Patent Application
20110297549
1. Technical Field
The present disclosure relates to composites of aluminum alloy and resin, particularly to an aluminum alloy-and-resin composite having high bonding strength between aluminum alloy and resin and a method for making the composite.
2. Description of Related Art
Adhesives, for combining heterogeneous materials in the form of a metal (such as light metals) and a synthetic resin are demanded in a wide variety of technical fields and industries, such as the automotive and household appliance fields. However, adhesives are generally only effective in a narrow temperature range of about −50° C. to about 100° C., which means they are not suitable in applications where operating or environmental temperatures may fall outside the range.
Therefore, other bonding methods have been applied that do not involve the use of an adhesive. One example of such methods is by forming bonds through injection molding or other similar process. However, the bonding strength of the metal and resin can be improved.
Therefore, there is room for improvement within the art.
Many aspects of the aluminum alloy-and-resin composite can be better understood with reference to the following figures. The components in the figures are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the aluminum alloy-and-resin composite. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views.
The anodic oxide film 13 is formed by anodizing the aluminum alloy substrate 11. Referring to
The resin composition 15 may be coupled to the anodic oxide film 13 by molding. During the molding process, molten resin coats surfaces of the anodic oxide film 13 and fills the nano-pores 131, thus strongly bonding the resin composition 15 to the anodic oxide film 13. Compared to the conventional injection molding process using non-anodic film, the composite 100 in this exemplary embodiment has a much stronger bond between the resin composition 15 and the substrate 11 (about quintuple bonding force). The resin composition 15 may be made up of crystalline thermoplastic synthetic resins having high fluidity. In this exemplary embodiment, polyphenylene sulfide (PPS), polyamide (PA), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT) can be selected as the molding materials for the resin composition 15, and all of the resins can bond firmly with the anodic oxide film 13 and the substrate 11.
It is to be understood that auxiliary components may be added to the resins to modify properties of the composition 15, for example, fiberglass may be added to PPS. The fiberglass may have a mass percentage of about 10-50%.
A method for making the composite 100 may include the following steps:
The aluminum alloy substrate 11 is provided.
The substrate 11 is degreased. The degreasing process may include the step of dipping the substrate 11 in a sodium salt solution for about 5-15 minutes. The sodium salt solution may include sodium carbonate having a concentration of about 30-50 grams per liter (g/L), sodium phosphate having a concentration of about 30-50 g/L, and sodium silicate having a concentration of about 3-5 g/L. The temperature of the sodium salt solution may be about 50-60° C. Once degreased, the substrate 11 is removed from the sodium salt solution and rinsed in water.
The surface of the substrate 11 is roughened. Roughening the substrate 11 may include the step of chemically etching. The chemical etching process may include the step of dipping the substrate 11 in an alkaline solution for about 1-2 minutes. The alkaline solution may include sodium hydroxide having a concentration of about 20-35 g/L, and sodium carbonate having a concentration of about 20-30 g/L. The temperature of the alkaline solution may be about 40-55° C. The chemical etching process roughens the surface of the substrate 11 so that it will be more uniformly anodized and to obtain a narrower range of diameters of the nano-pores 131 of the anodic oxide film 13. Next, the substrate 11 is removed from the alkaline solution and rinsed in water.
The substrate 11 is anodized to form the anodic oxide film 13. The anodizing process may be carried out in a sulfuric acid solution, with the substrate 11 being an anode, and a stainless steel board or a lead plate being a cathode. The sulfuric acid solution may have a concentration of about 100-250 ml/L. The electric current density through the sulfuric acid solution is about 0.5-4.9 A/dm2. Anodizing the substrate 11 may last for about 15-60 minutes. Then, the substrate 11 is rinsed in water and then dried.
It is to be understood that the anodizing process can also be carried out in a phosphoric acid solution or an oxalic acid solution.
Referring to
Tensile strength and shear strength of the composite 100 have been tested. The tests indicate that the tensile strength of the composite 100 is greater than 8 MPa, and the shear strength of the composite 100 is greater than 15 MPa. Furthermore, the composite 100 has been subjected to a temperature humidity bias test (72 hours, 85° C., relative humidity: 85%) and a thermal shock test (48 hours, −40-85° C., 4 hours/cycle, 12 cycles total), such testing did not result in decreased tensile strength and shear strength of the composite 100.
It is believed that the exemplary embodiment and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its advantages, the examples hereinbefore described merely being preferred or exemplary embodiment of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201010192062.9 | Jun 2010 | CN | national |
This application is one of the two related co-pending U.S. patent applications listed below. All listed applications have the same assignee. The disclosure of each of the listed applications is incorporated by reference into another listed application. AttorneyDocket No.TitleInventorsUS 33056ALUMINUM ALLOY-AND-RESINWEN-RONGCOMPOSITE AND METHODCHEN et al.FOR MAKING THE SAMEUS 33709ALUMINUM ALLOY-AND-RESINWEN-RONGCOMPOSITE AND METHODCHEN et al.FOR MAKING THE SAME
