Plating - Its Uses and History
Plating is a highly unique technology in that, while it has a long history,
it continues to support the cutting-edge manufacturing of today.
In this chapter, we will learn about the uses of plating and its history.
Where is plating used?
The dictionary defines “plating” as the act of covering the surface of an object (mainly metal) with a thin metallic layer, or as the act of coating achieved by that method. As this definition states, plating is a technology in which a thin film of metal is formed on the surface of a material to give it various functional or decorative properties.
In its broader sense, plating includes dry plating using vacuum technology and hot-dip plating using molten salt. In this story, however, we will be looking into wet plating technology that uses an aqueous solution (we will learn more about the different types of plating in Chapter 2).
Modern plating is used in a variety of products around us, including automobiles, computers, mobile devices, and home appliances. Although most plating is used on the inside of products, and is therefore rarely seen by us, plating is a technology that is closely interwoven with our everyday lives.
Now, let’s take a look at some typical products that use plating.
Mobile devices
These days, smartphones and tablets have become an indispensable part of our daily lives. These kinds of communication devices enabled the widespread use of plating technology. Most of the semiconductors and electronic components found inside these devices are created with the use of plating technology.
Computers
Computers and servers used in our homes and workplaces are also created with numerous types of plating technology. Plating is used on the CPUs, GPUs, and electronic circuit boards inside computers, the hard disk drives that store data, and the connectors that connect the computer to the external devices.
Automobiles
Plating is used in abundance in automobiles. With the current advances in electrification, in which, electricity is used as the vehicle’s power supply, and automated controls, such as ADAS in today’s automobiles, there has been a dramatic increase in the number of electronic components installed in vehicles. In addition, applying plating to mechanical parts strengthens their surfaces and gives them increased lubricant properties. On the exterior, plating is used on elements, such as emblems and grilles to give them a metallic luster, make them lighter in weight, and prevent corrosion.
Accessories
Plating objects with precious metals such as gold and silver gives them a metallic luster that is visually appealing.
In addition, by plating plastic, which is easy to mold into shapes, makes the object lighter in weight and less expensive compared to an item made of metal alone. It also makes possible to create more complex designs with the use of injection molding.
How long has plating been in use?
Plating began a very long time ago, in around 1500 BC. At around this there, It appears that in Assyria, in the northern part of Mesopotamia (currently Iraq), tin metal was being plated in order to prevent corrosion. In around 700 BC, nomadic people of Eastern Europe were using the “amalgamation process” to perform the gold-plating of bronze. In China, there are records remaining of the gold-plating of bronze ware in around 500 BC.
A major turning point in the long history of plating was the arrival of electrolytic plating (electroplating).
The voltaic cell devised by the Italian physicist Volta in 1800 made it possible for humans to put electricity to practical use. This achievement is commemorated with the use of Volta’s name in the words voltage and the “volt” units.
The voltaic cell
The voltaic cell devised by the Italian physicist Volta in 1800 made it possible for humans to put electricity to practical use. These achievements are commemorated with the use of Volta’s name in the words voltage and the “volt” units used for potential difference.
Electrolytic plating was invented in 1805, five years after the birth of the battery. The arrival of electrolytic plating led to the development of various methods for plating metals, and the applications increased greatly from the conventional use of rust prevention and decoration.
With the development of generators that could realize stable power generation, it became possible to support the mass production of machinery components and other items, and the scope of the use of plating expanded even further.
It is said that the origin of electroless plating (chemical plating) was the silver mirror reaction developed in Germany in 1835 to deposit silver on a glass surface. Mirrors are basically produced with the same method to this day, thus suggesting the history of chemical plating is actually carved into this most familiar item that we look into every morning.
At the beginning of the 20th century, copper began to be used with the same method as the silver (mirror reaction). Then, in around 1946, the electroless nickel, that is the most widespread chemical plating of today, was invented in America.
In Japan, plating technology was introduced from the continent together with Buddhism in the late Kofun period in around 700 AD, when plating began to be used on horse harnesses and other items. After that, it went on to be used on items, such as statues of Buddha, ornaments and swords. Of course, the plating at this time was performed with the amalgamation method using mercury.
Electrolytic plating did not come, however, until a much later era, at the end of the Edo period. It is said the first use of it was for the decoration of armor helmets by Shimazu Nariakira, who the feudal lord of the Satsuma clan. Electrolytic plating came into widespread use in Japan during the Meiji period (1868–1912). After World War II, its applications expanded beyond metals to include materials such as plastics and ceramics.
In this chapter, we have learned about the uses of plating and its history. We hope that this knowledge will give you a greater awareness of the many roles that plating technology plays in the world around you. In particular, plating is an essential technology for high-tech products, and it is likely to be used in an increasingly wide range of fields in the future.