阅读说明：本技术 一种铝及铝合金的阳极氧化电解着色工艺 (Anodic oxidation electrolytic coloring process for aluminum and aluminum alloy ) 是由 王相刚 夏良文 肖茂强 刘国永 于 2019-09-17 设计创作，主要内容包括：本发明公开了一种铝及铝合金的阳极氧化电解着色工艺,其包括如下工艺步骤：1)前处理：基材除油、碱蚀、阳极氧化处理,得预着色件；2)电解着色：将预着色件置于由下层为有机物溶液和上层为电解液组成的电解槽中静浸5～15s,预着色工件缓慢移动过程中控制直流输出电压为10～20V,工作时间为5～15s,后转换成交流输出电压为15～25V,工作时间为3～60s,得半成品；3)后处理：半成品经中温封孔处理、电泳处理,得成品。本发明通过完善铝及铝合金的阳极氧化电解着色工艺流程,采用特殊的上下层电解槽,使其具有效益高、环保、着色层装饰效果良好的优点,同时工艺简单,可大规模工业化生产。(The invention discloses an anodic oxidation electrolysis coloring process for aluminum and aluminum alloy, which comprises the following process steps: 1) pretreatment: removing oil from the base material, performing alkaline etching and anodizing treatment to obtain a pre-coloring part; 2) electrolytic coloring: placing the pre-coloring part in an electrolytic tank consisting of an organic matter solution at the lower layer and an electrolyte at the upper layer for static immersion for 5-15 s, controlling the direct current output voltage to be 10-20V and the working time to be 5-15 s in the slow moving process of the pre-coloring part, and then converting the pre-coloring part into an alternating current output voltage to be 15-25V and the working time to be 3-60 s to obtain a semi-finished product; 3) and (3) post-treatment: and (5) carrying out medium-temperature hole sealing treatment and electrophoresis treatment on the semi-finished product to obtain a finished product. The invention improves the anodic oxidation electrolysis coloring process flow of aluminum and aluminum alloy, adopts special upper and lower layer electrolytic tanks, has the advantages of high benefit, environmental protection and good coloring layer decorative effect, simultaneously has simple process and can realize large-scale industrial production.)

1. An anodic oxidation electrolysis coloring process for aluminum and aluminum alloy is characterized by comprising the following process steps:

1) pretreatment: removing oil from the base material, performing alkaline etching and anodizing treatment to obtain a pre-coloring part;

2) electrolytic coloring: placing the pre-coloring part in an electrolytic tank consisting of an organic matter solution at the lower layer and an electrolyte at the upper layer for static immersion for 5-15 s, controlling the direct current output voltage to be 10-20V and the working time to be 5-15 s in the slow moving process of the pre-coloring part, and then converting the pre-coloring part into an alternating current output voltage to be 15-25V and the working time to be 3-60 s to obtain a semi-finished product;

3) and (3) post-treatment: and (5) carrying out medium-temperature hole sealing treatment and electrophoresis treatment on the semi-finished product to obtain a finished product.

2. The anodic oxidation electrolytic coloring process for aluminum and aluminum alloys according to claim 1, wherein: the organic solution in the step 2) is selected from one of trichloroethylene, perchloroethylene and carbon tetrachloride.

3. The anodic oxidation electrolytic coloring process for aluminum and aluminum alloys according to claim 1, wherein: the electrolyte in the step 2) contains 10-15 g/L of cobalt salt, 3-5 g/L of tin salt, 1-1.5 g/L of selenate and 15-20 g/L of free sulfuric acid.

4. The anodic oxidation electrolytic coloring process for aluminum and aluminum alloys according to claim 1, wherein: the temperature of the bath solution of the electrolytic bath in the step 2) is 20-25 ℃.

5. The anodic oxidation electrolytic coloring process for aluminum and aluminum alloys according to claim 1, wherein: the anodic oxidation treatment in the step 1) adopts a water cooling mode, so that the temperature is controlled to be 15-20 ℃, the bath solution is a sulfuric acid solution with the concentration of 10-200 g/L, the anodic oxidation time is 20-60 min, and the current density is controlled to be 1.1-1.8A/dm²。

6. The anodic oxidation electrolytic coloring process for aluminum and aluminum alloys according to claim 1, wherein: the medium-temperature hole sealing treatment in the step 3) is to soak the semi-finished product in an aluminum acetate aqueous solution for hole sealing, the reaction temperature is 15-30 ℃, and the hole sealing time is 12-16 min.

Technical Field

The invention relates to surface treatment of metal materials, in particular to a surface coloring process of aluminum and aluminum alloy.

