Are you curious about the metals that surround us in our daily lives?
From the cast iron sewer covers we walk over every day to the aluminum used in our kitchen utensils, each metal has its unique characteristics and uses. Join us on a journey to explore the properties and applications of the most common metals used in our world today.
Discover how each metal is made, its benefits, and how it is used in various fields.
Get ready to learn about cast iron, stainless steel, zinc, aluminum, and magnesium alloy, and how they have revolutionized the world we live in.
1. Cast iron
Sewer covers are often overlooked in our daily surroundings and receive little attention.
Cast iron has a broad range of applications due to its superior fluidity and ability to be poured into intricate shapes.
Cast iron is a combination of elements, including carbon, silicon, and iron.
The fluidity during pouring improves with an increase in carbon content, which manifests as graphite and iron carbide.
The presence of graphite in cast iron enhances the sewer cover’s exceptional wear resistance.
Rust is typically only found on the surface and can be removed through polishing.
To prevent rust during casting, a layer of asphalt coating is applied to the surface of the cast iron, penetrating into the pores to prevent rust.
Nowadays, traditional casting materials are widely utilized by designers in various fields.
Material Characteristics: Cast iron boasts excellent fluidity, low cost, good wear resistance, minimal solidification shrinkage, high brittleness, high compressive strength, and excellent machinability.
Typical Uses: Cast iron has a long history of use and is utilized in construction, bridge engineering, engineering parts, homes, kitchen utensils, and various other fields.
2. Stainless steel
Stainless steel is an alloy composed of chromium, nickel, and other metal elements.
Its resistance to rusting is attributed to the chromium content in the alloy.
Chromium forms a durable and self-healing chromium oxide film on the surface of the alloy, which is not visible to the naked eye.
The commonly mentioned ratio of chromium to nickel in stainless steel is 18:10.
The term “stainless steel” encompasses more than 100 types of industrial stainless steel, each designed for specific applications and possessing excellent performance in its respective field.
In the early 20th century, designers made significant contributions to the development of stainless steel products, which previously had not been utilized in the field of corrosion resistance.
These design endeavors were highly innovative.
For instance, reusable medical devices that could be disinfected were introduced for the first time in the medical industry.
Stainless steel is categorized into four main types: austenite, ferrite, ferrite-austenite (composite), and martensite.
Austenitic stainless steel is commonly used in household products.
Material Characteristics: Austenitic stainless steel is known for its health benefits, anti-corrosion properties, fine surface treatment, high rigidity, versatility in processing, and difficulty in undergoing cold processing.
Typical Use: Of all the primary color stainless steels, austenitic stainless steel is the most suitable for coloring, providing satisfactory color appearance and shape. It is mainly used in decorative building materials, household goods, industrial pipelines, and building structures.
Martensitic stainless steel is utilized in the production of cutting tools and turbine blades.
Ferritic stainless steel, with its corrosion resistance, is used in durable washing machines and boiler parts.
Composite stainless steel boasts stronger corrosion resistance and is often used in corrosive environments.
Zinc is a shiny, silver-colored metal with a slightly bluish-gray tint, and is the third most commonly used non-ferrous metal after aluminum and copper.
Statistics from the US Bureau of Mines indicate that an average person consumes a total of 331 kg of zinc in their lifetime.
Zinc has a low melting point, making it an excellent material for casting.
Zinc castings are prevalent in our daily lives and can be found in the surface layer of door handles, watches, faucets, and electronic components. Zinc has high corrosion resistance, making it an ideal surface coating material for steel.
Aside from these uses, zinc is also an alloy material used in the production of brass with copper.
Zinc’s anti-corrosive properties extend beyond steel coatings, as it also supports the human immune system.
Material Characteristics: Zinc offers health benefits, anti-corrosion protection, excellent castability, high strength and hardness, affordability, a low melting point, resistance to creep, the ability to easily form alloys with other metals, and health benefits. It is fragile at room temperature but has good ductility at around 100°C.
