阅读说明：本技术 一种薄板铝合金零件化学铣切溶液及其方法 (Chemical milling solution and method for sheet aluminum alloy part ) 是由 蔡英楠 王朝琳 刘昊阳 隋金江 毛英坤 戴晓亮 苏剑英 于 2020-11-03 设计创作，主要内容包括：本发明属于金属表面处理及加工技术,涉及一种薄板铝合金零件化学铣切溶液及其方法。本发明薄板铝合金零件化学铣切溶液进行化铣的方法,先加热化铣溶液至70℃～90℃,将铝合金试件经过除油、出光、涂保护胶、刻形剥离化铣保护胶；利用所述化学铣切溶液进行多次化铣,在达到铣切深度后取出试件进行处理和检验。本发明能够有效地降低化铣件的质量损失率,避免零件出现尺寸超差、阶差、疵边、漏蚀、褶皱的问题,有效结合此化铣溶液及方法,使化铣零件合格率提升至99.1％,不仅可以提高车间产品的交付进度,而且还可以避免零件的浪费,累计节省零件报废所带来的成本超过千万,产生显著的经济效益。(The invention belongs to the technology of metal surface treatment and processing, and relates to a chemical milling solution and a chemical milling method for a sheet aluminum alloy part. The chemical milling method of the chemical milling solution for the sheet aluminum alloy part comprises the steps of heating the chemical milling solution to 70-90 ℃, and carrying out oil removal, light extraction, protective glue coating and shape stripping on an aluminum alloy test piece; and carrying out multiple chemical milling by using the chemical milling solution, and taking out the test piece for treatment and inspection after the milling depth is reached. The invention can effectively reduce the mass loss rate of the chemical milling part, avoid the problems of size over-tolerance, step difference, defect edge, leakage corrosion and wrinkle of the part, and effectively combine the chemical milling solution and the method to improve the qualification rate of the chemical milling part to 99.1 percent, thereby not only improving the delivery progress of workshop products, but also avoiding the waste of the part, accumulating and saving the cost caused by part scrapping to exceed ten million and generating remarkable economic benefit.)

1. The chemical milling solution for the sheet aluminum alloy part is characterized by comprising 100-270 g/l of sodium hydroxide, 3-22 g/l of sodium sulfide, 50-70 g/l of triethanolamine, 3-12 g/l of tributyl phosphate, 2-10 g/l of propylene glycol and 1-5 g/l of nitrilotriacetic acid.

2. The chemical milling solution for aluminum alloy sheet parts according to claim 1, wherein the chemical milling solution comprises 150-200 g/l sodium hydroxide, 8-15 g/l sodium sulfide, 50g/l + -3 g/l triethanolamine, 3-12 g/l tributyl phosphate (TBP), 2-10 g/l propylene glycol and 1-5 g/l nitrilotriacetic acid.

3. A chemical milling solution for sheet aluminum alloy parts according to claim 1, characterized in that propylene glycol is added in the range of 2g/l to 10 g/l.

4. The chemical milling solution for sheet aluminum alloy parts according to claim 1, wherein the nitrilotriacetic acid is added in the range of 1g/l to 5g/l, and the nitrilotriacetic acid provides coordination bonds for metal ions, and has small molecules, strong complexing ability, and capability of forming stable complexes with metal ions.

5. A method for chemically milling by using the chemical milling solution for the sheet aluminum alloy parts as claimed in claims 1 to 4 is characterized in that the chemical milling solution is heated to 70-90 ℃, and an aluminum alloy test piece is subjected to oil removal, light extraction, protective glue coating and chemical milling protective glue shape stripping; and carrying out multiple chemical milling by using the chemical milling solution, and taking out the test piece for treatment and inspection after the milling depth is reached.

6. The method for chemically milling the sheet aluminum alloy part through the chemical milling solution according to claim 5, wherein the part is rotationally milled four times in a clockwise or counterclockwise manner during chemical milling, and the chemical milling area with the largest area during the last chemical milling is at the bottommost end by selecting the initial chemical milling area and the initial chemical milling mode.

