Materials and properties

Paper

Less than 200gsm

Example of a paper

Cartridge paper

Board

Over 200gsm and measured in microns

Example of a board

Duplex Board

Thermoforming polymer

A polymer without any cross links, so it can be reheated and reshaped

Example of a thermoforming polymer

Acrylic

Thermosetting polymer

A polymer with cross links, preventing it from being reheated and reshaped. It burns when heated

Example of thermosetting polymer

Epoxy resin

Elastomer

A type of poly,er with weak intermolecular forces, allowing it to be easily deformed and return to its original shape

Example of elastomer

Natural rubber and silicone

Hardwood

Wood from a deciduous tree with a tight grain, causing it to be dense and heavy

Example of hardwood

Oak

Softwood

Wood from a coniferous tree with a loose grain pattern, causing it to be lighter than a hardwood

Example of softwood

Spruce

Manufactured board

A wood made from gluing scraps of wood together, not natural and cheaper than other types of wood

Example of manufactured board

MDF

Ferrous metals

Metals that contain iron, allowing them to be magnetic, hard and strong, but susceptible to rust

Example of ferrous metal

Cast iron

Non ferrous metal

Metals that contain no iron, preventing rust but are not magnetic or as hard and strong.

Example of non ferrous metal

Copper

Ceramics

Inorganic and non metallic material that is hardened when fired, allowing it to be a good insulator, hard and strong but brittle

Uses of ceramics

Kitchenware, electronics and biomedical applications

Composite material

Material made of two or more different materials, designed to have properties that are superior to those of the individual components

Example of a composite material

Glass reinforced plastic (GRP)

Smart material

A material that changes property in reaction to a stimuli

Example of a smart material

Thermochromic pigment

Modern material

An engineered material created within the last 50 years

Example of a modern material

Kevlar

Test for tensile strength in industry

Tensometer machine - test piece is clamped, and stretched by the free moving clamp, causing it to snap. The data collected is plotted onto a graph, giving information on the maximum load.

Test for tensile strength in workshop

One end of material is clamped into vice while a weight is placed onto the other, measuring deflection.

Testing for hardness in industry (Brinell and Vickers)

Test piece is loaded into place and an indenter is pushed into the material. The area of the indent is measured and is then divided by the force used to calculate hardness.

Brinell indenter

Metal sphere

Vickers indenter

Diamond square based pyramid

Testing for hardness in industry (Rockwell)

Test piece is loaded into place and an indenter is pushed into the material. The indenter is then punched back into the material with a greater force in the same spot, and the distance between the first and second indent is measured and used to calculate hardness

Testing for hardness in workshop

Centrepunch is dropped through a pipe onto the tested material

Testing for toughness in industry

iPod impact test - notch is cut into material and a hammer is released from a higher point into it, breaking the test piece

Testing for toughness in workshop

Material is placed into vice and hit with hammer

Testing for malleability / ductility in industry

Test piece is loaded into a bending machine and bent to a specific angle. Test piece is inspected for cracks

Testing for malleability / ductility in workshop

Test piece is placed into vice and metal pipe is placed over it, test piece is then bent to 90° and inspected for cracks

External cracks on piece tested for malleability / ductility

Shows a lack of ductility

Internal cracks on a piece tested for malleability / ductility

Shows a lack of malleability

Testing for corrosion in industry

Salt spray testing - Test material is placed into a closed testing chamber and sprayed with salt water solution for a set amount of time. Test piece is removed and inspected for signs of corrosion.

Testing for corrosion in workshop

All identical test pieces are placed outside and left for a set amount of time, then collected and inspected for signs of corrosion