Different Types of Metals
Metals and technological advancements in manufacturing procedures provided humans with the industrial revolution. This prompted an exponential development of human civilization leading us to where we are today. There are now different types of metals all around us.
The Classification of Metals
A huge number of metals are currently available within nature. These metals can be divided in several ways depending on which characteristics or properties are employed as criteria.
- Classification by Iron Content
This is the most common method of classifying metals. When a metal has iron, it is called a ferrous metal. The iron makes the metal prone to corrosion and imparts magnetic properties. Metals that lack the presence of iron are known as non-ferrous metals. They also lack magnetic properties. Some examples are lead, aluminium, copper, zinc, and brass.
- Classification by Atomic Structure
Metals may be classified on the basis of their atomic structure as per the periodic table. Metal may be classified as alkaline, transition, or alkaline earth metal. Metals that belong to the same group tend to behave similarly when they react with other elements. So, they share similar chemical properties.
Selecting Suitable Metals
When choosing a suitable metal for a specific application, there are several factors to consider. These factors include ease of machining, melting point, space available, sufficient safety factors, temperature coefficient, density, and electrical and thermal conductivity. Let us look at different types of metals and the reason they are selected for their applications.
Iron comprises almost 5% of the Earth. Therefore, it is an easy metal to find. However, pure metal is not a stable element, as it immediately reacts with the oxygen present in the air, creating iron oxide.
Taking iron from its ores requires the use of a blast furnace. The first stage of the blast furnace will yield pig iron, which can be refined further to obtain pure iron. This iron usually ends up in steel and other alloys. This is why almost 90% of manufactured metals are ferrous in nature.
Although pure iron is stronger than most metals, it is prone to corrosion. To keep corrosion away, you will need to spend a lot of energy and money. Iron is also extremely heavy due to its high density.
Thus, steel was made by adding carbon to iron to alleviate these weaknesses to some extent. This combination of carbon and iron forms carbon steel, which is stronger than iron. As a result, steel is commonly used as a building material. Depending on its iron content, you can classify steel into three categories – low carbon steel, medium carbon steel, and high carbon steel.
It is impossible to overlook copper when discussing different types of metals. Copper is easy to form, which is why it has a long history and the applications it has today are the biggest instances of how important it is. Because copper does not come from nature in a pure form, smelting and extracting it from its ore is crucial.
Metals are good conductors but copper stands out as the best. You will find copper conductor wires in electrical circuits due to its extraordinary electrical conductivity. The only metal that can beat copper’s conductivity is silver. This may be why most cooking utensils are made from copper.
Bronze is also an alloy of copper. However, unlike zinc, bronze contains tin. You can improve its properties and aptness for a specific application. Bronze is hard, brittle, and resists fatigue well. Bronze also has good thermal and electrical conductivity as well as corrosion resistance.
Bronze is applied in the making of reflectors and mirrors. It is also employed within electrical connectors. Because of its resistance to corrosion, it is used in ship fittings and submerged parts.
Brass is an alloy of zinc and copper. The amount of each metal may vary because of the mechanical and electrical properties that are sought from the metal. It consists of trace amounts of several metallic elements, such as manganese, lead, and aluminium.
Brass serves as an excellent candidate for low friction use, such as in bearings, locks, musical instruments, tools and fittings, and plumbing. Brass is indispensable in inherently safe applications to allow usage and prevent sparks in inflammable surroundings.
Aluminium is derived primarily from bauxite, its ore. It is strong, light, and functional, and is the Earth’s most widespread metal. This is due to its properties, including being lightweight, durable, electrically conductive, and corrosion resistant; it can create alloys with almost all types of metals. Aluminium is easy to machine and does not magnetise.
Titanium is a crucial engineering metal because it is lightweight and strong. It also has high thermal stability, even at temperatures as extreme as 480°C. Due to these characteristics, it is applied in the aerospace industry.
It is also used in military equipment, and because it is corrosion-resistant, it is also used for medical purposes. You will also find titanium in sporting goods and the chemical industry.
Lead is a highly corrosion-resistant, machinable metal. Piping and paint symbolise some of its use cases. It was utilised as an anti-knocking delegate in gasoline. It was later discovered that its byproduct could cause serious health complications. You will find lead in car batteries, ammunition, lifting weights, radiation protection, and cable sheathing.