Study On The Transformation Of Bronze Rust And The Mechanism Of Promoting Or Protection Of Bronze Rust

In general,the bronze ware has been corroded before the excavation.The excavated bronze ware continues to be corroded in the atmospheric environment.At present,the protection methods of bronze ware have been gradually changed from traditional protection methods to researching on the corrosion mechanism of bronze.According to the corrosion mechanism,reasonable protection methods can be designed.Revealing the evolution and function of the patina provides a theoretical basis for the design of reasonable protection methods.This paper studies the transformation of bronze rust and the mechanism of the effect of patina on bronze.In this paper,the influence of anion on the conversion of CuCl has been detailed researched.The conversion process and conditions of various copper rusts was systematicly studied.The effect of cuprite and Cu₂Cl?OH?₃ on copper matrix were also studied.The condition of the molar concentration ratio of SO₄^2- and Cl^- was 0.30:0.00,0.25:0.05,0.20:0.10,0.15:0.15,0.10:0.20,0.05:0.25,0.00:0.30.The results of the conversion of CuCl is different in these conditions.When the concentration of SO₄^2-is greater than the Cl-,the products of the conversion of CuCl is Cu₄?SO₄??OH?₆.When the concentration of SO₄^2- is less than Cl-,the products of the conversion of CuCl is Cu₂Cl?OH?3.When the concentration of SO₄^2-is equal to Cl-,the products of the conversion of CuCl is Cu₂Cl?OH?₃ and Cu₄?SO₄??OH?₆The study found that:under the condition of SO₄^2-:Cl^-=0.05:0.25 and 0.00:0.30,Cu₄?SO₄??OH?₆ converts to Cu₂Cl?OH?₃.Under the condition of SO₄^2-:Cl^-=0.30:0.00,Cu₂Cl?OH?₃ converts to Cu₄?SO₄??OH?₆.Therefore,Cu₂ Cl?OH?₃ and Cu₄?SO₄??OH?₆ can convert to each other under certain conditions.The platinum electrode with the cuprite,the copper electrode with the cuprite and the bare copper electrode were soaked in 1%NaCl solution for 215 hours to study the corrosion process of different electrodes.The morphology and composition of the substrate and rust layer were analyzed by XRD,XPS and SEM-EDS.It is concluded that cuprite has a physical protective effect on the copper matrix,and the cuprite does not interact with the copper matrix.It also preliminarily explored the protective effect of Cu₂Cl?OH?₃ on copper matrix.