5.0% by mass or more and 18% by mass or less, Fe: 1.3% by mass or less, Cu: 5.0% by mass or less, Mg : An aluminum alloy containing 1.5 mass% or less, Ni: 1.5 mass% or less, and having a composition composed of the balance of Al and inevitable impurities.

And when the aluminum alloy member excellent in resin bondability of the present invention is produced by casting an aluminum alloy member having the above component composition, the eutectic Si solidification temperature at the time of casting is 755 ° C. or more and 780 ° C. It is obtained by setting the cooling rate to 0.1 ° C./second or more and 100 ° C./second or less in the following region.
An aluminum alloy member having the above surface characteristics can be obtained by adjusting the surface of the cast cast object to a predetermined shape and size and then subjecting the surface to a chemical etching treatment with an acid-based liquid.

In addition, the aluminum alloy member excellent in resin bondability according to the present invention is subjected to a blasting process using fine particles made of alumina fine particles or metal fine particles on the surface prior to chemical etching treatment with an acid-based liquid, and has an uneven shape in advance. By forming on the surface, an aluminum-resin composite with higher bonding strength can be obtained.
The uneven shape formed on the surface is preferably 1 to 100 μm in Rz value as the surface roughness.

According to the present invention, a complicated uneven shape is imparted to the surface of an aluminum alloy member used for manufacturing a composite. For this reason, for example, when a resin member is bonded to the surface by an injection molding method or the like, the anchor effect is effectively exerted by the complicated uneven shape, and an aluminum-resin composite having high bonding strength can be easily obtained.
Moreover, since an Al—Si based cast alloy can be used as the aluminum alloy material, a composite having a high degree of freedom in shape can be manufactured at low cost. In addition, the aluminum-resin composite produced in this way has extremely high adhesion strength and airtightness at the interface (aluminum-resin interface) between the aluminum alloy member and the resin molded body, and is exposed to harsh environments. Furthermore, the excellent adhesion strength and airtightness can be maintained, and high reliability can be maintained over a long period of time.

  Therefore, the aluminum-resin composite of the present invention is suitable for metal-resin integral molded parts in a wide range of fields including, for example, various sensor parts for automobiles, various switch parts for home appliances, condenser parts for various industrial equipments, etc. In particular, it is suitably used for a metal-resin integral molded part that requires a high bonding strength because the resin molded body protrudes in a butted state from a part of the surface of the aluminum alloy member.

Schematic diagram explaining the solidification structure of Al-Si alloy castings Schematic diagram explaining the cross-sectional structure after etching of Al-Si alloy castings The screen which observed the etching surface of Al-Si system alloy casting with the scanning electron microscope Diagram explaining the shape of specimen for measuring shear strength of aluminum-resin composite Diagram explaining the shear strength measurement test method for aluminum-resin test pieces

When manufacturing the aluminum-resin composite, the present inventors have intensively studied measures for improving the surface properties of aluminum alloy parts in order to improve the bondability with the resin member to be composited.
In order to improve the bondability with the resin member, it is effective to form irregularities with a high anchor effect on the surface of the aluminum alloy part. However, it is difficult to form irregularities with a high anchoring effect on an Al casting alloy having a wide metal composition range and a complicated metal structure.
Therefore, the present invention has found that, in an Al-Si based casting alloy, it is possible to form irregularities with high anchor effect on the surface by combining the generation of a specific composition and the subsequent etching treatment. is there.
Details will be described below.

First, the basic principle relating to the fact that complicated irregularities are easily formed on the surface of an Al—Si based alloy member will be described.
When a molten Al-Si alloy having a hypoeutectic-eutectic vicinity composition that is frequently used practically is solidified in a mold, as shown in FIG. Is filled with a lamellar Al—Si eutectic part (2). And the Al-Si eutectic part (2) becomes a form comprised from eutectic (alpha) -Al (3) and eutectic Si (4).

When an Al—Si based alloy member having such a metal structure is chemically etched with an acid solution such as hydrochloric acid, the eutectic α-Al (3) of the Al—Si eutectic part is selectively dissolved. . This is because the eutectic α-Al has lower Al purity than other parts.
As a result, only the eutectic Si (4) remains from the lamellar eutectic portion filling the space between the primary crystals α-Al (1), and the voids between the primary crystals α-Al that have become concave portions. Residual Si protrudes from the concave wall at the portion (5) (see FIG. 2).
FIG. 3 shows the result of observing the surface of the sample used in Examples described later with a scanning electron microscope. It can be seen that the Si crystal protrudes inside the concave portion formed between the primary crystals α-Al to form the convex portion.

The present invention intends to fulfill an anchor function when a resin member is joined to a concave portion between the primary crystals α-Al where residual Si protrudes from the wall surface.
In order to effectively exhibit the anchor effect, it is effective to make the concave portions to be formed fine and to make the convex portions formed by the protruding Si crystal fine and large. To make the protrusions formed by protruding Si crystals finer and larger, the manufacturing conditions, especially the cooling rate during solidification and chemical etching conditions, should be adjusted, depending on the Si content of the material Al-Si alloy. Is required.

As preferable manufacturing conditions will be described later, the size and distribution state of the protrusions that effectively exert the anchor function will be described.
When the surface structure of the aluminum alloy member is observed with a scanning electron microscope (Hitachi FE-SEM, S-4500 type), the size of the protrusions composed of eutectic Si crystals is 0.1 to 10 μm in terms of sphere equivalent particle diameter. It is necessary to. If the Si crystal size is less than 0.1 μm or less, the convex part itself made of eutectic Si crystal is easily broken, and the anchor action cannot be exhibited. On the other hand, even when the Si crystal size exceeds 10 μm, the size is too large to exhibit the anchoring action.

  In addition, the concave portion from which the residual Si protrudes on the wall surface is perpendicular to the thickness direction in the cross section in the thickness direction of the aluminum alloy member, and the top line passing through the highest portion of the uneven portion and the bottom line passing through the deepest portion The average opening width measured by scanning electron microscope observation is between 0.1 μm and 30 μm, preferably between 0.5 μm and 20 μm, more preferably between 1 μm and 10 μm. The depth is 0.1 μm or more and 30 μm or less, preferably 0.5 μm or more and 20 μm or less.

  If the average opening width of the concave portion is smaller than 0.1 μm, it is difficult for the molten resin to enter during injection molding, and a minute gap is generated at the interface between the aluminum alloy member and the resin molded body, resulting in excellent adhesion strength and airtightness. On the other hand, if it is attempted to make the width larger than 30 μm, the dissolution reaction proceeds excessively during the surface treatment (etching treatment) of the aluminum molded body, which means that the material surface is lost or the material thickness is increased. Problems arise, products with insufficient material strength occur, and productivity is reduced. In addition, if the depth is shallower than 0.1 μm, it is difficult to obtain a sufficient insertion portion of the resin molded body. Conversely, if the depth is more than 30 μm, the aluminum molded body is dissolved during the surface treatment (etching process). The reaction proceeds excessively, causing a problem that the surface of the material is missing or the thickness of the material is increased.

