Etching solution for aluminum-containing titanium alloy and etching method thereof

Abstract

The application discloses an etching solution for an aluminum-containing titanium alloy and an etching method thereof. The etching solution comprises the following components: a fluorine ion source, an oxidizing agent, a surface wetting agent, a reaction stabilizer, an etching accelerator, a side etching inhibitor and an aluminum flocculation treatment agent. The available aluminum-containing titanium alloy types include TA7, TC4, TA15, TB2, TC30 and the like. The etching solution is easy to prepare, can realize precision etching, and can reduce the harm to operators and the pollution to the environment. Meanwhile, the problem that the flocculation of the current aluminum-containing alloy etching blocks the nozzle and the flocculation of the etching solution covers the workpiece surface, thereby affecting the product precision and causing equipment failure is solved.

Description

Technical Field

[0001] This invention belongs to the field of titanium alloy metal material processing technology, specifically relating to an etching solution and etching method for aluminum-containing titanium alloys. Background Technology

[0002] Titanium and titanium alloys, as advanced metallic materials that are corrosion-resistant, lightweight, and high-strength, are ideal choices for manufacturing substrates for various special functional components. However, in actual precision machining processes, conventional stamping processes have significant limitations. They can easily cause warping and deformation of titanium metal substrates, and the dimensional accuracy of the flow channel edges and bottom cannot meet the requirement of 0.02mm. Furthermore, the assembly of such substrates requires extremely high consistency; any dimensional deviation of any substrate will cause the entire component to be scrapped. Therefore, conventional stamping processes cannot achieve high-precision machining of aluminum-titanium metal substrates.

[0003] Compared to conventional stamping processes, novel processing methods such as chemical etching offer new pathways for the precision machining of titanium metals. However, etching titanium alloys is far more challenging than common metals like aluminum, copper, and stainless steel. It not only suffers from severe lateral etching but also requires the development of specially formulated corrosion inhibitors to ensure the smoothness and straightness of the etched edges. Currently, the mainstream titanium etching formulation is the HF+HNO3 system. This system is not only highly polluting, with poor etching solution stability, insufficient processing precision, and high production costs, making it difficult to meet the precision machining requirements of aluminum-titanium metal substrates, but also presents a specific technical bottleneck—for aluminum-titanium metals, AlF3 flocculent substances are generated during etching, which easily clog etching channels, resulting in compromised etching efficiency, processing precision, and product quality.

[0004] Domestic and international researchers have conducted related explorations on titanium metal etching technology. Some scholars have studied the corrosion resistance of Ti and Ti6Al4V in solution, finding that these two materials exhibit the strongest corrosion resistance at 37℃ and 25℃, speculating that this phenomenon is related to the dissolution of the passivation film. Other studies have tested Ti6Al4V for biomedical applications in SBF solution at 37℃. x The corrosion resistance of Fe alloys was studied, but it was found that the titanium oxide film is easily damaged by halogen elements or solutions. However, existing publicly available etching methods all suffer from insufficient etching rates and limited production scale, making it impossible to efficiently prepare the required number of fluid channels on titanium plates.

[0005] In summary, high-precision machining of aluminum-titanium metal substrates faces numerous technical challenges. Existing etching systems and methods cannot simultaneously achieve machining accuracy, efficiency, environmental friendliness, and adaptability. Therefore, tackling key problems in aluminum-titanium metal etching technology and developing new adaptable etching solution systems and corresponding etching methods are crucial for realizing precision machining of aluminum-titanium metal substrates. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0007] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0008] Therefore, the object of the present invention is to overcome the shortcomings of the prior art and provide an etching solution for aluminum-containing titanium alloys.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an etching solution for aluminum-containing titanium alloys, characterized in that: based on the mass percentage of the raw material components of the etching solution, it comprises, Fluoride ion source 10%–30 wt%, oxidant 5%–15 wt%, surface wetting agent 0.1%–1.0 wt%, reaction stabilizer 0.3%–1.5 wt%, etching accelerator 2%–10 wt%, side etching inhibitor 0.5%–3.0 wt%, aluminum flocculent treatment agent: 0.4–2.0 wt%, balance is deionized water.

