materials

Question 1

list 6 modern materials and their properties and use + what are modern materials

Answer 1

Modern materials are newly developed materials (graphene, metal foams and titanium) or specific function (LCD, Metal foam, coated metal)

1. graphene - 1 layer of carbon atoms bound in hexagonal lattice- high strength to weight ratio, thin. used in batteries, aerospace and phones
2. titanium - high strength to weight ratio and no corrosion - used in artificial joints (doesn’t react with human tissue) and aircraft
3. Metal foam- metal containing gas filled pores that have high stiffness to weight ratio and are tough so used in vehicles for impact resistance and weight saving
4. liquid crystal display LCD - vary levels of red, blue, green to produce an displayed image - TV.
5. coated metals - protect metals by adding layer to prevent corrosion and rust in ferrous. such as galvanising, powder and dip coating and painting and electroplating and anodising.
6. Nanomaterials- 1-100nm particles. High SA:V, light , rigid and high tensile strength. electronics and odour resistant

Question 2

smart materials: what are they and 5 types

Answer 2

materials that react to external stimuli

1. Quantum tunneling composite (QTC) - polymer with tiny metal particles embedded. when squeezed, particles pushed together and electrons can flow so a current is generated. microswitches and outdoor.
2. polymorph- mouldable- shaped and reshaped at 62c- flexible. used for protoyping as it is very easy to shape
3. Shape memory alloy- revert back to original shape after stimulus taken off such as nitinol

4 photochromic pigment- vary to UV light levels - some spectacle lenses. pigment may degrade over time. change colour

5. Thermochromic pigment - vary according to temperature. change colour

Question 3

composite- what are they, why done and 2 types

Answer 3

2 or more materials together to enhance properties as the properties of 2 materials are combined. not durable

CRP- carbon reinforced plastic which is a thermoplastic reinforced with carbon. High strength to weight ratio and is very rigid. Carbon fibre used in aerospace engineering and in F1 chassis

GRP- glass reinforced plastic which is a polyester material reinforced with glass fibre. string lightweight- boats, surfboards and cars

Question 4

technical textiles- 4 types + define

Answer 4

material manufactured for function and performance. How fibres can be spun to make enhanced fabrics

1. conductive fabrics- coated / blended conductive metals which allow for an electric signal to pass with very little resistance. sportswear. gloves. mousepad
2. fire resistant fabrics- withstand heat and release burning by releasing chemicals. woven to produce protection against heat without dripping. racing driver and fire crew. eg Nomex which fibres thicken an absorb heat energy.
3. microfibres- can be microencapsulated to hold antimicrobial- encapsulate particles
4. Kevlar - plastic fibre which has high tensile strength. fibres are tightly spun- impossible to separate. cant be puncture by ballistics so used in body armour and to make bullet proof vests.