  In the present invention, the density of the plurality of concave portions in which the residual Si protrudes from the wall surface is one type within a range of an average opening width of 0.5 μm to 20 μm and a depth of 0.5 μm to 20 μm per 0.1 mm square or Two or more types of sizes may be present in the range of about 5 or more and 200 or less.

  Further, the plurality of concave portions from which the residual Si protrudes on the wall surface may have a double concave portion structure in which at least one or more internal concave portions are formed on the inner wall surface in part or all. Further, it may have an internal concavo-convex structure in which at least one internal protrusion is formed on the internal wall surface, and these double concave structure and internal concavo-convex structure may coexist. In some or all of the plurality of concave portions where the residual Si protrudes from the wall surface, the presence of such a double concave portion structure or internal concave-convex structure allows the concave portion of the aluminum alloy member and the insertion portion of the resin molded body to Are more firmly bonded to each other, and better adhesion strength and airtightness between the aluminum alloy member and the resin molded body are exhibited.

  Furthermore, when the surface structure of the above-mentioned aluminum alloy member is analyzed by mapping analysis using an energy dispersive X-ray analyzer (EMAX-7000 manufactured by Horiba Seisakusho), only silicon present in the eutectic part is distributed. It is necessary to occupy 5% or more and 80% or less. When the Si distribution site is less than 5%, an effective anchor effect does not appear. Conversely, if it exceeds 80%, the dissolution of the primary crystal α-Al that forms the wall surface of the concave portion cannot be ignored, the wall surface dissolves, and the Si crystal is deposited in the concave portion, which has an anchoring effect on the resin component. No longer works.

It is preferable that the protruding amount of the convex portion made of the eutectic Si crystal protrudes and precipitates on the inner surface of the concave portion in an amount of 0.001 or more and 1 g / m ² or less. If the amount is less than 0.001 g / m ² , an effective anchor effect is hardly exhibited. On the other hand, if it exceeds 1 g / m ² , the dissolution of primary crystal α-Al that forms the wall surface of the concave portion cannot be ignored, the wall surface dissolves, and the Si crystal is deposited in the concave portion, anchoring the resin component. The effect stops working.
The protruding amount of the convex portion is a value obtained by measuring the crystal particles collected by using a 0.1 μm PC membrane filter by gravimetric method after scraping off the Si crystal formed on the surface of the aluminum member using a brush. is there.

  Here, the concave portion formed in the primary crystal α-Al that effectively exhibits the anchor function together with the concave portion having the protruding portion of the eutectic Si crystal formed by selective dissolution of the eutectic α-Al. Will be described. The plurality of concave portions formed due to the uneven portions on the surface of the aluminum member are orthogonal to the thickness direction in the cross section in the thickness direction of the aluminum alloy member, and the top line passes through the highest portion of the uneven portions. In the half line between the bottom line passing through the deepest part, the average opening width measured by scanning electron microscope observation 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. The depth is 0.1 μm or more and 30 μm or less, preferably 0.5 μm or more and 20 μm or less.

  If the average opening width of the concave portion is smaller than 0.1 μm, it is difficult for the molten resin to enter during injection molding, and a minute gap is generated at the interface between the aluminum alloy member and the resin molded body, resulting in excellent adhesion strength and airtightness. On the other hand, if it is attempted to make the width larger than 30 μm, the dissolution reaction proceeds excessively during the surface treatment (etching treatment) of the aluminum molded body, which means that the material surface is lost or the material thickness is increased. Problems arise, products with insufficient material strength occur, and productivity is reduced. In addition, if the depth is shallower than 0.1 μm, it is difficult to obtain a sufficient insertion portion of the resin molded body. Conversely, if the depth is more than 30 μm, the aluminum molded body is dissolved during the surface treatment (etching process). The reaction proceeds excessively, causing a problem that the surface of the material is missing or the thickness of the material is increased.

  In the present invention, with respect to the density of the plurality of concave portions formed due to the uneven portions on the surface of the aluminum alloy member, the average opening width per 0.1 mm square is 0.5 μm to 20 μm and the depth is 0.5 μm to 20 μm. It is preferable that one or two or more kinds of sizes within the following ranges exist in a range of about 5 or more and 200 or less.

  In addition, the plurality of concave portions of the aluminum alloy member may have a double concave portion structure in which at least one or more internal concave portions are formed on the inner wall surface, in part or in whole, It may have an internal concavo-convex structure in which at least one or more internal protrusions are formed on the inner wall surface, and these double concave structure and internal concavo-convex structure may coexist. In some or all of the plurality of concave portions of the aluminum alloy member, such a double concave portion structure or internal concave-convex structure exists, so that the concave portion of the aluminum alloy member and the insertion portion of the resin molded body are more mutually connected. It bonds firmly and exhibits better adhesion strength and airtightness between the aluminum alloy member and the resin molded body.

Next, the preferable alloy composition of the Al—Si based alloy that is the subject of the present invention will be described.
In the present invention, Si: 5.0% by mass or more and 18% by mass or less, preferably 6.0% by mass or more and 12.5% by mass or less, Fe: 1.3% by mass or less, preferably 0.9% by mass or less, Cu: 5.0% by mass or less, preferably 4.5% by mass or less, Mg: 1.5% by mass or less, preferably 1.0% by mass or less, Ni: 1.5% or less, preferably 1.1% by mass It is preferable to target an alloy having a component composition that includes at most% and the balance of Al and inevitable impurities. The reason will be described below.

Si: 5.0 mass% or more and 18 mass% or less Si is added for the purpose of increasing the strength of the base material, decreasing the coefficient of thermal expansion, improving the castability, and the like. In particular, in the present invention, the protrusion of eutectic Si formed with the selective dissolution of eutectic α-Al in the eutectic structure contributes most to the resin bondability. If Si is less than 5.0%, the amount of Si is too small to obtain a sufficient eutectic structure, and an effective anchor effect is not exhibited. On the other hand, if it exceeds 18%, the anchor effect is inhibited by a large amount of precipitation of primary Si.

Fe: 1.3% by mass or less Fe is added to prevent seizure to the mold. However, if Fe exceeds 1.3% by mass, the strength is suddenly lowered, so that the strength reduction of the aluminum-resin composite after resin bonding is unavoidable.

Cu: 5.0% by mass or less Cu is added to increase the strength of the base material and improve the machinability. However, if Cu exceeds 5.0% by mass, castability is lowered, and the corrosion resistance of the aluminum-resin composite after resin bonding is remarkably lowered.

Mg: 1.5% by mass or less Mg is added to increase the strength of the base material and to improve the corrosion resistance of the aluminum-resin composite after resin bonding. However, when Mg exceeds 1.5 mass%, molten metal oxidation will generate | occur | produce and a lot of debris will arise.

Ni: 1.5% by mass or less Ni is added to stabilize high-temperature strength. However, when Ni exceeds 1.5 mass%, castability and age hardenability will fall.

Inevitable impurities Mn: 0.65% by mass or less, Zn: 3.0% by mass or less Inevitable impurities include Mn and Zn. When Mn exceeds 0.65 mass%, the machinability of the base material is lowered. On the other hand, if Zn exceeds 3.0% by mass, the corrosion resistance of the aluminum-resin composite after resin bonding is lowered. Therefore, it is preferable to limit Mn and Zn as inevitable impurities to the above amounts or less.

