Ceramics

Question 1

What is a ceramic?

Answer 1

A combination of non-metallic elements or a combination of metallic and non-metallic elements.

Question 2

What are some properties of ceramics?

Answer 2

> Usually inorganic
> Highly inert
> Hard and brittle
> High compressive strength
> Good electric and thermal insulators
> Good aesthetic appearance

Question 3

Advantages and Disadvantages of bioceramics?

Answer 3

Advantages:
> biocompatible
> wear resistant
> lightweight

Disadvantages:
> low tensile strength
> difficult to fabricate
> low toughness

Question 4

Why is the measured strength much smaller than the theoretical strength?

Answer 4

Defects in the ceramic act as stress concentrators.

Pre-existing cracks – present from processing

Pores – present from processing

Inclusions – present from processing

Surface flaws – present from processing

Surface flaws – due to machining damage

Surface flaws – due to damage

Question 5

3 Most important things?

Answer 5

1. Ceramics cannot be cast like metals due to their
   high melting points; typically formed from powders.
2. Three main forming techniques are pressing, casting and plastic forming.
3. The strength of ceramic materials is generally
   characterised through bend testing.