Anodization sealing process for an aluminum or aluminum alloy element for vehicles

Abstract

The invention discloses an anodization sealing process for an aluminum or aluminum alloy element for vehicles, including the steps for rinsing with pure water, electrolysis, rinsing once again, electrical deposition sealing, rinsing with pure water several times and baking. The aluminum or aluminum alloy element for vehicles obtained thus has improved alkali resistance and erosion resistance.

Claims

1. An anodization sealing process for an aluminum or aluminum alloy element for vehicles, characterized in that, the sealing process includes the following steps: (S1) rinsing an anodized aluminum or aluminum alloy element for vehicles with water until pH value of water after rinsing is 3.0˜7.0; (S2) immersing the rinsed anodized aluminum or aluminum alloy element of the step (S1) into an ammonium acetate solution of which pH value is 6.5˜8.0 and electrolyzing the element by a single-phase alternating current of 10˜15 V for 8˜15 min under 25˜30° C.; (S3) rinsing the element in the step (S2) with water until a pH value of water after rinsing is 5.0˜7.0; (S4) putting the element rinsed in the step (S3) into a bath solution and performing electric deposition sealing with a gradient voltage on the element, forming an organic sealing film on surface of the element, for which the organic sealing film is composed of acrylic resin and amino resin; (S5) rinsing the element electrically deposited with the organic sealing film of the step (S4) with water several times until pH value of water after rinsing is 8.0˜9.0, thus providing a washed element; and (S6) baking the washed element of the step (S5) under the temperature of 180˜200° C. for 20˜30 min; wherein the element has either a high gloss surface or a semigloss surface, and when the element has the high gloss surface, mass percent of solid components in the bath solution for the electric deposition sealing of the step (S4) is 8˜9%, and the bath solution has a pH value of 8.0˜8.5, a temperature of 20˜23° C., and a conductivity of 550˜770 μs/cm, and the gradient voltage is provided by increasing voltage from 0 V to 60˜80 V over 30 s and keeping the voltage at 60˜80 V for 50 s, then increasing the voltage from 60˜80 V to 100˜120 V over 30 s, and keeping the voltage at 100˜120 V for 50 s; when the element has the semigloss surface, mass percent of solid components in the bath solution for the electric deposition sealing of the step (S4) is 9˜10%, the bath solution has a pH value of 8.3˜8.6, a temperature of 20˜23° C., and a conductivity of 650˜950 μs/cm, and the gradient voltage is provided by increasing voltage from 0 V to 80˜100 V over 30 s and keeping the voltage at 80˜100 V for 50 s, then increasing the voltage from 80˜100 V to 140˜160 V over 30 s and keeping the voltage at 150˜160 V for 50 s.

2. The anodization sealing process as claimed in claim 1, characterized in that, the mass concentration of the ammonium acetate solution in the step (S2) is 0.5˜2 g/L.

3. The anodization sealing process as claimed in claim 1, characterized in that, the conductivity of the water after rinsing in the step (S3) is controlled to be 8˜60 μs/m.

4. The anodization sealing process as claimed in claim 1, characterized in that, when the element is required to have the high gloss surface, thickness of the organic sealing film formed by the electric deposition sealing is 2˜5 μm.

5. The anodization sealing process as claimed in claim 1, characterized in that, when the element is required to have the semigloss surface, thickness of the organic sealing film formed by the electric deposition sealing is 10˜15 μm.

6. The anodization sealing process as claimed in claim 1, characterized in that, a draining step is further provided between the step (S5) and the step (S6) in which the draining lasts 15˜25 min at a temperature of 20˜40° C. and a dust-free room of a level higher than 10000.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein:

(2) FIG. 1 is a section view of the aluminum or aluminum alloy element for vehicles made according to the third and fourth embodiments of the invention;

(3) FIG. 2 is a line graph of the gradient voltage used by the first embodiment of the invention; and

(4) FIG. 3 is a line graph of the gradient voltage used by the second embodiment of the invention

DETAILED DESCRIPTION OF THE INVENTION

(5) The technical solutions of the invention are further described with reference to the embodiments below. However, the invention is not limited to these embodiments.