Then, the method to manufacture the aluminum alloy member excellent in the resin bondability of this invention using the Al-Si type aluminum alloy which has the said component composition is demonstrated.
There is no restriction | limiting in particular in the preparation method of a molten alloy. Normal dissolution is sufficient.
Since the Al-Si alloy used in the present invention has a relatively high Si content and a low melting temperature, it is preferably formed into a desired shape by a casting method. From the viewpoint of obtaining highly accurate and stable mechanical characteristics, it is preferable to employ a die casting method. There are no particular restrictions on the casting conditions.

As described above, in order to obtain a complicated surface texture, it is preferable to refine the crystal structure after solidification. In this sense, the cooling rate needs to be 0.1 ° C./second or more and 100 ° C./second or less in the region where the eutectic Si solidification temperature during casting is 755 ° C. or higher and 780 ° C. or lower.
When the cooling rate is less than 0.1 ° C./second, the crystal structure becomes large, and the desired size and distribution state of the protrusions made of eutectic Si crystals can be obtained even after the subsequent chemical etching treatment. It becomes impossible to improve resin adhesion. Conversely, when the cooling rate exceeds 100 ° C./second, the eutectic Si crystal becomes too fine due to rapid cooling, and the anchor effect cannot be exhibited.

In order to adjust the shape and size of the obtained casting, after cutting away unnecessary portions such as runners, the resin joint surface is prepared by chamfering as necessary.
Examples of a method for forming an aluminum alloy member having a desired concavo-convex portion on the surface of the resin joint surface of a cast product in which the resin joint surface is arranged include, for example, hydrochloric acid, phosphoric acid, sulfuric acid, acetic acid, oxalic acid, Immerse in an etching solution consisting of an acid solution such as ascorbic acid, benzoic acid, butyric acid, citric acid, formic acid, lactic acid, isobutyric acid, malic acid, propionic acid, tartaric acid, etc. The method of the etching process to form is mentioned.

Etching solutions used for this purpose include acid solutions of hydrochloric acid solutions, phosphoric acid solutions, dilute sulfuric acid solutions, acetic acid having an acid concentration of 0.1 wt% to 80 wt%, preferably 1 wt% to 50 wt%. Examples thereof include an oxalic acid solution having an acid concentration of 5% by weight to 30% by weight, preferably 10% by weight to 20% by weight.
Further, for the purpose of further promoting dissolution of the eutectic α-Al, a halide may be added to these acid solutions. Examples of the halide include chlorides such as sodium chloride, potassium chloride, magnesium chloride, and aluminum chloride, fluorides such as calcium fluoride, bromides such as potassium bromide, etc., preferably safety and the like. In addition, the halogen ion concentration in the etching solution is usually 0.1 g / liter (g / L) or more and 300 g / L or less, preferably 1 g / L or more and 150 g / L or less. If it is less than 0.1 g / L, the effect of halogen ions is small, so that eutectic α-Al hardly dissolves, and there is a problem that a concave portion having a protruding portion of Si crystal is not formed, and exceeds 300 g / L. In such a case, since the dissolution reaction proceeds rapidly during the surface treatment (etching treatment) of the aluminum molded body, the concave portion formed by the selective dissolution of eutectic α-Al and In addition, there is a problem that it becomes difficult to control the protrusions of the Si crystal.

  In the present invention, as an etching solution for forming a desired concave portion on the surface of the aluminum alloy member, an acid solution having strong oxidizing power such as nitric acid or concentrated sulfuric acid having a concentration exceeding 80% by weight, sodium hydroxide, Alkaline solutions such as potassium hydroxide are not suitable. An acid solution having a relatively strong oxidizing power, such as concentrated sulfuric acid, has a film forming ability with respect to an aluminum alloy. On the contrary, a strong oxide film is formed on the surface of the aluminum alloy member, and it becomes difficult to dissolve the oxide film. Further, the dissolution mechanism of the alkali solution such as sodium hydroxide or potassium hydroxide in the aluminum alloy is the entire surface dissolution type, and the concave portion and the protruding portion of the Si crystal are formed by selective dissolution of the desired eutectic α-Al. Is difficult.

  In the present invention, the processing conditions for etching the surface of the aluminum alloy member using the above etching solution should be formed on the aluminum alloy member, such as the type of etching solution used, acid concentration, halogen ion concentration, etc. Normally, the bath temperature is 20 ° C. or higher and 80 ° C. or lower when the hydrochloric acid solution is used, and the immersion time is 1 minute or longer and 40 minutes or shorter. In the case of sulfuric acid solution, the bath temperature is 20 ° C. or more and 70 ° C. or less and the immersion time is 1 minute or more and 50 minutes or less. In the case of the oxalic acid solution, the bath temperature is 20 ° C. The immersion time is 1 to 20 minutes at 50 ° C. or less. In the case of an acetic acid solution, the bath temperature is 20 to 80 ° C. and the immersion time is 1 to 30 minutes. The higher the acid concentration and bath temperature of the etching solution used, the more remarkable the effect of the etching treatment, and the shorter the treatment time becomes possible, but the bath temperature is less than 20 ° C., the dissolution rate is slow and the eutectic α-Al It takes a long time to generate the concave portion and the Si protrusion due to the selective dissolution of, and at a bath temperature exceeding 80 ° C., the dissolution reaction proceeds rapidly, making it difficult to control the concave portion and the Si protrusion. With respect to the immersion time, if it is less than 1 minute, it is difficult to control the selective dissolution of the crystal α-Al.

In the etching process using an acidic solution in the present invention, a desired concave portion can be formed by repeating the etching process a plurality of times using different solutions.
Before the above-mentioned chemical etching treatment is performed and the concave portion is formed on the surface of the aluminum alloy member, the surface of the aluminum alloy member is blasted for the purpose of enabling a uniform etching treatment or enhancing the anchor effect. Unevenness can also be formed.

When an aluminum casting alloy having a complicated metal structure is subjected to a chemical etching process, unevenness of etching on the surface of the aluminum alloy member may occur, making uniform etching difficult. In the blast treatment, local plastic deformation and rapid heating and rapid cooling accompanying plastic deformation are repeated on the outermost surface of the aluminum alloy member due to the collision of the shot media, and the surface structure is refined and uniformized. Therefore, a uniform concave portion can be formed by performing chemical etching after blasting.
Further, since the aluminum surface after the blasting process is roughened, the resin bonding property can be improved by a double roughening process in which a concave portion is formed by performing a chemical etching process thereafter.

There are two types of blasting: shot blasting, which uses a centrifugal force of an impeller called an impeller to project the projection material, and air blasting, which uses an air compressor to project the projection material with compressed air, both of which are aluminum alloy members. It is possible to give surface roughness.
As a blasting method, air nozzle blasting is preferable. The reason why the air nozzle type is particularly preferable as a blasting method is that the jet pressure of the medium is higher than that of the shot type. For example, the media is stronger than the shot type blast with a low jet pressure. Can be made to collide with the surface, and as a result, a surface structure preferable for a uniform etching process can be formed, but a shot blasting process may be selected from the viewpoint of cost and efficiency.

