Processing method for forming an aluminum alloy surface having fine texture and matte appearance

Abstract

A processing method for forming an aluminum alloy surface having a fine texture and a matte appearance includes: chemically polishing an aluminum alloy surface to have a 60-degree gloss between 10 GU and 1,000 GU; performing an electrolytic treatment on the chemically polished aluminum alloy surface; and performing an anodizing treatment on the aluminum alloy surface that undergoes the electrolytic treatment. The electrolytic treatment is operated at a current density between 0.01 A/dm2 and 1.5 A/dm2 and a gradually increasing voltage from 0 V to 50 V for 3 minutes to 30 minutes. The anodizing treatment is operated at a current density between 0.1 A/dm2 and 2.5 A/dm2 and a voltage between 10 V and 20 V for 30 minutes to 120 minutes.

What is claimed is: 
     
         1 . A processing method for forming an aluminum alloy surface having a fine texture and a matte appearance, comprising:
 chemically polishing an aluminum alloy surface to have a 60-degree gloss between 10 GU and 1,000 GU;   performing an electrolytic treatment on the chemically polished aluminum alloy surface, wherein the electrolytic treatment is operated at a current density between 0.01 A/dm 2  and 1.5 A/dm 2  and a gradually increasing voltage from 0 V to 50 V for 3 minutes to 30 minutes; and   performing a first anodizing treatment on the aluminum alloy surface that undergoes the electrolytic treatment, wherein the first anodizing treatment is operated at a current density between 0.1 A/dm 2  and 2.5 A/dm 2  and a voltage between 10 V and 20 V for 30 minutes to 120 minutes;   wherein, based on a CIE L*a*b color system, the aluminum alloy surface that undergoes the first anodizing treatment has an L*value from 77 to 85, an a*value from −0.55 to −0.40, and a b*value from −0.7 to 0.3.   
     
     
         2 . The processing method according to  claim 1 , wherein the electrolytic treatment is performed in a first treatment solution having a temperature between 20° C. and 80° C. and a pH value between 8 and 11; wherein, based on a total weight of the first treatment solution being 100 wt %, the first treatment solution includes 3 wt % to 15 wt % of sodium carbonate and 1 wt % to 15 wt % of fluoride; wherein the fluoride is selected from the group consisting of sodium fluoride, potassium fluoride, ammonium hydrogen fluoride, and hydrofluoric acid. 
     
     
         3 . The processing method according to  claim 2 , wherein the first treatment solution further includes 5 wt % to 50 wt % of glycerol, 0.1 wt % to 10 wt % of a chelating agent, and 0.1 wt % to 10 wt % of an additive, the chelating agent is selected from the group consisting of sodium gluconate, ethylenediaminetetraacetic acid, citric acid, and potassium sodium tartrate, and the additive is selected from the group consisting of boric acid, sodium citrate, and triethanolamine. 
     
     
         4 . The processing method according to  claim 1 , wherein the first anodizing treatment is performed in a second treatment solution having a temperature between 5° C. and 20° C.; wherein, based on a total weight of the second treatment solution being 100 wt %, the second treatment solution includes 5% to 25% of sulfuric acid, 5 wt % to 20 wt % of oxalic acid, or a combination thereof. 
     
     
         5 . The processing method according to  claim 1 , wherein, after the process of performing the first anodizing treatment, the processing method further includes: performing a pore sealing treatment on the aluminum alloy surface that undergoes the first anodizing treatment. 
     
     
         6 . The processing method according to  claim 5 , wherein, after the process of performing the pore sealing treatment, the processing method further includes: forming a diamond cut surface on the aluminum alloy surface that undergoes the pore sealing treatment. 
     
     
         7 . The processing method according to  claim 6 , wherein, after the process of forming the diamond cut surface, the processing method further includes: performing a second anodizing treatment on the diamond cut surface; wherein the second anodizing treatment is operated at a current density between 0.1 A/dm 2  and 1.5 A/dm 2  and a voltage between 10 V and 20 V for 10 minutes to 60 minutes; wherein the second anodizing treatment is performed in a third treatment solution having a temperature between 5° C. and 20° C.; wherein, based on a total weight of the third treatment solution being 100 wt %, the third treatment solution includes 5% to 20% of sulfuric acid, 5 wt % to 20 wt % of oxalic acid, or a combination thereof. 
     
     
         8 . The processing method according to  claim 7 , wherein, after the process of performing the second anodizing treatment, the processing method further includes: performing a dyeing treatment on the diamond cut surface that undergoes the second anodizing treatment. 
     
     
         9 . The processing method according to  claim 5 , wherein the pore sealing treatment is a nickel sealing treatment, a hot-water sealing treatment, or a coating and sealing treatment, and a sealing material used in the coating and sealing treatment is a UV curing or thermal curing material that includes a polyurethane polymer, a polycarbonate polymer, aminosiloxane, epoxy siloxane, a nanosilicon compound, or any combination thereof. 
     
     
         10 . The processing method according to  claim 9 , wherein, after the process of performing the pore sealing treatment, the processing method further includes: forming a diamond cut surface on the aluminum alloy surface that undergoes the pore sealing treatment. 
     
     
         11 . The processing method according to  claim 10 , wherein, after the process of forming the diamond cut surface, the processing method further includes: performing a second anodizing treatment on the diamond cut surface; wherein the second anodizing treatment is operated at a current density between 0.1 A/dm 2  and 1.5 A/dm 2  and a voltage between 10 V and 20 V for 10 minutes to 60 minutes; wherein the second anodizing treatment is performed in a third treatment solution having a temperature between 5° C. and 20° C.; wherein, based on a total weight of the third treatment solution being 100 wt %, the third treatment solution includes 5% to 20% of sulfuric acid, 5 wt % to 20 wt % of oxalic acid, or a combination thereof. 
     
     
         12 . The processing method according to  claim 11 , wherein, after the process of performing the second anodizing treatment, the processing method further includes: performing a dyeing treatment on the diamond cut surface that undergoes the second anodizing treatment. 
     
     
         13 . The processing method according to  claim 5 , wherein, between the process of performing the first anodizing treatment and the process of performing the pore sealing treatment, the processing method further includes: performing a first dyeing treatment on the aluminum alloy surface that undergoes the first anodizing treatment; wherein the first anodizing treatment includes forming a porous aluminum oxide layer on the aluminum alloy surface, and the first dyeing treatment includes filling at least one dye into a plurality of pores of the porous aluminum oxide layer. 
     
     
         14 . The processing method according to  claim 13 , wherein, after the process of performing the pore sealing treatment, the processing method further includes: forming a diamond cut surface on the aluminum alloy surface that undergoes the pore sealing treatment. 
     
     
         15 . The processing method according to  claim 14 , wherein, after the process of forming the diamond cut surface, the processing method further includes: performing a second anodizing treatment on the diamond cut surface; wherein the second anodizing treatment is operated at a current density between 0.1 A/dm 2  and 1.5 A/dm 2  and a voltage between 10 V and 20 V for 10 minutes to 60 minutes; wherein the second anodizing treatment is performed in a third treatment solution having a temperature between 5° C. and 20° C.; wherein, based on a total weight of the third treatment solution being 100 wt %, the third treatment solution includes 5% to 20% of sulfuric acid, 5 wt % to 20 wt % of oxalic acid, or a combination thereof. 
     
     
         16 . The processing method according to  claim 15 , wherein, after the process of performing the second anodizing treatment, the processing method further includes: performing a second dyeing treatment on the diamond cut surface that undergoes the second anodizing treatment.