Silver Plating

Silver Electroplating Guide

Silver plating refers to the process of covering a conductive surface with silver to prevent it from corrosion while adding a lustrous shine to it.

Why metal silver is used?

Silver is a white colored semi precious metal with an oxidizing property. Due to its property of high electrical conductivity it is used in electronics and semiconductor industries. Silver is also an excellent conductor of heat and offers great solderability. It is malleable and has a high degree of Lubricity. Silver finds usage in bearing surfaces and anti-galling applications. Being ductile, it may be bent into any shape and is hence preferred by jewelry and flatware industries for its decorative appeal.

Thus, silver acts as an economically beneficial metal that may be put to good use for a relatively cheaper price as compared to other precious metals like gold or platinum.

Types of Silver plating

Silver plating may be of various types ranging from Matte plating to Bright and Semi-Bright plating. While some plating may be done without Chromate, others may use Chromate. Pure silver plating is also possible.

Different options of Silver plating

Many silver plating companies offer the facility of industrial plating on different electrical components, bus bars and bearing surfaces. Some companies offer corrosion resistant cyanide coating devoid of chromates in order to plate various ferrous and non-ferrous base metals.

Uses of Silver plating

·   The most common usage of silver plating is for ornamentation of jewelry, plates, cups, trophies and medals. The process adds a perfect polish to the surface on which the plating is done.

• Silver plating is used to improve solderability by hardening the surface and increasing wear-ability. It is also used to inhibit corrosion. The plating helps in reducing friction and to improve paint adhesion. It is good for altering conductivity and provides a shield against radiation.

• Since silverplating is a atomic deposition process, thin films of silver can be formed on surfaces.These can act as layers for additional nanotechnology.

• Silver finds application in electronics as a replacement for gold. Variable capacitors with silver plated plates require silver plating.

Alternatives to Silver electroplating

Every method of silver plating provides slight variations in the techniques followed. These may be classified as under:

- One of the processes involves covering a solid surface with a metal sheet, and then heating and applying pressure to fuse them together.

- Some processes may also involve vapor or sputter deposition under vacuum.

- Brush application with liquid silver.

- Apart from these, the Tollen's Test method and Old Sheffield Plate method are other vital methods. The Old Sheffield Plate method happens to be the earliest silver plating technology, which was modified in the 19th century with the introduction of innovative techniques like electroplating.

The Tollen's Test method is used to plate thin layers of silver over different objects like glass etc. The reaction takes place when Glucose/Dextrose is added to the Tollen's Reagent placed in a glass. Shaking the glass excites the reaction.

Precautions

Proper maintenance must be ensured for parts exposed to high humidity environments, since porous or cracked silver layer allows rapid galvanic corrosion of the underlying copper surface. This results in a copper exposure due to flaking of the plated layer and is referred to as red plague.