7. A method for chemically milling a sheet aluminum alloy part with a chemical milling solution according to claim 5, wherein after the aluminum alloy part is hung by a bolt, the speed of the aluminum alloy part entering a chemical milling solution tank is 0.4m/s, the speed of the aluminum alloy part exiting the tank is 0.4m/s, and the liquid entering and exiting the tank is uniform, so as to avoid the taper caused by the inconsistent thickness of the top end of the aluminum alloy part and the bottom end of the aluminum alloy part.

8. A method for chemically milling a sheet aluminum alloy part with the chemical milling solution according to claim 5, wherein the rotation speed is 0.02rad/min for uniform rotation, the rotation is carried out when the milling depth reaches one fourth, and the solution is left standing for 30-60 s.

9. A chemical milling solution for sheet aluminum alloy parts according to claim 5 wherein the parts are transported to a spray treatment above a water bath prior to rotational re-chemical milling.

Technical Field

The invention belongs to the technology of metal surface treatment and processing, and relates to a chemical milling solution and a chemical milling method for a sheet aluminum alloy part.

Background

The chemical milling and washing is widely applied to metal or alloy parts such as magnesium, aluminum, titanium, copper, iron and the like, but different milling solutions are required to be configured for parts made of different materials due to different material properties and performance requirements of the parts, milling process parameters such as solution formula, temperature, time and the like are strictly controlled, otherwise, the structure, shape and surface quality of the parts are uncontrollably influenced, and the parts are scrapped.

In 2010, a forming process of a certain type of chemical milling part, published in a scientific and technological paper of the young academic society of aviation, introduces a process method of forming a part and then chemically milling the part within a quenching period, namely a one-step forming method, and carries out technical analysis on the phenomenon of hammer marks on the surface of the certain type of part, and analyzes that the reason of the hammer marks is that the formed part is corrected by a hammer. Meanwhile, an improved method is provided for the reason of the hammer mark generation. However, the authors propose that some defects still exist, because the chemical milling allowance is manually cut after the chemical milling of the three-dimensional part, the manual cutting labor amount is large, the labor intensity is increased, the overall dimension of the part is ensured by manual filing, and how to reduce the manual work amount is a problem that needs to be discussed in the method, and the quality problem that occurs when the chemical milling of the skin with large chemical milling depth is not solved.

2012, "double-sided corrosion process for milling large-sized wallboard parts of a certain airplane", published in the young science and technology forum of the Chinese society of aviation, introduces a corrosion rate comparison test, a roughness comparison test and an intercrystalline corrosion test, mainly studies the influence of double-sided corrosion on corrosion rate, roughness and intercrystalline corrosion tendency at different temperatures, finds out control elements of the large-sized wallboard part milling processing through a simulation chemical milling test, and studies the influence of turning times on the thickness uniformity of large-sized and deeply-corroded parts. However, the method mainly aims at double-sided chemical milling, the test depends on a simulated chemical milling test, because influence factors are complex in the chemical milling process and the control variable difficulty is high, the simulation test and the actual operation come and go, the temperature influence analysis is not clear enough, a specific temperature interval is not obtained, and because double-sided chemical milling is adopted, difficult chemical milling pieces of a Z9 series machine in our factory are single-sided chemical milling, the turnover frequency adopted in the literature is not completely applicable to the aluminum alloy chemical milling parts or the practicability is poor.

CN101122025A discloses an aluminum alloy chemical milling solution and a milling method thereof, which provides a formula and a process of the aluminum alloy milling solution, wherein the components of the milling solution comprise sodium hydroxide, sodium sulfide, triethanolamine, ethylenediamine tetraacetic acid, sodium sulfate, industrial pure aluminum, deionized water and the like. The method mainly aims to obtain better surface roughness, generally requires that the milling depth reaches 5mm, cannot be applied to sheet aluminum alloy parts (the thickness of the sheet aluminum alloy parts is smaller and generally less than 5mm), and is difficult to eliminate the problems of size over-tolerance, step difference, defective edges, leakage corrosion, wrinkles and the like of the sheet aluminum alloy parts.

