WO2015101319A1

WO2015101319A1 - Metal-resin composite and method for producing the same

Info

Publication number: WO2015101319A1
Application number: PCT/CN2014/095816
Authority: WO
Inventors: Xiaojia He; Sihai ZENG; Wenhai Luo
Original assignee: Byd Company Limited
Priority date: 2013-12-31
Filing date: 2014-12-31
Publication date: 2015-07-09
Also published as: CN104742437B; CN104742437A

Abstract

A metal-resin composite and method for producing the same are provided. The metal-resin composite comprises: a metal substrate defining a hole formed on a surface thereof, and a thermoplastic resin composition formed on the metal substrate, wherein a part of the thermoplastic resin composition is filled in the hole, the hole comprises a lower hole part and a upper hole part communicating with the lower hole part, and a necking section is formed between the lower hole part and the upper hole part.

Description

METAL-RESIN COMPOSITE AND METHOD FOR PRODUCING THE SAME

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and benefits of Chinese Patent Application Serial No. 201310752849. X, filed with the State Intellectual Property Office of P. R. China on December 31, 2013, the entire content of which is incorporated herein by reference.

FIELD

The present disclosure relates to the field of metal-resin integrally molding, and more particularly to a method for producing a composite of a metal and a resin, and a metal-resin composite obtained by the same.

BACKGROUND

Currently, a metal substrate may be joined with a resin through the following three methods:

a. using an adhesive to join a metal substrate with a formed resin；

b. chemically etching the surface of a metal substrate to form a convex-concave microstructure, and injection molding a resin on the surface of the metal substrate to join the metal substrate with the resin； or

c. forming holes of nanometer level on the surface of a metal substrate by anodic oxidation or electro-chemical anode treatment, and injection molding a resin on the surface of the metal substrate to join the metal substrate with the resin.

However, all of the above methods have their shortcomings. For example, using an adhesive to join the metal substrate and the resin may have a poor adhesion force, poor resistance to acid or alkali, and the thickness of the adhesive may affect the size of the final product.

Then, the method for producing a metal-resin composite should be improved.

SUMMARY

Embodiments of the present disclosure seek to solve at least one of the problems existing in the prior art to at least some extent.

According to a first broad aspect of present disclosure, there is provided a metal-resin composite, comprising: a metal substrate defining a hole formed on a surface thereof, and a thermoplastic resin composition formed on the metal substrate, in which a part of the thermoplastic resin composition is filled in the hole, the hole comprises a lower hole part and a upper hole part communicating with the lower hole part, and a necking section is formed between the lower hole part and the upper hole part. According to embodiments of present disclosure, the metal-resin composite may show good adhesion force, good utility or be less pollution to the environment.

According to a second aspect of present disclosure, there is provided a method for producing a metal-resin composite, comprising steps of: laser ablating a surface of a metal substrate to form a upper hole part； laser ablating a bottom surface of the upper hole part to form a lower hole part； and injection molding a thermoplastic resin on the surface of the metal substrate to form the metal-resin composite. Using the method according to embodiments of present disclosure, a metal-resin composite may be obtained which may show good adhesion force, good utility or be less pollution to the environment. In details, in the method according to embodiments of present disclosure, a laser may be used to melt a surface of a metal to form a small melt pool containing molten metal by controlling the energy of the laser to input a certain amount of energy in a small spotty area, and further laser energy inputting may gasify the molten metal in the melt pool to form a cavity. Then lowering the focus of the laser will cause a new melt pool containing molten metal on the bottom of the cavity. When the cavity gets a proper depth, focusing the laser on the bottom of the cavity, and inputting an instantaneous large pulse to the bottom of the cavity, heating a part of molten metal in the center of the melt pool to a boiling temperature of the metal, and then the center gasified metal will expand rapidly with the molten metal in form of gas and boiling gas will wash away a part of the inner wall of the cavity to melt a part of metal in the lower part of the cavity, then a necking section is formed, and the lower part may have a special microstructure, for example folliculus pili-like microstructure. Then, a resin composition may be formed on the surface of the metal substrate, for example, the resin composition may be formed by injection molding. According to embodiments of present disclosure, the metal substrate may be placed in an injection-molding machine, and a resin may be formed by injection resin to the pre-treated surface of the metal substrate. It was found by the inventors of present disclosures that the resin composition may enter into the metal cavity having a folliculus pili-like microstructure, and tighter adhesion between the metal substrate and the resin for example thermoplastic resin composition may be achieved.

