CN103014711A - Aluminum alloy chemical-milling solution and milling method using same - Google Patents

Abstract

_{The invention} discloses an aluminum _alloy chemical milling solution and _a milling method thereof. Prepare a chemical milling solution with deionized water; then put the pretreated duralumin or superhard aluminum alloy into the solution, and carry out milling at an appropriate temperature and stirring speed; after reaching the depth of chemical milling, take out the test piece , to check the roughness of the aluminum alloy surface after chemical milling and calculate the chemical milling speed. The chemical milling solution designed by the technical scheme of the present invention is not only suitable for milling of hard aluminum and superhard aluminum alloy, but also has the advantages of high chemical milling speed, small surface roughness and convenient control of process parameters.

Description

A kind of aluminum alloy chemical milling solution and milling method thereof

technical field

The invention belongs to the field of metal processing, and more specifically relates to a new aluminum alloy chemical milling solution and milling process, which is mainly used for chemical milling processing of duralumin and superhard aluminum alloy.

Background technique

Chemical milling refers to immersing the part of the metal material to be processed in an appropriate chemical medium (solution). Due to the corrosion reaction between the surface of the workpiece and the chemical solution, the material is continuously dissolved and removed, thereby obtaining the required shape and shape of the part. size. Since chemical milling is a special processing technology with no tools, no chips, no stress, and no coordination problems between workpieces, it can process extra-thin, easily deformed, and large-area parts, and can reduce structural weight and process equipment. Shorten the production cycle. Therefore, the application range of chemical milling is more and more extensive, and it has become an irreplaceable method in the manufacture of low-temperature storage tanks for aircraft, spacecraft, and rocket structures and the processing of large-scale integrated circuit components for electronic computers.

In the forming process of aviation and aerospace industry parts, chemical milling of aluminum alloy components (such as aircraft skins, storage tanks, etc.) has become a reliable processing method that is much superior to traditional mechanical processing methods. The chemical milling effect of aluminum alloys (chemical milling rate, surface roughness, etch ratio, etc.) is not only related to pretreatment processes such as degreasing, light emitting, and protective coating, but more importantly, it is related to the composition and composition of the chemical milling solution. Process control is inseparable. The chemical milling solution of aluminum alloy can be roughly divided into two categories: acidic system and alkaline system. The acidic chemical milling solution of aluminum alloy is usually composed of 1.25mol/LFeCl ₃ ([1] Yi Huizhi, Deng Feiyue, Zhang Zhongting, Research on chemical milling process of 2197 Al-Li alloy, Surface Technology, 2010, 39(4): 73- 75; [2] Cakir O, Chemical etching of aluminum, Journal of Materials Processing Technology, 2008, 199 (1-3): 337-340) or FeCl ₃ +HCl+HNO ₃ +CuSO ₄ system ([3]Lada H , Park L, Fishter R E, Method and composition for removing aluminum coatings from nickel superallloys, US Patent No.4339282, 1981) composition. Although the chemical milling temperature of the acidic system is low (20-50°C or 60-70°C), the surface quality of the aluminum alloy after chemical milling is poor (the surface roughness Ra is about 7-10 μm).

