Eight common metal materials

Introduction to Metals

Metals are fundamental materials used across various industries due to their strength, durability, and versatility. They are characterized by their malleability, ductility, and excellent conductivity. From construction to electronics, metals play a crucial role in shaping modern technology and infrastructure. But how many types of metal are there? This article explores all kinds of metal, their classifications, and their most common applications.

Classification of Metals

Metals are categorized into different groups based on their composition and properties:
Ferrous vs. Non-Ferrous Metals: Ferrous metals contain iron (e.g., steel, cast iron), while non-ferrous metals do not (e.g., aluminum, copper, brass).
Base, Noble, and Precious Metals: Base metals like aluminum and copper are widely used, noble metals like platinum resist corrosion, and precious metals like gold and silver have high economic value.
Heavy vs. Light Metals: Heavy metals (e.g., lead, mercury) have high densities, while light metals (e.g., aluminum, titanium) are lightweight but strong.
Refractory Metals: Known for their resistance to heat and wear (e.g., tungsten, molybdenum).
White Metals: Low-melting-point metals like tin, lead, and zinc.

Most Common Metals and Their Applications

When discussing all metal types, some are more widely used than others. Below, we explore common types of metals and most common metal used in industry.

Steel

Overview: Steel is the most common metal used in industry due to its strength, affordability, and versatility. It is an alloy made primarily of iron and carbon, and depending on the amount of carbon and other elements added, it can be tailored to meet specific requirements.

Carbon Steel: Contains a higher carbon content, making it harder and stronger but less ductile. Commonly used in construction (beams, rebar) and automotive industries (structural parts).

Stainless Steel: Contains chromium (at least 10%) which makes it resistant to corrosion and stains. It is widely used in kitchenware, medical tools (scalpels, surgical instruments), and industrial equipment (pumps, valves).

Alloy Steel: This type contains additional elements such as chromium, molybdenum, or vanadium to enhance its properties. It is commonly used in machinery and tools where specific qualities (like hardness or wear resistance) are required.

Steel is the answer to “what is the most used metal”, as it dominates the manufacturing and construction sectors.

Aluminum

Overview: Aluminum is a lightweight, corrosion-resistant metal. It has a high strength-to-weight ratio, which makes it ideal for industries where weight is a critical factor, such as aerospace and automotive.

Applications:

Aerospace: Aircraft and spacecraft components.

Construction: Window frames, siding, and roofing materials due to its resistance to corrosion.

Packaging: Beverage cans and food packaging, thanks to its ability to form thin, strong sheets.

Copper

Overview: Copper is one of the oldest metals used by humans. It has excellent electrical and thermal conductivity, making it an essential material in the electrical industry.

Applications:

• Electrical Wiring: Copper’s high conductivity makes it the material of choice for electrical cables.
• Plumbing: Pipes and fittings are often made of copper due to its resistance to corrosion.
• Roofing: Used in roofing materials due to its durability and attractive patina.

Brass (Copper-Zinc Alloy)

Overview: Brass is an alloy of copper and zinc that combines the corrosion resistance of copper with the strength of zinc. It is malleable and can be formed into various shapes.

Applications:

• Musical Instruments: Trumpets, trombones, and saxophones are made of brass due to its acoustic properties.
• Decorative Items: Brass is used in coins, jewelry, and household items like doorknobs and light fixtures.
• Plumbing Fittings: Faucets, connectors, and valves due to its corrosion resistance.

Bronze (Copper-Tin Alloy)

Overview: Bronze is one of the earliest alloys created by humans and consists primarily of copper with a small amount of tin. It is known for its hardness and resistance to corrosion.

Applications:

• Sculptures: Many statues and art pieces are made from bronze due to its ability to be finely cast and its aesthetic appeal.
• Bearings and Bushings: Its wear resistance makes it ideal for applications that involve moving parts.
• Marine Applications: Bronze is highly resistant to corrosion in seawater, making it suitable for propellers, marine fittings, and underwater construction.

Titanium

Overview: Titanium is a strong yet lightweight metal known for its excellent resistance to corrosion and high temperatures. It is often used where strength-to-weight ratio is crucial.

