WO2014170946A1

WO2014170946A1 - PRODUCTION METHOD FOR Al-Mg-Si-BASED ALUMINIUM ALLOY MEMBER FOR RESIN BONDING, AND Al-Mg-Si-BASED ALUMINIUM ALLOY MEMBER FOR RESIN BONDING OBTAINED USING SAID METHOD

Info

Publication number: WO2014170946A1
Application number: PCT/JP2013/061217
Authority: WO
Inventors: 正憲遠藤; 誠己飯野; みゆき吉田; 昌司磯部
Original assignee: 日本軽金属株式会社
Priority date: 2013-04-15
Filing date: 2013-04-15
Publication date: 2014-10-23

Abstract

Provided is a production method for an Al-Mg-Si-based aluminium alloy member for resin bonding, said method being suitable for producing, by bonding a resin moulded body to a surface of the Al-Mg-Si-based aluminium alloy member, an aluminium/resin composite which maintains excellent adhesive properties and airtightness between the aluminium and resin therein, which exhibits excellent durability with respect to the original aluminium alloy therein, excellent extrusion processing properties, and excellent mechanical properties, and which is suitable for a variety of uses wherein exposure to severe environments may occur. In this production method for an Al-Mg-Si-based aluminium alloy member for resin bonding, an Al-Mg-Si-based aluminium alloy substrate having an Mn content of less than 0.05 mass% is: subjected to solution treatment under conditions in which the temperature is 500-600˚C for a period of 1-20 hours; subsequently subjected to ageing treatment under conditions in which the temperature is 150-300˚C for a period of 1-20 hours; and subjected thereafter to etching using an aqueous solution of sulphuric acid and/or nitric acid to impart a surface-treated layer upon a surface of the aluminium alloy substrate.

Description

Method for producing Al-Mg-Si based aluminum alloy member for resin bonding and Al-Mg-Si based aluminum alloy member for resin bonding obtained by this method

The present invention relates to a method of manufacturing an aluminum alloy member for resin bonding made of an Al-Mg-Si-based aluminum alloy and an aluminum alloy member obtained by this method, and is not particularly limited, but in a harsh environment. Manufacturing method of resin-bonded Al-Mg-Si based aluminum alloy member suitable for many applications including automotive parts, household appliance parts, industrial equipment parts, etc., which are exposed, and obtained by this method The present invention relates to an Al-Mg-Si aluminum alloy member for resin bonding.

Aluminum alloys are lightweight and have excellent workability, as well as excellent mechanical properties, and excellent thermal conductivity, electrical conductivity, corrosion resistance, etc., so they are used for building materials, home appliance materials, vehicles and ships. It is used for a large number of applications such as materials, and especially for Al-Mg-Si-based aluminum alloys, it is excellent in thermal conductivity and conductivity, so that it can be cooled, such as a heat sink using high thermal conductivity. It is widely used for parts and electrical and electronic parts such as busbars and electric wires that use high conductivity. Especially in recent years, in the case of the former use, it is necessary to insulate part of it. In the case of the latter application, it is required to partially insulate a resin that is partially insulative. Sought to join To have.

And when it is used for such applications and it is required to partially join the resin (partial resinization), means such as screws and adhesives have been used so far. In addition to the increase in the number of steps in the manufacturing process, the partial resinization by means also leads to an increase in weight, and the development of aluminum-resin bonding technology that does not require these means such as screws and adhesives. It was sought after.

Therefore, the present inventors previously provided a fine uneven shape on the surface of the aluminum alloy member by hydrochloric acid etching treatment, and using this uneven shape, the resin molded body was joined to the surface of the aluminum alloy member during resin molding. As a result, an aluminum / resin injection molded product (aluminum-resin) that retains excellent adhesion and airtightness even in harsh environments such as temperature, humidity, and dust, and also exhibits excellent durability and heat resistance. A method for producing a composite was provided (Patent Document 1). However, when this aluminum-resin bonding technology is applied to an Al-Mg-Si aluminum alloy as it is, the Al-Mg-Si aluminum alloy contains a relatively large amount of Si, and this Si is a chemical other than hydrofluoric acid. Si hardly dissolves on the surface of the aluminum alloy member during the etching process of Al-Mg-Si based aluminum alloy and deposits on the surface of the aluminum alloy member. As a result, there is a problem of adversely affecting the bondability between the aluminum and the resin.