Additional aspects and advantages of embodiments of present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DARWING

The disclosure is illustrated in the accompanying drawings, in which:

Fig. 1 shows a microscope photo of a metal substrate of example 1 comprising a hole formed on a surface of the metal substrate to be contacted with a thermoplastic resin composition；

Fig. 2 shows a 3D-SEM photo of a surface of the metal substrate in example 1；

Fig. 3 shows a cross sectional view of a metal-resin composite comprising a metal substrate and a thermoplastic resin composition； and

Fig. 4 shows an illustration of a metal-resin composite according to embodiments of present disclosure.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the present disclosure. The embodiments described herein are explanatory, illustrative, and used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure.

According to a first broad aspect of present disclosure, there is provided a metal-resin composite. Referring to Fig. 4, the metal-resin according to embodiments of present disclosure comprises a metal substrate 100 and a thermoplastic resin composition 200 formed on the metal substrate100, and a hole 300 is formed on a surface of the metal substrate 100 to be contacted with the thermoplastic resin composition 200. According to embodiments of present disclosure, a part of the thermoplastic resin composition 200 is filled in the hole 300, and the hole 300 comprises a lower hole part 400 and a upper hole part 500 and a necking section 600, in which the upper hole part 500 communicate with the lower hole part 400, and the necking section 600 is formed between the lower hole part 400 and the upper hole part 500.

In other words, according to embodiments of present disclosure, the metal-resin composite may comprises a metal substrate and a thermoplastic resin composition formed on the metal substrate, in which a hole may be formed on a surface of the metal substrate to be contacted with the thermoplastic resin composition, the thermoplastic resin composition is joined with the metal substrate by filling the hole with the thermoplastic resin composition, and the hole comprises an upper cavity and a lower cavity communicating with each other with the lower cavity having a narrow mouth.

According to embodiments of present disclosure, the metal-resin composite may show good adhesion force, good utility or be less pollution to the environment.

According to embodiments of present disclosure, the metal substrate may be made of at least one selected from a group consisting of stainless steel, aluminum alloy, and magnesium alloy. For example, the metal substrate may be made of SUS304 stainless steel and/or A6061 aluminum alloy. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, the upper hole part may have a largest diameter of about 0.1 to about 1000 microns, and preferably the upper hole part may have a largest diameter of about 0.02 to about 0.12 mm. According to embodiments of present disclosure, the necking section may have a diameter of about 0.05 to about 800 microns, and preferably the necking section may have a diameter of about 0.01 to about 0.08 mm. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, the necking section may have a diameter of about 0.01 to about 0.08 mm. And according to embodiments of present disclosure, the diameter of the necking section is less than a smallest diameter of the upper hole part. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, the upper hole part may have a depth of about 0.005 to about 0.2 mm, and preferably, the upper hole part may have a depth of about 0.008 to about 0.04 mm, and more preferably, the upper hole part may have a depth of about 0.008 to about 0.01 mm. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, the lower hole part may have a depth of about 0.03 to about 0.3 mm, and preferably 0.04 to about 0.07 mm, and more preferably 0.04 to about 0.045 mm. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, the lower hole part of the hole may comprise a main body having a folliculus pili-like microstructure, and preferably the folliculus pili-like microstructure may have a largest diameter of about 0.05 to about 0.09 mm, and more preferably, the folliculus pili-like microstructure has a largest diameter of about 0.06 to about 0.08 mm.Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, there is no specific limit to the number of the hole having a folliculus pili-like microstructure. For example, there are a plurality of holes having a folliculus pili-like microstructure, which may be arranged into several rows, such as a first row, a second row, a third row, and so on. According to embodiments of present disclosure, in each row, the holes having a folliculus pili-like microstructure should be spaced each other at a distance of about 0.05 to about 0.09mm, and the first hole having a folliculus pili-like microstructure in the second row should be staggered from the largest diameter of the first hole having a folliculus pili-like microstructure in the first row, and the row distance between the first and second rows may be about 0.03 mm to about 0.09 mm, and the third row may be identical to the first row, and so on. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, based on the total weight of the thermoplastic resin composition, the thermoplastic resin composition may comprise: a thermoplastic resin at a content of about 50 wt％ to about 80wt％, and a fiber material at a content of about 20 wt％ to about 50wt％. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, the thermoplastic resin may be at least one selected from a group consisting of polyphenylene sulfide resin, poly butylene terephthalate resin, polyhexamethylene adipamide resin, and polycarbonate resin. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

According to embodiments of present disclosure, the fiber material may be at least one selected from a group consisting of ceramic fiber, glass fiber, aluminum silicate fiber, and polyester fiber. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

In another aspect of present disclosure, there is provided with a method for producing a metal-resin composite. According to embodiments of present disclosure, the method comprises steps of: laser ablating a surface of a metal substrate to form a upper hole part； laser ablating a bottom surface of the upper hole part to form a lower hole part； and injection molding a thermoplastic resin composition on the surface of the metal substrate to form the metal-resin composite.

The resulting product of the method of present disclosure, namely a metal-resin composite may show good adhesion force, good utility or be less pollution to the environment.