By blasting, irregularities having a surface roughness Rz (Rz: 10-point average roughness according to JIS B 0601-1994) of 1 μm to 100 μm, preferably 5 μm to 50 μm are formed on the surface of the aluminum alloy member.
If the thickness is less than 1 μm, sufficient surface unevenness and uniform surface texture cannot be obtained, and if it exceeds 100 μm, problems such as material distortion occur due to a decrease in productivity and an increase in internal stress.

In addition, examples of the projecting material include materials such as fine particles of fine particles such as sand, alumina, and cast iron, and resins, which can be used depending on the purpose. In order to give unevenness to the aluminum alloy member, alumina having high hardness is preferable, but metal fine particles such as cast iron may be used with emphasis on cost and efficiency.
The surface area of the aluminum alloy member is increased by forming the concavo-convex portion by blasting, and the reactivity of the Al—Si eutectic portion with the etching solution for the eutectic α-Al increases, so that more desired concave portions There is an effect that it is easy to form. In addition, it is possible to reduce the consumption of the etching treatment solution, and it is also possible to remove dirt and the like on the surface of the aluminum alloy member.

  In the present invention, when an aluminum alloy member having a concave portion is formed by etching the aluminum alloy material as described above, or after the blast treatment, an aluminum alloy member having a concave portion is formed by performing an etching treatment. In this case, if necessary, the surface of the aluminum alloy material before the etching process or the blasting process is subjected to acid treatment with an acid solution for the purpose of degreasing, surface adjustment, removal of surface deposits and contaminants, and / or A pretreatment comprising an alkali treatment with an alkali solution may be performed.

Here, examples of the acid solution used for this pretreatment include those prepared with commercially available acid degreasing agents, mineral acids such as sulfuric acid, nitric acid, hydrofluoric acid, and phosphoric acid, organic acids such as acetic acid and citric acid, and the like. What was prepared using acid reagents, such as mixed acid obtained by mixing acid, etc. can be used, and as an alkaline solution, for example, what was prepared with a commercially available alkaline degreasing agent, caustic soda, etc. What was prepared with the alkali reagent, or what was prepared by mixing these things etc. can be used.
Regarding the operation method and treatment conditions of the pretreatment performed using the acid solution and / or the alkali solution, the operation method and treatment conditions of the pretreatment conventionally performed using this kind of acid solution or alkali solution, and For example, it can be performed by a method such as an immersion method or a spray method.

On the other hand, when the blast treatment is not performed before the chemical etching treatment, it is preferable to perform ultrasonic treatment after the chemical etching treatment.
As described above, when the blast treatment is not performed, the surface metallographic variation inevitable in the die casting forming process occurs. For this reason, when etching is performed, uniform dissolution may not occur and etching unevenness may occur.

  In order to prevent this, it is necessary to increase the amount of dissolution by the etching process by increasing the bath temperature during etching or by increasing the immersion time. The problem of depositing on the surface occurs. Since the deposited layer of eutectic Si crystal has a porous structure, the resin is easy to enter, but on the other hand, the adhesion to the Al alloy is very small and it is difficult to obtain a high bonding strength. Therefore, by ultrasonic treatment after the etching process, it is possible to selectively remove the deposited eutectic Si crystal existing in the outermost layer, and to leave only the eutectic Si crystal in the surface recess contributing to the resin bondability. Become.

In addition, even if the etching process using an acidic solution is performed more than necessary, and the desired convex Si is not obtained, it is deposited as a first-aid measure by performing ultrasonic water washing as an emergency measure. It can be removed and the desired convex Si can be left protruding.
On the other hand, it is possible to dissolve and remove Si with a solution containing fluoride ions, but in this case, it is difficult to control the removal of only the deposited Si layer and leaving only the desired convex Si protruding. Therefore, it is not preferable.

  And after performing the above pre-treatment on the surface of the aluminum alloy material or after performing the etching treatment for forming the concave portion, it may be washed with water if necessary. Tap water, ion-exchanged water, or the like can be used, and is appropriately selected depending on the aluminum alloy member to be manufactured. Furthermore, the aluminum alloy material that has been subjected to pretreatment or etching treatment is dried as necessary. This drying treatment may be natural drying that is allowed to stand at room temperature, or using an air blow, a dryer, an oven, or the like. Forced drying may be used.

Finally, the usage aspect of the aluminum alloy part which improved the bondability with the resin member of this invention is demonstrated easily.
The aluminum alloy member of the present invention is used as a raw material aluminum alloy shaped article when an aluminum-resin composite is produced by an injection molding method as described in each of the above patent documents. That is, an injection mold is prepared, the movable mold is opened, the aluminum alloy member of the present invention is inserted into one of the molds, the movable mold is closed, and then a desired thermoplastic synthetic resin composition is injected. If the movable mold is opened and released, a desired aluminum-resin composite can be obtained.
In the present invention, a particularly preferable injection-integrated molded article is an aluminum-resin composite including a resin molded body in which a thermoplastic resin is injection-molded on a part of the surface of an aluminum alloy member and bonded in a butt state.

  Here, for the thermoplastic resin for producing the aluminum-resin composite of the present invention, various thermoplastic resins can be used alone, but the physical properties and applications required for the aluminum-resin composite of the present invention. Considering the usage environment, the thermoplastic resin is preferably a polypropylene resin, a polyethylene resin, an acrylonitrile-butadiene-styrene copolymer (ABS), a polycarbonate resin (PC), a polyamide resin (PA), a polyphenylene sulfide, for example. (PPS) and other polyarylene sulfide resins, polyacetal resins, liquid crystal resins, polyethylene terephthalate (PET) and polyester resins such as polybutylene terephthalate (PBT), polyoxymethylene resins, polyimide resins, syndiotactic polystyrene resins, etc. Of these thermoplastics 2 or more types of mixtures are included, and performance such as adhesion between the aluminum alloy member and the resin molding, mechanical strength, heat resistance, dimensional stability (deformation resistance, warpage, etc.), electrical properties, etc. In order to improve further, it is more preferable to add fillers such as fiber, powder, and plate and various elastomer components to these thermoplastic resins.

  Here, as fillers added to the thermoplastic resin, inorganic fiber fillers such as glass fiber, carbon fiber, metal fiber, asbestos fiber and boron fiber, and high melting point organic fibers such as polyamide, fluororesin and acrylic resin are used. Examples include fillers, powder fillers such as quartz powder, glass beads, glass powder, calcium carbonate and other inorganic powders, and plate fillers such as glass flakes and silicates such as talc and mica. And 250 parts by weight or less, preferably 20 parts by weight or more and 220 parts by weight or less, and more preferably 30 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin. When the added amount of the filler exceeds 250 parts by weight, the fluidity is lowered and it becomes difficult to enter the concave portion of the aluminum alloy member, so that a good adhesion strength cannot be obtained or the mechanical properties are deteriorated. Occurs.

