Page 9 - MFi Vol.152 ATZ Extra Issue 2019
P. 9

                               Aluminum alloys used in automobiles : 3
              03               Aluminum alloy surface treatment

                                  The beautiful transmuting appearance of aluminum

                Aluminum Design Sheets
                                                                                 Anodizing     Self-coloring process
                                                                                               2-step coloring process
           The aesthetically pleasing appearance of aluminum is one of its   Surface  Pre-coating   Surface property
           major features. The sheen of luminous aluminum alloys can be                        Surface design
           further enhanced through electrolytic and chemical polishing, and
           they are used for decorative parts, such as vehicle moldings.
           Various surface treatment technologies can be used to accentuate
           the aesthetic qualities of aluminum.
             Interior use of aluminum design sheets

           Aluminum panels with surfaces beautifully processed and treated
           with hairlines and other designs are widely used for cockpit interior
           decoration, such as in center console panels and door trims.                                             Motor Fan illustrated

           Anodizing is a process that involves turning a piece of aluminum
           into an anode in an electrolytic solution to create a surface layer of
           oxidized aluminum. Colored oxide layers can be produced in black,
                                                                                     The beautiful sheen of aluminum
           red, blue, etc.                                                           sheets surely provides an incentive   ALUMINUM  AUTOMOBILE TECHNOLOGY
                                                                                     to choose them instead of resin.

                Pre-coated aluminum alloy sheet

           Surface treated aluminum sheet features great functionality.

              Functions                Special features                        Adhesive pre-coat
                                                                               aluminum alloy sheet
                            Press forming with volatile press oil is possible,
               Lubricity                                                           Polypropylene
                            allowing omission of the degreasing process.           resin
                            It is highly adhesive to PP resins, allowing
                            non-use of adhesive materials.
                                                                                 Weather strip
                            Coated layer containing pigments with
            Heat dissipation
                            excellent heat dissipation diffuses heat.
                                                                     High-adhesive strength pre-coated aluminum alloy sheet
                            It has excellent conductivity so that continuity
                            is achieved on the coated layer.       Aluminum alloy sheet material with a coating that is highly
                                                                   adhesive to resin is used to support the weather strip.
                KO treatment highly adhesive aluminum sheet

           A process to give an AC electrolysis treatment to aluminum sheet
           in an alkaline electrolytic solution in order to form a porous and
           dendritic oxide layer.                                                                      Dendritic porous
           The anode oxide layer has a thickness of 2~10μm                                             layer
                                                                                ON                     (200~250nm)
           Thickness after KO treatment: 200~250nm
            (The KO treatment sheet is very thin, only 1/10 to 1/40 the
                                                                                                   ON   Barrier layer
           thickness of an anode oxide layer.)                                                          (10~20nm)
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