According to embodiments of present disclosure, the upper hole part may be formed by: subjecting the surface of the metal substrate to a first spotty melting by laser ablating to form an upper melt pool containing molten metal； and subjecting the molten metal in the upper melt pool to a first gasifying to form the upper hole part. According to embodiments of present disclosure, the lower hole part is formed by: subjecting the bottom surface of the upper hole part to a second spotty melting by laser ablating to form a lower melt pool containing molten metal； and subjecting the molten metal in the lower melt pool to a second gasifying to form the lower hole part.

According to embodiments of present disclosure, the laser ablating may be performed for one time or for several times. According to embodiments of present disclosure, the laser ablating for one time may form one spotty melting, and the laser ablating for several times may form several spotty melting which may be joined together, then the upper melt pool may be formed.

According to embodiments of present disclosure, there is no specific limit to the laser machine and the parameter thereof to perform the laser ablating. According to embodiments of present disclosure, the laser machine may be LSF 20 Laser Marking Machine produced by HGLASER. According to embodiments of present disclosure, the first and second spotty melting are performed independently by using a laser with a frequency of about 8 to about 12 KHz, under an electrical current of about 14 to about 18 A for about 1 to about 100 microseconds. Preferably, the first and second spotty melting are performed independently for about 6 to about 20 microseconds. Using these parameters, the laser machine may be used to ablate the metal substrate and form the desired sizes of the upper and lower melt pool. Then, the adhesion force between the metal substrate and the thermoplastic resin composition of the resulting metal-resin composite may be further improved.

According to embodiments of present disclosure, there is no specific limit to the condition of the laser to perform the first and second gasifying. According to embodiments of present disclosure, the first gasifying is performed by using a laser with a frequency of about 8 to about 10 KHz, under an electrical current of about 20 to about 30 A for about 0.25 to about 100 microseconds, preferably, the first gasifying is performed for about 10 to about 20 microseconds. According to embodiments of present disclosure, the second gasifying is performed by using a laser with a frequency of about 9 to about 11 KHz, under an electrical current of about 28 to about 30 A for about 0.5 to about 20 microseconds. According to embodiments of present disclosure, the second gasifying is performed for about 0.5 to about 1 microsecond. Using these parameters, the laser machine may be used to generate an instantaneous large pulse, which may gasify the molten metal and may form the desired depth of the upper hole part and the lower hole part, and according to embodiments of present disclosure, the formed lower hole part has a narrow upper mouth and a lower folliculus pili-like microstructure.

According to embodiments of present disclosure, the metal substrate may be made of at least one selected from a group consisting of stainless steel, aluminum alloy, and magnesium alloy. For example, the metal substrate may be made of SUS304 stainless steel and/or A6061 aluminum alloy. Then, the adhesion force between the metal substrate and the thermoplastic resin composition of the resulting metal-resin composite may be further improved.

According to embodiments of present disclosure, the upper hole part may have a largest diameter of about 0.1 to about 1000 microns, and preferably the upper hole part may have a largest diameter of about 0.02 to about 0.12 mm. According to embodiments of present disclosure, the necking section may have a diameter of about 0.05 to about 800 microns, and preferably the necking section may have a diameter of about 0.01 to about 0.08 mm. Then, the adhesion force between the metal substrate and the thermoplastic resin composition of the resulting metal-resin composite may be further improved.

According to embodiments of present disclosure, the necking section may have a diameter of about 0.01 to about 0.08 mm. And according to embodiments of present disclosure, the diameter of the necking section is less than a smallest diameter of the upper hole part. Then, the adhesion force between the metal substrate and the thermoplastic resin composition of the resulting metal-resin composite may be further improved.

According to embodiments of present disclosure, the upper hole part may have a depth of about 0.005 to about 0.2 mm, and preferably, the upper hole part may have a depth of about 0.008 to about 0.04 mm, and more preferably, the upper hole part may have a depth of about 0.008 to about 0.01 mm. Then, the adhesion force between the metal substrate and the thermoplastic resin composition of the resulting metal-resin composite may be further improved.

According to embodiments of present disclosure, the lower hole part may have a depth of about 0.03 to about 0.3 mm, and preferably 0.04 to about 0.07 mm, and more preferably 0.04 to about 0.045 mm. Then, the adhesion force between the metal substrate and the thermoplastic resin composition of the resulting metal-resin composite may be further improved.

The “depth” of the upper hole part formed in the metal substrate means the distance from the surface to the bottom of the formed upper hole part, and the “depth” of the lower hole part means the distance from the bottom of the formed upper hole part to the bottom of the formed lower hole part.