  Examples of the elastomer component added to the thermoplastic resin include urethane type, core shell type, olefin type, polyester type, amide type, and styrene type elastomers. The melting temperature of the thermoplastic resin at the time of injection molding, etc. In addition, it is selected in consideration of 30 parts by weight or less, preferably 3 parts by weight or more and 25 parts by weight or less based on 100 parts by weight of the thermoplastic resin. When the added amount of the elastomer component exceeds 30 parts by weight, a further effect of improving the adhesion strength is not seen, and problems such as a decrease in mechanical properties occur. This blending effect of the elastomer component is particularly prominent when a polyester resin is used as the thermoplastic resin.

  Furthermore, the thermoplastic resin for producing the aluminum-resin composite of the present invention includes known additives generally added to thermoplastic resins, that is, flame retardants, colorants such as dyes and pigments, antioxidants, Stabilizers such as ultraviolet absorbers, plasticizers, lubricants, lubricants, mold release agents, crystallization accelerators, crystal nucleating agents, and the like can be appropriately added according to the required performance.

  In the present invention, for the injection molding of the thermoplastic resin performed by setting the aluminum alloy member in the injection mold, molding conditions required for the thermoplastic resin to be used can be adopted. It is important that the molten thermoplastic resin surely enters and solidifies into the concave part of the aluminum alloy member, and the mold temperature and cylinder temperature are compared within the range that the type and physical properties of the thermoplastic resin and the molding cycle allow. The lower limit temperature must be 90 ° C. or higher, preferably 130 ° C. or higher, especially for the mold temperature, but the upper limit is 100 depending on the type of thermoplastic resin used. From ℃ to a temperature about 20 ℃ lower than the melting point or softening point of the thermoplastic resin (if the elastomer component is added, the higher melting point or softening point) It is in the range. Further, the lower limit mold temperature is preferably set so as not to be lowered by 140 ° C. or more from the melting point of the thermoplastic resin.

  Further, the means for producing the aluminum-resin composite of the present invention is not limited to the injection molding method, and a thermocompression bonding method may be employed. That is, the desired aluminum-resin composite can be obtained by heating the aluminum alloy member in a range of about 90 ° C. to 300 ° C. and pressing a resin member made of a thermoplastic resin on the surface with pressure. Can be obtained.

Example 1;
[Preparation of Al alloy specimen]
Si: 11 mass%, Fe: 0.71 mass%, Cu: 2.46 mass%, Mn: 0.36 mass%, Mg: 0.29 mass%, Zn: 0.79 mass%, Ni: 0.00. An Al alloy melt containing 72% by mass was die-cast into a size of 180 mm × 150 mm × 3 mm. In this case, the setting conditions are: mold temperature: 170 ° C., molten metal temperature: 720 ° C., injection speed: 1.7 m / s, product filling time: 10 ms, average in-product flow velocity: 11 m / s. The cooling rate during casting is 40 ° C./second.

From the obtained casting, an Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out, and the casting surface of this Al alloy piece was chamfered by 0.3 mm from both sides to obtain a size of 37.5 mm × A 37.5 mm × 2.4 mm Al alloy specimen was prepared.
Next, the Al alloy test piece was subjected to an etching treatment by immersing it at 40 ° C. for 10 minutes in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% hydrochloric acid solution, followed by washing with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

[Observation of silicon crystals in aluminum alloy members]
The surface of the obtained Al alloy specimen is observed using a scanning electron microscope (Hitachi FE-SEM, S-4500 type), the size of the silicon crystal is observed, and the amount of precipitation is determined by the gravimetric method. It was measured.

  The observed surface of the aluminum alloy member is, for example, as shown in the SEM photograph of FIG. 3, and silicon crystals protrude and deposit inside the concave portions formed on the aluminum surface, and the formed convex portions were observed. . Further, the shape of such a convex portion was the same even when the observation place was changed. Moreover, after dropping the silicon crystal formed on the surface of the Al alloy test piece using a brush, the collected crystal particles were measured by a gravimetric method using a 0.1 μm PC membrane filter.

The average opening width of the concave portion observed on the surface of a certain region of the aluminum alloy member and the size and distribution of the eutectic silicon crystal that protrudes and precipitates inside the concave portion average opening width of 0.1 μm or more and 30 μm. In the following, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm.
As a result of conducting the silicon element and aluminum element analysis on the surface of the aluminum alloy member by the mapping analysis of the energy dispersive X-ray analyzer (EMAX-7000 manufactured by Horiba Seisakusho), only Si present in the eutectic portion is obtained. The distributed site accounted for 45%. In addition, the amount of eutectic silicon deposited on the surface of the aluminum alloy member was 0.001 g or more and 1 g or less per square meter. The size, distribution, and amount of the protruding silicon crystals were almost unchanged even when the observation location was changed.

[Shear fracture load measurement test]
The aluminum alloy member of Example 1 obtained as described above was set in a mold of an injection molding machine (ST10R2V manufactured by NISSEI), and a polyphenylene sulfide resin (Polyplastics Co., Ltd.) containing a filler as a thermoplastic resin. Using PPS grade name 1140A6), injection molding (including pressure holding time) 5 seconds, injection speed 60 mm / second, pressure holding pressure 90 MPa, molding temperature 310 ° C., mold temperature 180 ° C., mold temperature 180 ° C., injection molding, As shown in FIG. 4, the surface of the aluminum alloy member (6) having a size of 37.5 mm × 37.5 mm × 2.4 mm has a size of 15 mm length × 3 mm thickness × 6 mm height. An aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test in which a resin molded body (7) fixed to the surface of the Al alloy test piece was integrated was produced.

Using a shear strength measurement tester (manufactured by Shimadzu Corporation: 100 kN autograph), as shown in FIG. 5, the above-mentioned shear fracture load measurement test aluminum-resin test piece is bolted to the test piece fixing jig (8). Fixed at (9), applied a shear load by a push jig (10) at a position 0.1 mm away from the joint, and the peeled state of the joint between the aluminum alloy member (6) and the resin molded body (7) I investigated. When the peeling form is a cohesive failure in which even part of the resin remains on the aluminum alloy member (6) side, the condition is good (◯), and the resin is 70% or more of the bonding area on the aluminum alloy member (6) side. When the remaining cohesive failure was evaluated as the best (◎), and the case where the resin did not remain on the aluminum alloy member side but occurred at the bonding interface was evaluated as defective (×), the result was the best (◎). there were.
The results are shown in Table 1.

Example 2;
A 37.5 mm × 37.5 mm × 3 mm Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out from the Al alloy die cast casting produced in Example 1, and this Al alloy piece was chamfered by 0.6 mm only on one side, and the casting surface was cast on one side. An Al alloy test piece having a size of 37.5 mm × 37.5 mm × 2.4 mm having a surface was produced. # 100 alumina fine particles (composition: Al ₂ O ₃ : 96.6 wt%, TiO ₂ : 2.4 wt%, SiO ₂ : 0.6 wt%) with respect to the casting surface of this Al alloy test piece % And others), and the Rz value was adjusted to 5 μm as the surface roughness value, and then 54 g / L of aluminum chloride hexahydrate was added to a 2 wt% hydrochloric acid solution. After performing an etching treatment of immersing in an etching solution at 40 ° C. for 15 minutes, the substrate was washed with water and dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 55%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Carried out and evaluated each.
The results are shown in Table 1 together with the results of Example 1.

