Composite materials

Content

• Types of composite materials
• Examples of composite materials

Thecomposite materials are those that are made up of two or more different elements or substances, whose combination gives the resulting matter the joint characteristics of its components, that is, those of the two original substances at the same time.

This allows a specific selection of components to obtain materials endowed with unusual characteristics in terms of rigidity, lightness, resistance, conduction of electricity, corrosion resistance, etc.

Most composite materials are artificially created by man, although some may appear in nature, product of the evolution of the living creatures. And in many cases they are binder materials that benefit from the chemical interaction of their components.

In general terms, composite materials are characterized by:

• Consist of two or more physically distinguishable but mechanically separable components.
• Show several chemically different phases (elements), insoluble among themselves and also separated by an intermediate phase or interface.
• Possess high synergy, that is, its mechanical properties are superior to the simple sum of those of its components separately.
• Distinguish from polyphasic materials, such as metal alloys, in which it is possible to alter the phases present through thermal variation (heat).
• Possess a reinforcing agent (an added phase) and a matrix (reinforced phase).

Types of composite materials

The following types of composite materials can be identified:

• Particle Reinforcement Composites. Dispersed in a softer matrix and ductile, components of a hard and brittle material are dispersed discreetly and evenly.
• Dispersion-hardened composites. They present reinforcing particles of very minute sizes, dispersed in the base matrix.
• Fiber-reinforced composite materials. These materials usually contain tensile resistant fibers in a matrix usually made of resin that envelops the fibers, transferring the load from the broken fibers to the intact ones and gaining particular resistance.
• Structural composite materials. Made up of both simple and composite materials, usually in a laminar (sandwich) way such as those used in construction, to combine the properties of both materials in the same wall.

It can serve you: Examples of Natural and Artificial Materials

Examples of composite materials

1. Cermet. A conjunction of ceramic and metal, they were designed to withstand high temperatures and withstand abrasion, like ceramics, but enjoy the malleability of metals. Usually the matrix of these materials is metal (nickel, molybdenum, cobalt) and the reinforcement phase is carbohydrates refractories (oxides, albumin, borides) typical of ceramics. This allows the manufacture of cutting tools that combine toughness with stainless steel and have longer service lives., especially the new developments based on titanium and cobalt.
2. Nacre. This is an example of a composite material of natural origin, without human intervention. It is a hard, white organic-inorganic substance with iridescent reflections, which forms the inner layer of the shell of many mollusks, such as mother of pearl. In fact, these animals can secrete this mixture of calcium carbonate and biopolymers to repair their shells or encompass impurities or microbial agents that penetrate it, thus giving rise to pearls..
3. Plywood. Also called multilaminate, plywood, plywood or plywood, It is a board of thin sheets of wood glued to each other with their fibers in transverse orientation, using synthetic resins, pressure and heat. It is coated with sulfuric acid after processing to be odorless, which contains polymers and benzenes and is particularly useful in construction.
4. Adobe. Unfired bricks are called thus, that is, fillings for construction, made of clay and sand or other masses of mud, mixed with straw and dried in the sun. They have been used since ancient times to make walls and rudimentary constructions, usually in the form of bricks (rectangular). Despite being an excellent thermal insulator, adobe absorbs a lot of moisture by capillarity, losing its hardness, so it must be installed on a water-repellent base of stones or, modernly, concrete.
5. Concrete. Also called "concrete", it is the composite material most used at the same time in construction, it is a junction of various substances: cement, sand, gravel or gravel and water. With this joint, a homogeneous mixture is obtained that sets and hardens in a few hours until obtaining a stony consistency.. Most civil engineering works involve the use of concrete.
6. Oriented Strand Board. Called OSB (Oriented Strand Board in English), are a type of conglomerate boards, an evolution of plywood, because instead of joining several sheets of wood, it is done with several layers of shavings or wood chips all oriented in the same direction, thus obtaining a homogeneous material from phenolic resins or polyurethane, formaldehyde or melamine. Often other additives are also incorporated to improve resistance to fire, humidity or to repel insects.
7. Pykrete. This composite material is made with 14% sawdust or some other organic wood pulp, in an 86% ice matrix. Its name comes from its inventor, Geoffrey Pyke, who proposed it to the Royal British Navy to make hard-to-sink aircraft carriers. Pykrete has hardness close to concrete, low melt index and enormous resistance to tensions.
8. Glass reinforced plastic. Known as GFRP (Glass-Fiber Reinforced Plastic in English), It is a composite material that forms a plastic or resin matrix, reinforced with glass fibers. The result is a lightweight, strong, easy-to-mold material, often popularly called “fiberglass”.. It is widely used in the manufacture of parts, in the nautical and telecommunications industry, as well as in the construction sector.
9. Asphalt concrete. Very used in paving roads or highways, asphalt concrete It consists of a mixture of asphalt and mineral aggregates of various kinds, to obtain a uniform and bituminous paste that, when applied hot, hardens and waterproofs, constituting an ideal material for urban public works.
10. Bone. Another example of composite materials in nature are bones, made up of higher animals inside a bone matrix reinforced by collagen fibers, a protein that gives it its natural resistance, thanks to the calcium from which its structure is mineralized. This results in a hard, brittle, but lightweight item.