Alkaline chemical milling solutions for aluminum alloys are usually composed of NaOH and dissolved Al; in addition, Na ₂ S, triethanolamine (TEA), ethylenediaminetetraacetic acid (EDTA), NaNO ₃ , Na ₂ CO ₃ , ethyl Glycol or glycerin, and a little corrosion inhibitor or other additives, etc. For example, Yi Huizhi, Li Bo, Yin Maosheng, Mao Daheng, Lin Cui, etc. respectively used the NaOH+Na ₂ S+TEA+dissolved Al system to chemically mill 2197, 5A90, and LY12 aluminum alloys, and optimized the solution ratio and milling process. Cutting temperature ([1] Yi Huizhi, Deng Feiyue, Zhang Zhongting, Research on Chemical Milling Process of 2197 Al-Li Alloy, Surface Technology, 2010, 39(4): 73-75; [4] Li Bo, An Al-Li Alloy Chemical milling solution, Chinese patent 201110341285.1; [5] Yin Maosheng, Liao Guangqi, Wen Qingjie, Cheng Hongxia, Research on chemical milling process of aluminum alloy barrel, Material Protection, 2005, 38(8): 24-25; [6] Mao Daheng , Han Defu, Zhou Yajun, Zhang Can, Chemical Milling Process of 2197 Al-Li Alloy, Mechanical Engineering Materials, 2011, 35(5): 77-79; [7] Lin Cui, Cai Jian, Zeng Fengguang, Huang Qian, Du Nan , Zhao Qing, LY12 aluminum alloy milling process and factors affecting processing quality, Failure Analysis and Prevention, 2010, 5(1):8-16). On this basis, Xie Chunying and Yin Maosheng also added a little HX corrosion inhibitor and additives to improve the roughness and uniformity of the aluminum alloy surface after chemical milling ([8] Xie Chunying, Liu Min, Zhu Kai, Wen Qingjie, Aluminum Alloy Chemical Milling Fatigue Performance, Corrosion and Protection, 2008, 29(4): 185-188; [9] Yin Maosheng, Liao Guangqi, Jiang Hongjun, Analysis of Common Faults in Aluminum Alloy Chemical Milling, Coating and Plating, 2008, (8): 47-49). In addition, Yi Huizhi and Gross respectively used NaOH+Na ₂ S+dissolved Al+EDTA+Na ₂ CO ₃ , NaOH+NaNO ₃ +ethylene glycol or glycerol system to carry out chemical milling on 2197 and 2219 aluminum alloys ( [1] Yi Huizhi, Deng Feiyue, Zhang Zhongting, Research on chemical milling process of 2197 Al-Li alloy, Surface Technology, 2010, 39(4): 73-75; [10] Gross D W, Chemical milling process and etchants therefor, US Patent No. 4588474, 1984).

Although the above alkaline chemical milling solution can be used for milling processing of various aluminum alloys, there are high chemical milling temperature (75-110°C), large chemical milling rate range (0.010-0.070mm/min), surface There are problems such as large difference in roughness (Ra=0.8～4.0μm), especially when the depth of chemical milling exceeds 5mm, the roughness of the material surface increases significantly.

With the development of the aviation industry, the precision control requirements for the milling process conditions and surface quality of aluminum alloy parts are getting higher and higher. Therefore, it is necessary to optimize the combination and precise control of the composition of the aluminum alloy milling solution and the milling process. The chemical milling process of aluminum alloy has the characteristics of high chemical milling speed, small surface roughness, and simple process control, so as to ensure the quality of chemical milling parts and the production delivery schedule.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, through the combined design of the composition and proportion of the chemical milling solution, the chemical milling process of aluminum alloy has the characteristics of high chemical milling speed and small surface roughness, and has process parameter control It is convenient and simple, and is suitable for the technical requirements of chemical milling of hard aluminum and superhard aluminum alloy, so as to ensure the high quality and process control of chemical milling aluminum alloy.

Technical purpose of the present invention is achieved through the following technical solutions:

An aluminum alloy milling solution, each component is as follows: 140-200g/L NaOH, 6-30g/L Na ₂ S, 25-50g/LTEA, 10-30g/L EDTA, 10-40g/L Na ₂ S ₂ O ₃ ·5H ₂ O, 10-40g/L Al, the solvent is water; when preparing, add 1/3 volume of water to the chemical milling groove, and then add NaOH, Na ₂ S, EDTA under stirring conditions, Then add Na ₂ S ₂ O ₃ ·5H ₂ O, TEA and pure aluminum dissolved in water in advance to make up the remaining water, and stir well.

When using the above solutions for milling applications, the specific process is as follows:

Heat the chemical milling solution to 75-95°C, then grind, clean and chemically degrease successively with 200#-2000# water sandpaper (10g/L NaOH+30g/L Na ₂ SiO ₃ 9H ₂ O at 70°C +664 detergent system for 2 minutes, the system is an aqueous solution), flowing water washing, light (soaking in room temperature, 300g/L nitric acid aqueous solution for 5 minutes), flowing water washing, hot air drying at 60-80°C and other pre-treated duralumin Or the super-duralumin test piece is put into the solution, and the milling process is carried out at the solution stirring speed of 50-200rpm. After reaching the depth of chemical milling or etching for a certain period of time, take out the specimen and perform treatments such as light extraction (immersion in 300g/L nitric acid aqueous solution at room temperature for 5min), flowing water washing, and hot air drying.