Example 3;
A 37.5 mm × 37.5 mm × 3 mm Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out from the Al alloy die cast casting produced in Example 1, and this Al alloy piece was chamfered by 0.6 mm only on one side, and the casting surface was cast on one side. An Al alloy test piece having a size of 37.5 mm × 37.5 mm × 2.4 mm having a surface was produced. The cast surface of this Al alloy test piece was subjected to an etching treatment of immersing at 66 ° C. for 8 minutes in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 2 wt% hydrochloric acid solution. Then, it was washed with water and dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 30%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, aluminum-resin test pieces (aluminum-resin composites) for shear strength measurement test were respectively prepared using a resin, and shear strength measurement test of the aluminum-resin test pieces was performed. Was implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 4;
Except for changing the mold temperature at the time of resin injection molding to 160 ° C., an aluminum alloy member was produced in the same manner as in Example 1 above, and then in the same manner as in Example 1 above, shear strength was obtained using resin. An aluminum-resin test piece for a measurement test was prepared, and a shear strength measurement test was performed and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 5;
In the same manner as in Example 1 above, an Al alloy test piece was prepared, and then in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% sulfuric acid solution at 40 ° C. for 8 minutes. After performing the immersion etching treatment, it was washed with water and dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.
When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 35%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 6;
In the same manner as in Example 1 above, an Al alloy test piece was prepared, and then 10 ° C. at 40 ° C. in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% phosphoric acid solution. After performing an etching treatment soaking for 1 minute, it was washed with water and dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.
When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 40%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 7;
In the same manner as in Example 1 above, an Al alloy test piece was prepared, and then at 50 ° C. in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate to a 5 wt% oxalic acid solution. The aluminum alloy member was produced by performing the etching process which wash | cleans with water after being immersed for 1 minute, and then washed with water and dried with 120 degreeC hot air for 5 minutes.
When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 30%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 8;
In the same manner as in Example 1 above, an Al alloy test piece was prepared, then subjected to an etching treatment that was immersed in a 5 wt% hydrochloric acid solution at 66 ° C. for 10 minutes, washed with water, and dried with hot air at 120 ° C. for 5 minutes. An aluminum alloy member was produced.
When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 40%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 9;
[Preparation of Al alloy specimen]
Si: 11 mass%, Fe: 0.71 mass%, Cu: 2.46 mass%, Mn: 0.36 mass%, Mg: 0.29 mass%, Zn: 0.79 mass%, Ni: 0.00. An Al alloy melt containing 72% by mass was die-cast into a size of 180 mm × 150 mm × 1.6 mm. In this case, the setting conditions are: mold temperature: 170 ° C., molten metal temperature: 720 ° C., injection speed: 1.7 m / s, product filling time: 10 ms, average in-product flow velocity: 11 m / s. The cooling rate during casting is 90 ° C./second.

An Al alloy piece having a size of 37.5 mm × 37.5 mm × 1.6 mm was cut out from the obtained casting, and the casting surface of the Al alloy piece was chamfered by 0.3 mm from both sides to obtain a size of 37. A 5 mm × 37.5 mm × 1 mm Al alloy specimen was prepared.
Next, the Al alloy test piece was subjected to an etching treatment in which it was immersed in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% hydrochloric acid solution at 40 ° C. for 7 minutes, and then washed with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 40%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 10;
[Preparation of Al alloy specimen]
Al alloy melt containing Si: 6.9% by mass, Fe: 0.38% by mass, Mg: 0.29% by mass, Cu: 0.01% by mass, Ni: 0.01% by mass, 180 mm × 150 mm × Die casting was performed to a size of 3.0 mm. In this case, the setting conditions are: mold temperature: 170 ° C., molten metal temperature: 720 ° C., injection speed: 1.7 m / s, product filling time: 10 ms, average in-product flow velocity: 11 m / s. The cooling rate during casting is 40 ° C./second.
From the obtained casting, an Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out, and the casting surface of this Al alloy piece was chamfered by 0.3 mm from both sides to obtain a size of 37.5 mm × A 37.5 mm × 2.4 mm Al alloy specimen was prepared.
Next, the Al alloy test piece was subjected to an etching treatment in which it was immersed in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% hydrochloric acid solution at 40 ° C. for 7 minutes, and then washed with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 35%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 11;
An Al alloy piece having a size of 37.5 mm × 37.5 mm × 3.0 mm was cut out from the Al alloy die cast casting produced in Example 1, and the cast surface of this Al alloy piece was chamfered by 0.3 mm from both sides. An Al alloy specimen having a size of 37.5 mm × 37.5 mm × 2.4 mm was produced.
Next, the Al alloy test piece was subjected to an etching treatment of immersing in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 2 wt% hydrochloric acid solution at 40 ° C. for 35 minutes, and then washed with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. Accounted for 75%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 12;
An Al alloy piece having a size of 37.5 mm × 37.5 mm × 3.0 mm was cut out from the Al alloy die cast casting produced in Example 1, and the cast surface of this Al alloy piece was chamfered by 0.3 mm from both sides. An Al alloy specimen having a size of 37.5 mm × 37.5 mm × 2.4 mm was produced.
Next, the Al alloy test piece was subjected to an etching treatment of immersing at 40 ° C. for 2 minutes in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% hydrochloric acid solution, and then washed with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. Accounted for 10%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 13;
[Preparation of Al alloy specimen]
Si: 9.0 mass%, Fe: 0.72 mass%, Cu: 2.54 mass%, Mn: 0.36 mass%, Mg: 0.29 mass%, Zn: 0.71 mass%, Ni: An Al alloy melt containing 0.69% by mass was die-cast into a size of 180 mm × 150 mm × 3.0 mm. In this case, the setting conditions are: mold temperature: 170 ° C., molten metal temperature: 720 ° C., injection speed: 1.7 m / s, product filling time: 10 ms, average in-product flow velocity: 11 m / s. The cooling rate during casting is 40 ° C./second.

From the obtained casting, an Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out, and the casting surface of this Al alloy piece was chamfered by 0.3 mm from both sides to obtain a size of 37.5 mm × A 37.5 mm × 2.4 mm Al alloy specimen was prepared.
Next, the Al alloy test piece was subjected to an etching treatment in which it was immersed in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% hydrochloric acid solution at 40 ° C. for 10 minutes, and then washed with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 40%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 14;
[Preparation of Al alloy specimen]
Si: 9.0% by mass, Fe: 0.71% by mass, Cu: 2.46% by mass, Mn: 0.34% by mass, Mg: 0.29% by mass, Zn: 0.69% by mass, Ni: A cast product was produced by casting an Al alloy molten metal containing 0.68% by mass in a copper JIS boat mold. In this case, the setting conditions are: mold temperature: 120 ° C., molten metal temperature: 720 ° C. The cooling rate during casting is 2.5 ° C./second.