According to embodiments of present disclosure, the lower hole part of the hole may comprise a main body having a folliculus pili-like microstructure, and preferably the folliculus pili-like microstructure may have a largest diameter of about 0.05 to about 0.09 mm, and more preferably, the folliculus pili-like microstructure has a largest diameter of about 0.06 to about 0.08 mm.Then, using the size and geometrical shape of the lower hole part, the adhesion force between the metal substrate and the thermoplastic resin composition of the resulting metal-resin composite may be further improved.

According to embodiments of present disclosure, there is no specific limit to the number of the hole having a folliculus pili-like microstructure formed on the surface of the metal substrate. For example, there may be a plurality of holes having a folliculus pili-like microstructure, which may be arranged into several rows, such as a first row, a second row, a third row, and so on. According to embodiments of present disclosure, the plurality of holes having a folliculus pili-like microstructure may be formed by means of the method described for one folliculus pili-like microstructure. According to embodiments of present disclosure, the first row is firstly formed, secondly the second row, then the third row, and so on. According to embodiments of present disclosure, in each row, the holes having a folliculus pili-like microstructure should be spaced each other at a distance of about 0.05 to about 0.09mm, and the first hole having a folliculus pili-like microstructure in the second row should be staggered from the largest diameter of the first hole having a folliculus pili-like microstructure in the first row, and the row distance between the first and second rows may be about 0.03 mm to about 0.09 mm, and the third row may be identical to the first row, and so on. Then, the adhesion force between the metal substrate and the thermoplastic resin composition may be further improved.

Additionally, according to embodiments of present disclosure, the scanning speed of the laser machine may be used to control the above spacing distance and the row distance, and then the scanning speed may be controlled by controlling the effective vector step, effective vector delay time, and releasing time Q, for example based on the following relationship:

Scanning speed ＝ (Inherent constant of the laser machine) X (Effective vector step) / (Effective vector delay time)

According to embodiments of present disclosure, the effective vector step may be 0.01 microns, effective vector delay time may be 15 microseconds, and releasing time Q may be 8 microseconds, Q frequency may be 10 kHz. Then, the holes having a folliculus pili-like microstructure may be tighter in terms of special arrangement, which may be favor to the joining of the metal substrate and the resin composition.

According to embodiments of present disclosure, there is no specific limit to the amount of the thermoplastic resin composition, which may be determined based on the size of the mold and the metal substrate, as long as the metal substrate and the thermoplastic resin composition may be formed into an integral metal-resin composite. Preferably, the volume amount between the thermoplastic resin composition and the metal substrate may be 1: 1.

According to embodiments of present disclosure, before laser ablating the metal substrate, the metal substrate may be subjected to pre-treatment, comprising: cutting the metal substrate into 15mm X 80 mm rectangle sheets； grinding and polishing the sheets in a polishing machine； and subjecting the sheets to deoiling, water washing and drying. There is no specific limit to the polishing machine, which may be any commonly known by the person skilled in the art, and the means for deoiling, water washing and drying are also not limited, which may be any well-known technologies.

In order to make the technical problem, the technical solution and the advantageous effects of the present disclosure more clear, the present disclosure will be further described below in detail with reference to examples thereof. It would be appreciated that particular examples described herein are merely used to understand the present disclosure. The examples shall not be construed to limit the present disclosure. The raw materials used in the examples and the comparative examples are all commercially available, without special limits.

In the following examples and comparative examples, Universal material test machine (Sold by InstaPure, Type: 3369) is used to characterize the shearing force of the metal substrate, polyphenylene sulfide resin and poly butylene terephthalate resin are obtained from QiDe Engineering Plastics Ltd., glass fiber and ceramic fiber is obtained from Aoke Glass Fiber company. SUS304 stainless steel and aluminum alloy A6061, used as metal substrate, are obtained from Gangxiang Metal Material Company, polishing machine is a 833 Polishing Machine from Hengtai, and the laser machine is LSF 20 Laser Marking Machine produced by HGLASER.

Preparation Example 1

SUS304 stainless steel and aluminum alloy A6061 with thickness of 0.8mm respectively were cutted into 15 mm X 80 mm rectangle sheets； grinding and polishing the sheets in a polishing machine； and subjecting the sheets to deoiling, water washing and drying, then the metal substrate of SUS304 stainless steel or aluminum alloy A6061 were obtained.

Example 1

(1) The surface of an aluminum alloy A6061 metal substrate was subjected to a laser ablating for 20 microseconds to achieve a spotty melting on the surface thereof and form an upper melt pool containing molten metal, using a laser machine under a condition of 8 kHz laser frequency, and 14A electrical current.

(2) As shown in Fig. 1, energy was continuously inputted when the diameter of the laser beam was kept at 0.12 mm above the upper melt pool with the laser machine having a frequency of 10 KHz and an electrical current of 30 A, to subject the molten metal in the upper melt pool to first gasifying, and the time of first gasifying is 0.5 microsecond, and an upper cavity with a depth of 0.2 mm was formed as shown in Fig. 1.