By the way, this Al-Mg-Si aluminum alloy is not only excellent in corrosion resistance and extrusion processability, but also has high mechanical properties obtained by heat treatment, and also has good anodizing properties, so it is constant. By applying heat treatment (solution treatment) and aging treatment, fine Mg ₂ Si intermetallic compounds are deposited, making them suitable for various applications such as building materials, housings for home appliances, and parts for vehicles and ships. (Alternatively, it is known that the Al-Mg-Si-based aluminum alloy sheet is hardened at 500 ° C or higher, and tempered at 200 to 400 ° C.) And, by subjecting the Mg ₂ Si intermetallic compound precipitated in the tempering treatment to an etching treatment to dissolve and remove with an acid aqueous solution, and providing a photosensitive film (photosensitive layer) on the roughened surface formed by the etching treatment, Aluminum alloy It is known to produce an aluminum support for a lithographic printing plate support that has excellent adhesion between a metal plate and a photosensitive film (Patent Document 3), and is further subjected to homogenization treatment and hot rolling to obtain a surface. An Al-Mg-Si-based aluminum alloy plate with an exposed Mg ₂ Si crystallized material is formed, and this aluminum alloy plate is anodized or etched to desorb the Mg ₂ Si crystallized product. For resin-coated can barrels where the surface is coated with a polyester, polyolefin, or polyamide resin film with good adhesion using the anchor effect of recesses or holes formed by the separation of Mg ₂ Si crystals An aluminum alloy plate is also known (Patent Document 4).

However, even in these Patent Documents 3 to 4, the Mg ₂ Si crystallized product produced by the heat treatment has various forms such as an acicular phase, a rod-like intermediate phase β ′, and a plate-like stable phase β depending on the conditions of the heat treatment. Therefore, the uneven shape formed after etching changes depending on the heat treatment conditions and is not stable. For example, automobiles such as heat sink members for electric and electronic parts, aluminum base heat dissipation bases for LED lighting, water jacket members for liquid cooling units, etc. Adhesion strength and air tightness at the metal-resin interface when exposed to harsh environments such as industrial parts, home appliance parts, industrial equipment parts, etc. The development of metal-resin composites with good properties has been demanded.

WO2009 / 151, 099A1 publication Japanese Patent Laid-Open No. 10-088,300 JP 59-220,395 JP 2000-309,839 A

And the present inventors do not impair the characteristics of Al-Mg-Si-based aluminum alloys, for example, automotive parts, household appliance parts, industrial equipment parts, etc. that are exposed to harsh environments. As a result of various studies on a method for producing an Al-Mg-Si-based aluminum alloy member for resin bonding suitable for use in many applications, it is surprising that Mn is effective for improving mechanical strength. When the content is 0.05% by mass or more, the shear strength of the manufactured aluminum-resin composite at the Al-Mg-Si-based aluminum alloy-resin molded body interface is significantly reduced. It has been found that the adhesion strength and airtightness of the resin deteriorate.

Therefore, the present inventors further improved the shear strength at the Al-Mg-Si aluminum alloy-resin molded body interface, and improved the adhesion strength and air tightness at this interface, under severe conditions. As a result of intensive investigations to develop resin-bonded Al-Mg-Si based aluminum alloy members suitable for many applications that are exposed to exposure to Al-Mg-Si with an Mn content of less than 0.05 mass A surface treatment layer with an extremely fine uneven shape of crosshead type or expanded metal type is formed on the surface by solution treatment of the aluminum alloy base material under the prescribed conditions and aging treatment under the prescribed conditions Thus, the present inventors have found that the shear strength at the interface with the resin molded body provided on the surface treatment layer can be improved, thereby completing the present invention.

Therefore, an object of the present invention is to maintain excellent adhesion and airtightness between aluminum and resin by bonding a resin molded body to the surface of an aluminum alloy member made of an Al-Mg-Si based aluminum alloy. -Mg-Si-based aluminum alloys with excellent durability, extrudability, and mechanical properties, and aluminum-resin composites suitable for various applications that are exposed to harsh environments Another object of the present invention is to provide a method for producing an Al—Mg—Si based aluminum alloy member for resin bonding suitable for the purpose.

Another object of the present invention is an aluminum which is manufactured by the above-described method and has excellent adhesion and airtightness, as well as excellent durability, extrudability and mechanical properties, and is suitable for various applications. -To provide an Al-Mg-Si-based aluminum alloy member for resin bonding suitable for manufacturing a resin composite.

That is, in the present invention, an aluminum alloy base material made of an Al—Mg—Si based aluminum alloy having a Mn content of less than 0.05% by mass is subjected to a solution treatment under conditions of 500 to 600 ° C. and 1 to 20 hours. Then, after cooling, an aging treatment is performed under conditions of 150 to 300 ° C. and 1 to 20 hours, and then an etching treatment with an acidic etchant composed of sulfuric acid and / or an aqueous solution of nitric acid is performed, and the surface of the aluminum alloy substrate is applied. A method for producing an Al—Mg—Si based aluminum alloy member for resin bonding, characterized by providing a surface treatment layer.

