C15.4 Glass, ceramics and composites

Question 1

What is glass mainly out of?

Answer 1

Sand - limestone = sodium carbonate

Question 2

What is the most common form of glass?

Answer 2

Called soda - lime glass

Question 3

How is glass made?

Answer 3

The raw materials heated to 1500 degrees
They melt and react form molten gas. As the glass turns into a solid - this particles do not form a regular pattern. It is as if the particles in the molten glass are frozen in place

Question 4

How can different types of glass be made?

Answer 4

Can be made by varying the glass - making mixture or by incorporating other material into the glass

Question 5

What is borosilicate glass used for?

Answer 5

Used for ovenware and test-tubes

Question 6

What are some examples of ceramics?

Answer 6

Titles - bricks - bathroom sinks

Question 7

What are the properties of ceramics?

Answer 7

Hard but generally brittle
Electrical insulators and resistant to chemical attack
Made by moulding wet clay into the desire shapes - and the heating them in a furnace to around 1000 degrees

Question 8

What does clay contain?

Answer 8

Compounds of metals such as aluminium and pottasium - and non-metals such as silicon and oxygen

Question 9

What type of bonding is present in Ceramics?

Answer 9

Ionic and covalent bonding

Question 10

How are ions and atoms arranged in ceramics?

Answer 10

Arranged in a giant structure that form layers

Question 11

What happens when the clay is wet?

Answer 11

Water molecules get between the layers of clay and make it slimy (as on a potter’s wheel)

Question 12

What happens when the clay is fired up in a furnance?

Answer 12

Water is driven out and strong bonds form between the layers in the giant structure - changing the properties dramatically

Question 13

What happens if there is a high temperature in the furnace?

Answer 13

The higher the temperature inside the kiln or furnace - the harder the ceramic formed

Question 14

Why are ceramics brittle?

Answer 14

Because a sharp blow can distort layers in their structure so that ions with like charges are adjacent and repel each other away - cracking the ceramic object

Question 15

What is a composite made up of?

Answer 15

2 materials - making a product with improved properties for a particular use. With one material acting as a binder for the other material - improving a desirable property that neither of the original materials could offer alone

Question 16

What is reinforcement?

Answer 16

One material surrounding and binding together fibres or fragments of the other material

Question 17

What are the properties of composite glass-ceramic?

Answer 17

Hard and very tough - No longer brittle as the glass melts between the crystals in the ceramics - so any cracks cannot spread through the whole structure

Question 18

Why can a polymer layer be added to a materials surface?

Answer 18

Makes the surface waterproof - harder - stronger

Question 19

How can the properties of concrete can be improved?

Answer 19

By reinforcing it with steel rods or mesh

Question 20

What is the compressive strength?

Answer 20

A measure of how well a material resists being crushed when a force is applied

Question 21

What is the tensile strength?

Answer 21

The tension a material can withstand without breaking

Question 22

How can concrete be made?

Answer 22

From cement - stand and gravel mixed with water and left to set
Concrete is a very hard composite and is very strong in compression

Question 23

How can concrete be made more resistant?

Answer 23

Can be made more resistant to bending forces by setting it around a matrix of steel rods - forming reinforced steel