(6) FIG. 1 shows a section view of the aluminum or aluminum alloy element for vehicles made from the process of the invention. The aluminum or aluminum alloy element for vehicles include inner, middle and outer layers, in which the inner layer is a substrate 1 made by aluminum or aluminum alloy materials; the outer layer is electrically deposited organic sealing film 4 made by mixing the acrylic resin with the amino resin; and the middle layer refers to an anodized film 2 and electrolytic colorization layers 3. The anodized film 2 is distributed between the inner layer and the outer layer to tightly engage with the substrate and the electrically deposited sealing layer. The electrolytic colorization layers 3 are filled in the small pores formed by the anodized film 2.

First Embodiment

(7) The test sample is 40*100*2 mm, EN AW 6401 (extrusion profile).

(8) The anodized aluminum or aluminum alloy semi-finished product for vehicles is sealed by the following sealing process. The aluminum or aluminum alloy semi-finished product is made from the following process in which the surface of the aluminum or aluminum alloy semi-finished product is subject to mechanical polishing treatment including grinding and cutting by using the cloth wheel and polishing wax; the mechanically polished aluminum or aluminum alloy semi-finished product is immersed into a deoil solution including sodium pyrophosphate 12 g/L, sodium phosphate 40 g/L, sodium carbonate 35 g/L, sodium dodecyl sulfate 12 g/L, sodium silicate 10 g/L and OP-10 2 g/L and processed for 8 min under 45° C.; the deolied aluminum or aluminum alloy semi-finished product is rinsed by purer water for 4 min under room temperature and the conductivity of water after rinsing is controlled to be 50 μs/m; the rinsed aluminum or aluminum alloy semi-finished product is put in the solution in which the concentration of phosphoric acid is 750 g/L, and that of aluminum ion is 40 g/L, and subject to electrolytic polishing under the temperature of 65° C. and current density of 8 A/dm.sup.2; the electrolytically polished aluminum or aluminum alloy semi-finished product is rinsed by pure water for 4 min under room temperature, and the pH value of the water after rinsing is controlled to be 5.7; the rinsed aluminum or aluminum alloy semi-finished product is immersed into sodium hydroxide with temperature of 28° C. and concentration of 30 g/L for cleaning for 30 s; the film-removed aluminum or aluminum alloy semi-finished product is rinsed twice by pure water for 4 min, and the conductivity of the pure water after rinsing twice is controlled to be 50 μs/m; and the aluminum or aluminum alloy semi-finished product rinsed twice is immersed into the solution in which the concentration of phosphoric acid is 180 g/L and that of aluminum ion is 12 g/L, and the anodized aluminum or aluminum alloy semi-finished product is obtained through anodization for 20 min under the temperature of 17° C. and the voltage of 16 V.

(9) The aluminum or aluminum alloy semi-finished product for vehicles is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is 5.7 and the conductivity of the same is 15 μs/m.

(10) The semi-finished product rinsed by pure water is immersed into the ammonium acetate solution having a pH value of 7.1 and a mass concentration of 1.2 g/L under room temperature, and is electrolysed by a single-phase alternating current of 14V for 10 min under 28° C.

(11) The semi-finished product thus treated is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is 5.7 and the conductivity of the same is 10 μs/m.

(12) The semi-finished product thus rinsed is put into the bath solution and subject to electric deposition sealing with a gradient voltage by using the ELECRON AG-210 paint available from Kansai Paint Co., Ltd. The mass percent of the solid components in the bath solution is 8.6%. The bath solution has a pH value of 8.3, an electric deposition temperature of 21.3° C., and a conductivity of 563 μs/cm. The line graph of the gradient voltage is shown in FIG. 2, in which it takes 30 s for the voltage to increase from 0 V to 70 V, the voltage is kept at 70 V for 30 s, and it takes 30 s for the voltage to increase to 100 V and then the voltage is kept at 100 V for 50 s.

(13) The element electrically deposited with an organic sealing film is rinsed twice by pure water under room temperature, in which the element is first rinsed by pure water for 4 min, and the water after rinsing has a pH value of 8.3 and a conductivity of 13 μs/m; and the element is then rinsed by purse water for 6 min, and the water after rinsing has a pH value of 8.2 and a conductivity of 11 μs/m, until the remaining bath solution on the surface of the element is washed away.

