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Aluminum alloy surface treatment oil removal, polishing process and formula
for smooth aluminum surface brightness, after forming of aluminum is generally through mechanical polishing. But mechanical polishing after oxidation and get a smooth oxide film, gloss is often not enough. To require high gloss decorative oxide film products, after mechanical polishing, chemical polishing or electrolytic polishing. Pure aluminum or high purity aluminum magnesium alloy after chemical polishing or electrolytic polishing can get high gloss surface reflection coefficient, electrolytic polishing, in particular, can be a very satisfactory results. Unfortunately, due to containing nitric acid (generally three acid polishing solution HNO3） , heating operation, the separating nitrogen dioxide ( NO2） Gas and produce & other; Huanglong & throughout; Public nuisance. And quality stability of electrolytic polishing liquid contain chromic anhydride, causing environmental pollution by chromium waste water, and three wastes disposal problem. Naturally, people want to try do not produce & other; Huanglong & throughout; Chemical polishing and electrolytic polishing technology of chromium. Mechanical polishing aluminum surfaces: 1, mechanical polishing process is: rough grinding, fine grinding, polishing, polishing bright, sand blasting, brushing or rolling light, industrial aluminum profile according to the TAB surface roughness to properly take different processes. Second, chemical degreasing, chemical degreasing process is through chemical reaction and physical chemistry, remove the oil on the surface of the parts. Chemical degreasing with weak alkaline solution. Chemistry in addition to the oil formula and technological conditions: 1, formulation: 30 - sodium hydroxide 0, 50 g/L, industrial detergent. 5 - 1 ml/L, 70 - water 125G。 2, process conditions: temperature: 50 - 60 ℃ time: 1 - 2 min 3, after degreasing, rinse with water. 4, chemistry in addition to the oxide film: pickling processing to counteract surface residual alkali liquor, and apart from its natural oxidation film, to show parts of aluminium and aluminium alloy matrix, for aluminum alloy containing silicon production, must use mixed solution for acid pickling, to remove the dark silicon floating on the surface of the ash. Acid liquid formula: concentrated nitrate solution temperature of 200 ~ 270 ml/L: room temperature time: 1 - 3 min to remove aluminum alloy surface oxidation film containing silicon and silicon float ash acid lotion recipe: nitric acid 3 volume; Hydrofluoric acid volume 1. Temperature: room temperature time: 5 - 15 min aluminium and aluminium alloy after chemical pickling parts, must be immediately with flowing water and cold water washing, acid to remove residues, and then going to the water, in case of chemical polishing. 5, chemical polishing, chemical polishing is the use of aluminum and aluminum alloy manufacture in selective since the dissolution of acidic or alkaline electrolyte solution, to leveling system of polishing surface, in order to reduce its surface roughness, PH of chemical processing method. This kind of polishing method has simple equipment, no power, and shall not be restricted to a shape size, with high speed and low processing cost. The purity of aluminium and aluminium alloy has a great influence on the quality of chemical polishing, the purity of it, the higher the polishing quality is better, and more. Chemical polishing is the brief of viscous liquid film theory. Polishing liquid formulation and process conditions: formula one: ( Weight) Concentrated phosphoric acid 75%; Sulfuric acid 8. 8%; Nitric acid 8. 8%; Urea 3. 1%; Ammonium sulfate 4. 4%; Copper sulfate, 0. 02%. Temperature: 100 200 ℃ time: 2 - 3 min formula: (2 Weight) Concentrated phosphoric acid 85%; Nitric acid 5%; Ice acetic acid 10%. Temperature: 90 105 ℃ time: 2 - 5 min polishing liquid dispensing method: 1, the phosphoric acid, sulfuric acid and nitric acid according to certain first ( %） Weight, industrial aluminum gradually in a polishing groove, careful block. 2, again according to the formula composition, water dissolving a certain ( %） Weight of ice acetic acid, urea, ammonium sulfate, copper sulfate, stir in the tank. 3, then, in the condition of stirring, gradually adjust the polishing liquid to the formula the required temperature range, chemical polishing can be achieved. Three, the influence of the chemical polishing process conditions: 1, the temperature effect: temperature should be controlled in 90 - Between 115 ℃, the best temperature is 105 ℃. 2, the influence of the polishing time: polishing polishing is inversely proportional to the temperature and time, low temperature to extend the time of polishing, high temperature shrinkage and polishing time.