From the obtained casting product, an Al alloy piece having a size of 37.5 mm × 37.5 mm × 5 mm was cut out, and the Al alloy piece was cut by 2.6 mm from both sides to obtain a size of 37.5 mm × 37.5 mm × A 2.4 mm Al alloy specimen was prepared.
Next, the Al alloy test piece was subjected to an etching treatment by immersing it at 40 ° C. for 10 minutes in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% hydrochloric acid solution, followed by washing with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 40%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 15;
[Preparation of Al alloy specimen]
Si: 9.0% by mass, Fe: 0.71% by mass, Cu: 2.46% by mass, Mn: 0.34% by mass, Mg: 0.29% by mass, Zn: 0.69% by mass, Ni: A cast product was produced by casting an Al alloy molten metal containing 0.68% by mass in a copper JIS boat mold. In this case, the setting conditions are: mold temperature: 350 ° C., molten metal temperature: 720 ° C. The cooling rate during casting is 0.25 ° C./second.

From the obtained casting product, an Al alloy piece having a size of 37.5 mm × 37.5 mm × 5 mm was cut out, and the Al alloy piece was cut by 2.6 mm from both sides to obtain a size of 37.5 mm × 37.5 mm × A 2.4 mm Al alloy specimen was prepared.
Next, the Al alloy test piece was subjected to an etching treatment in which it was immersed in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 5 wt% hydrochloric acid solution at 40 ° C. for 10 minutes, and then washed with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. Accounted for 45%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 1 together with the results of Example 1.

Example 16;
A 37.5 mm × 37.5 mm × 3 mm Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out from the Al alloy die cast casting produced in Example 1, and this Al alloy piece was chamfered by 0.6 mm only on one side, and the casting surface was cast on one side. An Al alloy test piece having a size of 37.5 mm × 37.5 mm × 2.4 mm having a surface was produced. Shot blasting is performed on the cast surface of the Al alloy test piece using stainless fine particles (made of SUS304) having a particle size of 100 to 120 μm, and the Rz value is set to 2 μm as the surface roughness value. After performing an etching treatment of immersing in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in the solution for 15 minutes at 40 ° C., washing with water and drying with hot air at 120 ° C. for 5 minutes, An aluminum alloy member was produced.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 50%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Carried out and evaluated each.
The results are shown in Table 1 together with the results of Example 1.

Example 17;
A 37.5 mm × 37.5 mm × 3 mm Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out from the Al alloy die cast casting produced in Example 1, and this Al alloy piece was chamfered by 0.6 mm only on one side, and the casting surface was cast on one side. An Al alloy test piece having a size of 37.5 mm × 37.5 mm × 2.4 mm having a surface was produced. Alumina fine particles having a particle diameter of 2000 to 2378 μm (composition: Al ₂ O ₃ : 96.6 wt%, TiO ₂ : 2.4 wt%, SiO ₂ : 0.6 wt%, and Etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate to 2 wt% hydrochloric acid solution after air blasting using other method and setting Rz value to 50 μm as surface roughness value After being etched at 40 ° C. for 15 minutes, it was washed with water and dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. The size and the distribution thereof are such that the average opening width of the concave portion is 0.1 μm or more and 30 μm or less, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and only the Si present in the eutectic portion is distributed. It accounted for 55%.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Carried out and evaluated each.
The results are shown in Table 1 together with the results of Example 1.

Comparative Example 1;
An Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out from the Al alloy die cast casting produced in Example 1, and the casting surface of this Al alloy piece was chamfered by 0.3 mm from both sides to obtain a large size. A 37.5 mm × 37.5 mm × 2.4 mm Al alloy specimen was prepared.
Next, the Al alloy test piece was subjected to an etching treatment that was immersed in an etching solution of 30 wt% hydrochloric acid solution at 90 ° C. for 20 minutes, then washed with water and dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member. did.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. As for the size and distribution thereof, the average opening width of the concave portion exceeds 30 μm, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and the region where only Si present in the eutectic portion is distributed is 100%. Occupied.
In addition, the amount of eutectic silicon deposited on the surface of the aluminum alloy member exceeded 1 g per square meter, and the size, distribution, and amount of silicon crystals that protruded were almost unchanged even when the observation location was changed. .
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 2.

Comparative Example 2;
A 37.5 mm × 37.5 mm × 3 mm Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out from the Al alloy die cast casting produced in Example 1, and this Al alloy piece was chamfered by 0.6 mm only on one side, and the casting surface was cast on one side. An Al alloy test piece having a size of 37.5 mm × 37.5 mm × 2.4 mm having a surface was produced. # 100 alumina fine particles (composition: Al ₂ O ₃ : 96.6 wt%, TiO ₂ : 2.4 wt%, SiO ₂ : 0.6 wt%) with respect to the casting surface of this Al alloy test piece After the air blast treatment using the above-mentioned Al), the Al alloy piece was subjected to an etching treatment of immersing in an etching solution of 30 wt% hydrochloric acid solution at 90 ° C. for 6 minutes, washed with water, and heated with hot air at 120 ° C. for 5 minutes. The aluminum alloy member was produced by drying for a minute.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. As for the size and distribution thereof, the average opening width of the concave portion exceeds 30 μm, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and the region where only Si present in the eutectic portion is distributed is 100%. Occupied.
In addition, the amount of eutectic silicon deposited on the surface of the aluminum alloy member exceeded 1 g per square meter, and the size, distribution, and amount of silicon crystals that protruded were almost unchanged even when the observation location was changed. .
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 2 together with the results of Comparative Example 1.

Comparative Example 3;
A 37.5 mm × 37.5 mm × 3 mm Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out from the Al alloy die cast casting produced in Example 1, and this Al alloy piece was chamfered by 0.6 mm only on one side, and the casting surface was cast on one side An Al alloy test piece having a size of 37.5 mm × 37.5 mm × 2.4 mm having a surface was produced. The cast surface of this Al alloy test piece was subjected to an etching treatment that was immersed in an etching solution of 30 wt% hydrochloric acid solution at 90 ° C. for 10 minutes, then washed with water and dried with hot air at 120 ° C. for 5 minutes to obtain an aluminum alloy. A member was prepared.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. As for the size and distribution thereof, the average opening width of the concave portion exceeds 30 μm, the sphere equivalent particle diameter is 0.1 μm or more and 10 μm or less, and the region where only Si present in the eutectic portion is distributed is 100%. Occupied.
In addition, the amount of eutectic silicon deposited on the surface of the aluminum alloy member exceeded 1 g per square meter, and the size, distribution, and amount of silicon crystals that protruded were almost unchanged even when the observation location was changed. .
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 2 together with the results of Comparative Example 1.

Comparative Example 4;
An Al alloy piece having a size of 37.5 mm × 37.5 mm × 3.0 mm was cut out from the Al alloy die cast casting produced in Example 1, and the cast surface of this Al alloy piece was chamfered by 0.3 mm from both sides. An Al alloy specimen having a size of 37.5 mm × 37.5 mm × 2.4 mm was produced.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared and evaluated using a resin.
The results are shown in Table 2.

