Metals Flashcards
1
Q
What are the 7 noble metals?
A
Gold + RIPPOR
Rhodium Iridium Platnium Paladium Osmium Ruthenium
2
Q
Gold
- Melting temp
A
1337ºC
3
Q
Platnium
- Melting temp
- Increases (3)
- Adds what qualities to Au alloys
- Decreases (1)
- Usually what %
A
- 2045ºC
- Increases melting range, coefficient of thermal expansion, strength
- Adds hardness and elastic qualities
- Decreases grain size
- Usually 3-4%
4
Q
Palladium
- Melting temp
- Prevents what of Ag?
- Decreases (1)
- Increases (3)
A
- 1825ºC
- Prevents corrosion of Ag
- Decreases grain size
- Increases strength, toughness, hardness
5
Q
Iridium
- Melting temp
- Adding 0.005% does what?
- Increases (1)
- Imparts what two properties
A
- 2716º
- Refines grain size (uniform grain size)
- Castability
- Hard and brittle
6
Q
What base metals are used in dental alloys? (7)
A
STING ZC
Silver Tin Indium Nickel Gallium
Zinc
Copper
7
Q
Silver
- Melting temp
- Best conductor of what (2)
- Stronger and harder than what? (1)
- Softer than what (1)
- Severely tarnished by what?
- Does what to alloy?
A
- 1234ºC
- Heat and electricity
- Gold
- Copper
- Sulfur
- Whitens alloy
8
Q
Copper
- Melting temp
- Increases (3)
- Decreses (3)
A
- 1084ºC
- Increases strength, hardness, ductility
- Decreases tarnish, corossion, melting temp
9
Q
Tin
- Melting temp
- Combines with Pt and Pd to increase what
- Not found in % greater than?
A
- 505ºC
- Hardness
- Not >5%
10
Q
Indium
- Melting temp
- Replaces what in some alloys
- Increases (1)
A
- 430ºC
- Zinc in some alloys
- Increases castability
11
Q
Zinc
- Melting temp
- What unique property?
A
- 693ºC
2. Scavenger for oxides
12
Q
High noble classification
Noble
Base metal
A
A. > = 60% noble and >= 40% Au
B. >= 25% noble
C. =< 25% noble, predominantly base