The technical scheme of the present invention is first to utilize appropriate amount of analytically pure NaOH, Na ₂ S, triethanolamine (TEA), ethylenediaminetetraacetic acid (EDTA), Na ₂ S ₂ O ₃ , industrial pure Al and deionized water to prepare chemical milling solution; then put the pre-treated duralumin or superhard aluminum alloy into the solution, and carry out milling treatment at an appropriate temperature and stirring speed; after reaching the depth of chemical milling, take out the test piece, and inspect the The roughness of the aluminum alloy surface and calculate the chemical milling speed. Use a vernier caliper or a balance with an accuracy of one ten-thousandth to measure the thickness and weight of the specimen before and after chemical milling, and calculate the chemical milling speed. At the same time, the surface roughness of the aluminum alloy after chemical milling was measured by a surface roughness measuring instrument. The beneficial effect of the invention is that the designed chemical milling solution is not only suitable for milling of hard aluminum and superhard aluminum alloy, but also has the advantages of high chemical milling speed, small surface roughness and convenient control of process parameters. The specific experimental data are as follows:

(1) High milling speed Using the invented milling solution to mill 2219, LY12, 2195, 7075, 7A60 and other aluminum alloys; the calculated milling speed of the milling solution for aluminum alloys is 0.030-0.060mm/ Changes between minutes. It takes about 1.5 to 3.0 hours for a chemical milling depth of 5mm.

(2) The surface roughness is small. Using the invented chemical milling solution, the aluminum alloys such as 2219, LY12, 2195, 7075, and 7A60 have been milled; after the surface roughness measurement, the surface roughness of the aluminum alloy when the chemical milling depth reaches 5mm Ra varies between 0.8 and 2.0 μm, which meets the precision requirements of chemical milling parts.

Detailed ways

Further illustrate technical scheme of the present invention below in conjunction with specific embodiment

Implementation plan one

(1) According to the volume of the prepared solution and the amount of 180g/L NaOH, 20g/L Na ₂ S, 40g/LTEA, 10g/L EDTA, 20g/LNa ₂ S ₂ O ₃ 5H ₂ O, 30g/L Al Take the components of the solution; first add 1/3 volume of water to the chemical milling tank, add NaOH, Na ₂ S, EDTA in turn under stirring conditions, and then add Na ₂ S ₂ O ₃ 5H ₂ dissolved in water in advance O, TEA and pure aluminum, make up the remaining water, and stir well.

(2) Heat the chemical milling solution to 85°C, then grind, clean and degrease successively with 200#-2000# water sandpaper (10g/L NaOH+30g/LNa ₂ SiO ₃ 9H ₂ O at 70°C +664 detergent system for 2 minutes), flowing water washing, outlighting (soaking in room temperature, 300g/L nitric acid solution for 5 minutes), flowing water washing, hot air drying at 60-80°C, etc. After pretreatment, put the 2219 aluminum alloy into the solution , the milling treatment was performed at a solution stirring speed of 100 rpm. After reaching the depth of chemical milling or etching for a certain period of time, take out the specimen and perform treatments such as light extraction (immersion in room temperature, 300g/L nitric acid solution for 5min), flowing water washing, and hot air drying.

(3) After inspection, the chemical milling speed of 2219 aluminum alloy is 0.050mm/min; when the chemical milling depth reaches 5mm, the surface roughness Ra of aluminum alloy is 0.9μm.

Experimental plan two

(1) According to the volume of the prepared solution and the amount of 160g/L NaOH, 15g/L Na ₂ S, 30g/LTEA, 20g/L EDTA, 15g/LNa ₂ S ₂ O ₃ 5H ₂ O, 40g/L Al Take the components of the solution; first add 1/3 volume of water to the chemical milling tank, add NaOH, Na ₂ S, EDTA in turn under stirring conditions, and then add Na ₂ S ₂ O ₃ 5H ₂ dissolved in water in advance O, TEA and pure aluminum, make up the remaining water, and stir well.