In addition, the present invention provides an Al—Mg—Si based aluminum alloy for resin bonding, which is obtained by the above method and has a surface treatment layer having an extremely fine concavo-convex structure of a crosshead type or an expanded metal type on the surface. It is a member. Here, in the present invention, the “cross-head type ultra-fine concavo-convex structure” means a concavo-convex structure in which the tip portion of a part or all of the many convex portions forming the fine concavo-convex structure has a substantially cross shape. In addition, in the present invention, the “expanded metal type extremely fine concavo-convex structure” refers to a case in which the fine concavo-convex structure has an expanded metal-like structure in which metal fibers are entangled in a network.

In the present invention, regarding the Al—Mg—Si based aluminum alloy constituting the aluminum alloy base material, Mg is 0.2% by mass or more and 4.0% by mass or less, preferably 0.3% by mass or more and 1.5% by mass. In addition, the Si content is 0.1% by mass or more and 2.5% by mass or less, preferably 0.3% by mass or more and 1.5% by mass or less. , It should be as little as possible, less than 0.05% by weight, preferably less than 0.04% by weight. When the Mg content is less than 0.2% by mass, there is a problem that Mg ₂ Si does not sufficiently precipitate, and conversely, when it exceeds 4.0% by mass, there arises a problem that castability deteriorates. Further, if the Si content is less than 0.1% by mass, there is a problem that Mg ₂ Si does not sufficiently precipitate. Conversely, if the Si content exceeds 2.5% by mass, Si melts during solution treatment, which causes blistering. As a result, there is a danger that the solution treatment at a high temperature becomes difficult. Further, when the Mn content is 0.05% by mass or more, this Mn is preferentially combined with Si to form coarse precipitates (Al—Mn—Si alloy), and as a result, Al—Mg. The shear strength at the interface between the Si-aluminum alloy and the resin molded body is remarkably reduced, and the adhesion strength and airtightness at this interface are also reduced.

In the present invention, first, an aluminum alloy substrate made of the Al-Mg-Si-based aluminum alloy as described above is subjected to a solution treatment under the conditions of 500 ° C. or higher and 600 ° C. or lower and 1 hour or longer and 20 hours or shorter. Mg and Si are dissolved in Al to form Mg ₂ Si intermetallic compounds. If the temperature condition at this time is lower than 500 ° C., Mg and Si in the alloy cannot be dissolved in Al, whereas if it is higher than 600 ° C., Al itself melts.

Further, in the present invention, after the above solution treatment is completed and once cooled, an aging treatment is performed again under the conditions of 150 ° C. or more and 300 ° C. or less and 1 hour or more and 20 hours or less, and the solution treatment is generated. Mg ₂ Si intermetallic compound in a desired shape, that is, a shape of Mg ₂ Si intermetallic compound suitable for obtaining a surface treatment layer of a desired cross-head type or expanded metal type fine concavo-convex structure by subsequent etching treatment. To metamorphose. If the temperature condition at this time is lower than 150 ° C., Mg ₂ Si having a desired shape does not precipitate. On the other hand, if it is higher than 300 ° C., Mg ₂ Si is excessively enlarged and the dispersibility is lowered.

And in this aging treatment, when the above temperature condition is less than 200 ° C., it is transformed into an Mg ₂ Si intermetallic compound suitable for obtaining a surface treatment layer of a cross-head type ultra fine concavo-convex structure by etching treatment, In addition, when the temperature is 200 ° C. or higher, it tends to be transformed into an Mg ₂ Si intermetallic compound suitable for obtaining a surface treatment layer having an expanded metal type fine concavo-convex structure by etching treatment, and an Al—Mg—Si based aluminum alloy -From the viewpoint of improving the shear strength at the interface of the resin molded body, the temperature condition is preferably 200 ° C or higher and 300 ° C or lower.

The aluminum alloy substrate thus prepared is then subjected to an etching treatment using an acidic etching solution composed of an aqueous solution of sulfuric acid and / or nitric acid, and Mg ₂ Si present on the surface of the aluminum alloy substrate. An intermetallic compound is dissolved, and a surface treatment layer of a desired crosshead type or expanded metal type extremely fine uneven structure is formed on the surface of the aluminum alloy substrate.

Here, the sulfuric acid and / or nitric acid aqueous solution used as the acidic etching solution has an acid concentration of 1% by weight to 60% by weight, preferably 5% by weight to 50% by weight in the case of sulfuric acid aqueous solution. In the case of an aqueous nitric acid solution, the acid concentration should be 5 to 60% by weight, preferably 10 to 50% by weight. It is preferable to add a nitric acid aqueous solution having an acid concentration of 5% by weight to 30% by weight to a sulfuric acid aqueous solution having an acid concentration of 5% by weight to 50% by weight. If the acid concentration of the acidic etching solution is lower than the above range, the reaction may not proceed sufficiently and the dissolution amount may be insufficient. On the other hand, if the acid concentration is higher than the above range, the reaction rate becomes too fast and it is difficult to control the dissolution amount. become. For the above acidic etching solution, for the purpose of controlling the amount of dissolution, chromic acid, phosphoric acid, acetic acid, oxalic acid, ascorbic acid, benzoic acid, butyric acid, citric acid, formic acid, lactic acid, Acids other than sulfuric acid and nitric acid such as isobutyric acid, malic acid, propionic acid, and tartaric acid may be added.

