Cyanide-free silver-based composite plating solution, silver-based composite plating layer and preparation method thereof

Abstract

The invention discloses a cyanide-free silver-based composite plating solution, a silver-based composite plating layer and a preparation method of the silver-based composite plating layer. The cyanide-free silver-based composite plating solution comprises silver nitrate, a multicomponent complexing agent, conductive salt, a buffering agent, a cationic surfactant, an additive and micro-nano particles; the multielement complexing agent takes triethylenetetramine or / and soluble salt thereof as a main complexing agent, and takes one or more of triethylenetetramine hexaacetic acid or triethylenetetramine hexaacetic acid salt, ethylenediaminetetraacetic acid or ethylenediaminetetraacetic acid salt, and citric acid or citrate as an auxiliary complexing agent; the concentration of the silver nitrate is 0.1-0.7 mol / L, the concentration ratio of the main complexing agent to the silver nitrate is 1-6:1, the concentration of the auxiliary complexing agent is 0.05-1 mol / L, the concentration of theconductive salt is 0.2-1.2 mol / L, the concentration of the cationic surfactant is 0.0005-0.003 mol / L, and the buffering agent is used for the pH value of the cyanide-free silver-based composite plating solution to be 1-7. The cyanide-free silver-based composite plating solution is stable, and the prepared silver-based composite plating layer has the functions of friction reduction and wear resistance and has good compactness.

Description

technical field [0001] The invention relates to the technical field of metal surface treatment, in particular to a cyanide-free silver-based composite plating solution, a silver-based composite coating and a preparation method thereof. Background technique [0002] Silver plating is widely used in the power electronics industry and aerospace industry because of its excellent conductivity and weldability, and is also widely used as a decorative coating in tableware, jewelry and other crafts and artworks. DL / T486-2010 High Voltage AC Isolating Switch and Grounding Switch Standard clearly stipulates that the contact surface of the isolating switch and grounding switch must be plated with a silver coating with a thickness of not less than 20 μm. However, the cyanide silver plating process is still commonly used in industrial production so far. The ability of cyanide to form a stable metal complex with silver ions is the key factor. However, cyanide is highly toxic and can be use...

AI Technical Summary

Problems solved by technology

Mehmet Uysal of Turkey prepared Ag-graphene-WC nanocomposite coatings through chemical composite plating technology in 2016, which confirmed the significant effect of graphene on improving the hardness and friction properties of the coatings, but did not take effective technical measures to improve the graphite in the coatings. The compounding amount of ethylene and WC has limited improvement on the anti-friction and wear properties of the coating