Benzotriazole (BTA) and tolyltriazole (TTA) were used to passivate pure copper and chromium bronze alloys for environmental protection. Using the chemical immersion treatment, a dense film of chromium-free passivation layer was formed on surfaces of both the pure copper and chromium bronze alloys. Microstructure, crystalline phases and chemical bonds of the passivation layers were systematically characterized, and the passivation mechanisms were studied. The passivation layer was mainly consisted of CuO, Cu₂O, polymers of Cu-BTA-TTA and Cu(I)BTA-TTA. The formation mechanism of the chromium-free passivation layer was identified as combined oxidation and adsorption, and the main passivation processes included oxidation and dissolution of the matrix, adsorption of BTA and its derivatives, self-stabilization process of the adsorbed film, and filling of passivation film’s voids by oxide particles.

苯并三唑 (BTA) 和甲苯基三唑 (TTA) 用于钝化纯铜和铬青铜合金以保护环境。采用化学浸渍处理，在纯铜和铬青铜合金的表面均形成一层致密的无铬钝化层。系统地表征了钝化层的微观结构、晶相和化学键，并研究了钝化机制。钝化层主要由CuO、Cu ₂O，Cu-BTA-TTA 和 Cu(I)BTA-TTA 的聚合物。无铬钝化层的形成机理被认为是氧化和吸附相结合，主要的钝化过程包括基体的氧化和溶解、BTA及其衍生物的吸附、吸附膜的自稳定过程和填充氧化物颗粒钝化膜的空隙。