Die-casting aluminum alloy surface blackening treatment agent, preparation method and application thereof

Abstract

The application discloses a kind of surface blackening treatment agent formula of die-casting aluminum alloy and its preparation method and application;The surface blackening treatment agent formula of die-casting aluminum alloy includes fluorozirconate, hydrogen peroxide, ammonium fluorozirconate and water.The application of the surface blackening treatment agent formula of die-casting aluminum alloy in workpiece surface treatment includes: workpiece is sandblasted, then first water washing is carried out, after degreasing treatment, second water washing is carried out, then workpiece is soaked in blackening treatment agent, after third water washing, varnish or gloss oil protection is carried out, and finally drying is carried out.The existing surface decoration treatment method of die-casting aluminum alloy is solved, uneven phenomenon is prone to occur, and powder spraying, baking, oil spraying and other operations are complicated, and the problem of high cost.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy surface treatment, specifically to a blackening agent formulation for die-cast aluminum alloys, its preparation method, and its application. Background Technology

[0002] ADC12 die-cast aluminum alloy is an Al-Si-Cu alloy. ADC12 contains the balance of aluminum (Al), 1.5–3.5% copper (Cu), 9.6–12.0% silicon (Si), ≤0.3% magnesium (Mg), ≤1.0% zinc (Zn), ≤1.3% iron (Fe), ≤0.5% manganese (Mn), ≤0.5% nickel (Ni), ≤0.2% tin (Sn), ≤200ppm calcium (Ca), ≤0.1% lead (Pb), and ≤0.005% cadmium (Cd). ADC12 is a widely used material in the aluminum casting industry. Products made from this material have high load-bearing capacity, high mechanical properties, good machinability, good demolding performance, and a high casting yield. It is particularly suitable for thin-walled parts and can meet the requirements of high-performance aluminum alloy die castings. Because ADC12 die-cast aluminum alloy has a high silicon content (9.6-12%), surface decoration methods are usually limited to powder coating, baking paint, and spray painting. The appearance and color obtained by the above surface decoration methods are prone to unevenness, and the processes of powder coating, baking paint, and spray painting are cumbersome and costly. Summary of the Invention

[0003] The purpose of this invention is to provide a blackening agent formulation for die-cast aluminum alloy surfaces, its preparation method, and its application. This solves the problems of existing surface decoration treatment methods for die-cast aluminum alloys, which are prone to unevenness and involve cumbersome and costly processes such as powder coating, baking paint, and oil spraying.

[0004] To achieve the above objectives, the present invention provides a blackening agent formulation for die-cast aluminum alloy surfaces, the formulation comprising fluorozirconic acid, hydrogen peroxide, ammonium fluorozirconate, and water.

[0005] In a preferred embodiment of the present invention, the mass percentages of each component in the blackening agent formulation for die-cast aluminum alloys are as follows: 30-40% fluorozirconic acid, 20-30% hydrogen peroxide, 5-10% ammonium fluorozirconate, and the balance being water.

[0006] In a preferred embodiment of the present invention, the mass percentages of each component in the blackening agent formulation for die-cast aluminum alloys are as follows: 35-38% fluorozirconic acid, 22-25% hydrogen peroxide, 6.5-7.5% ammonium fluorozirconate, and the balance being water.

[0007] The present invention also provides a method for preparing the above-mentioned blackening agent formulation for die-cast aluminum alloy surfaces, comprising: mixing fluorozirconic acid, hydrogen peroxide, ammonium fluorozirconate and water, wherein the mixing conditions include: a temperature of 45-55°C and a time of 2-3 min.

[0008] The present invention also provides an application of the above-mentioned die-cast aluminum alloy surface blackening agent formulation in workpiece surface treatment, comprising: sandblasting the workpiece, followed by a first water wash, degreasing treatment followed by a second water wash, then immersing the workpiece in the blackening agent, followed by a third water wash, followed by varnishing or varnishing for protection, and finally drying.

[0009] In a preferred embodiment of the present invention, the degreasing solution for degreasing treatment comprises the following components by mass percentage: 10-20% ammonium bifluoride, 5-15% citric acid, 2-8% taurine, and the balance dipropylene glycol.

[0010] In a preferred embodiment of the present invention, the workpiece is immersed in the blackening agent at a temperature of 50-60°C for 10-20 minutes.