In addition, with respect to the processing conditions of the etching process using the above acidic etching solution, the processing temperature is usually 20 ° C. or higher and 90 ° C. or lower, preferably 30 ° C. or higher and 80 ° C. or lower, and the processing time is usually 1 minute or longer and 20 minutes or shorter. Hereinafter, it is preferably 5 minutes or more and 15 minutes or less. If the processing temperature under the processing conditions of this etching process is lower than 20 ° C., the reaction may not proceed sufficiently and the amount of dissolution may be insufficient. On the other hand, if the processing temperature is higher than 90 ° C., the reaction rate becomes too high and Control becomes difficult. Similarly, if the processing time of the etching process is shorter than 1 minute, the reaction may not proceed sufficiently and the amount of dissolution may be insufficient. On the other hand, if the processing time is longer than 20 minutes, the production efficiency decreases and the mass productivity deteriorates. .

In the present invention, when contaminants or the like remain on the surface of the aluminum alloy substrate obtained as described above, this aluminum is used for the purpose of degreasing, surface adjustment, and removal of surface deposits and contaminants. Prior to the etching treatment of the alloy substrate, it is preferable to perform a pretreatment of immersing in an aqueous alkali solution after immersing in an aqueous acid solution. Examples of the acid aqueous solution used for this purpose include those prepared with commercially available acidic 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 these acids. It is preferable to use a 1 to 50% by weight aqueous solution of an acid such as that prepared by using an acid reagent such as a mixed acid obtained by mixing the above, and examples of the alkaline aqueous solution include a commercially available alkaline degreasing agent. It is preferable to use a 1 to 50% by weight aqueous solution of an alkali such as one prepared, one prepared with an alkali reagent such as caustic soda, or one prepared by mixing these materials. In both cases, the alkaline aqueous solution is preferably about 0.5 to 10 minutes.

In the aluminum alloy member obtained by the present invention, the trace of the Mg ₂ Si intermetallic compound dissolved by the above etching treatment becomes a concave portion, and the surface of the aluminum alloy member has a fine crosshead type or expanded metal type. A surface treatment layer having a concavo-convex structure is formed, and this surface treatment layer exhibits excellent aluminum resin bondability with the resin molded body.

And in the aluminum alloy member of the present invention, it is estimated that the surface treatment layer of the cross head type or expanded metal type ultra fine uneven structure observed on the surface of the aluminum alloy member is formed by the following mechanism. Is done.
That is, in the Al—Mg—Si based aluminum alloy containing Mg and Si, the crystal structure of the produced Mg ₂ Si intermetallic compound depends on the temperature conditions during solution treatment and aging treatment, as shown in FIG. The transformation is as follows: needle shape (a) → rod shape (b) → plate shape (c) → random cubic shape (d). The crystal structure of this random cubic shape (d) is formed by overlapping the plate-like (c) crystals of Mg ₂ Si intermetallic compound, but the crosshead type ultra-fine uneven structure is such a random cube precipitating Mg ₂ Si intermetallic compound having a crystal structure of the shape (d), expressing the Mg ₂ Si intermetallic compound when dissolved in an aqueous solution of sulfuric acid and / or nitric acid. Here, in order to precipitate the Mg ₂ Si intermetallic compound having a crystal structure of a random cubic shape (d), it is better to sufficiently quench and increase the temperature during the aging treatment, On the other hand, in order to prevent precipitation, it is preferable to make quenching insufficient or to lower the temperature during the aging treatment. In addition, in the Al-Mg-Si-based aluminum alloy, if the Mn content is large, Mn forms an Al-Mn-Si-based aluminum alloy and the formation of Mg ₂ Si intermetallic compound is hindered. There is a high possibility of insufficient insertion. In this case, even if the temperature during the aging treatment is increased, the transformation from needle-like (a) → rod-like (b) → plate-like (c) does not occur, and as a result, the bondability between the aluminum and the resin is positive. It is not possible to develop a contributing crosshead-type extremely fine uneven structure. In addition, the surface treatment layer of the expanded metal type ultra-fine concavo-convex structure is obtained when the above plate-like (c) Mg ₂ Si intermetallic compound crystals are dissolved without being overlapped and dissolved by etching treatment. The higher the temperature during the aging treatment, the more the Mg ₂ Si intermetallic compound precipitates. Therefore, the higher the temperature during the aging treatment, the larger the expanded metal type electrode after the etching treatment. It is considered that a fine uneven structure is easily developed.