Disclosure of Invention

The purpose of the invention is as follows: provides a chemical milling solution and a chemical milling method for sheet aluminum alloy parts, which can effectively alloy chemical milling quality and have high efficiency.

The technical scheme of the invention is as follows: a chemical milling solution for sheet aluminum alloy parts comprises 100-270 g/l of sodium hydroxide, 3-22 g/l of sodium sulfide, 50-70 g/l of triethanolamine, 3-12 g/l of tributyl phosphate, 2-10 g/l of propylene glycol and 1-5 g/l of nitrilotriacetic acid.

150 g/l-200 g/l of sodium hydroxide, 8 g/l-15 g/l of sodium sulfide, 50g/l +/-3 g/l of triethanolamine, 3-12 g/l of tributyl phosphate (TBP), 2 g/l-10 g/l of propylene glycol and 1 g/l-5 g/l of nitrilotriacetic acid.

The addition of the propylene glycol, which is in the range of 2g/l to 10g/l, can reduce the surface tension and can be mixed with water to ensure that the chemical milling solution forms a continuous phase on the surface of the aluminum alloy, and the thickness and the size of the milled part are uniform.

The addition of the nitrilotriacetic acid is within the range of 1g/l to 5g/l, the nitrilotriacetic acid can provide coordination bonds for metal ions, has small molecules and strong complexing ability, can form a stable complex with the metal ions, enhances the stability of a chemical milling solution, and reduces the size problems of flow marks, step differences and the like of milled parts due to the change of solution components caused by severe milling reaction of the solution.

A method for carrying out chemical milling by using the chemical milling solution for the sheet aluminum alloy part comprises the steps of heating the chemical milling solution to 70-90 ℃, and carrying out oil removal, light extraction, protective glue coating and shape etching stripping on an aluminum alloy test piece; and carrying out multiple chemical milling by using the chemical milling solution, and taking out the test piece for treatment and inspection after the milling depth is reached.

During chemical milling, the parts are subjected to rotary chemical milling four times in a clockwise or anticlockwise mode, and the chemical milling area with the largest area during the last chemical milling is located at the bottommost end by selecting the initial chemical milling area and mode.

After the aluminum alloy part is hung by a bolt, the speed of the aluminum alloy part entering a chemical milling solution tank is 0.4m/s, the speed of the aluminum alloy part exiting the tank is 0.4m/s, and the liquid entering and exiting the tank of the aluminum alloy part is uniform, so that the taper caused by the inconsistent thickness of the top end of the aluminum alloy part and the bottom end of the aluminum alloy part is avoided.

The rotation speed is 0.02rad/min, the milling machine rotates at a constant speed when reaching one fourth of the milling depth, and the milling machine needs to stand for 30-60 s to avoid the wrinkle problem of parts.

Before the rotation is carried out for chemical milling again, the parts are conveyed to the upper part of the water tank for spraying treatment, so that the over-corrosion problem caused by residual solution is avoided.

The invention has the technical effects that: the invention can effectively reduce the mass loss rate of the chemical milling part, avoid the problems of size over-tolerance, step difference, defect edge, leakage corrosion and wrinkle of the part, and effectively combine the chemical milling solution and the method to improve the qualification rate of the chemical milling part to 99.1 percent, thereby not only improving the delivery progress of workshop products, but also avoiding the waste of the part, accumulating and saving the cost caused by part scrapping to exceed ten million and generating remarkable economic benefit.

Drawings

FIG. 1 is a schematic diagram of the latching and flipping of a rotary chemical mill during chemical milling.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be described in further detail with reference to the accompanying drawings and specific embodiments.

