Materials Science: Properties, History, and Nanotechnology
Introduction to Materials Science
Everything in the universe exists in a material form. Matter, as it occurs in nature, has specific properties. Matter is constituted by particles. The Big Bang created atoms, initially Hydrogen and Helium. The nucleus of stars produces heavier atoms like Iron. Supernova explosions create the rest of the heavy atoms. Materials can be used as pure substances or mixtures.
Types of Materials
- Raw Materials: Obtained directly from nature, such as wood, granite, and sand.
- Processed Materials: Derived from raw materials, like panels, quartz, and synthetic glass.
- Technological Materials: Created through technological processes, such as plastics and fibers.
- Recycled Materials: Obtained from the reuse of existing materials, like glass and paper.
- Use Goods: Useful objects, such as metals and computers.
Mechanical Properties of Materials
- Hardness: Resistance to being scratched.
- Toughness: Resistance to impact.
- Malleability: Ability to be deformed into sheets.
- Ductility: Ability to be deformed into wires.
- Plasticity: Ability to deform easily under stress and retain the new shape.
- Elasticity: Ability to deform under stress and return to the original shape.
- Resistance Mechanisms: Compression, traction, torsion, flexion, and shear.
Materials in History
The use of materials has evolved through the Stone Age, Bronze Age, Iron Age, and the development of new materials.
Metals
Metals are conductors of heat and electricity, are tenacious and plastic, solid at ambient temperature, and can be oxidized. They are used in instruments, machines, construction, and packaging.
Metal Classification
- Ferrous Metals: Contain iron.
- Non-Ferrous Metals: Do not contain iron.
Obtaining Metals
Metals are found in the Earth’s crust, either freely or combined with other elements forming minerals. The main sources of minerals are sulfides and oxides. Mena is a mineral with a high concentration of a particular metal that makes its exploitation profitable. Ganga is the mineral residue after the metal is extracted from the ore.
Extraction Techniques
Metals can be extracted from ore by:
- Heat: Utilizing differences in density and melting points.
- Electricity: Utilizing differences in charges and applying an electric field.
Steel, Titanium, and Coltan
Steel is an alloy of Iron and Carbon that improves iron’s toughness, resistance, plasticity, and corrosion resistance. Titanium is the 4th most abundant metal in the Earth’s crust, as hard as steel but lighter, stronger than Aluminum, and has greater corrosion resistance. It is used in aerospace and medicine. Coltan is a mixture of two minerals: columbite and tantalite. Columbite is the ore of Niobium, and tantalite is the ore of Tantalum, used in rechargeable batteries.
Polymers
Polymers are macromolecules composed of repeating chemical units called monomers. They have high plasticity, high elasticity, mechanical and electrical strength, are cheap and easy to produce, inert, and long-lasting. However, they are not biodegradable, and incineration produces toxic substances. They are used in packaging, construction, coatings, and special applications like missile capsules. They have replaced traditional materials in many applications.
Nanotechnology
Nanotechnology allows the manipulation of atoms at the nanoscale. Carbon Fullerene has a structure like a soccer ball and is used in biomedical applications. Nanotubes are fullerene derivatives with an elongated shape. Nanotechnology is used to create water-repellent fabrics, coatings, and batteries.