Surface Treatment Compositions And Method For Removing Si Component And Reduced Metal Salt On The Aluminum Dicast Substrate In Etching Process

摘要

PURPOSE: A surface treatment composition and a surface treatment method for removing silicon and reductive metallic salts generated during etching of an aluminum die casting material without generation of nitric acid gas (NOx) and hydrofluoric acid gas (HF) are provided. CONSTITUTION: In a surface treatment composition of an aluminum die casting material used in removing silicon and reductive metallic salts generated on the surface of the material after etching treatment of an aluminum die casting material, the surface treatment composition of the aluminum die casting material comprises 300 to 950 g/L of hydrogen peroxide, 1 to 300 g/L of organic salts containing fluorine ions selected from the group consisting of ammonium bifluoride (NH4HF2), ammonium fluoride (NH4F) and a mixture thereof, and a balance of water, wherein the surface treatment composition of the aluminum die casting material further comprises 1 to 3 g/L of aqueous ether selected from ethylene glycol monobutyl ether, dipropylene glycol monoethyl ether and a mixture thereof. The surface treatment method comprises the process of removing silicon and reductive metallic salts on the surface of the etched aluminum die casting material after etching the aluminum die casting material by dipping an aluminum die casting material into the surface treatment composition.