Materials Flashcards
What is a modern material?
Materials developed through new/improved techniques, last 100 years
Smart material
Material that change properties depending on an outside stimulus E.G. stress, temp, PH, moisture
What are Composite materials
Combination of 2 or more materials to produce a new material with combined properties
Example of modern composite material
Carbon fibre reinforced polymer ( mix of c fibre + moulded polymer
Example of traditional composite material?
Plywood, multiple layers of cross grained veneers (thin slice of wood)
Example of a smart material?
thermochromic pigment, shape memory alloys
Example of a modern material?
titanium, high strength: weight, resists corrosion
Ferrous metal
Metal or alloy that contains iron E.G. steel, usually attract a magnet and usually corrode by rusting
Non-ferrous metal
A metal or alloy that does not contain iron. E.G. copper does not attract a magnet, not all corrode
What is an alloy?
Mixture of two metals or a metal mixed with other elements, distorts layers of metal, makes tougher
What does gsm mean ?
Grams per square metre
Define paper and board
Materials manufactured from wood fibre and recycled pulp
What gsm is paper ?
Under 200 gsm
What gsm is board?
Over 200 gsm
Define strength
Ability to withstand forces without breaking
Define hardness
Ability to withstand scratching abrasion or denting
Define toughness
How easy it is to break or snap
Define elasticity
Whether a material can stretch/ bend and then return to its original shape
Define malleability
Ability to be bent and shaped
Ductility
Ability to be drawn into wires
Electrical conductivity
If a material can conduct electricity
Thermal conductivity
How easily heat can travel through a material
Fusibility
How easy a material is to fuse together or melt E.G. solder has high fusibility
Density
Mass per unit volume
Absorbency
How good at soaking up moisture
What are hardwoods?
Broad leaved deciduous trees, slow growing. Usually but not always hard E.G. oak
What are softwoods?
Trees with needle type leaves (coniferous) fast growing
What are manufactured woods?
Flat uniform boards made from other woods (grains or layers) of various types
Define thermoforming plastics?
Plastics that are easily heated melted and remoulded. Easy to recycle and reuse
Give an example of a thermoforming plastic it’s properties and uses
Polypropylene, tough and flexible variety of colours. Plastic chairs-flexibility makes comfort
What is a thermosetting plastic
Plastics that undergo a chemical change when heated and moulded, permanently in that shape, cannot be remoulded (hard + rigid) so they are non recyclable
Give an example of a thermosetting plastic it’s properties and uses
Epoxy resin rigid durable corrosion resistant, good electrical insulator. Used for circuit boards and wind turbine rotor blades
Biodegradable plastics?
Plastics that may break down in air water or decompose in soil
Give an example of a biodegradable plastic it’s properties and uses
PLA brittle but strong, used in 3d printing
