141results about How to "Improves tarnish resistance" patented technology

A silver-colored, tarnish-resistant, corrosion-resistant alloy is provided. The alloy includes 92.5–95% silver, combined with a master alloy of 24–34% zinc; 60–74% copper; 0.5–1.8% silicon; 0.0–8.0% tin, or 0.0–1.5% indium, wherein percentages are in terms of weight. The alloy can be used for jewelry items, tableware items, dental items or other items that should resist tarnishing or corrosion and which require a non-brittle alloy.

The invention relates to alkaline cyanide-free silver plating electroplating liquid and a silver plating method. The electroplating liquid is composed of the following components including 20 g / L-50 g / L of silver nitrate, 40 g / L-100 g / L of 5,5-dimethyl hydantoin, 70 g / L-100 g / L of potassium pyrophosphate, 0.8 g / L-1.2 g / L of 3,3'-dithiobis-1-propanesulfonic acid disodium salt, 0.10 g / L-0.15 g / L of benzotriazole, 10 mg / L-15 mg / L of N,N'-bi-oleoyl-Ethylenediamine-Sodium Diethyl sulfonate, 0.10 g / L-0.30 g / L of polyethylene glycol and the balance water, wherein due to a pH adjusting agent, the pH value of the system ranges from 8 to 12. By means of the alkaline cyanide-free silver plating electroplating liquid, all the components are matched and work collaboratively, stability is good, the copper replacement resisting performance is high, and the scattering capability of the plating liquid is high; crystal grains of a silver plated layer are fine, the crystal grains are densely and neatly arranged, the surface is flat and bright, glossiness is good, and the color changing resisting capability is high; and the hardness of the plated layer is high, the combining force with a base body is high, and the alkaline cyanide-free silver plating electroplating liquid is suitable for application and popularization.