Patent Application
20120301704
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.
1. Technical Field
The present disclosure relates to titanium/titanium alloy-and-resin composites, particularly to a titanium/titanium alloy-and-resin composite having high bonding strength between titanium/titanium 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 and a synthetic resin are in demand in a wide variety of technical fields and industries, such as the automotives and household appliances fields. However, the bonding strength of the metal and resin is weak. Furthermore, 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. Due to the above reason, 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 further improved.
Therefore, there is room for improvement within the art.
Many aspects of the disclosure 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 disclosure. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views.
The nano-porous oxide film 12 is titanium dioxide film. In this embodiment, the nano-porous oxide film 12 is formed by anodizing the substrate 11.
Referring to
The resin compositions 13 may be coupled to the surface of the nano-porous oxide film 12 by molding. During the molding process, molten resin coats the surface of the nano-porous oxide film 12 first, and under the action of the greater specific surface area and the strong absorbent property of the nano-porous oxide film 12 fills the nano-pores 123 completely, thus strongly bonding the resin compositions 13 to the nano-porous oxide film 12 and the substrate 11. Compared to the conventional injection molding process in which the titanium/titanium alloy substrate is not anodized, the composite 100 in this exemplary embodiment has a much stronger bond between the resin compositions 13 and the substrate 11 (about quintuple the bonding force). The resin compositions 13 may be made up of crystalline thermoplastic synthetic resins having high fluidity. In this exemplary embodiment, polyphenylene sulfide (PPS) and polyamide (PA) can be selected as the molding materials for the resin compositions 13. These resin compositions 13 can bond firmly with the nano-porous oxide film 12 and the substrate 11.
It is to be understood that auxiliary components may be added to the resins to modify properties of the resin compositions 13, for example, fiberglass may be added to PPS. The fiberglass may have a mass percentage of about 30% with regard to the PPS and the fiberglass.
A method for making the composite 100 may include the following steps:
The titanium/titanium alloy substrate 11 is provided.
The substrate 11 is ultrasonically cleaned using anhydrous ethanol and acetone respectively, and then rinsed.
The substrate 11 is chemically polished. The chemical polishing process may be carried out in a water solution containing hydrofluoric acid (HF) and nitric acid (HNO3), or a water solution of HF and HNO3. The water solution may be obtained by mixing a HF (having a mass percentage of about 40%), a HNO3 (having a mass percentage of about 68%), and deionized water at a volume ratio of about 1:1:8. During the polishing process, the water solution may be agitated to improve the polishing effect. Next, the substrate 11 is rinsed in water and then dried.
The substrate 11 is anodized to form the nano-porous oxide film 12. The anodizing process may be carried out in a water solution containing HF and sodium sulfate (Na2SO4), or a water solution of HF and Na2SO4, with the substrate 11 being an anode, and a stainless steel board being a cathode. The voltage between the anode and the cathode is adjusted to about 15 V-25 V and then directly put into the water solution to start the process. During the anodizing process, the water solution is agitated to control the temperature of the substrate 11 to be not too high and simultaneously even the concentration distribution in the water solution. The Na2SO4 may have a molar concentration of about 0.5 mol/L-2 mol/L in the water solution. The HF may have a mass concentration of about 0.5%-1.0% in the water solution. Anodizing the substrate 11 may last for about 15 minutes-20 minutes. Once anodized, the nano-porous oxide film 12 is formed on the substrate 11. Next, the substrate 11 having the nano-porous oxide film 12 is rinsed in water and then dried.
The thickness of the nano-porous oxide film 12, and the pore diameter of the nano-pores 123 in this embodiment are only an example. The thickness of the nano-porous oxide film 12 and the pore diameter of the nano-pores 123 can be changed by adjusting the voltage, the concentration of the water solution, and the lasting time of the anodizing process.
Referring to
The shear strength of the composite 100 has been tested. The tests indicated that the shear strength of the composite 100 was 20 MPa-30 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° C.-85° C., 4 hours/cycle, 12 cycles total), such testing did not result in decreased 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 |
|---|---|---|---|
| 201110135326.1 | May 2011 | CN | national |
