The Corrosion Behavior Research Of Copper Foil Material

In China, gilding has a long history. It is used in many cultural relics and works of art. Copper foil adhibition sterned from gold gilding, the price of the copper foil is very inexpensive. From the appearance, the copper foil is similar to gold foil. So the application of copper foil is more and more extensive. But the plastic and softness of copper foil is lower than that of gold, when the copper foil is made out, it must have the strong cold plastic deformation with 99.5% of compression, the thickness of the copper foil is about 400nm, which is close to nanoscale, and the micro-defects are bound to appear, which may lead to the lower corrosion resistance. Therefore, the durability of copper foil needs to be investigated, so the major research object is the failure behavior of the copper foil material, so as to provide the guidence for copper foil adhibition process and the protection of the products.By using commercial copper foil and gold gluing oil, the sample of copper gilding was prepared with traditional gilding techniques. Through the investigation of copper foil's preservation condition, it was shown that the acid mist and corrosive gas pollution, temperature, humidity, UV have damage effects on copper foil. The accelerated corrosion test was designed to simulate the actual environments which generate damage and corrosion to copper foil.The copper foil material was treated for corrosion by means of sulfur dioxide, nitrogen dioxide and their mixture gas atmosphere and different concentrations of sulfuric acid, nitric acid and their mixture solution. The effect of corrosion is evaluated by some corrosion evaluation method, such as optical microscope, SEM and EDS, to observe changes in microstructure, surface morphology of corrosion cracking and corrosion products. After characterization, it is found that the surface color of the treated copper gilding changed, micro-cracks, holes and other defects were increased. Serious corrosion generated with some black product was emerge in some areas. The surface morphology of brass plate was changed too, the color of brass gradually turned red, the corrosion products and pitting increased, obvious intergranular corrosion appeared. Both copper foil and brass plate have the phenomenon of dezincification, the copper foil had more serious corrosion than brass plate than in the acid environment. Copper gilding samples was produced based on traditional gilding techniques. The copper foil, copper gilding material and gold gluing oil is treated by means of UV radiation to analyze the UV impact. The results showed that many changes was produced in gold gluing oil after UV irradiation, for example:the surface began to wrinkle, Gear-shaped stripes appear. Copper foil and copper gilding has changed, local corrosion spots appeared, the number of the surface cracks and holes increased. Growth over time, this phenomenon will show increasing trend. The damage to gold gluing oil and copper foil and copper gilding indeed occurred after UV irradiation. The aging of gold gluing oil increased the damage to copper gilding. In the same irradiation time, the damage to copper gilding is serious to copper foil.