Types Of Materials
Types Of Materials
Here is a quick look at some of the types of materials commonly used in materials science.
A ceramic is a non-metallic material composed of inorganic molecules, normally prepared by heating a powder or slurry. Many common ceramics are made up of oxides or nitride compounds and are highly crystalline with long-range molecular order. Some ceramics are partially or fully amorphous, with no long-range molecular order; these are typically classified as glassy materials.
Composites are mixtures of two or more bonded materials. Composites are the mixture of multiple materials, which in combination offer superior properties to the materials alone. Structural composites usually refer to the use of fibers which are embedded in a plastic. These composites offer high strength with very little weight.
Concrete is a ceramic composite made up of water, sand, gravel, crushed stone, and cement. The ingredients are mixed together thoroughly, and are poured into a form. After the concrete is completely dry, it has excellent compressive strength.
Electronic / Optical
Electronic/optical materials are tailored to conduct electricity or light. These materials may be metals, ceramics or polymers. These materials are carefully formulated to control the intensity, scattering, and bending of electrons or photons which pass through them.
Glassy materials are hard, brittle, and noncrystalline. The lack of crystalline grains often results in optical transparency. The glass we are used to is a ceramic usually consisting of a mixture of silicates or sometimes borates or phosphates formed by fusion of silica or of oxides of boron or phosphorus with a flux and a stabilizer into a mass that cools to a rigid condition without crystallization.
Metals are comparatively malleable, optically reflective, and electrically conductive. Most metals and alloys are easily shaped by forming. Their disassociate electron bonding makes them excellent conductors of electricity and heat. Almost all metals have an orderly arrangement of atoms, resulting in a crystalline structure that may have multiple crystal phases bordering eachother.
A metamaterial is an engineered material specifically designed to exhibit a behavior that can only occur at specific organizations and sizes of materials. Metamaterials often seem to break the rules of physical behavior. Though many metamaterials phenomenon have not yet been usefully produced at scale, they include materials with negative Poisson’s ratios (they expand when stretched instead of getting thinner), unusual interactions with light and other forms of electromagnetic radiation (cloaking and other phenomena), and nanomaterial effects like iridescence and molecular filtering of light and sound.
Plastics/polymers are made up of millions of repeated links to make long molecules or networks that are tangled or crosslinked together. Almost all polymers use carbon atoms in very long chains. The carbon atoms may be attached to other carbon, oxygen, nitrogen, and hydrogen atoms. Polymers may or may not have an orderly arrangement of atoms.
Semiconductors are a special case of electronic material that combines two differently electrically conductive materials, usually ceramics. A semiconductor is also known as a P-N junction, where one material allows ‘loose’ electrons to move through an ordered structure, and the other allows holes (where an electron could be, but is not) to move in the same way. This behavior and the interactions between charge carriers and photons and phonons allows semiconductors to store binary information, form logic gates, and convert between voltage, light, heat, and force as sensors and emitters.
Wood is a composite material made from lignin and cellulose. Wood makes use of a lignin matrix and cellulose fibers to form a polymer composite. The lignin holds the cellulose compressively in place so that the cellulose fibers can carry tensile loads. Wood has excellent structural properties, in light of its low weight and high strength.