Abstract:
A housing includes a substrate, a transition layer disposed on the substrate, and a color layer disposed on the transition layer. The transition layer is a mixing coating layer of metal carbonitride. The metal contains titanium and one of which selected from the group consisting of aluminum, chromium, and iron. The color layer is a titanium-chromium-aluminum layer. An electronic device using the housing is also described.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is related to the U.S. patent applications listed below. The current application and the related application have the same assignee. The disclosure of each of the applications is incorporated by reference into the other application. 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                 Attorney Docket No. 
                 Title 
                 Inventors 
               
               
                   
               
             
             
               
                 US50158 
                 HOUSING AND ELECTRONIC 
                 CHUN-JIE 
               
               
                   
                 DEVICE USING THE SAME 
                 ZHANG 
               
               
                 US50159 
                 HOUSING AND ELECTRONIC 
                 CHUN-JIE 
               
               
                   
                 DEVICE USING THE SAME 
                 ZHANG 
               
               
                   
               
             
          
         
       
     
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to housings, especially to a housing having high hardness and an enamel appearance, and an electronic device using the housing. 
         [0004]    2. Description of Related Art 
         [0005]    Housings of electronic devices may be decorated by white paint. However, the paint coating is thick, has low light transmittance and low glossiness, and thus cannot present an enamel appearance. Furthermore, the paint coatings are typically soft and prone to abrasion. 
         [0006]    Therefore, there is room for improvement within the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0007]    Many aspects of the disclosure can be better understood with reference to the following figure. The components in the figure 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. 
           [0008]      FIG. 1  is a schematic view of an electronic device in accordance with an exemplary embodiment. 
           [0009]      FIG. 2  is a partial cross-sectional view of a housing in accordance with an exemplary embodiment. 
           [0010]      FIG. 3  is a schematic view of a vacuum depositing device in accordance with an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]      FIG. 1  shows an electronic device  100  according to an exemplary embodiment. The electronic device  100  may be a mobile phone, a PDA, a notebook computer, for example. The exemplary embodiment uses a mobile phone as an example to describe the electronic device  100 . 
         [0012]    The electronic device  100  includes a housing  10 , and a main body  20 . The housing  10  is configured to assemble with the main body  20 . Electrical elements and a displaying assembly (not shown) can be received in the main body  20 . 
         [0013]    Referring to  FIG. 2 , the housing  10  includes a substrate  11 , a base layer  13  formed on the substrate  11 , a transition layer  15  formed on the base layer  13 , and a color layer  17  formed on the transition layer  15 . 
         [0014]    The substrate  11  can be made of aluminum, aluminum alloy, or stainless steel. 
         [0015]    The base layer  13  is made of metal. The metal may be titanium, chromium, or iron. The base layer  13  has a thickness ranging from about 0.5 micrometers (μm) to about 0.8 μm. The base layer  13  firmly bonds the transition layer  15  to the substrate  11 . 
         [0016]    The transition layer  15  is a mixing coating layer made of first and second metal carbonitrides. The first metal carbonitride typically includes titanium carbonitrade. The second metal carbonitride typically includes one of the following: aluminum carbonitride, chromium carbonitride, and iron carbonitride. In the transition layer  15 , the titanium carbonitride has a mass percentage of about 60% to about 80%, the aluminum carbonitride, the chromium carbonitride, or the iron carbonitride has a mass percentage of about 20% to about 40%. When the transition layer  15  includes titanium carbonitride and aluminum carbonitride, the titanium carbonitride has a mass percentage of about 80%, and the aluminum carbonitride has a mass percentage of about 20%. When the transition layer  15  includes titanium carbonitride and chromium carbonitride, the titanium carbonitride has a mass percentage of about 65%, and the chromium carbonitride has a mass percentage of about 35%. When the transition layer  15  includes titanium carbonitride and iron carbonitride, the titanium carbonitride has a mass percentage of about 70%, and the iron carbonitride has a mass percentage of about 30%. The transition layer  15  has a thickness ranging from about 1 μm to about 4 μm. The transition layer  15  has a high hardness, which enhances the hardness of the housing  10 . 
