Copper is a highly versatile metal known for its exceptional malleability, ductility, and superior conductivity of heat and electricity. These properties make it an essential material in a wide range of industries.

In this edition, we continue from our previous newsletter to explore copper’s practical applications and performance characteristics. Discover how copper plays a crucial role in both everyday products and advanced industrial systems.

Most of us have likely held a 10-won coin in our hands at some point—an everyday example of copper’s practical use. Copper is an ideal material for coins due to its excellent wear and corrosion resistance, ensuring durability over time.

(Note: 10-won, 100-won, and 500-won coins are common denominations in Korean currency (₩), approximately equivalent to USD 0.01, 0.07, and 0.35, respectively.)

Its natural antimicrobial properties also make copper a preferred material for high-touch surfaces in public spaces, such as stair railings, hallway handrails, and elevator buttons. The 10-won coin is made of brass, an alloy of copper and zinc. Other Korean coins, such as the 100-won and 500-won coins, also use copper-based alloys combined with nickel. These combinations help the coins withstand frequent handling without significant wear or damage.

Thanks to these characteristics, copper remains a vital component in currency systems worldwide.

Copper's exceptional conductivity and malleability make it an ideal material for electrical applications. It bends easily and efficiently transfers both electricity and heat. Copper, especially in the form of thin, elongated wires used in electrical cables, often appears reddish. This color is due to its property of reflecting only red and orange light while absorbing other wavelengths in the visible spectrum.

Compared to other metals such as silver, gold, and aluminum, copper stands out for its superior electrical conductivity and cost-effectiveness. These qualities make it a core material in industries ranging from wiring and cables to various electrical systems.

Copper is ever-present in our daily lives, whether it's charging our smartphones, powering lights, or running electronic devices. It is indispensable in nearly every electrical system—inside homes, buildings, automotive batteries, solar power systems, and high-speed data transmission lines.

In short, copper is a vital resource that keeps our modern world connected and energized.

While copper is not a metal that rusts easily, it reacts with moisture in the air, causing its surface to develop a distinctive blue-green color. A prime example of this transformation is the Statue of Liberty in New York Harbor.

The Statue of Liberty, a gift from France to celebrate the 100th anniversary of America's independence, was crafted from hammered copper plates, with an internal iron skeleton providing support. Upon its completion, the statue’s exterior was a reddish-brown hue, but over more than a century of exposure to the elements, the copper gradually developed a verdigris patina, a natural oxidation process unique to copper.

This Patina, formed by copper's reaction with air and moisture, serves as a protective layer, preventing further corrosion or rusting. Known as patina, this oxidation layer acts as a natural shield that preserves the integrity of the copper beneath. Because of this unique property, the color of the Statue of Liberty is remembered differently by each person—some recall it as reddish-brown, while others recognize the verdigris green we see today.

Patina: A thin oxidized layer or color change that naturally develops on metal surfaces over time, commonly seen in copper, bronze, and brass.

In this edition of our newsletter, we've explored some of the key applications and characteristics of copper. In the next issue, we’ll dive deeper into the various types of copper alloys and their unique properties.

If you have any questions, feel free to reach out to the SGO Research Lab at 📧info@sgoilless.co.kr.

We look forward to bringing you more valuable insights in next month's SGO Newsletter! :)