ceramics Flashcards
1
Q
structure of ceramic
A
regular crystal structure - crystalline
2
Q
4 mechanical properties of ceramics
A
- high hardness
- strong in compression, weak in tension
- notch sensitive
- brittle
3
Q
why are porcelains weak under tension and how can this be solved?
A
porous
vacuum used to reduce porosity
4
Q
3 methods of bonding porcelain to metal
A
- thermal contraction
- mechanical interlocking
- chemical bonding
5
Q
how does porcelain usually fail?
A
brittle - crack on fitting surface which propagates through to exterior surface
6
Q
why does veneer fail if cement layer too thick?
A
cement more flexible, cement bends + veneer cracks
