Silver coating (pIating silvers silver as the main precious metal plating)
chemically prepared on the substrate material. Electronics industry, the manufacturing of instrumentation and radio parts are widely used silver-plated to reduce contact resistance of metal surfaces, metal welding; household utensils, cutlery and all kinds of crafts reach through the silver-plated decorative purposes; searchlights and other metal mirror reflector also need silver. Silver atoms tend to spread and slippage along the material surface the wins moisture in the atmosphere, easy to produce the silver to be causing a short circuit. Silver plating is not suitable for printed circuit board plating. Silver-plated items encountered in the atmosphere of sulfur dioxide, hydrogen sulfide, halide, the surface of the silver layer quickly generate the silver chloride, silver sulfide, sulfuric acid and silver, making it the gloss disappears, and gradually turned into pale yellow a blue-violet black brown. Solderability of the coating, the electrical conductivity variation. The anti-silver layer color method: chemical passivation, electrolytic passivation, coated with organic protective film, electroplating, other precious metals. Electrolytic silver plating solution is basically
widely used 100 years ago to use the cyanide silver plating solution containing excess of free cyanide. Reported a variety of non-cyanide plating bath, such as nitrate, iodide, thiourea, thiocyanate, sulphamate, thiosulfate, sulfosalicylic acid and other bath, but did not get the industrial border recognition. Cyanide silver plating solution of potassium silver cyanide and free potassium cyanide. In order to obtain the bright coating, you can add the appropriate brightener. The bath throwing power and covering power better coating crystalline detailed, look for the silver-white, nearly 100% of the current efficiency. Gold pieces to enter the bath when the steel, copper and its co-883 jyin oath j silver-plated surface will form a replacement silver layer, which not only affect the coating and substrate binding, iron and copper ions, but also pollute the bath, so before plating into the silver-plated slot must be a special pre-treatment. The commonly used method is the amalgamation, immersion silver, pre-and silver-plated.
Silver alloy plating alloying elements antimony, cadmium, zinc, lead, tin, copper world pie network information , nickel, cobalt, palladium, platinum, gold. Silver alloy coating has a better performance than the silver coating, such as high hardness, wear resistance, sulfidation resistance and resistance to seawater corrosion. Plating silver-based composite coating particles of MoS2, graphite, Al2O3,, of BeO, La2O3, particle size of 0.1 ~ 0.3μm. According to the requirement to determine the selection of the particles, for example world pie network information , plus graphite particles can improve the self-lubricating ability of the coating; plus La2O3 can improve the wear resistance of coatings and anti-corrosion ability.