The yellowing of nickel silver shielding covers is primarily caused by oxidation or sulfurization reactions on the surface when exposed to environmental factors such as oxygen, moisture, and sulfur-containing compounds. This leads to the formation of copper oxide or copper sulfide, a process that accelerates in humid, high-temperature, or corrosive gas environments. Such yellowing not only affects the appearance but may also reduce the electromagnetic shielding performance and conductivity of the cover.

To effectively prevent yellowing, both production processes and usage protection measures must be implemented. During production, treatments such as electroplating (e.g., nickel or tin plating), chemical passivation, and ultrasonic cleaning are employed to remove grease and impurities, forming a dense protective layer to minimize oxidation. For usage and storage, applying anti-oxidation coatings or protective oils and ensuring a dry, sealed storage environment can significantly reduce exposure to acidic, alkaline, or corrosive gases. Additionally, regular maintenance and surface cleaning to remove contaminants will help maintain the Shielding Cover’s stability and performance.