A method for blackening 2024 aluminum alloy nickel-tungsten mixed salt low-voltage electrolysis

Abstract

The invention relates to a method for performing low-voltage electrolytic black coloring on a 2024 aluminum alloy by means of nickel-tungsten mixed salt, which comprises the following steps: pretreating a whole aluminum alloy workpiece, taking the pretreated workpiece as an anode, taking a lead plate as a cathode, and performing electrolytic oxidation, wherein the cathode-anode area ratio is 3:1, and the electrolytic distance is 5 cm; in an electrolyte comprising 150 g / L of sulfuric acid, 2.5 g / L of boric acid and 2 g / L of aluminum sulfate, oxidizing for 30 minutes, and ensuring that an oxidation film layer is formed on the aluminum alloy workpiece; and then taking the aluminum alloy workpiece as the cathode, taking the lead plate as the anode, and performing electrolytic coloring, wherein the coloring time is 3-12 minutes, the voltage is 3-7 V, the cathode-anode area ratio is 1:3, the interelectrode distance is 5 cm, and an electrolyte comprises 10 g / L of nickel sulfate, 5 g / L of sodium tungstate, 3 g / L of tartaric acid, 2.5 g / L of ammonium sulfate and 2.5 g / L of boric acid. The method is simple in process, low in coloring voltage and energy-saving.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, in particular to a low-voltage electrolytic blackening method of 2024 aluminum alloy nickel-tungsten mixed salt. Background technique [0002] The early coloring of aluminum and aluminum alloys mainly includes dipping coloring, natural coloring, electrolytic coloring, etc. Among them, electrolytic coloring technology is widely used in production because of its cost saving, easy control, and better quality of colored film. . The electrolytic coloring technology of aluminum and its alloys originated in Europe in the 1940s. In 1960, Asada Taihei improved this technology and registered it as a patent in Japan. Then from the mid-1960s to the 1970s, there was a climax of research on electrolytic coloring. In recent years, tin salt and tin-nickel mixed salt are mainly used in China to produce black series, but there are phenomena such as impure color, slag falling, uneven coloring, unstable electrol...

AI Technical Summary

Problems solved by technology

In recent years, tin salt and tin-nickel mixed salt are mainly used in China to produce black series, but there are phenomena such as impure color, slag falling, uneven coloring, unstable electrolyte, etc., and the coloring of true black occupies a very important position in coloring technology , has become the focus of research in European and American countries in recent years. Therefore, it is very important to study a coloring process with good reproducibility and stable electrolyte.