Comparative Example 5;
A 37.5 mm × 37.5 mm × 3 mm Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out from the Al alloy die cast casting produced in Example 1, and this Al alloy piece was chamfered by 0.6 mm only on one side, and the casting surface was cast on one side. An Al alloy test piece having a size of 37.5 mm × 37.5 mm × 2.4 mm having a surface was produced. # 100 alumina fine particles (composition: Al ₂ O ₃ : 96.6 wt%, TiO ₂ : 2.4 wt%, SiO ₂ : 0.6 wt%) with respect to the casting surface of this Al alloy test piece %, And others).
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared and evaluated using a resin.
The results are shown in Table 2 together with the results of Comparative Example 1.

Comparative Example 6;
An Al alloy piece having a size of 37.5 mm × 37.5 mm × 3.0 mm was cut out from the Al alloy die cast casting produced in Example 1, and the cast surface of this Al alloy piece was chamfered by 0.3 mm from both sides. An Al alloy specimen having a size of 37.5 mm × 37.5 mm × 2.4 mm was produced.
Next, the Al alloy test piece was subjected to an etching treatment immersed in a 5 wt% sodium hydroxide solution at 50 ° C. for 5 minutes, then washed with water and dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared and evaluated using a resin.
The results are shown in Table 2.

Comparative Example 7;
[Preparation of Al alloy specimen]
Si: 9.0% by mass, Fe: 0.71% by mass, Cu: 2.46% by mass, Mn: 0.34% by mass, Mg: 0.29% by mass, Zn: 0.69% by mass, Ni: A cast product having a size of 40 mm × 200 mm × 60 mm was produced by casting a molten Al alloy containing 0.68% by mass by sand mold casting using shell sand. In addition, the setting conditions in this case are molten metal temperature; 720 degreeC. The cooling rate during casting is 0.045 ° C./second.

From the obtained casting product, an Al alloy piece having a size of 37.5 mm × 37.5 mm × 5 mm was cut out, and the Al alloy piece was cut by 2.6 mm from both sides to obtain a size of 37.5 mm × 37.5 mm × A 2.4 mm Al alloy specimen was prepared.
Next, the Al alloy test piece was subjected to an etching treatment of immersing in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 10 wt% hydrochloric acid solution at 40 ° C. for 10 minutes, and then washed with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. As for the size and distribution thereof, the average opening width of the concave portion exceeds 30 μm, the sphere equivalent particle diameter exceeds 10 μm, and the portion where only Si present in the eutectic portion occupies 50%. It was.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 2.

Comparative Example 8;
[Preparation of Al alloy specimen]
Si: 11 mass%, Fe: 0.71 mass%, Cu: 2.46 mass%, Mn: 0.36 mass%, Mg: 0.29 mass%, Zn: 0.79 mass%, Ni: 0.00. An Al alloy melt containing 72% by mass was prepared by alloying by an atomizing method, followed by cold compression and sintering, and an extruded product having a size of 90φ and 200 mm was produced by hot extrusion. In addition, the cooling rate at the time of alloy powder preparation by the atomizing method is 300 ° C./second.

From the obtained extruded product, an Al alloy piece having a size of 37.5 mm × 37.5 mm × 3 mm was cut out, and the cast surface of this Al alloy piece was chamfered by 0.3 mm from both sides to obtain a size of 37.5 mm. An Al alloy test piece of 37.5 mm × 2.4 mm was produced.
Next, the Al alloy test piece was subjected to an etching treatment of immersing in an etching solution prepared by adding 54 g / L of aluminum chloride hexahydrate in a 10 wt% hydrochloric acid solution at 40 ° C. for 10 minutes, and then washed with water. Then, it was dried with hot air at 120 ° C. for 5 minutes to produce an aluminum alloy member.

When the silicon crystal of the aluminum alloy member was observed in the same manner as in Example 1, the measured average opening width of the concave portion and the eutectic silicon crystal that protruded and precipitated inside the surface of the certain region of the aluminum alloy member were measured. As for the size and distribution thereof, the average opening width of the concave portion is less than 0.1 μm, the sphere equivalent particle diameter is less than 0.1 μm, and the portion where only Si existing in the eutectic portion is distributed is 40%. Occupied.
Further, the amount of eutectic silicon deposited on the surface of the aluminum alloy member is 0.001 g or more and 1 g or less per square meter, and the size, distribution, and amount of the protruding silicon crystals are almost unchanged even when the observation place is changed. There was no change.
Subsequently, in the same manner as in Example 1, an aluminum-resin test piece (aluminum-resin composite) for a shear strength measurement test was prepared using a resin, and a shear strength measurement test of the aluminum-resin test piece was performed. Implemented and evaluated.
The results are shown in Table 2.

Claims (9)

  An Al—Si-based aluminum alloy member having a plurality of concave portions each having an average opening width of 0.1 μm or more and 30 μm or less having a plurality of convex portions made of a eutectic silicon crystal on an inner surface, wherein the eutectic is a part An aluminum alloy member excellent in resin bondability, wherein a convex portion made of silicon crystal has a sphere equivalent particle diameter of 0.1 μm or more and 10 μm or less.   2. The aluminum alloy member according to claim 1, wherein when silicon element and aluminum element analysis are performed by mapping analysis of fluorescent X-rays, a region where only silicon existing in the eutectic portion is distributed is 5% or more and 80% or less. An aluminum alloy member excellent in resin bondability characterized by 3. The resin bonding property according to claim 1 or 2, wherein the convex portion made of the eutectic silicon crystal protrudes and precipitates on the inner surface of the concave portion in an amount of 0.001 g / m ² or more and 1 g / m ² or less. Aluminum alloy member.   4. The aluminum alloy shaped body according to claim 1, wherein a plurality of concave portions having an average opening width of 0.1 μm or more and 30 μm or less that do not have a convex portion of the eutectic silicon crystal are simultaneously present. An aluminum alloy member excellent in resin bondability characterized by the above.   It is an aluminum alloy which comprises the aluminum alloy member excellent in resin bondability of any one of Claims 1-4, Comprising: Si: 5.0 mass% or more, 18 mass% or less, Fe: 1.3 mass %, Cu: 5.0% by mass or less, Mg: 1.5% by mass or less, Ni: 1.5% or less, and the balance having a component composition consisting of Al and inevitable impurities alloy.   A method for producing an aluminum alloy member by casting a molten aluminum alloy having the component composition according to claim 5, wherein the cooling rate is in a region where the eutectic Si solidification temperature during casting is 755 ° C. or higher and 780 ° C. or lower. The manufacturing method of the aluminum alloy member excellent in resin bondability characterized by being 0.1 degree-C / second or more and 100 degree-C / second or less.   The method for producing an aluminum alloy member excellent in resin bondability according to claim 6, wherein after the cast cast object is adjusted to a predetermined shape and size, the surface is subjected to chemical etching treatment with an acid-based liquid.   The aluminum alloy member excellent in resin bondability according to claim 7, wherein irregularities of 1 to 100 µm are preliminarily imparted with an Rz value as a surface roughness prior to a process of performing chemical etching treatment with an acid-based liquid on the surface. Manufacturing method.   9. The resin bonding property according to claim 8, wherein the surface having a roughness of 1 to 100 [mu] m as the surface roughness is formed by blasting using fine particles of either alumina fine particles or metal fine particles, or both. A method for producing an aluminum alloy member.