[0010] As a preferred embodiment of the etching solution for aluminum-containing titanium alloys described in this invention, wherein: the fluoride ion source is selected from at least one of ammonium fluoride, potassium fluoride, and anhydrous hydrogen fluoride; the oxidant is selected from cerium ammonium nitrate; the surface wetting agent is selected from at least one of isomeric alcohol ether phosphate and nonylphenol polyoxyethylene ether phosphate; the reaction stabilizer is selected from at least one of ammonium citrate, sodium citrate, and ferric ammonium citrate; the etching accelerator is selected from at least one of sodium chloride, potassium chloride, and magnesium chloride; and the aluminum flocculant treatment agent is selected from at least one of hydrofluoric acid, liquid hydrogen fluoride, fluoroborate, special phosphonic acid, and phosphonate.

[0011] Another object of the present invention is to overcome the shortcomings of the prior art and provide a method for etching aluminum-containing titanium alloys using an etching solution, characterized in that it includes: The fluoride ion source, oxidant, surface wetting agent, reaction stabilizer, etching accelerator, and side etching inhibitor are mixed evenly and stirred gradually during the addition process to obtain a mixed solution. Adjust the mixed solution to acidic conditions; The titanium alloy metal plate to be etched is coated with a film, a film is placed on the coated metal plate for exposure, and the exposed metal plate is developed. The metal plate is sprayed and etched using a mixed solution. After 60 seconds of etching, an aluminum flocculent treatment agent is added to the circulating tank, and the spray etching of the metal plate continues to obtain the final product.

[0012] As a preferred embodiment of the etching method of the present invention, wherein the mixed solution is adjusted to acidity, the pH of the system is adjusted to 2-3.

[0013] In a preferred embodiment of the etching method described in this invention, the spray pressure during the spray etching operation is 1.5~3 kg / cm². 2 .

[0014] In a preferred embodiment of the etching method described in this invention, the spraying temperature is 40~50℃ and the spraying time is 5~15min.

[0015] As a preferred embodiment of the etching method of the present invention, the nozzle for spray etching is a hollow cone nozzle with a spray angle of 60~90°, a horizontal / vertical spacing of 150~250 mm, and a height distance between the workpiece and the nozzle of 200~300 mm.

[0016] Another object of the present invention is to overcome the shortcomings of the prior art and provide an application of an etching solution in etching aluminum-containing titanium alloys.

[0017] As a preferred embodiment of the application described in this invention, the metal plate to be etched includes a bipolar plate, a titanium-aluminum composite plate, and a heat exchange core plate for computing servers and nuclear power plants.

[0018] As a preferred embodiment of the application described in this invention, the aluminum-containing titanium alloy types include TA7, TC4, TA15, TB2, and TC30.

[0019] Beneficial effects of this invention: (1) The present invention provides an etching solution for aluminum-containing titanium alloys. The etching solution is easy to prepare, can achieve precision etching, and can reduce harm to operators and pollution to the environment. At the same time, it solves the problems of flocculent material clogging the nozzle and flocculent material covering the workpiece surface, which affect product accuracy and equipment failure in the current etching of aluminum alloys.

[0020] (2) The etching method provided by the present invention can form high-precision etching of aluminum-containing titanium precision plates, which can be applied to applications such as bipolar plates, titanium-aluminum composite plates and nuclear power heat exchange core plates, and can solve the problem of high processing cost of aluminum-containing titanium alloy forming etching. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 The microchannel heat exchange TC4 metal flow channel plate made for Example 1.

[0022] Figure 2 These are AlF3 flocculent deposits that appear during the etching process. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0025] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0026] The raw materials used in this invention are as follows: ammonium fluoride (NH4F) was purchased from Wuhan Chujiang Haoyu Chemical Technology Development Co., Ltd., cerium ammonium nitrate was purchased from Sinopharm Chemical Reagent Co., Ltd., isotridecyl alcohol polyoxyethylene ether phosphate was purchased from Wuhan Jihechang New Material Co., Ltd., ammonium citrate was purchased from Hunan Dongting Citric Acid Chemical Co., Ltd., sodium chloride was purchased from Hunan Xiangli Salt Chemical Co., Ltd., and polyacrylonitrile-thiourea copolymer compound was purchased from Hunan Linte Technology Co., Ltd., model 3302.

