Precious metals is a category encompassing diverse metals that are rare and/or the world considers to be of high worth economically. Their value is the result of several factors including these three:
* Rarity or scarcity
* Various functions in industrial processes
* Employment as an investment commodity
Precious metals also have certain chemical qualities that make them fall into this group. In general, they are less chemically reactive than other metals. They also have a high luster as well as a higher melting point. Just as important is the similarity of usage. A precious metal has both a practical and decorative function.
Common Precious Metals
Certain precious metals have a higher profile among the public than others do. The best-known are gold and silver. They are commonly used in decorative art and pleasing jewelry but are also treasured in certain industrial applications.
* Gold (Au): Gold is preferred in coatings for such qualities as – anti-corrosive, durability, solderability, non-reactivity with other metals and uniform electrical conductivity. This latter characteristic is ideal in coating electronic components while the reflective surface of gold has found usage in office buildings and radiation shields.
* Silver (Ag): Silver has many of the same qualities of gold but actually is more malleable and durable. In addition, it has a higher level of conductivity – both thermal and electrical. Through thin film coating, silver acts to transfer some of these qualities to a base substrate. This makes it popular in certain electronic components.
The use of precious metal alloys in PVD and other forms of thin film coating is also an efficient method of passing on specific chemical traits to substrates making them more viable and reliable products in the electronics industry.
The Precious Metals of the Platinum Group
Gold and silver may be the names that come to mind when the term “precious metals” is mentioned. They are not, however, the only metals that occupy this group. Within this rare metallic association are the members of the Platinum Group. They consist of 6 specific metals who, like gold and silver have aesthetic as well as industrial uses. The groups consist of the following related metals:
1. Platinum (Pt)
2. Palladium (Pd)
3. Rhodium (Rh)
4. Ruthenium (Ru)
5. Osmium (Os)
6. Iridium (Ir)
Of these six precious metals, the most commonly employed are the top two:
* Platinum (Pt): As thin film material, it improves corrosion resistance and hardness metal. Pt is durable and stable at high temperatures. It is wonderful in decorative applications such as jewelry but also used in the dentistry and aeronautic industries.
* Palladium (Pd): This precious metal is anti-corrosive and provides stability in hot environments. The catalytic converters of automobiles employ it as do manufacturers of electronics and, of course jewelers.
The other precious metals as well as their alloys, also perform these duo roles. They are both utilitarian and aesthetically pleasing.
Precious Metals and Thin Film Coating
Precious metals are rare and of economic worth. In today’s world, they may act as thin film coating materials. By imparting their qualities to the substrate material, precious metals make something basic not only practical but also pleasing to the eye.