[0011] This invention provides a blackening agent formulation for die-cast aluminum alloy surfaces, its preparation method, and its application. The blackening agent formulation includes fluorozirconic acid, hydrogen peroxide, ammonium fluorozirconate, and water. The application of this blackening agent formulation in workpiece surface treatment includes: sandblasting the workpiece, followed by a first water wash, degreasing, a second water wash, immersing the workpiece in the blackening agent, a third water wash, and then applying a clear varnish or varnish for protection, followed by drying. The blackening agent provided by this invention can form a black decorative layer on the surface of die-cast aluminum alloys, with uniform color. Furthermore, the manufacturing cost of the blackening agent is low, and its coating process is simpler and less expensive compared to powder coating, baking paint, and spray painting.

[0012] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0013] The specific embodiments of the present invention will be described in detail below.

[0014] Example 1

[0015] 30% fluorozirconic acid, 20% hydrogen peroxide, 5% ammonium fluorozirconate, and the balance water are mixed under the following conditions: temperature 45℃, time 2 min. The workpiece is then sandblasted, followed by a first water wash, degreasing treatment, a second water wash, and then immersed in a blackening agent (immersion temperature 50℃, time 10 min). After a third water wash, a varnish or varnish is applied for protection, and finally, the workpiece is dried. The degreasing solution used for the degreasing treatment comprises the following components by mass percentage: 10% ammonium hydrogen fluoride, 5% citric acid, 2% taurine, and the balance dipropylene glycol.

[0016] Example 2

[0017] 40% fluorozirconic acid, 30% hydrogen peroxide, 10% ammonium fluorozirconate, and the balance water are mixed under the following conditions: temperature 55℃, time 3 min. The workpiece is then sandblasted, followed by a first water wash, degreasing treatment, a second water wash, and then immersed in a blackening agent (immersion temperature 60℃, time 20 min). After a third water wash, a varnish or varnish is applied for protection, and finally, the workpiece is dried. The degreasing solution used for the degreasing treatment comprises the following components by mass percentage: ammonium hydrogen fluoride 20%, citric acid 5%, taurine 8%, and the balance dipropylene glycol.

[0018] Example 3

[0019] 35% fluorozirconic acid, 25% hydrogen peroxide, 7% ammonium fluorozirconate, and the balance water are mixed under the following conditions: temperature 50℃, time 2 min. The workpiece is then sandblasted, followed by a first water wash, degreasing, a second water wash, and then immersed in a blackening agent (immersion temperature 55℃, time 15 min). After a third water wash, a clear varnish or varnish is applied for protection, and finally, the workpiece is dried. The degreasing solution used for the degreasing treatment comprises the following components by mass percentage: 15% ammonium hydrogen fluoride, 10% citric acid, 5% taurine, and the balance dipropylene glycol.

[0020] The blackening agents prepared in Examples 1-3 can form a black decorative layer on the surface of die-cast aluminum alloys, with uniform coating color.

[0021] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0022] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0023] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A blackening agent for the surface of die-cast aluminum alloys, characterized in that, The surface blackening agent for die-cast aluminum alloys includes fluorozirconic acid, hydrogen peroxide, ammonium fluorozirconate, and water; the mass percentages of each component in the surface blackening agent for die-cast aluminum alloys are as follows: fluorozirconic acid 30-40%, hydrogen peroxide 20-30%, ammonium fluorozirconate 5-10%, and the balance being water.

2. The surface blackening agent for die-cast aluminum alloys according to claim 1, characterized in that, The mass percentages of each component in the surface blackening agent for die-cast aluminum alloys are as follows: fluorozirconic acid 35-38%, hydrogen peroxide 22-25%, ammonium fluorozirconate 6.5-7.5%, and the balance being water.

3. The preparation method of the surface blackening agent for die-cast aluminum alloys according to claim 1, comprising: Fluorozyric acid, hydrogen peroxide, ammonium fluorozirconate, and water are mixed under the following conditions: temperature 45-55℃, time 2-3 minutes.

4. The application of the blackening agent for die-cast aluminum alloy surfaces according to claim 1 in blackening treatment, comprising: The workpiece is sandblasted, then washed with water for the first time, degreased, washed with water for the second time, then immersed in a blackening agent, washed with water for the third time, and then protected with varnish or gloss oil, and finally dried. The degreasing solution used for the degreasing treatment includes the following components by mass percentage: ammonium fluoride 10-20%, citric acid 5-15%, taurine 2-8%, and the balance dipropylene glycol. The workpiece is immersed in the blackening agent at a temperature of 50-60℃ for 10-20 minutes.