(14) The element rinsed twice is drained. The draining process is performed for 20 min under the temperature of 25.3° C. and in the dust-free room of a level higher than 10000.

(15) The drained element is baked for 23 min under the temperature of 185˜195° C., to obtain the aluminum or aluminum alloy element for vehicles electrically deposited with an organic sealing film.

(16) The above described is the natural color oxidization and high gloss electric deposition sealing process and the sample thus obtained is numbered A.

Second Embodiment

(17) The test sample is 40*100*2 mm, EN AW 6063 (extrusion profile).

(18) The anodized aluminum or aluminum alloy semi-finished product for vehicles is sealed by the following sealing process. The anodized aluminum or aluminum alloy semi-finished product is made from the following process in which the surface of the aluminum or aluminum alloy semi-finished product is subject to mechanical polishing treatment including grinding and cutting by using the cloth wheel and polishing wax; the mechanically polished aluminum or aluminum alloy semi-finished product is immersed into a deoil solution including sodium pyrophosphate 14 g/L, sodium phosphate 38 g/L, sodium carbonate 36 g/L, sodium dodecyl sulfate 10 g/L, sodium silicate 9 g/L and OP-10 3 g/L and processed for 6 min under 45° C.; the deolied aluminum or aluminum alloy semi-finished product is rinsed by purer water for 4 min under room temperature and the conductivity of water after rinsing is controlled to be 40 μs/m; the rinsed aluminum or aluminum alloy semi-finished product is put in the solution in which the concentration of phosphoric acid is 800 g/L, and that of aluminum ion is 38 g/L, and subject to electrolytic polishing under the temperature of 70° C. and current density of 10 A/dm.sup.2; the electrolytically polished aluminum or aluminum alloy semi-finished product is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is controlled to be 6.0; the rinsed aluminum or aluminum alloy semi-finished product is immersed into sodium hydroxide with temperature of 30° C. and concentration of 28 g/L for cleaning for 35 s; the film-removed aluminum or aluminum alloy semi-finished product is rinsed twice by pure water for 5 min, and the conductivity of the pure water after rinsing twice is controlled to be under 40 μs/m; and the aluminum or aluminum alloy semi-finished product rinsed twice is immersed into the solution in which the concentration of phosphoric acid is 200 g/L and that of aluminum ion is 8 g/L, and the anodized aluminum or aluminum alloy semi-finished product for vehicles is obtained through anodization for 25 min under the temperature of 18° C. and the voltage of 16 V.

(19) The aluminum or aluminum alloy semi-finished product for vehicles is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is 5.7 and the conductivity of the same is 15 μs/m.

(20) The semi-finished product rinsed by pure water is immersed into the ammonium acetate solution having a pH value of 7.1 and a mass concentration of 12 g/L under room temperature, and is electrolysed by a single-phase alternating current of 14 V for 10 min under 28° C.

(21) The semi-finished product thus treated is rinsed by pure water for 5 min under room temperature, and the pH value of the pure water after rinsing is 5.7 and the conductivity of the same is 10 μs/m.

(22) The semi-finished product thus rinsed is put into the bath solution and subject to electric deposition sealing with a gradient voltage by using the ELECRON AG-300 paints available from Kansai Paint Co., Ltd. The mass percent of the solid components in the bath solution is 9.5%. The bath solution has a pH value of 8.5, an electric deposition temperature of 22.4° C., and a conductivity of 723 μs/cm. The line graph of the gradient voltage is shown in FIG. 2, in which it takes 30 s for the voltage to increase from 0 V to 90 V, the voltage is kept at 90 V for 30 s, and it takes 30 s for the voltage to increase to 150 V and then the voltage is kept at 150 V for 50 s.

(23) The element electrically deposited with an organic sealing film is rinsed twice by pure water under room temperature, in which the element is first rinsed by pure water for 4 min, and the water after rinsing has a pH value of 8.3 and a conductivity of 13 μs/m; and the element is then rinsed by purse water for 6 min, and the water after rinsing has a pH value of 8.2 and a conductivity of 11 μs/m, until the remaining bath solution on the surface of the element is washed away.

(24) The element rinsed twice is drained. The draining process is performed for 20 min under the temperature of 25.3° C. and in the dust-free room of a level higher than 10000.