(3) The bottom of the upper cavity was subjected to a laser ablating for 20 microseconds to achieve a spotty melting on the surface thereof and form an upper melt pool containing molten metal as shown in Fig. 1, using a laser machine under a condition of 8 kHz laser frequency, and 14A electrical current.

(4) The molten metal was subjected to second gasifying using a laser machine under a condition of a frequency of 10 KHz and an electrical current of 30 A for 1 microsecond, as shown in Fig. 1, a lower cavity was formed with an upper narrow mouth (diameter thereof is 0.08 mm) and a folliculus pili-like microstructure (largest diameter is 0.06 mm) , and the lower cavity has a depth of 0.3 mm.

(5) Cavities with a folliculus pili-like microstructure were formed on the metal substrate using a same method with the above method to form lower cavity. As shown in Fig. 2, a 3D SEM photo of the surface of Aluminum alloy 6061 metal substrate, the space distance of the cavities having folliculus pili-like microstructure is 0.05 mm, and row distance thereof is 0.09 mm.

(6) The resulting metal substrate of step (5) was placed in a mold, and were injection molded with a thermoplastic resin composition consisting of 70wt％ of polyphenylene sulfide (PPS) and 30wt％ glass fiber, and the volume of the thermoplastic resin composition to that of the aluminum alloy 6061 is 1: 1, then an integral metal-resin composite S1 was obtained. Fig. 3 shows a cross sectional view of a metal-resin composite comprising a metal substrate and a thermoplastic resin composition, in which black part means the thermoplastic resin composition, white part is an aluminum alloy 6061 metal substrate having a folliculus pili-like microstructure. As shown in Fig. 3, the metal and the resin were joined together tightly, and forming a metal-resin composite.

The obtained metal-resin composite S1, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Example 2

(1) The surface of an aluminum alloy A6061 metal substrate was subjected to a laser ablating for 10 microseconds to achieve a spotty melting on the surface thereof and form an upper melt pool containing molten metal, using a laser machine under a condition of 12 kHz laser frequency, and 18A electrical current.

(2) Energy was continuously inputted when the diameter of the laser beam was kept at 0.02mm above the upper melt pool with the laser machine having a frequency of 10 KHz and an electrical current of 30 A, to subject the molten metal in the upper melt pool to first gasifying, and the time of first gasifying is 0.25 microsecond, and an upper cavity with a depth of 0.2 mm was formed.

(3) The bottom of the upper cavity was subjected to a laser ablating for 10 microseconds to achieve a spotty melting on the surface thereof and form an upper melt pool containing molten metal, using a laser machine under a condition of 12kHz laser frequency, and 18A electrical current.

(4) The molten metal was subjected to second gasifying using a laser machine under a condition of a frequency of 10KHz and an electrical current of 30A for 0.5 microsecond, a lower cavity was formed with an upper narrow mouth (diameter thereof is 0.01mm) and a folliculus pili-like microstructure (largest diameter is 0.06mm) , and the lower cavity has a depth of 0.07mm.

(5) 1000 cavities with a folliculus pili-like microstructure were formed on the metal substrate using a same method with the above method to form lower cavity, in which the space distance of the cavities having folliculus pili-like microstructure is 0.05mm, and row distance thereof is 0.09mm.

(6) The resulting metal substrate of step (5) was placed in a mold, and were injection molded with a thermoplastic resin composition consisting of 70wt％ of poly butylene terephthalate and 30wt％ ceramic fiber, and the volume of the thermoplastic resin composition to that of the aluminum alloy 6061 is 1: 1, then an integral metal-resin composite S2 was obtained.

The obtained metal-resin composite S2, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Example 3

(1) The surface of an aluminum alloy A6061 metal substrate was subjected to a laser ablating for 6 microseconds to achieve a spotty melting on the surface thereof and form an upper melt pool containing molten metal, using a laser machine under a condition of 9 kHz laser frequency, and 14 A electrical current.

(2) Energy was continuously inputted when the diameter of the laser beam was kept at 0.02mm above the upper melt pool with the laser machine having a frequency of 9 KHz and an electrical current of 30 A, to subject the molten metal in the upper melt pool to first gasifying, and the time of first gasifying is 20 microsecond, and an upper cavity with a depth of 0.035 mm was formed.

(3) The bottom of the upper cavity was subjected to a laser ablating for 20 microseconds to achieve a spotty melting on the surface thereof and form an upper melt pool containing molten metal, using a laser machine under a condition of 9 kHz laser frequency, and 14 A electrical current.

