DT- Material Properties

Physical Properties

Any property that is measurable and that describes a state of a material.

Mechanical Properties

Properties of a material that involve the relationship between stress and strain or a reaction to an applied force.

Chemical Properties

A property of a material that only becomes evident during or after a chemical reaction.

Density

The mass per unit of volume of a material. Its importance is in portability of a product's weight and size.

Thermal Expansion

A measure of the degree of increase in dimensions (length, area or volume) when an object is heated.

Thermal Conductivity

The measure of how fast heat is conducted through a slab of material with a given temperature difference across the slab.

Melting Point

The temperature a material transforms from a solid into a liquid.

Electrical Conductivity

The measure of a material's ability to conduct electricity. A material with low resistivity will conduct electricity well.

Corrosion

An electrochemical reaction where metals react with their environment to form oxides, salts, or other compounds.

Reactivity (food safe)

A chemical property of a material that represents the extent to which a material will react with another (including air) to become unsafe for use to come in contact with food.

Hygroscopy

A chemical property of a material that has the ability to
absorb moisture from the surrounding environment.

absorb moisture from the surrounding environment.

Flammability

A measure of how quickly a material can be ignited and how quickly it burns.

Tensile Strength

The ability of a material to withstand pulling forces.

Compressive strength

The ability of a material to withstand being pushed or squashed

Stiffness

A material's ability to resist deflection (bending deformation) and maintain its shape.

Young's Modulus

A measure of the stiffness of an elastic material and defined by stress/strain.

Toughness

The ability to withstand shock or absorb energy without fracturing.

Hardness

It is the resistance of a material to surface deformation.

Elasticity

The extent to which a material will return to its original shape after being deformed, once the force causing the deformation is removed.

Hook's Law- definition

This law describes how elastic materials behave when loaded in one direction (uniaxially).

Hook's Law- theory

A force applied to a spring will cause it to extend by an amount proportional to the force.

Plasticity

The ability of a material to be changed in shape permanently.

Malleability

A material's ability to be plastically deformed under compressive forces.

Ductility

The ability of a material to be drawn or extruded into an extended shape such as a wire.

Composite Materials

A material comprised of two or more materials to improve their physical, mechanical and chemical properties and/or aesthetics characteristics.

Fibreglass or Glass Reinforced Plastic (GRP)

Combines the high strength of thin glass fibres with the ductility and chemical resistance of epoxy resin a plastic; the brittleness that the glass fibres have when isolated is not a characteristic of the composite.

Carbon fibre

It consists of a matrix, in the form of a plastic resin which sets hard and is reinforced by carbon fibres, the matting. The matting is chopped-up strands woven together. Carbon fibres are woven in a uniform pattern and are very strong (stronger than most other materials).

Reinforced concrete

Is a composite material that combines concrete (a material produced by mixing together sand, cement, gravel and water) which is strong in compression with steel reinforcing bars or which are strong in tension.

SMART Materials

Materials that have one or more properties that can be significantly changed in response to changes in their environment.

Piezoelectricity

A property of a smart material. A piezoelectric material gives off a small electrical discharge when deformed and experiences an increase in its volume when an electrical current passes through it.

electrical discharge when deformed and experiences an increase in its volume when an electrical current passes through it.

Shape memory material

A material that "remembers" and returns to a predefined shape after being deformed. This is achieved in response to changes in temperature or stress.

Photochromicity

A photochromic material changes colour in response to an increase in light. When the light source is removed, it returns to its original colour.

Magneto-rheostatic

This smart property relates to a fluid that can undergo a dramatic change in its viscosity when exposed to a magnetic field. This effect is reversed when the magnetic field is removed.

Electro-rheostatic

This smart property relates to a fluid that can undergo a dramatic change in its viscosity when exposed to an electric field. This effect is reversed when the electric field is removed.

Thermoelectricity

This refers to a smart material comprised of two dissimilar conductors that produce an electric current when heated.

Biodegradable materials

Materials that break down in the environment after disposal or at the end of their useful life.