(25) The drained element is baked for 23 min under the temperature of 185˜195° C., to obtain the aluminum or aluminum alloy element for vehicles electrically deposited with an organic sealing film.

(26) The above described is the natural color oxidization and semigloss electric deposition sealing process and the sample thus obtained is numbered B.

Third Embodiment

(27) The test sample is 40*100*2 mm, EN AW 5210 (extrusion profile).

(28) The anodized aluminum or aluminum alloy semi-finished product for vehicles is sealed by the following sealing process. The anodized aluminum or aluminum alloy semi-finished product for vehicles is made from the following process in which the surface of the aluminum or aluminum alloy semi-finished product is subject to mechanical polishing treatment including grinding and cutting by using the cloth wheel and polishing wax; the mechanically polished aluminum or aluminum alloy semi-finished product is immersed into a deoil solution including sodium pyrophosphate 15 g/L, sodium phosphate 35 g/L, sodium carbonate 40 g/L, sodium dodecyl sulfate 10 g/L, sodium silicate 8 g/L and OP-10 3 g/L and processed for 5 min under 50° C.; the deolied aluminum or aluminum alloy semi-finished product is rinsed by purer water for 5 min under room temperature and the conductivity of water after rinsing is controlled to be 30 μs/m; the rinsed aluminum or aluminum alloy semi-finished product is put in the solution in which the concentration of phosphoric acid is 850 g/L, and that of aluminum ion is 35 g/L, and subject to electrolytic polishing under the temperature of 70° C. and current density of 10 A/dm.sup.2; the electrolytically polished aluminum or aluminum alloy semi-finished product is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is controlled to be 5.0; the rinsed aluminum or aluminum alloy semi-finished product is immersed into sodium hydroxide with temperature of 32° C. and concentration of 25 g/L for cleaning for 40 s; the film-removed aluminum or aluminum alloy semi-finished product is rinsed twice by pure water for 5 min, and the conductivity of the pure water after rinsing twice is controlled to be 30 μs/m; and the aluminum or aluminum alloy semi-finished product rinsed twice is immersed into the solution in which the concentration of phosphoric acid is 200 g/L and that of aluminum ion is 5 g/L, and the anodized aluminum or aluminum alloy semi-finished product is obtained through anodization for 30 min under the temperature of 18 V and the voltage of 16 V.

(29) The anodized aluminum or aluminum alloy semi-finished product for vehicles could be subject to a conventional electrolytic colorization process or electrolytically colorized by the following process. The anodized aluminum or aluminum alloy semi-finished product for vehicles is electrolysed in the sulfuric acid having a concentration of 20 g/L and the stannous sulfate having a concentration of 20 g/L under the temperature of 22° C. and the voltage of 14˜16 V for 20 min until an electrolytic colorization layer is formed on the semi-finished product. The electrolytically colorized aluminum or aluminum alloy semi-finished product for vehicles is sealed by the following sealing process.

(30) The aluminum or aluminum alloy semi-finished product for vehicles is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is 6.0 and the conductivity of the same is 12 μs/m.

(31) The semi-finished product rinsed by pure water is immersed into the ammonium acetate solution having a pH value of 7.3 and a mass concentration of 1.5 g/L under room temperature, and is electrolysed by a single-phase alternating current of 10 V for 10 min under 28° C.

(32) The semi-finished product thus treated is rinsed by pure water for 5 min under room temperature, and the pH value of the pure water after rinsing is 5.8 and the conductivity of the same is 12 μs/m.

(33) The semi-finished product thus rinsed is put into the bath solution and subject to electric deposition sealing with a gradient voltage by using the ELECRON AG-210 paint available from Kansai Paint Co., Ltd. The mass percent of the solid components in the bath solution is 8.6%. The bath solution has a pH value of 8.3, an electric deposition temperature of 21.3° C., and a conductivity of 563 μs/m. It takes 30 s for the gradient voltage to increase from 0 V to 60 V, the gradient voltage is kept at 60 V for 50 s, and it takes 30 s for the gradient voltage to increase to 100 V and then the gradient voltage is kept at 100 V for 50 s.

