Engineering ceramics and composites Flashcards
What is the source of silicon carbide?
Silica sand (containing silicon) and carbon in a furnace
Forms of supply of silicon carbide
Fine powder or bonded mass
Properties of silicon carbide
- High melting point
- Good thermal conductivity
- Hard
- Semiconductor
- Corrosion resistant
Uses of silicon carbide
- Car brakes
- Certain seals and bearings
- LEDs
- Parts for rocket engines; gas turbine components
Source of tungsten carbide
1:1 tungsten and carbon
Forms of supply of tungsten carbide
Fine grey powder
can be formed into shapes by sintering
Properties of tungsten carbide
- High strength
- Rigid & extremely hard
- Resistant to deformation, deflection and impact; twice as stiff as steel
- High density
- Heat resistance
- Good conductivity
- Quite inert
Common applications of tungsten carbide
- Cutting tools and tips for machining, mining and drilling
- Neutron reflector in nuclear reactors
- Surgical instruments
Source of borosilicate glass
- Silica sand
- Boric oxide
- Soda ash
- Alumina (aluminium oxide)
Forms of supply of borosilicate glass
- Rod
- Tube
Moulded and processed into custom shapes and sizes
Properties of borosilicate glass
- Low thermal expansion coefficient
- High strength
- Chemical stability (very high corrosion resistance)
Uses of borosilicate glass
- Laboratory glassware
- Cookware eg beakers
- Syringes (medical)
- Optical equipment eg lenses for microscopes (due to stability)
Source of glass reinforced plastic
Glass fibre embedded in a polymer
Form of supply of GRP
- Sheet
- Fabric
Typical properties of fibreglass
- Low density
- Very strong (high strength-to-weight vs many metals; much better than steel)
- Design flexibility
- Chemically inert; durable
- High impact resistance without permanent deformation (tough)
Where is GRP used?
- Skis
- Sailing boats / canoes
- Aircraft
- -> strong and light so less performance impact
- Pipes
- Corrugated sheet
- -> light, tough, resistant to water
What does GRP stand for?
Glass-reinforced plastic (fibreglass)
What is CRP made using?
- Carbon fibres or carbon nanotubes
- Resin eg epoxy resin
Forms of supply of CRP
- Fabric
- Sheet
Properties of carbon-fibre reinforced plastics
- Very strong
- Very stiff and rigid
- Low density
Common applications of CRP carbon-fibre reinforced plastics
- Aircraft body
- Automotive vehicle body panels
- Sports equipment eg bicycle frame
What is reinforced concrete made using?
- Aggregate (sand and gravel)
- Embedded in cement
- With metal rods (eg steel, called rebar)
How is reinforced concrete supplied?
Fluid mixture
Properties of reinforced concrete
- High compressive strength
- Rods ensure it can withstand tensile stress (normal concrete has weak tensile strength)
- Can be damaged by corrosion; weathering
Where is reinforced concrete used?
- Building materials
- Foundations
- Bridges and roads