Further, in the aluminum alloy member obtained by the present invention, the abundance ratio of the crosshead type uneven structure observed in the surface treatment layer of the aluminum alloy member [ie, scanning electron microscope (Hitachi FE-SEM, S-4500 type) ) Is used to observe the SEM image (FIG. 2 in the case of Example 1), and the result is obtained by image processing as shown in FIG. The area ratio is calculated as the existence ratio of the cross-head concavo-convex structure] is usually 20% to 90%, preferably 35% to 80%. If the ratio of the concave portion on the surface of the aluminum alloy member is lower than 20%, the amount of resin entering the concave portion may be insufficient, which may cause a problem of adversely affecting the resin bonding property. Then, the aluminum part for supporting the resin that has entered the recess is extremely reduced, and as a result, there is a possibility that a problem of adversely affecting the resin bondability may occur. Moreover, about Example 2 and Example 4, the same measuring method [Namely, SEM image (FIG. 5 in the case of Example 2) using a scanning electron microscope (Hitachi FE-SEM, S-4500 type)) Then, the presence ratio of the expanded metal structure was calculated from the area ratio of the concave portion in the measurement visual field 0.1 mm square obtained by image processing as shown in FIG. Usually, when it is 10% or more, preferably 20% or more, improvement in bonding strength and airtightness can be obtained.

The aluminum alloy member obtained by the method of the present invention has a surface treatment layer of an extremely fine concavo-convex structure of a crosshead type or an expanded metal type formed on the surface thereof. The resin molded body is formed on the necessary part of the aluminum alloy member by injection molding of a thermoplastic resin using a so-called aluminum alloy member that is injected into a mold and injects a predetermined thermoplastic resin into the mold and solidifies. When an aluminum-resin composite is manufactured by bonding, an excellent aluminum resin bonding property is exhibited.

Here, as the thermoplastic resin used in producing the aluminum-resin composite using the aluminum alloy member of the present invention, various thermoplastic resins can be used alone, but the aluminum alloy of the present invention is used. Considering the physical properties required for the aluminum-resin composite produced using the members, applications, usage environment, etc., the thermoplastic resin is preferably a polypropylene resin, a polyethylene resin, an acrylonitrile-butadiene-styrene copolymer, for example. (ABS), polycarbonate resin (PC), polyamide resin (PA), polyarylene sulfide resin such as polyphenylene sulfide (PPS), polyacetal resin, liquid crystalline resin, polyester such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) Resin, polyoxymethylene resin, polyimide resin, Examples include syndiotactic polystyrene resin and a mixture of two or more of these thermoplastic resins, and adhesion between an aluminum shaped body and a resin molded body, mechanical strength, heat resistance, dimensional stability (resistance resistance) In order to further improve performance such as deformation, warpage, and electrical properties, it is preferable to add fillers such as fibrous, granular, and plate-like materials and various elastomer components to these thermoplastic resins. It is good.

Fillers added to thermoplastic resins include inorganic fiber fillers such as glass fibers, carbon fibers, metal fibers, asbestos fibers and boron fibers, and high melting point organic fibers such as polyamides, fluororesins and acrylic resins. And powder fillers such as silica powder, glass beads, glass powder, inorganic powders such as calcium carbonate, and plate fillers such as glass flakes, silicates such as talc and mica, etc. In addition, it is added in an amount of 250 parts by weight or less, preferably 20 parts by weight or more and 220 parts by weight or less, 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, there is a problem that the fluidity is lowered and it is difficult to enter the concave portion of the aluminum shaped body, and good adhesion strength cannot be obtained or the mechanical properties are deteriorated. .

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 to 25 parts by weight 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.

Further, 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. The temperature ranges 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). Good it is. 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.

Note that the aluminum-resin composite manufacturing method performed using the aluminum alloy member of the present invention is not limited to the above-described thermoplastic resin injection integral molding method, and a thermocompression bonding method may be employed. That is, first, an aluminum alloy member is heated to a temperature of about 90 to 300 ° C. in accordance with the melting temperature of the thermoplastic resin to be used, and a thermoplastic resin molding is pressed against the surface of the aluminum alloy member under pressure. A desired aluminum-resin composite is produced by melting a part of the surface of the molded body to enter the concave portion of the surface of the aluminum alloy member, and further cooling under pressure.