(34) The element electrically deposited with an organic sealing film is rinsed twice by pure water under room temperature, in which the element is first rinsed by pure water for 4 min, and the water after rinsing has a pH value of 8.4 and a conductivity of 12 μs/m; and the element is then rinsed by purse water for 6 min, and the water after rinsing has a pH value of 8.3 and a conductivity of 10 μs/m, until the remaining bath solution on the surface of the element is washed away.

(35) The element rinsed twice is drained. The draining process is performed for 20 min under the temperature of 25.3° C. and in the dust-free room of a level higher than 10000.

(36) The drained element is baked for 23 min under the temperature of 185˜195° C., to obtain the aluminum or aluminum alloy element for vehicles electrically deposited with an organic sealing film.

(37) The above described is the natural color oxidization and high gloss electric deposition sealing process and the sample thus obtained is numbered C.

Fourth Embodiment

(38) The test sample is 40*100*2 mm, EN AW 6060 (extrusion profile).

(39) The anodized aluminum or aluminum alloy semi-finished product for vehicles is made from the same process as described in the second embodiment.

(40) The anodized aluminum or aluminum alloy semi-finished product for vehicles could be subject to a conventional electrolytic colorization process or electrolytically colorized by the following process. The anodized aluminum or aluminum alloy semi-finished product for vehicles is electrolysed in the sulfuric acid having a concentration of 20 g/L and the stannous sulfate having a concentration of 20 g/L under the temperature of 22° C. and the voltage of 14˜16 V for 20 min until an electrolytic colorization layer is formed on the semi-finished product. The electrolytically colorized aluminum or aluminum alloy semi-finished product for vehicles is sealed by the following sealing process.

(41) The aluminum or aluminum alloy semi-finished product for vehicles is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is 5.8 and the conductivity of the same is 13 μs/m.

(42) The semi-finished product rinsed by pure water is immersed into the ammonium acetate solution having a pH value of 6.8 and a mass concentration of 1.0 g/L under room temperature, and is electrolysed by a single-phase alternating current of 12 V for 10 min under 28° C.

(43) The semi-finished product thus treated is rinsed by pure water for 5 min under room temperature, and the pH value of the pure water after rinsing is 5.7 and the conductivity of the same is 9 μs/m.

(44) The semi-finished product thus rinsed is put into the bath solution and subject to electric deposition sealing with a gradient voltage by using the ELECRON AG-300 paints available from Kansai Paint Co., Ltd. The mass percent of the solid components in the bath solution is 9.5%. The bath solution has a pH value of 8.5, an electric deposition temperature of 22.4° C., and a conductivity of 723 μs/cm. It takes 30 s for the gradient voltage to increase from 0 V to 100 V, the gradient voltage is kept at 100 V for 50 s, and it takes 30 s for the gradient voltage to increase to 160 V and then the gradient voltage is kept at 160 V for 50 s.

(45) The element electrically deposited with an organic sealing film is rinsed twice by pure water under room temperature, in which the element is first rinsed by pure water for 4 min, and the water after rinsing has a pH value of 8.3 and a conductivity of 15 μs/m; and the element is then rinsed by purse water for 6 min, and the water after rinsing has a pH value of 8.1 and a conductivity of 13 μs/m, until the remaining bath solution on the surface of the element is washed away.

(46) The element rinsed twice is drained. The draining process is performed for 20 min under the temperature of 25.3° C. and in the dust-free room of a level higher than 10000.

(47) The drained element is baked for 23 min under the temperature of 185˜195° C., to obtain the aluminum or aluminum alloy element for vehicles electrically deposited with an organic sealing film.

(48) The above described is the natural color oxidization and semigloss electric deposition sealing process and the sample thus obtained is numbered D.

First Comparative Example

(49) The test sample is 40*100*2 mm, EN AW 6401 (extrusion profile). The process for making the anodized aluminum or aluminum alloy semi-finished product for vehicles is the same as that described in the first embodiment and thus will not be described here.