(4) The molten metal was subjected to second gasifying using a laser machine under a condition of a frequency of 10 KHz and an electrical current of 30 A for 1 microsecond, a lower cavity was formed with an upper narrow mouth (diameter thereof is 0.01 mm) and a folliculus pili-like microstructure (largest diameter is 0.055 mm) , and the lower cavity has a depth of 0.04 mm.

(5) 5000 cavities with a folliculus pili-like microstructure were formed on the metal substrate using a same method with the above method to form lower cavity, in which the space distance of the cavities having folliculus pili-like microstructure is 0.05 mm, and row distance thereof is 0.03 mm.

(6) The resulting metal substrate of step (5) was placed in a mold, and were injection molded with a thermoplastic resin composition consisting of 70wt％ of polycarbonate (PC) resin and 30wt％ aluminum silicate fiber, and the volume of the thermoplastic resin composition to that of the aluminum alloy 6061 is 1: 1, then an integral metal-resin composite S3 was obtained.

The obtained metal-resin composite S3, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Example 4

(1) The surface of an aluminum alloy A6061 metal substrate was subjected to a laser ablating for 6 microseconds to achieve a spotty melting on the surface thereof and form an upper melt pool containing molten metal, using a laser machine under a condition of 8 kHz laser frequency, and 14 A electrical current.

(2) Energy was continuously inputted when the diameter of the laser beam was kept at 0.02 mm above the upper melt pool with the laser machine having a frequency of 10 KHz and an electrical current of 28 A, to subject the molten metal in the upper melt pool to first gasifying, and the time of first gasifying is 0.5 microsecond, and an upper cavity with a depth of 0.03 mm was formed.

(3) The bottom of the upper cavity was subjected to a laser ablating for 20 microseconds to achieve a spotty melting on the surface thereof and form an upper melt pool containing molten metal, using a laser machine under a condition of 8 kHz laser frequency, and 14 A electrical current.

(4) The molten metal was subjected to second gasifying using a laser machine under a condition of a frequency of 10 KHz and an electrical current of 20 A for 1 microsecond, a lower cavity was formed with an upper narrow mouth (diameter thereof is 0.01 mm) and a folliculus pili-like microstructure (largest diameter is 0.07 mm) , and the lower cavity has a depth of 0.04 mm.

(5) 5000 cavities with a folliculus pili-like microstructure were formed on the metal substrate using a same method with the above method to form lower cavity, in which the space distance of the cavities having folliculus pili-like microstructure is 0.07 mm, and row distance thereof is 0.09 mm.

(6) The resulting metal substrate of step (5) was placed in a mold, and were injection molded with a thermoplastic resin composition consisting of 70wt％of polyhexamethylene adipamide (PA) resin and 30wt％ polyester fiber, and the volume of the thermoplastic resin composition to that of the aluminum alloy 6061 is 1: 1, then an integral metal-resin composite S4 was obtained.

The obtained metal-resin composite S4, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Example 5

Metal-resin composite S5 was prepared according to a method similar to example 1, with a difference that aluminum alloy 6061 was replaced with SUS304 stainless steel.

The obtained metal-resin composite S5, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the SUS304 stainless steel and the resin, and the results were listed in Table 1.

Example 6

Metal-resin composite S6 was prepared according to a method similar to example 1, with a difference that aluminum alloy 6061 was replaced with SUS304 stainless steel, and the thermoplastic resin composition consisting of 70wt％ of polyphenylene sulfide (PPS) and 30wt％ glass fiber was replaced with a thermoplastic resin composition consisting of 50wt％ of polyhexamethylene adipamide (PA) resin and 50wt％ glass fiber.

The obtained metal-resin composite S6, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the SUS304 stainless steel and the resin, and the results were listed in Table 1.

Example 7

Metal-resin composite S7 was prepared according to a method similar to example 1, with a difference that aluminum alloy 6061 was replaced with SUS304 stainless steel, and the thermoplastic resin composition consisting of 70wt％ of polyphenylene sulfide (PPS) and 30wt％ glass fiber was replaced with a thermoplastic resin composition consisting of 70wt％ of polycarbonate (PC) resin and 30wt％ glass fiber.

The obtained metal-resin composite S7, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the SUS304 stainless steel and the resin, and the results were listed in Table 1.

Example 8

Metal-resin composite S8 was prepared according to a method similar to example 1, with a difference that the thermoplastic resin composition consisting of 70wt％ of polyphenylene sulfide (PPS) and 30wt％ glass fiber was replaced with a thermoplastic resin composition consisting of 50wt％ of polyhexamethylene adipamide (PA) resin and 50wt％ glass fiber.

The obtained metal-resin composite S8, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Example 9

Metal-resin composite S9 was prepared according to a method similar to example 1, with a difference that the thermoplastic resin composition consisting of 70wt％ of polyphenylene sulfide (PPS) and 30wt％ glass fiber was replaced with a thermoplastic resin composition consisting of 70wt％ of polycarbonate (PC) and 30wt％ glass fiber.