According to the present invention, a resin molded body is bonded to the surface of an aluminum alloy member made of an Al-Mg-Si-based aluminum alloy, thereby maintaining excellent adhesion and airtightness between the aluminum and the resin, and Al-Mg -Manufacturing Al-Mg-Si-based aluminum alloy members for resin bonding suitable for manufacturing aluminum-resin composites having the inherent durability, extrudability, and mechanical properties of Si-based aluminum alloys Can do. Moreover, since the produced aluminum-resin composite has excellent adhesion and airtightness, it can be used in harsh environments such as automobile parts, home appliance parts, industrial equipment parts and the like. Suitable for various applications where there is an opportunity to be exposed.

FIG. 1 is an explanatory diagram for explaining a mechanism (estimation) for forming a surface treatment layer having an extremely fine uneven structure of a crosshead type or an expanded metal type in the method of the present invention.

FIG. 2 is a photograph showing an SEM image obtained when the surface of the aluminum alloy member obtained in Example 1 of the present invention was observed with a scanning electron microscope.

FIG. 3 is a photograph showing a processed image after the image processing of the SEM image of FIG.

FIG. 4 is a photograph showing an SEM image obtained when the resin-side surface shape of the aluminum-resin composite obtained in Example 1 after complete aluminum removal was observed with a scanning electron microscope.

FIG. 5 is a photograph showing an SEM image of the same aluminum alloy member surface as in FIG. 2 obtained in Example 2 of the present invention.

FIG. 6 is a photograph showing an SEM image in which a part of FIG. 5 is enlarged.

FIG. 7 is a photograph similar to FIG. 3 showing the processed image after the image processing of the SEM image of FIG.

FIG. 8 is a photograph showing a processed image after image processing in which only the expanded metal structure portion in the SEM image of FIG. 5 is extracted by image processing.

FIG. 9 is a photograph showing an SEM image of the resin-side surface shape similar to that of FIG. 4 obtained in Example 2.

FIG. 10 is a photograph showing an SEM image of the same aluminum alloy member surface as in FIG. 2 obtained in Example 3 of the present invention.

FIG. 11 is a photograph similar to FIG. 3 showing a processed image after image processing of the SEM image of FIG.

FIG. 12 is a photograph showing an SEM image of the resin-side surface shape similar to FIG. 4 obtained in Example 3.

FIG. 13 is a photograph showing an SEM image of the same aluminum alloy member surface as in FIG. 2 obtained in Example 4 of the present invention.

FIG. 14 is a photograph showing an SEM image in which a part of FIG. 13 is enlarged.

FIG. 15 is a photograph similar to FIG. 3 showing the processed image after the image processing of the SEM image of FIG.

FIG. 16 is a photograph similar to FIG. 8 showing a processed image after image processing in which only the expanded metal structure in the SEM image of FIG. 13 is extracted by image processing.

FIG. 17 is a photograph showing an SEM image of the resin-side surface shape similar to FIG. 4 obtained in Example 4.

FIG. 18 is a photograph showing an SEM image of the same aluminum alloy member surface as in FIG. 2 obtained in Example 5 of the present invention.

FIG. 19 is a photograph similar to FIG. 3 showing the processed image after the image processing of the SEM image of FIG.

20 is a photograph showing an SEM image of the resin-side surface shape similar to that of FIG. 4 obtained in Example 5. FIG.

FIG. 21 is a photograph showing an SEM image of the same aluminum alloy member surface as in FIG. 2 obtained in Example 6 of the present invention.

22 is a photograph similar to FIG. 3 showing a processed image after the image processing of the SEM image of FIG.

FIG. 23 is a photograph showing an SEM image of the resin-side surface shape similar to FIG. 4 obtained in Example 6.

FIG. 24 is a photograph showing an SEM image of the same aluminum alloy member surface as in FIG. 2 obtained in Comparative Example 1 of the present invention.

25 is a photograph similar to FIG. 3 showing a processed image after the image processing of the SEM image of FIG.

FIG. 26 is a photograph showing an SEM image of the resin-side surface shape similar to that of FIG. 4 obtained in Comparative Example 1.

FIG. 27 is a photograph showing an SEM image of the same aluminum alloy member surface as in FIG. 2 obtained in Comparative Example 2 of the present invention.

FIG. 28 is a photograph similar to FIG. 3 showing the processed image after the image processing of the SEM image of FIG.

29 is a photograph showing an SEM image of the resin-side surface shape similar to that of FIG. 4 obtained in Comparative Example 2. FIG.

FIG. 30 is an explanatory view showing an aluminum resin test piece (aluminum-resin composite) for a shear fracture load measurement test produced using the aluminum alloy member obtained in each example and each comparative example.

FIG. 31 is an explanatory diagram for explaining a state in which an aluminum resin test piece is fixed to a test piece fixing jig of a shear fracture load measurement tester and a shear fracture load is measured.

Hereinafter, embodiments of the present invention will be described in detail based on examples and comparative examples of the present invention.

