What is metal?

Metal is the pure chemical element you would find on the periodic table. 91 of the 118 elements on the periodic table are metals – which make them some of the most plentiful elements in the world.

On the periodic table, all the elements are divided into metals and non-metals. What makes something a “metal” is that it occurs naturally in nature, has a luster, is a good conductor of heat and electricity, and is much denser than non-metals.

What is an alloy?

An alloy is made up of a mixture of metals or a metal combined with one or more other elements. The resulting mixture forms a substance with properties that often differ from pure metals, such as increased strength or hardness. For example, combining iron with non-metallic carbon produces an alloy called stainless steel.
Alloys are used in different applications, from steel alloys used in automobiles manufacturing, bridge structures, surgical tools, titanium alloys used in the aerospace industry, and ship or submarine manufacturing.

Alloys are made in such a manner that they have some synergistic properties such as corrosion resistance, high mechanical strength, hardness, and others.

Examples of alloys are steel, solder, brass, pewter, duralumin, bronze, and amalgams.

Aluminum bronze

The aluminum bronze is described as an alloy containing 88-95% copper and 5-12% aluminum. The aluminum bronze has good bearing properties, and they are used for manufacturing bushes and moving parts of machine.

Annealing

Annealing is described as a heat treatment process for restoring the ductility of metals work-hardened by semi fabrication.

Anodizing

An anodizing is described as a process of enhancing the corrosion resistance of aluminum by thickening the natural oxide film over the surface. The coating may be colored with dyes or a few colors by tailoring the composition of the alloy treated.

Austenitic

An austenitic is a major class of alloy steel, and it is most widely used. Austenitic alloys have 18% Cr and 8% Ni in their composition, which increases their durability.

Base metals

Base metals are described as the major non-ferrous metals of industries. Precious metals and minor metals are not part of base metals.

Beryllium copper

Beryllium copper is a copper alloy that contains a small amount of beryllium. It is commonly used in the manufacturing of springs and non-sparking tools.

Binary alloy

The binary alloy is described as an alloy made up of the composition of two metals. Cast iron and other alloys are examples of a binary alloy.

Blast furnace

A blast furnace is defined as a furnace in which a mixture of ore and coke is raised to a high temperature by blowing air at the bottom. Metal and slag are continuously tapped from the bottom, and a fresh charge is added at the top. Mainly used for the manufacturing of iron, steel, and lead.

Brass

Brass belongs to the family of copper-zinc alloys, and their contribution is 60% and 40%, respectively. The variations in composition give different colors and physical characteristics.

Brazing brass

Brazing brass is a binary alloy of 50% copper, and 50% zinc. It is commonly used for joining iron and steel at a lower temperature than welding.

Briquette

• In ferroalloys materials, a briquette is a granular form of the precise amount of alloying metal joined by a binder.
• Briquette is also produced with the help of various particulate materials. It is done by exerting pressure over the particulate material under confined space to decrease its area or create high-density briquettes.

Bronze.

Bronze is an alloy made up of the combination of 90% copper and 10% tin. Bronze having commonly two variants: aluminum bronze and manganese bronze. It is also known as high tensile brass.

Cadmium copper

Cadmium copper is an alloy made by copper with a small addition of cadmium for greater strength. It is a standard metal for the overhead conductor on electric railways.

Cupro nickel

Cupro-nickel is a binary alloy made up of copper-containing about 30% nickel. It is commonly used for coinage.

Duplex stainless steel

Duplex stainless steel is a fast-growing class of stainless steel. It is made up of a combination of austenitic and ferritic types of steel with intermediate nickel content. Duplex stainless steel is commonly used for high-strength applications.

Electrical steel

Electrical steel is described as steel made up of iron-containing 0-7% silicon. Electrical steel for use in laminations of electric motors, transformers, etc.

Electroplated Nickel Silver (EPNS)

Electroplated nickel silver is a tertiary alloy made up of a combination of three elements copper (60%), nickel (20%), and zinc (20%). It is commonly used for the manufacturing of cutlery and decorative items.

Electro zinc

Electro zinc plating is described as a process in which a layer of zinc is deposited over the metal sheet or coil electrolytically, not hot-dipped.

Ferritic

Ferritic is described as a class of stainless steel with no nickel content. It is a lower-cost material. It is good for high-temperature applications like automobile exhaust but not good for aggressively corrosive conditions.

Ferro-alloy

Ferroalloys are defined as alloys made up of iron by the mixture of additional elements like carbon, nickel, manganese, silicon, and many others.

Ferrous

Ferrous is referred to as a term used to represent elements containing iron. Cast iron, steel, and others are examples of ferrous materials.

Fusible alloy

A fusible alloy is described as an alloy that has a very low melting point. It is an easily fusible material and is used in chucks and fixtures.

Galvalume

Galvalume is described as oxidation-proof rolled steel coated with an alloy of 55% aluminum and 45% zinc for the advantages of both galvanizing and aluminizing.

Gunmetal

Gunmetal is a strong alloy made up of a combination of 85% copper, 5% each of tin, lead, and zinc. Gunmetal is generally used for the manufacturing of valves, gears, and statues.

High speed steel

High-speed steel is described as a ferrous-based alloy of high hardness, high wear resistance, and high heat resistance. Cutting tools are made up of high-speed steel.

High Strength Low Alloy (HSLA)

High strength low alloy steel refers to steels used in pipelines, engineering products, and construction of higher strength and corrosion resistance products compared with carbon steel. The desired properties are obtained by small additions of alloying elements such as manganese, molybdenum, and vanadium.

Maraging steels

Maraging steel is nickel-containing steel that attains its highest strength by heat treatment followed by aging for several hours at a lower temperature. It has high toughness and weldability.

Master alloy

Master alloy is described as an alloy that is usually non-ferrous and made up of high content of alloying metals.

Context and Applications

The topic of terminology of metal alloys is significant in various courses and professional exams of undergraduate, graduate, postgraduate, doctorate levels. For example:

• B.Tech in Mechanical Engineering
• B.Tech in Civil Engineering
• M.Tech in Material Science

Common Mistakes

Following are the common mistakes performed by students:

• Students often get confused with brass and bronze. Remember that both are alloys of copper. Brass is an alloy of copper made by alloying zinc with copper, while bronze is an alloy of copper made by alloying tin with copper.
• Sometimes, students forget the contribution of different elements in single alloy.

Related Concepts

• High-chromium
• Pig iron
• Electro-galvanizing
• Stress-corrosion

Practice problems