Background

The traditional aluminum and aluminum alloy anode oxidation electrolytic coloring realizes the industrial mass production of only a few salts such as stannous sulfate (champagne, bronze and black), nickel sulfate (champagne, bronze and black), potassium permanganate (golden yellow), copper sulfate (purple copper), selenium dioxide (K gold) and the like, and the color diversity is relatively monotonous compared with the coloring. The light resistance and weather resistance of the dyeing are far better than those of electrolytic coloring, and the dyeing can not be used outdoors, so that the dyeing has great limitation. In addition, in order to improve the decorative effect of the anodic oxidation coloring, toxic nickel metals are often required to be added and a large amount of metal salt solution is consumed, so how to simultaneously realize good decoration and high weather resistance for aluminum and aluminum alloy products, and the preparation method is environment-friendly and high in benefit, and becomes one of the key technologies for which the development is urgently needed for rate and surface treatment of aluminum alloy.

Disclosure of Invention

The invention aims to provide an anodic oxidation electrolysis coloring process for aluminum and aluminum alloy aiming at the defects of the prior art.

The technical scheme adopted by the invention is as follows: an anodic oxidation electrolysis coloring process for aluminum and aluminum alloy comprises the following process steps:

1) pretreatment: removing oil from the base material, performing alkaline etching and anodizing treatment to obtain a pre-coloring part;

2) electrolytic coloring: placing the pre-coloring part in an electrolytic tank consisting of an organic matter solution at the lower layer and an electrolyte at the upper layer for static immersion for 5-15 s, controlling the direct current output voltage to be 10-20V and the working time to be 5-15 s in the slow moving process of the pre-coloring part, and then converting the pre-coloring part into an alternating current output voltage to be 15-25V and the working time to be 3-60 s to obtain a semi-finished product;

3) and (3) post-treatment: and (5) carrying out medium-temperature hole sealing treatment and electrophoresis treatment on the semi-finished product to obtain a finished product.

Specifically, the invention adopts a regulation mode of combining the special arrangement of the upper layer and the lower layer of the electrolytic bath with the limited working voltage and working time parameters, so that color stripes can be formed after electrolytic coloring, and an ideal coloring effect can be obtained by properly changing the voltage parameters and the time parameters.

As a further improvement of the scheme, the organic solution in the step 2) is selected from one of trichloroethylene, perchloroethylene and carbon tetrachloride. Specifically, the organic solution is incompatible with the electrolyte, and thus stripes of different barrier film strengths may be generated when the pre-colored workpiece is slowly moved in the two-layer solution.

As a further improvement of the scheme, the electrolyte in the step 2) contains 10-15 g/L of cobalt salt, 3-5 g/L of tin salt, 1-1.5 g/L of selenate and 15-20 g/L of free sulfuric acid. Specifically, the electrolyte does not contain toxic metal elements, so that the electrolyte has the advantage of environmental protection, and the types of three salt solutions are limited, namely, a cobalt salt, a tin salt and a selenate are specially used as a complex system of the electrolyte, so that a product with good decorative effect and good performance of a coloring layer can be obtained.

As a further improvement of the scheme, the temperature of the bath solution of the electrolytic bath in the step 2) is 20-25 ℃.

As a further improvement of the scheme, the anodic oxidation treatment in the step 1) adopts a water cooling mode, so that the temperature is controlled to be 15-20 ℃, the bath solution is a sulfuric acid solution with the concentration of 10-200 g/L, the anodic oxidation time is 20-60 min, and the current density is controlled to be 1.1-1.8A/dm²。

As a further improvement of the scheme, the medium-temperature hole sealing treatment in the step 3) is to soak the semi-finished product in an aluminum acetate aqueous solution for hole sealing, the reaction temperature is 15-30 ℃, and the hole sealing time is 12-16 min.

The invention has the beneficial effects that: the invention improves the anodic oxidation electrolysis coloring process flow of aluminum and aluminum alloy, adopts special upper and lower layer electrolytic tanks, has the advantages of high benefit, environmental protection and good coloring layer decorative effect, simultaneously has simple process and can realize large-scale industrial production.

Detailed Description

The present invention is specifically described below with reference to examples in order to facilitate understanding of the present invention by those skilled in the art. It should be particularly noted that the examples are given solely for the purpose of illustration and are not to be construed as limitations on the scope of the invention, as non-essential improvements and modifications to the invention may occur to those skilled in the art, which fall within the scope of the invention as defined by the appended claims. Meanwhile, the raw materials mentioned below are not specified in detail and are all commercial products; the process steps or preparation methods not mentioned in detail are all process steps or preparation methods known to the person skilled in the art.