[0027] The instruments used in this embodiment of the invention are: the spraying equipment is from Shenzhen Chengshengjie Automation Equipment Co., Ltd., and the two-dimensional measuring equipment is Viewmax (Hexagon).

[0028] In this embodiment of the invention, etching is performed using Guangxin UV-curable acid etching resist ink (model KSM-UV201). The coating method is screen printing, with a thickness of 10~12 μm. After coating, pre-baking is performed at 80~90℃ for 15~20 min (hot air drying).

[0029] The exposure process used a parallel UV light exposure machine as the light source, with a main emission wavelength of 365 nm (i-line UV light); the exposure energy was controlled at 100–150 mJ / cm². 2 Exposure was performed using a vacuum-sealed film mask with an exposure time of 15–30 s. The exposure environment was a dust-free environment with ambient temperature controlled at 22–26 ℃ and relative humidity of 55%–65%.

[0030] Performance testing method in this embodiment of the invention: Appearance and contour inspection: A two-dimensional image measuring instrument (accuracy ±2μm) is used to observe the surface of the workpiece after development to determine whether the residual film in the unexposed area has been completely peeled off, and whether the film layer in the exposed area is intact, without peeling, drilling, or scratches; the line width and line spacing of the etched pattern are measured; other visual judgments such as flocculent matter are also made.

[0031] Example 1 This embodiment provides an etching method for aluminum-containing titanium alloys, specifically including the following steps: (1) 20 wt% ammonium fluoride (NH4F) ion source, 10 wt% cerium ammonium nitrate oxidant, 0.5 wt% isotridecyl alcohol polyoxyethylene ether phosphate ester surface wetting agent, 1 wt% ammonium citrate reaction stabilizer, 5 wt% sodium chloride etching accelerator, and 1.5 wt% polyacrylonitrile-thiourea copolymer compound are slowly mixed evenly under stirring conditions, with the remainder being deionized water. The stirring time is 15 minutes until all substances are dissolved to obtain a mixed solution.

[0032] (2) Use hydrochloric acid to adjust the acidity of the mixed solution to between 2 and 3.

[0033] (3) Etching process parameters: spray pressure is 2.5 kg / cm 2 Etching temperature: 45℃; Spraying time: 10min; Nozzle: hollow cone nozzle; Spraying angle: 70°; Horizontal / vertical spacing: 200 mm; Height distance between workpiece and nozzle: 250 mm.

[0034] (4) Apply the prepared etching solution to the etching of aluminum-containing titanium alloy: Coat the titanium alloy metal plate (TC4) to be etched; cover the coated metal plate with a film for exposure treatment, and develop the exposed metal plate. (5) 60 seconds after etching begins, add 1 wt% of aluminum flocculent treatment agent ATMP to the circulation tank.

[0035] (6) Continue to etch the metal plate using etching solution to obtain the etched aluminum-titanium alloy, such as Figure 1 As shown.

[0036] Example 2 The difference between this embodiment and embodiment 1 is that the amount of ammonium fluoride (NH4F) in step (1) is adjusted to 10wt%, and the amount of deionized water is adjusted accordingly so that the total amount of etching solution is kept at 100wt%. The remaining steps are the same as in embodiment 1, and the etched aluminum-titanium alloy is obtained.

[0037] Example 3 The difference between this embodiment and embodiment 1 is that the amount of ammonium fluoride (NH4F) in step (1) is adjusted to 30wt%, and the amount of deionized water is adjusted accordingly so that the total amount of etching solution is kept at 100wt%. The remaining steps are the same as in embodiment 1, and the etched aluminum-titanium alloy is obtained.

