Research On 2060 Al-Li Alloy Milling And 2024 Aluminum Alloy Milling Bath Recycling Technology

In this paper,the effects of the main components and process parameters of2060-T8 aluminum lithium alloying milling liquid on the surface roughness,milling speed and machining accuracy were studied.The additive RA10 suitable for 2060aluminum lithium alloying milling was screened.The related performance after milling was tested,and the adjustment method of chemical milling bath fluid was also explored.The regeneration and solution circulation process of 2024-T3 aluminum alloy corrosive machining fluid was studied.The new extraction method of aluminum ions-precipitation Method,its extraction rate can be as high as 96%or more,and the concentration control of alloy elements in 2024 aluminum alloy during the circulation of chemical milling bath fluid was discussed.The essence of increasing the milling speed by increasing the concentration of Na OH in the milling process of aluminum alloy is to increase the dissolution rate of the aluminum hydroxide gel and increase the reaction rate of aluminum and water.:2Al+2Na OH+6H₂O=2Na[Al(OH)₄]+3H₂?;Na₂S acts as a corrosion inhibitor and forms Cu₂S precipitates with Cu⁺,reducing the selective corrosion of the aluminum alloy surface,and acting as a depolarizing agent to accelerate the dissolution of Al.Na₂CO₃acts as a corrosion inhibitor to form Li₂CO₃precipitation with Li⁺,which reduces the selective corrosion of the surface of the aluminum-lithium alloy,and as a corrosive agent,it increases the milling speed of the aluminum alloy to a certain extent.The experimental results show that the formula suitable for 2060-T8aluminum-lithium alloy milling is:Na OH 160?180g/L,Na₂S 30?40g/L,TEA50?60g/L,Na₂CO₃42.4?74.2g/L,RA100.4?1.0g/L,temperature 90?100?.Roughness is the most critical process index.The roughness of 2060-T8 under the 2024aluminum alloy chemical milling process is 1.55?m,and the roughness of this process can reduce the roughness by 30%.The Al³⁺concentration in the 2060-T8 aluminum-lithium alloying milling bath is less than 70g/L.When the milling speed is less than 30?m/min,Na OH can be added to speed up the conversion.When the concentration of Al³⁺is higher than 70g/L and the conversion speed is slower than 30?m/min,the bath temperature is increased to100°C,and the 2060-T8 chemical milling bath fluid fails when the concentration of Al³⁺is about 100g/L.It is not necessary to add Na₂CO_3,Na₂S,TEA,RA10 within the life of chemical milling bath fluid.The essence of aluminum ions in the CO₂precipitation bath is that CO₂captures the OH^-in Al(OH)₄^-,and then generates Al(OH)₃precipitation to achieve the purpose of removing Al³⁺.The removal rate of Al³⁺in the bath fluid can reach more than 96%,which creates the conditions for the recycling and regeneration process of the aluminum alloy milling bath fluid.After the chemical milling fluid is adjusted,its chemical milling performance is basically restored,which is conducive to the recycling of the chemical milling fluid,and it can carry out multiple effective cycles,ideally it can carry out unlimited cycles.Through design experiments to analyze the bath fluid and the precipitates,the results show that the concentration of each alloy element in the aluminum alloy bath fluid can be controlled within the ion concentration corresponding to its solubility product.