(50) An aluminum or aluminum alloy element electrically deposited with an organic sealing film is obtained by performing the following cold sealing and hot sealing processes on the anodized aluminum or aluminum alloy semi-finished product for vehicles. The A 609-A/-B cold sealing agent and Surtec 347 hot sealing agent available from SurTec International Gmbh are used as the sealing agent. With respect to the cold sealing, the temperature is 30° C., the pH value is 6.4, the sealing time is 8 min, the concentration of A 609-A cold sealing agent is 18 g/L and the concentration of A 609-B cold sealing agent is 6 g/L. With respect to the hot sealing, the temperature is 96° C., the pH value is 6.3, the sealing time is 25 min, and the concentration of Surtec 347 hot sealing agent is 3 g/L.

(51) The above described is the natural color oxidization and conventional sealing process, and the sample thus obtain is numbered E.

Second Comparative Example

(52) The test sample is 40*100*2 mm, EN AW 6401 (extrusion profile). The process for making the anodized aluminum or aluminum alloy semi-finished product for vehicles is the same as that described in the first embodiment and thus will not be described here.

(53) The anodized aluminum or aluminum alloy semi-finished product for vehicles is sealed by the following sealing process.

(54) The anodized aluminum or aluminum alloy semi-finished product for vehicles is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is 5.7 and the conductivity of the same is 15 μs/m.

(55) The semi-finished product rinsed by pure water is rinsed by hot water of the temperature of 75° C. for 5 min, and the pH value of the water after rinsing is 5.8 and the conductivity of the same is 12 μs/m.

(56) The semi-finished product rinsed by the hot water is rinsed by pure water for 5 min, and the pH value of the water after rinsing is 5.7 and the conductivity of the same is 10 μs/m.

(57) The semi-finished product thus rinsed is put into the bath solution and subject to electric deposition sealing by using the ELECRON AG-210 paint available from Kansai Paint Co., Ltd. The mass percent of the solid components in the bath solution is 8.6%. The bath solution has a pH value of 8.3, an electric deposition temperature of 21.3° C., and a conductivity of 563 μs/cm. The voltage of the electric deposition sealing is 110 V and the electric deposition time is 120 s.

(58) The element electrically deposited with an organic sealing film is rinsed twice by pure water under room temperature, in which the element is first rinsed by pure water for 4 min, and the water after rinsing has a pH value of 8.3 and a conductivity of 13 μs/m; and the element is then rinsed by purse water for 6 min, and the water after rinsing has a pH value of 8.2 and a conductivity of 11 μs/m, until the remaining bath solution on the surface of the element is washed away.

(59) The element rinsed twice is drained. The draining process is performed for 20 min under the temperature of 25.3° C. and in the dust-free room of a level higher than 10000.

(60) The drained element is baked for 23 min under the temperature of 185˜195° C., to obtain the aluminum or aluminum alloy element for vehicles electrically deposited with an organic sealing film.

(61) The above described is the natural color oxidization and conventional high gloss electrophoresis sealing process and the sample thus obtained is numbered F.

Third Comparative Example

(62) The test sample is 40*100*2 mm, EN AW 6063 (extrusion profile). The process for making the anodized aluminum or aluminum alloy semi-finished product for vehicles is the same as that described in the first embodiment and thus will not be described here.

(63) The anodized aluminum or aluminum alloy semi-finished product for vehicles is sealed by the following sealing process.

(64) The anodized aluminum or aluminum alloy semi-finished product for vehicles is rinsed by pure water for 5 min under room temperature, and the pH value of the water after rinsing is 5.7 and the conductivity of the same is 15 μs/m.

(65) The semi-finished product rinsed by pure water is rinsed by hot water of the temperature of 75° C. for 5 min, and the pH value of the water after rinsing is 5.8 and the conductivity of the same is 12 μs/m.

(66) The semi-finished product rinsed by the hot water is rinsed by pure water for 5 min, and the pH value of the water after rinsing is 5.7 and the conductivity of the same is 10 μs/m.

(67) The semi-finished product thus rinsed is put into the bath solution and subject to electric deposition sealing by using the ELECRON AG-300 paints available from Kansai Paint Co., Ltd. The mass percent of the solid components in the bath solution is 9.5%. The bath solution has a pH value of 8.5, an electric deposition temperature of 22.4° C., and a conductivity of 723 μs/cm. The voltage of the electric deposition sealing is 150 V and the electric deposition time is 180 s.