(2) Heat the chemical milling solution to 90°C, then grind, clean and degrease successively with 200#-2000# water sandpaper (10g/L NaOH+30g/LNa ₂ SiO ₃ 9H ₂ O at 70°C LY12 aluminum alloy after pre-treatment such as washing in +664 detergent system for 2min), flowing water washing, light emitting (soaking in room temperature, 300g/L nitric acid solution for 5min), flowing water washing, hot air drying at 60-80°C, etc., was put into the solution , milling treatment was performed at a solution stirring speed of 50 rpm. After reaching the depth of chemical milling or etching for a certain period of time, take out the specimen and perform treatments such as light extraction (immersion in room temperature, 300g/L nitric acid solution for 5min), flowing water washing, and hot air drying.

(3) After inspection, the chemical milling speed of LY12 aluminum alloy is 0.040mm/min; when the chemical milling depth reaches 5mm, the surface roughness Ra of aluminum alloy is 1.2μm.

Experimental scheme three

(1) According to the volume of the prepared solution and the amount of 200g/L NaOH, 30g/L Na ₂ S, 50g/LTEA, 25g/L EDTA, 30g/LNa ₂ S ₂ O ₃ 5H ₂ O, 20g/L Al Take the components of the solution; first add 1/3 volume of water to the chemical milling tank, add NaOH, Na ₂ S, EDTA in turn under stirring conditions, and then add Na ₂ S ₂ O ₃ 5H ₂ dissolved in water in advance O, TEA and pure aluminum, make up the remaining water, and stir well.

(2) Heat the chemical milling solution to 95°C, then grind, clean, and chemically degrease successively with 200#-2000# water sandpaper (10g/L NaOH+30g/LNa ₂ SiO ₃ ·9H ₂ O at 70°C 2195 aluminum alloy after pretreatment such as washing in +664 detergent system for 2 minutes), flowing water washing, light emitting (soaking in room temperature, 300g/L nitric acid solution for 5 minutes), flowing water washing, hot air drying at 60-80°C, etc., was put into the solution , milling treatment was performed at a solution stirring speed of 150 rpm. After reaching the depth of chemical milling or etching for a certain period of time, take out the specimen and perform treatments such as light extraction (immersion in room temperature, 300g/L nitric acid solution for 5min), flowing water washing, and hot air drying.

(3) After inspection, the chemical milling speed of 2195 aluminum alloy is 0.060mm/min; when the chemical milling depth reaches 5mm, the surface roughness Ra of aluminum alloy is 1.6μm.

Experimental plan four

(1) According to the volume of the prepared solution and the amount of 140g/L NaOH, 10g/L Na ₂ S, 35g/LTEA, 18g/L EDTA, 25g/LNa ₂ S ₂ O ₃ 5H ₂ O, 25g/L Al Take the components of the solution; first add 1/3 volume of water to the chemical milling tank, add NaOH, Na ₂ S, EDTA in turn under stirring conditions, and then add Na ₂ S ₂ O ₃ 5H ₂ dissolved in water in advance O, TEA and pure aluminum, make up the remaining water, and stir well.

(2) Heat the chemical milling solution to 80°C, then grind, clean and degrease successively with 200#-2000# water sandpaper (10g/L NaOH+30g/LNa ₂ SiO ₃ 9H ₂ O at 70°C 7075 aluminum alloy after pretreatment such as washing in +664 detergent system for 2 minutes), flowing water washing, light emitting (soaking in room temperature, 300g/L nitric acid solution for 5 minutes), flowing water washing, hot air drying at 60-80°C, etc., was put into the solution , Milling treatment was performed at a solution stirring speed of 120 rpm. After reaching the depth of chemical milling or etching for a certain period of time, take out the specimen and perform treatments such as light extraction (immersion in room temperature, 300g/L nitric acid solution for 5min), flowing water washing, and hot air drying.

(3) After inspection, the chemical milling speed of 7075 aluminum alloy is 0.045mm/min; when the chemical milling depth reaches 5mm, the surface roughness Ra of aluminum alloy is 1.3μm.