Applications:

• Aerospace: Titanium is extensively used in aircraft and spacecraft components for its strength-to-weight ratio and heat resistance.
• Medical Implants: Due to its biocompatibility, it is used in joint replacements, dental implants, and surgical tools.
• Sports Equipment: It is used in high-performance sporting goods, such as bicycles, golf clubs, and tennis rackets.

Nickel

Overview: Nickel is a hard, silvery-white metal known for its resistance to corrosion and high temperatures. It is often used as an alloying element to improve the properties of other metals.

Applications:

• Stainless Steel: Nickel is a key component in stainless steel, contributing to its resistance to corrosion.
• Batteries: Used in rechargeable batteries, such as those in electric vehicles (e.g., nickel-metal hydride batteries).
• Industrial Equipment: It is used in machinery, turbines, and reactors that operate in high-temperature and corrosive environments.

Most Common Metals Used in Manufacturing

When it comes to processing metals, each material type presents unique challenges and opportunities. Depending on factors like hardness, ductility, and alloy composition, the processing techniques must be carefully selected to ensure optimal performance in end applications.

Steel Processing

Steel, a versatile and widely used material, requires specific approaches based on its composition. Hot working methods like forging and rolling are crucial for shaping steel into large components, such as beams and pipes. The heat involved in these processes softens the steel, making it more malleable. For parts requiring tighter tolerances or smoother finishes, cold working methods such as cold rolling or drawing are often employed. Cold working improves steel’s strength and dimensional accuracy, which is vital for automotive components or precision machinery.

When it comes to machining, steel is processed using turning, milling, and drilling to achieve complex geometries. For harder grades, such as high-carbon or alloy steel, specialized tools and slower cutting speeds are necessary to prevent tool wear.

Aluminum Processing

Aluminum, known for its light weight and corrosion resistance, is typically processed through casting or extrusion. In casting, molten aluminum is poured into molds to create complex parts with intricate shapes. This is commonly used in automotive and aerospace industries. Extrusion, on the other hand, involves forcing heated aluminum through a die to produce long, uniform shapes. It’s widely used for structural components like window frames or railings, where strength and light weight are essential.

Aluminum is also easily processed using machining, particularly when precision is required. Its relatively soft nature allows it to be shaped efficiently, whether through turning, drilling, or milling.

Copper Processing

Copper, being one of the most conductive metals, undergoes cold working for many applications, such as electrical wiring. Through drawing, copper is stretched into wires of varying thickness, maintaining high conductivity while increasing strength. For other uses, casting is common, especially in plumbing fittings or industrial components, where intricate shapes are necessary.

Copper’s welding properties are also significant, particularly in the construction of electrical systems. Processes like MIG and TIG welding are used to join copper pipes and fittings, ensuring that the joins maintain excellent conductivity and durability.

Brass Processing

Brass, an alloy of copper and zinc, is valued for its casting ability, often being poured into molds for applications like decorative items or plumbing fixtures. Its machinability makes it a preferred choice for producing precision components, whether for mechanical parts or decorative products. The drawing process is also used to create thin wires or sheets of brass for electronics or jewelry.

Bronze Processing

Bronze, an alloy of copper and tin, is renowned for its durability, especially in harsh environments. This material is often cast to create sculptures, marine components, or industrial parts. Its resistance to corrosion in seawater makes it ideal for marine applications. When machined, bronze is typically used for parts that need to resist wear, such as bushings, bearings, or gears.

Forging is another method used for bronze to produce stronger, more durable components like propellers or fittings for marine equipment. This process refines the material’s grain structure, improving its mechanical properties.

Titanium Processing

Titanium, a metal prized for its strength and low weight, presents specific challenges during processing due to its hardness and resistance to heat. Machining titanium requires careful control of cutting speeds and the use of specialized tooling to prevent excessive heat buildup. When welded, titanium requires high-precision TIG welding to ensure structural integrity, particularly for aerospace or medical applications.

Forging and extrusion are also used for titanium components, especially in aerospace, where both strength and weight are critical. These processes help form complex geometries while maintaining the metal’s exceptional properties.

Nickel Processing

Nickel, known for its corrosion resistance and heat tolerance, is often used in high-temperature applications, making casting a suitable method for producing complex parts, such as turbine blades. Heat treatment processes, such as annealing, are used to enhance the metal’s strength and resistance to wear. When machining nickel alloys, which are harder and more difficult to work with than many other metals, careful attention is paid to tool selection and cutting parameters.