         [0017]    The color layer  17  is a titanium-chromium-aluminum layer. In the color layer  17 , the titanium has a mass percentage of about 10% to about 15%, the chromium has a mass percentage of about 20% to about 35%, and the aluminum has a mass percentage of about 50% to about 70%. In a first exemplary embodiment, the titanium has a mass percentage of about 15%, the chromium has a mass percentage of about 25%, and the aluminum has a mass percentage of about 60%. In a second exemplary embodiment, the titanium has a mass percentage of about 15%, the chromium has a mass percentage of about 20%, and the aluminum has a mass percentage of about 65%. In a third exemplary embodiment, the titanium has a mass percentage of about 10%, the chromium has a mass percentage of about 20%, and the aluminum has a mass percentage of about 70%. The color layer  17  has a thickness ranging from 4 μm to about 6 μm, and is white due to its chemical make-up and thickness. The chromium in the color layer  17  enhances the glossiness of the color layer  17 , allowing the color layer  17  and the housing  10  to present an enamel appearance. 
         [0018]    Vickers hardness tests have been performed on the housing  10  and the substrate  11 . The tests indicated that the substrate  11  had a Vickers hardness of about 250 HV to about 300 HV, while the housing  10  had a Vickers hardness of about 800 HV to about 1000 HV, which is far greater than the Vickers hardness of the substrate  11 . 
         [0019]    Alternatively, the base layer  13  can be omitted, and the transition layer  15  is directly deposited on the substrate  11 . 
         [0020]    In the exemplary embodiment, the housing  10  is formed by the following method. 
         [0021]      FIG. 3  shows an exemplary vacuum depositing device  30 . The vacuum depositing device  30  includes a coating chamber  31 , and a fixing element  33 , a titanium target  35 , a chromium target  36 , an iron target  37 , and an aluminum target  38  all positioned in the coating chamber  31 . The vacuum depositing device  30  may be a magnetron sputtering device, or a multi-arc ion plating device. In the exemplary embodiment, the vacuum depositing device  30  is a multi-arc ion plating device. 
         [0022]    The substrate  11  is cleaned in an ultrasonic cleaning device (not shown) filled with absolute ethanol for about 25 min to about 35 min. 
         [0023]    The substrate  11  is mounted on the fixing element  33 . The coating chamber  31  is evacuated to about 5.0×10 −3  Pa and is heated to about 160° C. to about 200° C. A power of about 3 kW to about 5 kW is applied to the vacuum depositing device  30 . Argon gas having a purity of about 99.999% may be used as a working gas and is fed into the coating chamber  31  at a flow rate of about 600 standard-state cubic centimeters per minute (sccm) to about 800 sccm. The argon gas is ionized to plasma. The plasma strikes the surface of the substrate  11  to clean the surface of the substrate  11 . Plasma cleaning the substrate  11  may take about 15 min to about 20 min. The targets in the coating chamber  31  are unaffected by the plasma cleaning process. 
         [0024]    The base layer  13  is deposited on the pretreated substrate  11 . The titanium target  35 , the chromium target  36 , or the iron target  37  is selected. A bias voltage of about −300 V to about −350 V is applied to the substrate  11 . Argon gas may be used as a working gas and is fed into the coating chamber  31  at a flow rate of about 100 sccm to about 150 sccm. Depositing of the base layer  13  may take about 8 min to about 15 min. 
         [0025]    The transition layer  15  is deposited on the base layer  13 . The titanium target  35  and chromium target  36 , the titanium target  35  and iron target  37 , or the titanium target  35  and aluminum target  38  are selected. A bias voltage of about −200 V to about −250 V is applied to the substrate  11 . Argon gas may be used as a working gas and is fed into the coating chamber  31  at a flow rate of about 100 sccm to about 150 sccm. Nitrogen (N 2 ) and acetylene (C 2 H 2 ) are used as reaction gases and are fed into the coating chamber  31 . The N 2  has a flow rate of about 20 sccm to about 40 sccm. The C 2 H 2  has a flow rate of about 15 sccm to about 30 sccm. Depositing of the transition layer  15  may take about 25 min to about 45 min. 
         [0026]    The color layer  17  is deposited on the transition layer  15 . The titanium target  35 , the chromium target  36 , and the aluminum target  38  are selected. A bias voltage of about −250 V to about −300 V is applied to the substrate  11 . Argon gas may be used as a working gas and is fed into the coating chamber  31  at a flow rate of about 150 sccm to about 200 sccm. Depositing of the color layer  17  may take about 50 min to about 80 min. 
         [0027]    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.