Electroplating is a process known also known as metal plating which applies a thin metal coating to a substrate, thus improving various characteristics of a metal, such as corrosion resistance, and can even introduce new ones, such as conductivity or magnetism. One particularly desirable benefit of metal plating is the enhancement it can have on resistance to high temperatures – if applied properly.
All metals react to high temperatures differently and have different melting points, so it is important to use a metal with the right heat resistance. High-temperature alloys often have an iron, nickel or cobalt base, and typically contain refractory metals; a group of metals characterised by their high melting points.
Refractory metals are the most heat-resistant of any metal, making them ideal metal coatings when dealing with high temperatures. They also oxidize at relatively low temperatures which means that a protective coating needs to be applied to them before using them in high-temperature environments.
Why it’s important to use the correct metal coating
When selecting a finishing solution for metal plating for a part, it’s crucial to know the conditions that part will undergo. While not the only consideration, knowing the maximum temperature your part could reach could prevent any heat damage to your product which, in extreme cases, could lead to irreversible damage. It can also prolong the use of a part.
Some metal coatings may be suitable but do not have the same properties that other metals have, for example, some metals are less conductive and others are more corrosive, meaning your part might not perform as well as it could.
Types of metal plating for high temperatures include:
Nickel is a metal that is renowned for its hardness as well as excellent corrosion resistance, wear resistance, resistance to the elements. Nickel coatings are sometimes alloyed with tungsten, tin, boron and manganese to improve resistance to corrosion, hardness and conductivity further. Nickel plating is often used in the automotive, aerospace, communication and textile industries.
Copper has outstanding thermal and electrical properties, offers protection from corrosion and is highly malleable. These characteristics make it incredibly valuable to the electrical, heating and industrial sectors. Copper plating can also be used as a heat treat stop-off for masking because it allows for selective heat-treating. However, copper is highly active, which means it is unsuitable for some applications.
Gold plating plays a vital role in electrical components due to its excellent conductivity, but it is also commonly used in the aerospace, medical and jewellery industries due to its protective properties against corrosion, wear and heat. Though expensive, gold plating is incredibly effective and could result in a cost-saving over a longer period.
Like gold, silver is a noble metal that resists corrosion and oxidisation. Silver plating protects against corrosion, withstands chemicals and acids well, and provides exceptional thermal and electrical conductivity. Silver can also be alloyed with most metals reasonably easily. Due to these characteristics, the telecommunications, auto, electronics and solar energy industries all use silver coating heavily. It is also valuable in the medical field due to its antimicrobial properties.
Zinc resists corrosion exceptionally well; a characteristic that can be enhanced further by alloying it with other metals such as nickel. Zinc nickel plating, originally developed for the automotive industry due to its excellent protection in high temperatures, has 10 times the resistance of zinc plating. Zinc plating is often used to plate nuts, bolts and small components and can be used as an undercoat on a surface before painting do to its excellent adhesiveness.
Dorsetware can provide you with suitable recommendations for metal plating coatings for high temperature applications. We offer metal finishing services in Dorset, Hampshire, Wiltshire, and Devon, including nickel electroplating, zinc, silver, gold, and copper plating services as listed above. For more information, you can contact us by filling out our online form today.