Method for trivalent chromium electroplating of non-micro-crack crystalline chromium and chromium alloy coating in ionic liquid

Abstract

The invention discloses a method for trivalent chromium electroplating of a non-micro-crack crystalline chromium and chromium alloy coating in a 1-butyl-3-methyl imidazole hydrosulfate ([BMIM]HSO4) ionic liquid system, relating to a surface engineering and surface treatment technology. The method comprises the configuration of a novel ionic liquid plating solution, an electroplating technological process and the like. The current efficiency of the electroplating chromium and chromium alloy coating of a plating solution system can reach more than 95%, and is 45% higher than that of a conventional aqueous solution system; moreover, the defects that the plating solution of a normal aqueous solution system is poor in stability, easy in combustion, short in service life and high in toxicity and volatility, and an additive brightening agent and a stabilizing agent are easy to be out of operation can be overcome by using the method. The prepared non-micro-crack crystalline chromium and chromium alloy coating disclosed by the invention is compact and smooth in surface, has a strong combining capacity with a substrate, is excellent in corrosion resistance and high in hardness, is suitable for the demands on corrosion prevention, decoration and the like of the surfaces of metals and alloys, is easy in operation, and has the characteristics of economic practicality and low toxicity.

Description

technical field

[0001] The present invention relates to the method for ionic liquid electroplating metal chromium and chromium alloy, particularly 1-butyl-3-methylimidazolium bisulfate ([BMIM]HSO 4 ) A method for electroplating trivalent chromium in ionic liquid without microcracks in crystalline chromium and chromium alloy coatings. Background technique

[0002] And chromium alloy coatings, especially crystalline chromium and chromium alloy coatings prepared by electroplating methods have excellent corrosion resistance, wear resistance, high temperature oxidation resistance, and good decoration. It has been widely used in magnetic materials and soft magnetic materials. There are two major problems in electroplating chromium and chromium alloy coating technology in ordinary aqueous solution system: first, organic additives are generally added to the plating solution, because these organic substances will also participate in the electroplating reaction and cause the coating ...

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