(68) The element electrically deposited with an organic sealing film is rinsed twice by pure water under room temperature, in which the element is first rinsed by pure water for 4 min, and the water after rinsing has a pH value of 8.3 and a conductivity of 13 μs/m; and the element is then rinsed by purse water for 6 min, and the water after rinsing has a pH value of 8.2 and a conductivity of 11 μs/m, until the remaining bath solution on the surface of the element is washed away.

(69) The element rinsed twice is drained. The draining process is performed for 20 min under the temperature of 25.3° C. and in the dust-free room of a level higher than 10000.

(70) The drained element is baked for 23 min under the temperature of 185˜195° C., to obtain the aluminum or aluminum alloy element for vehicles electrically deposited with an organic sealing film.

(71) The above described is the natural color oxidization and conventional semigloss electrophoresis sealing process and the sample thus obtained is numbered G.

(72) In order to conduct a better comparative analysis upon the aluminum or aluminum alloy element for vehicles according to the first to fourth embodiments and the first to third comparative examples, a test verification is carried out in accordance with the strictest standard TL 182 of Volkswagen anodized parts in the current vehicle industry which was published in November 2012 and is applicable to some high-end automobiles of Volkswagen, including Audi R8, the result of which is shown in Table 1.

(73) TABLE-US-00001 TABLE 1 Test Project Se- Experi- Stan- Test Test rial mental dard Require- Equip- No. Project Title Test Method ments ment 1 Neutral DIN At 25 ± 2° No change Salt Spray Salt EN C., NaCl brought by Test Box Spray Test ISO Concentration of erosion 9227 50 ± 5 g/L, at the pH 6.5-7.2 appearance 2 Copper- DIN At 25 ± 2° No change Salt Spray Accel- EN C., NaCl brought by Test Box erated ISO Concentration of erosion Acetic 9227 50 ± 5 g/L, at the Acid Salt pH 6.0-7.0, appearance Spray Test and then dis- solved in CuL.sub.2•H.sub.2O.sub.2 Concentration of 0.26 ± 0.02 g/L, 48 h 3 Acid and TL At 22~35° C., No change N/A Alkali 182 immersed in to of the Resis- solution of pH 1 appearance tance for 10 min, compared Test rinsed in water with its and the dried, initial state placed at 40° C. for one hour (cooling not permitted, and next-step test is continued), immersed into the solution of pH 13.5, rinsed in water and then dried 4 Temper- TL Placed at No Crack, High- ature 182 160° C. for No change Temper- Resistance 24 hours of the ature appearance Test Box compared with its initial state 5 Climate PV Test in hot No visible N/A Resistance 3930 and humid change of environment the appear- (Florida Exposure ance compared Test) for a with its 2-year period initial state

(74) TABLE-US-00002 TABLE 2 Performance Test Result of Aluminum or Aluminum Alloy Element for Vehicles according to the First to Fourth Embodiments and the First to Third Comparative Examples Test Project Sample Number Serial No. A B C D E F G 1 Q Q Q Q Q Q Q 2 Q Q Q Q U U U 3 Q Q Q Q U Q Q 4 Q Q Q Q U Q Q 5 Q Q Q Q Q Q Q Q—Qualified, U—Unqualified

(75) As depicted above, even though the element made by using the conventional anodization sealing process has good climate resistance, the element could generally not meet the requirements for 48-hour Copper-Accelerated Acetic Acid Salt Spray erosion resistance test, 24-hour 160° C. temperature resistance test as well as acid resistance and temperature maintenance and alkali resistance test The element made by using the conventional electrophoresis sealing process passes the alkali resistance and heat resistance tests, but tiny erosion points occur on the element after the CASS test for which the standard requirement could not met. On the other hand, the aluminum or aluminum alloy element for vehicles made by the sealing process of the invention could meet the requirements of all the tests, and present climate resistance obviously better than that made by the conventional electrophoresis sealing process.

(76) The embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art could make various alterations, supplements or alternatives to these embodiments without departing from the spirit of the invention or beyond the scope defined by the appended claims.

(77) Even though a detailed description of the invention is made here with reference to some embodiments, various changes or amendments are obvious to those skilled in the art without departing from the spirit of the invention.

LIST OF REFERENCE NUMERALS

(78) 1 Substrate 2 Anodized Film 3 Electrolytic Colorization Layer 4 Electrically deposited Organic Sealing Film