Patent Application
20130171473
1. Technical Field
The present disclosure relates to a method for making patterns or logos on metal articles and metal articles made thereby.
2. Description of Related Art
Electronic devices, such as cellular phones often use metal housings. These metal housings are usually decorated with logos or patterns. A method for making these decorations on a metal member includes masking selected regions of the metal member using ink and sandblasting the other unmasked regions. As such, the sandblasted regions have a roughened surface and the masked regions have a smooth surface to form a logo on the metal member. However, masking is a time-consuming process. Moreover, the ink used for a mask may be unfriendly to the environment.
Therefore, there is room for improvement within the art.
Many aspects of the present disclosure can be better understood with reference to the drawings. The components in the drawings 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 views.
An exemplary process for making patterns on a metal article may include the following steps.
Referring to
The metal substrate 11 may be cleaned to remove purities, such as greases. Commercial metal cleaning agents can be used to wash the metal substrate 11.
A light-absorbing coating 15 is coated on selected regions 112 of the outer surface 110. The selected regions 112 cooperatively form a desired pattern. The light-absorbing coating 15 mainly comprises graphite powder, binder, and thinner. The light-absorbing coating 15 is mainly used to reduce the surface laser reflectivity of metal and enable the metal to absorb more laser energy, thereby rapidly heating up the metal under laser radiation and ensuring a good effect in a subsequent laser-quenching process. The light-absorbing coating 15 can disappear after the laser-quenching process.
After the light-absorbing coating 15 is dried, the selected regions 112 coated with the light-absorbing coating 15 are treated by laser-quenching, thereby hardening the selected regions 112. The laser-quenching uses a laser to scan the selected regions 112 to rapidly heat the selected regions 112. Gas (such as inert gas) is blown onto the selected regions 112 to rapidly cool down the selected regions 112 radiated by laser during the laser scanning, preventing the selected regions 112 from melting. The laser-quenching substantially does not change the chemical composition of the metal substrate 11, but causes metal crystalline grains of the selected regions 112 to be smaller than their original size, thereby improving the surface hardness and other mechanical properties of the selected regions 112. By laser-quenching, the selected regions 112 achieve a significantly improved surface hardness which is about 2-3 times the original surface hardness of the selected regions 112. The light-absorbing coating 15 disappears when the laser-quenching is finished.
Referring to
However, even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201110453185.8 | Dec 2011 | CN | national |