[0038] Example 4 The difference between this embodiment and embodiment 1 is that the amount of cerium ammonium nitrate in step (1) is adjusted to 5wt%, and the amount of deionized water is adjusted accordingly so that the total amount of etching solution is kept at 100wt%. The remaining steps are the same as in embodiment 1, and the etched aluminum-titanium alloy is obtained.

[0039] Example 5 The difference between this embodiment and embodiment 1 is that the amount of cerium ammonium nitrate in step (1) is adjusted to 15wt%, and the amount of deionized water is adjusted accordingly so that the total amount of etching solution is kept at 100wt%. The remaining steps are the same as in embodiment 1, and the etched aluminum-titanium alloy is obtained.

[0040] Example 6 The difference between this embodiment and embodiment 1 is that the amount of polyacrylonitrile-thiourea copolymer in step (1) is adjusted to 0.5wt%, and the amount of deionized water is adjusted accordingly so that the total amount of etching solution is kept at 100wt%. The remaining steps are the same as in embodiment 1, and the etched aluminum-titanium alloy is obtained.

[0041] Example 7 The difference between this embodiment and embodiment 1 is that the amount of polyacrylonitrile-thiourea copolymer in step (1) is adjusted to 3.0 wt%, and the amount of deionized water is adjusted accordingly so that the total amount of etching solution is kept at 100 wt%. The remaining steps are the same as in embodiment 1, and the etched aluminum-titanium alloy is obtained.

[0042] Example 8 The difference between this embodiment and embodiment 1 is that the amount of ATMP added in step (5) is replaced with 0.5 wt%, and the amount of deionized water is adjusted accordingly so that the total amount of etching solution is kept at 100 wt%. The remaining steps are the same as in embodiment 1, and the etched aluminum-titanium alloy is obtained.

[0043] Example 9 The difference between this embodiment and embodiment 1 is that the amount of ATMP added in step (5) is replaced with 2.0 wt%, and the amount of deionized water is adjusted accordingly so that the total amount of etching solution is kept at 100 wt%. The remaining steps are the same as in embodiment 1, and the etched aluminum-titanium alloy is obtained.

[0044] Comparative Example 1 The difference between this comparative example and Example 1 is that cerium ammonium nitrate is not added, and the amount of deionized water is adjusted to keep the total amount of etching solution at 100 wt%. The remaining steps are the same as in Example 1, and the etched aluminum-titanium alloy is obtained.

[0045] Comparative Example 2 The difference between this comparative example and Example 1 is that isomeric tridecyl alcohol polyoxyethylene ether phosphate is not added, and the amount of deionized water is adjusted accordingly to keep the total amount of etching solution at 100 wt%. The remaining steps are the same as in Example 1, and the etched aluminum-titanium alloy is obtained.

[0046] Comparative Example 3 The difference between this comparative example and Example 1 is that ammonium citrate is not added, and the amount of deionized water is adjusted accordingly to keep the total amount of etching solution at 100 wt%. The remaining steps are the same as in Example 1, and the etched aluminum-titanium alloy is obtained.

[0047] Comparative Example 4 The difference between this comparative example and Example 1 is that sodium chloride is not added, and the amount of deionized water is adjusted to keep the total amount of etching solution at 100 wt%. The remaining steps are the same as in Example 1, and the etched aluminum-titanium alloy is obtained.

[0048] Comparative Example 5 The difference between this comparative example and Example 1 is that no polyacrylonitrile-thiourea copolymer compound is added, and the amount of deionized water is adjusted to keep the total amount of etching solution at 100 wt%. The remaining steps are the same as in Example 1, and the etched aluminum-titanium alloy is obtained.

[0049] Comparative Example 6 The difference between this comparative example and Example 1 is that polyATMP is not added, and the amount of deionized water is adjusted to keep the total amount of etching solution at 100 wt%. The remaining steps are the same as in Example 1, and the etched aluminum-titanium alloy is obtained.

[0050] The performance of the finished products obtained in the examples and comparative examples was tested, and the results are shown in Table 1.

[0051] Table 1

[0052] Note: OK means that the dimensional requirements are met (straightness > 90%, side etching ≤ 0.03mm, and the etched line width and shape are complete) and the product surface cleanliness requirements are met (no black spots and no shadows on the surface).