[Example 1]
1. Preparation of aluminum alloy base material After casting an Al-Mg-Si based aluminum alloy containing Si: 0.21% by mass, Mg: 0.42% by mass, and Mn: 0.01% by mass in a casting furnace, extrusion processing Then, a flat bar (aluminum alloy base material) having a size of 2050 mm × 800 mm × 3 mm was formed.

2. Preparation of aluminum alloy member The flat bar obtained above was subjected to solution treatment under conditions of 520 ° C. and 1 hour, then allowed to naturally cool to room temperature in an air atmosphere, and then at 190 ° C. and 3 hours. An aging treatment was performed. Further, from the obtained flat bar after the solution treatment and aging treatment (after heat treatment), a post-heat treatment aluminum alloy substrate having a size of 40 mm × 40 mm × 3 mm was cut out.

The heat-treated aluminum alloy base material obtained above was immersed in 30 wt% nitric acid aqueous solution at room temperature for 1 minute, then thoroughly washed with ion-exchanged water, and then immersed in 5 wt% sodium hydroxide aqueous solution at 50 ° C for 1 minute. Then, it was washed with water and further pretreated by immersing it in a 30 wt% nitric acid aqueous solution at room temperature for 1 minute and then washing with water.

Next, the pre-treated aluminum alloy base material after the heat treatment was subjected to an etching treatment in which it was immersed in a 10 wt% -sulfuric acid aqueous solution at 30 ° C. for 10 minutes and then washed with water. The aluminum alloy member of Example 1 was produced by drying for a minute.

The surface of the aluminum alloy member of Example 1 obtained in this way was observed with a scanning electron microscope (Hitachi FE-SEM, model S-4500), and thereafter image processing was performed to obtain a length of 0. The existence ratio (area ratio) of the concave portion having a size of 1 to 10.0 μm was calculated. In addition, using an X-ray diffraction apparatus (Rigaku RAD-rR), the integrated diffraction strength value of the intermetallic compound existing on the surface of the obtained aluminum alloy base material was measured, and the result showed that The ratio of Mg ₂ Si intermetallic compound was determined. FIG. 2 shows the SEM image of the surface of the aluminum alloy member obtained at this time, FIG. 3 shows the processed image after the image processing, and Table 1 shows the result.

3. Preparation of aluminum-resin composite 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 polyphenylene containing a filler as a thermoplastic resin. Using sulfide resin (PPS manufactured by Polyplastics Co., Ltd., grade name 1140A6), injection time (including pressure holding time) 5 seconds, injection speed 60 mm / second, pressure holding pressure 90 MPa, molding temperature 310 ° C., mold temperature 180 ° C. As shown in FIG. 30, the surface of the aluminum alloy member 1 having a size of 40 mm × 40 mm × 3 mm has a size of 40 mm long side × 10 mm short side × 5 mm height. An aluminum-resin composite of Example 1 was prepared in which the resin molded body 2 was integrally bonded with an area of 40 mm × 10 mm × 5 mm. Two aluminum-resin composites of Example 1 were prepared for the resin side surface observation and for the shear fracture load measurement test.

4). Observation of the resin-side surface of the aluminum-resin composite The aluminum-resin composite obtained in Example 1 was immersed in a 10 wt% -sodium hydroxide aqueous solution at 80 ° C. for 10 hours to completely cover the aluminum side of the aluminum-resin composite. The surface of the obtained specimen is observed with a scanning electron microscope (Hitachi FE-SEM, S-4500 type), and an aluminum-resin composite is obtained. The shape of the surface of the resin molded body side at the aluminum-resin bonding interface was examined, and the existence ratio of the concavo-convex structure of the crosshead type or the expanded metal type was examined. The SEM image of the resin molded body surface obtained at this time is shown in FIG. 4 and the results are shown in Table 1.

5. Next, using a shear strength measurement tester (manufactured by Shimadzu Corporation: 100 kN autograph), as shown in FIG. An aluminum resin test piece is fixed with a bolt (not shown), a pressing jig 4 is applied on the resin molded body 2 at a position 0.1 mm away from the joint, and a shear load is applied to the resin molded body 2 by the pressing jig 4. The peeled state (shear strength) of the joint between the aluminum member test piece 1 and the resin molded body 2 was examined. As for the peeling form at this time, the case where the resin of the resin molded body 2 is “cohesive failure” remaining at a ratio of 70% or more of the bonding area on the aluminum member test piece 1 side is the best (（). The case of “cohesive failure” that remains even partially on the aluminum member test piece 1 side is judged as good (◯), and the case where the resin does not remain on the aluminum member test piece 1 side and peeling occurs at the joining interface is defective ( X). The result was the best (◎).
The results are shown in Table 1.