Example 1:

(1) the chemical milling solution is heated to 75 ℃, and the problems of part wrinkling and non-chemical milling surface crease caused by overhigh temperature are avoided. An aluminum alloy test piece with the thickness of 1.5mm is subjected to oil removal, nitric acid bright dipping, protective glue coating and shape etching stripping chemical milling protective glue. The chemical milling solution comprises the following components: 180g/l of sodium hydroxide, 12g/l of sodium sulfide, 53g/l of triethanolamine and 3-12 g/l of tributyl phosphate (TBP).

(2) The mode that adopts the rotary milling divides into the quartic chemical milling, can avoid four tip of part to appear the inhomogeneous problem of thickness, because the part is thinner, adopts the rotary milling can avoid because of the part damage that the regional over-corrosion that cuts of partial chemical milling caused, the part chemical milling area after the rotary milling does not have the fold, does not have the super poor, and the part non-chemical milling face does not have the crease, and sheet metal aluminum alloy part thickness homogeneity is strong.

The chemical milling area with the largest area during the last chemical milling is arranged at the bottommost end so as to avoid the crease of the non-chemical milling surface of the part in the thinnest state.

a. Milling depth 1.1mm, and corrosion rate 0.02 mm/min; b. and (3) milling for about 14min (milling depth of 0.28mm) each time by adopting a rotary milling mode. And taking out the test piece after reaching the milling depth, and carrying out light extraction, water washing, drying and other treatment.

(3) Through inspection, the thickness of the test piece after chemical milling is between 0.36mm and 0.46mm, and the problems of step difference, defective edge, leakage corrosion, wrinkle and the like do not occur.

Example 2:

(1) the chemical milling solution was heated to 80 ℃. A2.5 mm aluminum alloy test piece is subjected to oil removal, nitric acid bright dipping, protective glue coating and shape etching stripping chemical milling protective glue. The chemical milling solution comprises the following components: 150 g/l-250 g/l of sodium hydroxide, 3 g/l-22 g/l of sodium sulfide, 50g/l +/-3 g/l of triethanolamine, 3-12 g/l of tributyl phosphate (TBP) and 2 g/l-10 g/l of propylene glycol.

(2) The method comprises the following steps of dividing chemical milling into four times by adopting a rotary chemical milling mode, wherein a chemical milling area with the largest area is positioned at the bottommost end a when the chemical milling is carried out for the last time, the milling depth is 2.1mm, and the corrosion rate is 0.02 mm/min; b. and (3) milling for about 26min (milling depth of 0.52mm) each time by adopting a rotary milling mode. And taking out the test piece after reaching the milling depth, and carrying out light extraction, water washing, drying and other treatment.

(3) Through inspection, the thickness of the test piece after chemical milling is between 0.35mm and 0.43mm, and the problems of step difference, defective edge, leakage corrosion, wrinkle and the like do not occur.

Example 3:

(1) the chemical milling solution was heated to 90 ℃. A3.0 mm aluminum alloy sheet test piece is subjected to oil removal, nitric acid bright dipping, protective glue coating and shape etching stripping chemical milling protective glue. The chemical milling solution comprises the following components: 150 g/l-250 g/l of sodium hydroxide, 3 g/l-22 g/l of sodium sulfide, 50g/l +/-3 g/l of triethanolamine, 3-12 g/l of tributyl phosphate (TBP), 2 g/l-10 g/l of propylene glycol and 1 g/l-5 g/l of nitrilotriacetic acid.

(2) The method comprises the following steps of dividing into four times of chemical milling by adopting a rotary chemical milling mode, wherein a chemical milling area with the largest area is positioned at the bottommost end a during the last chemical milling, the milling depth is 2.6mm, and the corrosion rate is 0.025 mm/min; b. and (3) milling for about 26min (milling depth of 0.65mm) each time in a rotary milling mode. And taking out the test piece after reaching the milling depth, and carrying out light extraction, water washing, drying and other treatment.

(3) Through inspection, the thickness of the test piece after chemical milling is between 0.38mm and 0.43mm, and the problems of step difference, defective edge, leakage corrosion, wrinkle and the like do not occur.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present invention shall be included in the protection scope of the present invention, and the present invention shall not be detailed in the conventional art.