With such a broad range of materials available for designers, it's sometimes hard to understand all the terms. Here, Chris Lefteri reveals what they mean
Alloys - A term that generally describes a combination of metal with at least one other element. This resulting alloy is stronger than its constituent metal. Most engineering applications for metals are alloys.
Biopolymer - An increasingly common term defining plastics that are generated from renewable natural sources, a large number of which are derived from starch. They are often bio-degradable, and so do not harm the environment.
Ceramics - Non-organic, non-metallic materials. A large group of materials that includes, glass, diamond, brick, clay, porcelain and advanced ceramics such as silicone carbide, silicone nitride and aluminium oxide.
Composite - A material combined with at least one other material, which results in superior physical or mechanical properties.
Ductile - The ability of a material to be permanently deformed under tension without fracturing. This is different to elasticity which is refers to a material’s ability to return to its original form.
Elastomer - Commonly known as rubber. Thermoplastic elastomers (TPE) are a variety that can be easily moulded.
Ferrous metals - Ferrous and non-ferrous are common ways of characterising metals. Ferrous metals comprise iron, generally containing at least 50%. Steels and irons make up most of this family.
Glass - Types of glass include: optical glass, sealing glasses, glass ceramics, borosilicate glasses, soda-like glasses, and lead glasses.
Hardness - A hard material is one that resists indentation, which means it resists scratching, wear and abrasion and is difficult to machine. Ceramics are one of the hardest types of materials.
Physical properties - Compared to mechanical properties, physical properties can be measured without destroying or changing the material. Colour, density and transparency are two physical properties.
Plastic - In addition to the common understanding of this word, it is also an alternative to the word polymer. Plasticity also refers to the ability of any material to flow.
Polymer - A Long chain of molecules built of repeated (poly) groups of atoms (monomer). Polymers can be synthetic or natural. Types of polymers include: PVC, polypropylene, polystyrene, polyethylene, bakelite, cellulose acetate, polycarbonate and phenolics (engineered plastics).
Mechanical properties - Refers to characteristics of materials that are usually measured through changing or destroying the material, eg strength, hardness, elasticity.
Non-ferrous metals - Metallic materials that do not contain iron. Non-ferrous metals is a much larger family containing everything else: copper, aluminium, nickel, chromium, etc.
Stiffness - The ability of a material to withstand deflection. Based on the ratio of stress to movement.
Smart materials - Materials that respond in a specific manner an external stimulus is applied. Examples of smart materials include piezoelectric crystal, which changes shape when an electric charge is applied or release a small electric charge when struck.
Tensile strength - A measure of the amount of stress a material is able to withstand when it is stretched.
Thermoplastic polymer - A polymer which, when reheated, will soften. Most recyclable plastics are thermoplastic.
Thermoset polymers - Together with thermoplastic polymers, thermosets are a very simple and popular way of classifying plastics. Unlike thermoplastics, thermosets do not generally soften when heated.
Toughness - A term often confused with hardness (see above). It applies to the ability of a material to absorb impact energy without breaking. Ceramics are generally very hard, but not tough.