[Examples 2 to 5 and Comparative Examples 1 and 2]
After casting an Al—Mg—Si based aluminum alloy having the composition shown in Table 1 for Mg, Si, and Mn in a casting furnace, a flat bar (aluminum alloy substrate) was formed in the same manner as in Example 1, and then The aluminum alloy members of Examples 2 to 6 and Comparative Examples 1 and 2 were prepared in the same manner as in Example 1 except that solution treatment, aging treatment, and etching treatment with an aqueous sulfuric acid solution were performed under the conditions shown in Table 1. Prepared.

Example 6
The post-heat treatment aluminum alloy base material obtained in the same manner as in Example 1 is subjected to the same pretreatment as in Example 1, and then immersed in a 10 wt% nitric acid aqueous solution at 30 ° C. for 10 minutes and then washed with water. And then washed with water and dried with hot air at 80 ° C. for 5 minutes to produce an aluminum alloy member.

For the aluminum alloy members of Examples 2 to 6 and Comparative Examples 1 and 2 prepared in this manner, the presence ratio of the concave portions and the concavo-convex structure of the crosshead type or the expanded metal type are the same as in Example 1 above. And the peeling state (shear strength) of the joint between the aluminum member test piece 1 and the resin molded body 2 was examined and evaluated.
The results are shown in Table 1.

Further, FIG. 5 shows an SEM image of the surface of the aluminum alloy member obtained in Example 2, FIG. 6 shows an enlarged image of the SEM image, FIG. 7 shows a processed image after the image processing, and FIG. FIG. 8 shows a processed image obtained by extracting only the expanded metal structure portion in FIG. 8, and FIG. 9 shows an SEM image of the surface of the resin molded body.
FIG. 10 shows the SEM image of the surface of the aluminum alloy member obtained in Example 3, FIG. 11 shows the processed image after the image processing, and FIG. 12 shows the SEM image of the surface of the resin molded body.

FIG. 13 shows an SEM image of the surface of the aluminum alloy member obtained in Example 4, FIG. 14 shows an enlarged image of the SEM image, FIG. 15 shows a processed image after the image processing, and an expanded view in the SEM image of FIG. FIG. 16 shows a processed image obtained by extracting only the metal structure portion by image processing, and FIG. 17 shows an SEM image of the surface of the resin molded body.
FIG. 18 shows the SEM image of the surface of the aluminum alloy member obtained in Example 5, FIG. 19 shows the processed image after the image processing, and FIG. 20 shows the SEM image of the surface of the resin molded body.

FIG. 21 shows an SEM image of the surface of the aluminum alloy member obtained in Example 6, FIG. 22 shows a processed image after the image processing, and FIG. 23 shows an SEM image of the surface of the resin molded body.

24 shows the SEM image of the surface of the aluminum alloy member obtained in Comparative Example 1, FIG. 25 shows the processed image after the image processing, and FIG. 26 shows the SEM image of the surface of the resin molded body.
Moreover, the SEM image of the aluminum alloy member surface obtained in Comparative Example 2 is shown in FIG. 27, the processed image after the image processing is shown in FIG. 28, and the SEM image of the resin molded body surface is shown in FIG.

Claims

An aluminum alloy base material made of an Al—Mg—Si based aluminum alloy having a Mn content of less than 0.05% by mass is subjected to a solution treatment under conditions of 500 to 600 ° C. and 1 to 20 hours, and then cooled to 150%. After performing an aging treatment under conditions of ˜300 ° C. and 1˜20 hours, an etching treatment with an acidic etchant composed of an aqueous solution of sulfuric acid and / or nitric acid is performed to provide a surface treatment layer on the surface of the aluminum alloy substrate. A method for producing an Al—Mg—Si based aluminum alloy member for resin bonding, characterized in that:
The method for producing an Al-Mg-Si-based aluminum alloy member for resin bonding according to claim 1, wherein the aging treatment temperature is 200 to 300 ° C.
The Al-Mg-Si-based aluminum alloy contains Mg in a range of 0.2 to 4.0% by mass and Si in a range of 0.1 to 2.5% by mass. The manufacturing method of the Al-Mg-Si type aluminum alloy member for resin joining as described.
The production of an Al-Mg-Si based aluminum alloy member for resin bonding according to any one of claims 1 to 3, wherein after the aging treatment, prior to the etching treatment, a pretreatment of immersing in an aqueous alkaline solution and then in an alkaline aqueous solution is performed. Method.
The method for producing an Al-Mg-Si aluminum alloy member for resin bonding according to any one of claims 1 to 4, wherein the processing conditions of the etching process are 20 to 90 ° C and a processing time of 1 to 20 minutes.
An Al-Mg-Si for resin bonding, which is obtained by the method according to any one of claims 1 to 5 and has a surface treatment layer having an extremely fine concavo-convex structure of a crosshead type or an expanded metal type on the surface. Aluminum alloy members.