Method of preparing aluminum alloy resin composite and aluminum alloy-resin composite obtainable by the same

1. A method of preparing an aluminum alloy-resin composite, comprising the steps of:

S1: anodizing a surface of an aluminum alloy substrate to form an oxide layer on the surface, wherein the oxide layer is formed with nanopores;

S2: immersing the resulting aluminum alloy substrate obtained at step S1 in an alkaline solution having a pH of about 10 to about 13, to form corrosion pores on an outer surface of the oxide layer, wherein the corrosion pores have a larger diameter than the nanopores, the corrosion pores and the nanopores form a double-layer pore structure, and the corrosion pores are in communication with the nanopores, wherein the alkaline solution includes an aqueous solution comprising at least one selected from a soluble carbonates, a soluble alkali, a soluble phosphate, a soluble sulfate, and a soluble borate; and

S3: injection molding a resin onto the surface of the resulting aluminum alloy substrate obtained at step S2 in a mold to obtain the aluminum alloy-resin composite.

2. The method according to claim 1 , wherein the alkaline solution includes an aqueous solution comprising at least one selected from a group of Na 2 CO 3 , NaHCO 3 , NaOH, NaH 2 PO 4 , Na 2 HPO 4 , Na 3 PO 4 , Na 2 SO 3 , and Na 2 B 4 O 7 .

3. The method according to claim 1 , wherein the alkaline solution includes at least one of Na 2 CO 3 and NaHCO 3 .

4. The method according to claim 3 , wherein, in the alkaline solution, the at least one of Na 2 CO 3 and NaHCO 3 has a concentration of about 0.1 wt %-15 wt %.

5. The method according to claim 1 , wherein the step S2 comprises:

repeatedly immersing the resulting aluminum alloy obtained at step S1 in the alkaline solution for more than one time, wherein each immersing lasts for about 1 minute to about 60 minutes; and

cleaning the aluminum alloy with water after each immersing.

6. The method according to claim 5 , wherein the step S2 comprises repeatedly immersing the resulting aluminum alloy obtained in step S1 in the alkaline solution for about 2-10 times.

7. The method according to claim 1 , wherein the nanopores have an average diameter of about 10 nm to about 100 nm, the corrosion pores have an average diameter of about 200 nm to about 2000 nm, and the oxide layer has a thickness of about 1 μm to about 5 μm.

8. The method according to claim 1 , wherein anodizing the surface of the aluminum alloy substrate comprises:

providing the aluminum alloy substrate as an anode in a H 2 SO 4 solution with a concentration of about 10 wt % to about 30 wt %; and

electrolyzing the aluminum alloy substrate at a temperature of about 10° C. to about 30° C. at a voltage of about 10V to about 100V for about 1 minute to about 40 minutes to form the oxide layer with a thickness of about 1 μm to about 10 μm on the surface of the aluminum alloy substrate.

9. The method according to claim 1 , further comprising applying a pretreatment to the aluminum alloy substrate, wherein the pretreatment includes: oil removal, a first washing with water, alkali etching, a second washing with water, neutralizing, and a third washing with water.

10. The method according to claim 1 , wherein the resin is a thermoplastic resin.

11. The method according to claim 10 , wherein the thermoplastic resin includes a main resin and a polyolefin resin.

12. The method according to claim 11 , wherein the main resin includes polyphenylene ether and polyphenylene sulfide, and the polyolefin resin has a melting point of about 65° C. to about 105° C.

13. The method according to claim 12 , wherein, in the main resin, the weight ratio of the polyphenylene ether to the polyphenylene sulfide is about 3:1 to about 1:3.

14. The method according to claim 11 , wherein the main resin includes a polyphenylene oxide and a polyamide, and the polyolefin resin has a melting point of about 65° C. to about 105° C.

15. The method according to claim 14 , wherein, in the main resin, the weight ratio of the polyphenylene oxide to the polyamide is about 3:1 to about 1:3.

16. The method according to claim 11 , wherein the main resin includes polycarbonate, and the polyolefin resin has a melting point of about 65° C. to about 105° C.

17. The method according to claim 11 , wherein, based on 100 weight parts of the thermoplastic resin, the main resin is about 70 weight parts to about 95 weight parts, and the polyolefin resin is about 5 weight parts to about 30 weight parts.

18. The method according to claim 11 , wherein the polyolefin resin includes a grafted polyethylene.

19. The method according to claim 10 , wherein based on 100 weight parts of the thermoplastic resin, the thermoplastic resin further includes a flow improver with about 1 weight part to about 5 weight parts; and wherein the flow improver includes a cyclic polyester.

20. The method according to claim 10 , wherein the resin further includes a filler, and the filler comprises at least one of a fiber filler and a powder inorganic filler; and wherein, the fiber filler includes at least one selected from a group of fiberglass, carbon fiber and polyamide fiber; and the powder inorganic filler includes at least one selected from a group of silica, talc, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, glass and kaolin.