Typical Use: Zinc is utilized in electronic components and is one of the alloy materials that make up bronze. It is also known for its cleanliness and corrosion resistance and is used in roof materials, photoengraving discs, mobile phone antennas, and camera shutter devices.
4. Aluminum (AL)
In comparison to gold, which has been used for 9000 years, aluminum, a white metal with a subtle blue tint, is relatively new as a metal material.
Aluminum was discovered and named in the early 18th century. Unlike other metal elements, aluminum does not exist in nature in its pure form, but is extracted from bauxite, which contains 50% alumina (also known as bauxite).
Despite its extraction process, aluminum is one of the most abundant metal elements on earth.
When aluminum first appeared, it was not immediately utilized in everyday life.
Over time, new products were developed to take advantage of its unique properties and characteristics, and this high-tech material gradually gained a larger market presence.
Despite its relatively short history of use, the output of aluminum products on the market far exceeds that of other non-ferrous metal products combined.
Material Characteristics: Aluminum is flexible and malleable, easily made into alloys, boasts a high strength-to-weight ratio, has excellent corrosion resistance, conducts electricity and heat well, and is recyclable.
Typical Uses: Aluminum is utilized in the skeletons of vehicles, aircraft parts, kitchen utensils, packaging, and furniture. It is also used to reinforce large building structures, such as the London Eye in Piccadilly Circus and the top of the Chrysler Building in New York.
5. Magnesium alloy
Magnesium is a crucial non-ferrous metal that is lighter than aluminum and can form high-strength alloys with other metals.
Magnesium alloys have the benefits of low specific gravity, high specific strength and stiffness, good thermal conductivity, damping, shock absorption, and electromagnetic shielding capabilities, ease of processing and molding, and recyclability.
For a long time, magnesium and magnesium alloys were only used in limited quantities in aviation, aerospace, and military industries due to their high cost and technological constraints. They were therefore referred to as “noble metals”.
Today, magnesium is the third most commonly used metal engineering material after steel and aluminum and is utilized in aerospace, automobile, electronics, mobile communication, metallurgy, and other fields.
It is anticipated that magnesium will become increasingly important in the future due to rising production costs of other structural metals.
Magnesium alloy makes up 68% of aluminum alloy, 27% of zinc alloy, and 23% of steel. It is frequently utilized in automobile parts, 3C product shells, building materials, and more.
Many ultra-thin laptops and mobile phone shells are made of magnesium alloy.
Since the last century, people have had a lasting appreciation for the appearance and shine of metal. While plastic products can imitate a metal-like appearance, they lack the luster, hardness, temperature resistance, and texture of actual metals.
Magnesium alloy, as a new type of metal raw material, gives off a high-tech vibe.
Its corrosion resistance is 8 times that of carbon steel, 4 times that of aluminum alloy, and over 10 times that of plastic, making it the most corrosion-resistant of all alloys.
Commonly used magnesium alloys are non-flammable, especially in steam turbine parts and building materials, avoiding the risk of sudden combustion.
Magnesium ranks eighth in terms of reserves in the earth’s crust, and most of its raw materials are extracted from seawater, ensuring stable and sufficient resources.
Material Characteristics: Magnesium alloy is known for its lightweight structure, high rigidity and impact resistance, excellent corrosion resistance, good thermal conductivity and electromagnetic shielding, non-flammability, low heat resistance, and recyclability.
Typical Uses: Magnesium alloy is widely used in aerospace, automobile, electronics, mobile communication, metallurgy, and other fields.
Copper is an incredibly versatile metal that plays a significant role in our lives.
Many of humanity’s earliest tools and weapons were made of copper. Its Latin name, “cuprum,” comes from the island of Cyprus, which was rich in copper resources.
The abbreviation “Cu,” derived from the island’s name, is now used as the code name for the metal.
Copper plays a vital role in modern society, serving as a carrier of power transmission in building structures. Additionally, it has been used for thousands of years as a raw material for body decorations across various cultures.