Experimental scheme five

(1) According to the volume of the prepared solution and the amount of 150g/L NaOH, 20g/L Na ₂ S, 45g/LTEA, 15g/L EDTA, 20g/LNa ₂ S ₂ O ₃ 5H ₂ O, 30g/L Al Take the components of the solution; first add 1/3 volume of water to the chemical milling tank, add NaOH, Na ₂ S, EDTA in turn under stirring conditions, and then add Na ₂ S ₂ O ₃ 5H ₂ dissolved in water in advance O, TEA and pure aluminum, make up the remaining water, and stir well.

(2) Heat the chemical milling solution to 75°C, then grind, clean and degrease successively with 200#-2000# water sandpaper (10g/L NaOH+30g/LNa ₂ SiO ₃ 9H ₂ O at 70°C 7A60 aluminum alloy after pretreatment such as washing in +664 detergent system for 2 minutes), flowing water washing, light emitting (soaking in room temperature, 300g/L nitric acid solution for 5 minutes), flowing water washing, hot air drying at 60-80°C, etc., was put into the solution , Milling treatment was performed at a solution stirring speed of 80 rpm. After reaching the depth of chemical milling or etching for a certain period of time, take out the specimen and perform treatments such as light extraction (immersion in room temperature, 300g/L nitric acid solution for 5min), flowing water washing, and hot air drying.

(3) After inspection, the chemical milling speed of 7A60 aluminum alloy is 0.035mm/min; when the chemical milling depth reaches 5mm, the surface roughness Ra of aluminum alloy is 1.1μm.

The present invention has been described as an example above, and it should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacements that can be made by those skilled in the art without creative labor all fall within the scope of this invention. protection scope of the invention.

Claims (6)

1. An aluminum alloy chemical milling solution is characterized in that each component is as follows: 140-200g/L NaOH, 6-30g/L Na ₂ S, 25-50g/LTEA, 10-30g/L EDTA, 10- 40g/L Na ₂ S ₂ O ₃ ·5H ₂ O, 10-40g/L Al, the solvent is water. 2. A method for preparing an aluminum alloy chemical milling solution as claimed in claim 1, characterized in that, when preparing, add 1/3 volume of water in the chemical milling groove, add NaOH, NaOH and NaOH successively under stirring conditions ₂ S, EDTA, and then add Na ₂ S ₂ O ₃ ·5H ₂ O, TEA and pure aluminum dissolved in water in advance, make up the remaining water, and stir well. 3. a method utilizing the aluminum alloy chemical milling solution as claimed in claim 1 to carry out chemical milling, is characterized in that, carries out according to the following steps: Step 1, pre-treat the sample, successively perform grinding with 200#-2000# water sandpaper, cleaning treatment, and chemical degreasing, that is, 10g/L NaOH+30g/L Na ₂ SiO ₃ 9H ₂ O+ at 70°C Wash in the aqueous solution system of 664 detergent for 2 minutes, wash with flowing water, and soak in 300g/L nitric acid aqueous solution at room temperature 20-25 degrees Celsius for 5 minutes, wash with flowing water, and dry with hot air at 60-80°C; Step 2, heating the aluminum alloy milling solution to 75-95°C, putting the sample treated in step 1 into the solution, and performing milling treatment at a solution stirring speed of 50-200rpm; Step 3. After reaching the depth of chemical milling, take out the sample and carry out the subsequent treatment of light extraction, that is, immerse in 300g/L nitric acid aqueous solution at room temperature of 20-25 degrees Celsius for 5 minutes, wash in running water, and dry with hot air at 60-80 degrees Celsius. 4. A method of chemical milling using the aluminum alloy chemical milling solution according to claim 1, wherein the sample is a duralumin or super duralumin specimen. 5. A method of chemical milling using the aluminum alloy chemical milling solution as claimed in claim 1, wherein the sample is 2219, LY12, 2195, 7075, 7A60 aluminum alloy according to claim 3. . 6. A method according to claim 5 utilizing the aluminum alloy chemical milling solution as claimed in claim 1, wherein the chemical milling speed of the aluminum alloy by the chemical milling solution is 0.030-0.060mm/ min, it takes 1.5 to 3.0 hours to reach a chemical milling depth of 5 mm, and the surface roughness Ra of the aluminum alloy varies between 0.8 and 2.0 μm, which meets the precision requirements of chemical milling parts.