The obtained metal-resin composite S9, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Comparative Example 1

Metal-resin composite DS1 was prepared according to a method similar to example 1 with a difference that the lower melt pool and the lower cavity were not formed on the metal substrate.

The obtained metal-resin composite DS1, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Comparative Example 2

Metal-resin composite DS2 was prepared according to a method similar to example 1 with a difference that the condition for the second gasifying is 8 KHZ laser frequency, 14A electrical current and the time for the second gasifying is 20 microseconds.

The obtained metal-resin composite DS2, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Comparative Example 3

DS3 was prepared by an electro-chemical etching method comprising the steps of：

(1) Surface treatment 1: Each aluminum alloy 6061 sheet as an anode was placed in an anodizing bath containing a 20wt％ H₂SO₄ solution, the aluminum alloy was electrolyzed at a voltage of 20 V at 18℃ for 10 min, and then the aluminum alloy sheet was blow-dried. The cross section of the aluminum alloy 6061 sheet after the surface treatment 1 was observed by a metalloscope, to find out that an aluminum oxide layer with a thickness of 5μm was formed on the surface of the electrolyzed aluminum alloy sheet. The surface of the aluminum alloy 6061 sheet after the surface treatment 1 was observed by an electron microscope, to find out that nanopores with an average pore size of about 40nm to about 60nm and a depth of 1μm was formed in the aluminum oxide layer.

(2) Surface Treatment 2:

500 ml of 10wt％ sodium carbonate solution (pH＝12) with a temperature of 20℃ was prepared in a beaker. The aluminum alloy 6061 sheet after step (1) was immersed in the sodium carbonate solution, taken out after 5min, and placed in a beaker containing water to be immersed for 1 min. After 5 cycles, after water immersing for the last time, the aluminum alloy sheet was blow-dried. The surface of the aluminum alloy sheet after the surface treatment 2 was observed by an electron microscope, to find out that corrosion pores with an average pore size of 300nm to 1000 nm and a depth of 4 μm were formed in the surface of the immersed aluminum alloy sheet. It may also be observed that there was a double-layer three-dimensional pore structure in the aluminum oxide layer, and the corrosion pores were communicated with the nanopores.

(3) Molding:

The resulting metal substrate was placed in a mold, and were injection molded with a thermoplastic resin composition consisting of 70wt％ of polyphenylene sulfide (PPS) and 30wt％ glass fiber, then an integral metal-resin composite DS3 was obtained.

The obtained metal-resin composite DS3, after being standed for 24 hours was placed in the Universal material machine for a tension test, the average shearing stress may reflect the adhesion force between the aluminum alloy 6061 and the resin, and the results were listed in Table 1.

Table 1

It may be seen from the test results in Table 1 that the metal-resin composites S1-S9 have a significantly improved average shearing force than those of metal-resin composites DS1-DS3, demonstrating good adhesion force between the metal substrate and the resin, namely the metal-resin prepared by the method of present disclosure may have good adhesion force.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that the above embodiments cannot be construed to limit the present disclosure, and changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the present disclosure.

Claims

A metal-resin composite, comprising:

a metal substrate defining a hole formed on a surface thereof, and

a thermoplastic resin composition formed on the metal substrate, wherein

a part of the thermoplastic resin composition is filled in the hole,

the hole comprises a lower hole part and a upper hole part communicating with the lower hole part, and

a necking section is formed between the lower hole part and the upper hole part.
The metal-resin composite of claim 1, wherein the metal substrate is made of at least one selected from a group consisting of stainless steel, aluminum alloy, and magnesium alloy.
The metal-resin composite of claim 1, wherein the upper hole part has a largest diameter of about 0.1 to about 1000 microns.
The metal-resin composite of claim 3, wherein the upper hole part has a largest diameter of about 0.02 to about 0.12 mm.
The metal-resin composite of claim 1, wherein the necking section has a diameter of about 0.05 to about 800 microns.
The metal-resin composite of claim 5, wherein the necking section has a diameter of about 0.01 to about 0.08 mm.
The metal-resin composite of any one of claims 1-6, wherein the diameter of the necking section is less than a smallest diameter of the upper hole part.
The metal-resin composite of claim 1, wherein the upper hole part has a depth of about 0.005 to about 0.2 mm.
The metal-resin composite of claim8, wherein the upper hole part has a depth of about 0.008 to about 0.04 mm.
The metal-resin composite of claim 1, wherein the lower hole part has a depth of about 0.03 to about 0.3 mm.
The metal-resin composite of claim 10, wherein the lower hole part has a depth of about 0.04 to about 0.07 mm.
The metal-resin composite of claim 1, wherein the lower hole part of the hole comprises a main body having a folliculus pili-like microstructure.
The metal-resin composite of claim 12, wherein the folliculus pili-like microstructure has a largest diameter of about 0.05 to about 0.09 mm.
The metal-resin composite of claim 13, wherein the folliculus pili-like microstructure has a largest diameter of about 0.06 to about 0.08 mm.
The metal-resin composite of claim 1, wherein based on the total weight of the thermoplastic resin composition, the thermoplastic resin composition comprises:

a thermoplastic resin at a content of about 50 wt％ to about 80wt％, and

a fiber material at a content of about 20 wt％ to about 50wt％.
The metal-resin composite of claim 15, wherein the thermoplastic resin is at least one selected from a group consisting of polyphenylene sulfide resin, poly butylene terephthalate resin, polyhexamethylene adipamide resin, and polycarbonate resin.
The metal-resin composite of claim 15, wherein the fiber material is at least one selected from a group consisting of ceramic fiber, glass fiber, aluminum silicate fiber, and polyester fiber.
A method for producing a metal-resin composite, comprising steps of:

laser ablating a surface of a metal substrate to form a upper hole part；

laser ablating a bottom surface of the upper hole part to form a lower hole part； and

injection molding a thermoplastic resin composition on the surface of the metal substrate to form the metal-resin composite.
The method of claim 18, wherein the upper hole part is formed by:

subjecting the surface of the metal substrate to a first spotty melting by laser ablating to form an upper melt pool containing molten metal； and

subjecting the molten metal in the upper melt pool to a first gasifying to form the upper hole part.
The method of claim 18, wherein the lower hole part is formed by:

subjecting the bottom surface of the upper hole part to a second spotty melting by laser ablating to form a lower melt pool containing molten metal； and

subjecting the molten metal in the lower melt pool to a second gasifying to form the lower hole part.
The method of claim 19 or 20, wherein the first and second spotty melting are performed independently by using a laser with a frequency of about 8 to about 12 KHz, under an electrical current of about 14 to about 18 A for about 1 to about 100 microseconds.
The method of claim 21, wherein the first and second spotty melting are performed independently for about 6 to about 20 microseconds.
The method of claim 19, wherein the first gasifying is performed by using a laser with a frequency of about 8 to about 10 KHz, under an electrical current of about 20 to about 30 A for about 0.25 to about 100 microseconds.
The method of claim 23, wherein the first gasifying is performed for about 10 to about 20 microseconds.
The method of claim 20, wherein the second gasifying is performed by using a laser with a frequency of about 9 to about 11 KHz, under an electrical current of about 28 to about 30 A for about 0.5 to about 20 microseconds.
The method of claim 25, wherein the second gasifying is performed for about 0.5 to about 1 microsecond.
The method of claim 18, wherein the metal substrate is made of at least one selected from a group consisting of stainless steel, aluminum alloy, and magnesium alloy.
The method of claim 18, wherein the upper hole part has a largest diameter of about 0.1 to about 1000 microns.
The method of claim 28, wherein the upper hole part has a largest diameter of about 0.02 to about 0.12 mm.
The method of claim 18, wherein a necking section is formed between the lower hole part and the upper hole part, and the necking section has a diameter of about 0.05 to about 800 microns.
The method of claim 30, wherein the necking section has a diameter of about 0.01 to about 0.08 mm.
The method of claim 30, wherein the diameter of the necking section is less than a smallest diameter of the upper hole part.
The method of claim 18, wherein the upper hole part has a depth of about 0.005 to about 0.2 mm.
The method of claim 33, wherein the upper hole part has a depth of about 0.008 to about 0.04 mm.
The method of claim 18, wherein the lower hole part has a depth of about 0.03 to about 0.3 mm.
The method of claim 35, wherein the lower hole part has a depth of about 0.04 to about 0.07 mm.
The method of claim 18, wherein the lower hole part of the hole comprises a main body having a folliculus pili-like microstructure.
The method of claim 37, wherein the folliculus pili-like microstructure has a largest diameter of about 0.05 to about 0.09 mm.
The method of claim 38, wherein the folliculus pili-like microstructure has a largest diameter of about 0.06 to about 0.08 mm.
The method of claim 18, wherein based on the total weight of the thermoplastic resin composition, the thermoplastic resin composition comprises:

a thermoplastic resin at a content of about 50 wt％ to about 80wt％, and

a fiber material at a content of about 20 wt％ to about 50wt％.
The method of claim 40, wherein the thermoplastic resin is at least one selected from a group consisting of polyphenylene sulfide resin, poly butylene terephthalate resin, polyhexamethylene adipamide resin, and polycarbonate resin.
The method of claim 40, wherein the fiber material is at least one selected from a group consisting of ceramic fiber, glass fiber, aluminum silicate fiber, and polyester fiber.