[0053] In this invention, ammonium fluoride (NH4F) serves as a fluoride ion source, offering higher safety than HF and enabling the stripping of titanium oxide and titanium metal. Cerium ammonium nitrate, a strong oxidant, accelerates etching. Isomeric tridecyl alcohol polyoxyethylene ether phosphate acts as a surfactant, enhancing the permeability of the etching solution. Ammonium citrate stabilizes the solution and facilitates the slow release of etching ions. Chloride ions from sodium chloride accelerate the reaction. The polyacrylonitrile-thiourea copolymer acts as a side-etching complexing agent, protecting the sides during spraying and improving etching straightness. ATMP enables the complexation and precipitation of aluminum ions, preventing the formation of AlF3 in the system. Figure 2 The ATMP appears in the system as flocculent matter, and it can preferentially combine with Al ions to form complexes and precipitate. At the same time, the precipitate is cleaned in the circulation tank to ensure that the etching proceeds smoothly.

[0054] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. An etching solution for aluminum-containing titanium alloys, characterized in that: The etching solution comprises, by mass percentage, the raw material components, including, Fluoride ion source 10%–30 wt%, oxidant 5%–15 wt%, surface wetting agent 0.1%–1.0 wt%, reaction stabilizer 0.3%–1.5 wt%, etching accelerator 2%–10 wt%, side etching inhibitor 0.5%–3.0 wt%, aluminum flocculent treatment agent: 0.4–2.0 wt%, balance is deionized water.

2. The etching solution for aluminum-containing titanium alloys as described in claim 1, characterized in that: The fluoride ion source is selected from at least one of ammonium fluoride, potassium fluoride, and anhydrous hydrogen fluoride; the oxidant is selected from cerium ammonium nitrate; the surface wetting agent is selected from at least one of isomeric alcohol ether phosphate and nonylphenol polyoxyethylene ether phosphate; the reaction stabilizer is selected from at least one of ammonium citrate, sodium citrate, and ferric ammonium citrate; the etching accelerator is selected from at least one of sodium chloride, potassium chloride, and magnesium chloride; and the aluminum flocculent treatment agent is selected from at least one of hydrofluoric acid, liquid hydrogen fluoride, fluoroborate, special phosphonic acid, and phosphonate.

3. The etching method for aluminum-containing titanium alloys using the etching solution as described in claim 1 or 2, characterized in that: include, The fluoride ion source, oxidant, surface wetting agent, reaction stabilizer, etching accelerator, and side etching inhibitor are mixed evenly and stirred gradually during the addition process to obtain a mixed solution. Adjust the mixed solution to acidic conditions; The titanium alloy metal plate to be etched is coated with a film, a film is placed on the coated metal plate for exposure, and the exposed metal plate is developed. The metal plate is sprayed and etched using a mixed solution. After 60 seconds of etching, an aluminum flocculent treatment agent is added to the circulating tank, and the spray etching of the metal plate continues to obtain the final product.

4. The etching method as described in claim 3, characterized in that: The mixed solution is adjusted to acidity, wherein the pH of the system is adjusted to 2-3.

5. The etching method as described in claim 3, characterized in that: The spraying pressure for the spray etching operation is 1.5~3 kg / cm². 2 .

6. The etching method as described in claim 3, characterized in that: The spraying temperature is 40~50℃, and the spraying time is 5~15min.

7. The etching method as described in claim 3, characterized in that: The nozzles used for spray etching are hollow cone nozzles with a spray angle of 60~90°, a horizontal / vertical spacing of 150~250 mm, and a height distance of 200~300 mm between the workpiece and the nozzle.

8. The application of the etching solution as described in claim 1 or 2 in etching aluminum-containing titanium alloys.

9. The application as described in claim 8, characterized in that: The aluminum-containing titanium alloy includes bipolar plates, titanium-aluminum composite plates, and heat exchange core plates for computing servers and nuclear power plants.

10. The application as described in claim 8, characterized in that: The aluminum-containing titanium alloy models include TA7, TC4, TA15, TB2, and TC30.

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