From its initial use as a simple means of transmitting information to its current critical role in complex modern communication applications, this malleable and orange metal has been an integral part of our development and progress.
Copper is an excellent conductor, with conductivity second only to silver. It is also one of the oldest metals used by humanity, after gold.
Material Characteristics: Copper has good corrosion resistance, excellent thermal conductivity, electrical conductivity, hardness, flexibility, and ductility. It also has a unique appearance after being polished.
Typical Uses: Copper is used for wire, engine coils, printed circuits, roofing materials, piping, heating materials, jewelry, and cooking utensils. It is also a key component in making bronze alloys.
The most common form of chromium is utilized as an alloying element in stainless steel to improve its hardness.
Chromium plating is usually divided into three categories: decorative coating, hard chromium coating, and black chromium coating.
Chromium coating is widely used in engineering.
Decorative chromium coating is typically plated on top of a nickel layer as the outermost surface layer, producing a mirror-like polishing effect. As a post-treatment process, the thickness of the chromium coating is only 0.006 mm.
When considering chromium plating, it is crucial to take into account the potential hazards of the process.
In recent years, there has been a growing trend of replacing hexavalent decorative chromium water with trivalent chromium water, as hexavalent chromium has strong carcinogenic properties, while trivalent chromium is considered to be relatively less toxic.
Material Characteristics: Chromium has a very high finish, excellent anti-corrosion properties, is hard and durable, easy to clean, and has a low friction coefficient.
Typical Uses: Decorative chromium plating is commonly used as a coating material for various automotive components, including door handles and bumpers. It is also used in bicycle parts, bathroom faucets, furniture, kitchen utensils, and tableware.
Hard chrome plating is more commonly used in industrial fields, such as in the rams of operation control blocks, jet engine components, plastic molds, and shock absorbers.
Black chrome plating is primarily used for the decoration of musical instruments and in solar energy utilization.
Titanium is a unique metal known for its light weight and strong, corrosion-resistant properties. It maintains its tone at room temperature and has a melting point similar to platinum, making it ideal for use in aerospace and military precision parts.
Through various treatments, titanium can be given different colors. It also has exceptional resistance to acid and base corrosion, and even after several years of being soaked in “aqua regia,” it remains shiny. Additionally, just a 1% addition of titanium to stainless steel significantly improves its rust resistance.
Titanium is highly valued for its low density, high temperature resistance, and corrosion resistance. Its density is half that of steel, but it has comparable strength. It can maintain its high strength in a temperature range of -253°C to 500°C, making it suitable for use in space applications.
Titanium alloy is an excellent choice for making the shells of rocket engines, artificial satellites, and spacecrafts, and is often referred to as “space metal.” Its advantages have made it a prominent and rare metal since the 1950s.
Titanium is a highly stable and corrosion-resistant metal that does not react with other metals. This makes it ideal for use in products that come into contact with people, as it does not cause allergies or affect the autonomic nerves or taste. In fact, titanium is considered a “biophilic metal,” as it has no adverse effects on human health.
The main drawback of titanium is that it is difficult to refine. This is due to its tendency to combine with elements such as oxygen, carbon, nitrogen, and others at high temperatures. Despite this, titanium is not considered a rare metal, as it makes up about 6 parts per thousand of the Earth’s crust and is more abundant than copper, tin, manganese, and zinc combined.
Titanium has several key material characteristics that make it a desirable metal for many applications. These include: high strength, excellent weight-to-strength ratio, good weldability, low conductivity, low thermal expansion, and a high melting point.
Titanium is widely used in a variety of products, including golf clubs, tennis rackets, portable computers, cameras, suitcases, surgical implants, aircraft skeletons, chemical equipment, and maritime equipment. It is also used as a white pigment in paper, paint, and plastics.
By reading this article, you have gained knowledge about 8 common metals. However, there are many more types of metals found on the Earth. If you would like to learn more about different types of metals, you can read the following article.