Chromium-free die-casting aluminum sealing agent and preparation method and application thereof

The invention discloses a chromium-free die-casting aluminum sealing agent and a preparation method and application thereof. The chromium-free die-casting aluminum sealing agent comprises the following components in parts by weight: 15 to 150 parts of 3-glycidyloxypropyl trimethoxy silane, 560 to 970 parts of water, 10 to 100 parts of absolute ethyl alcohol, 5 to 75 parts of 4-sulfamylbenzoic acid or sodium benzoate, 0.1 to 65 parts of chitosan or cellulose, 0.01 to 15 parts of cerous nitrate or cobalt nitrate, 0.1 to 10 parts of nano silicon dioxide or water-based silica sol, and 0.5 to 25 parts of EDTA (Ethylene Diamine Tetraacetic Acid) disodium or sodium citrate. The chromium-free die-casting aluminum sealing agent can greatly improve the corrosion resistance of die-casting aluminum, can completely replace traditional hexavalent chromium passivation, does not contain fluorine and is more environmentally friendly. 本发明公开了一种无铬压铸铝封闭剂、制备方法及其应用，所述封闭剂包括以下重量份的组份：3-缩水甘油醚氧丙基三甲氧基硅烷15-150份、水560-970份、无水乙醇10-100份、4-磺胺基