AURUMED KF 55

Type 4
yellow / Au 55.0 
copper-free

Composition: Au 55.0 / Ag 27.0 / Pd 12.0 / In 4.0 / Zn 1.4 / Sn 0.5 / Ir 0.1
Standard: DIN EN ISO 22674 und DIN EN ISO 9693
Colour: yellow
Melting range °C: 1090–960
Soft annealing: -
Hardening: 15 mins at 500 °C / air
Preheating temperature °C: 850
Casting temperature °C: 1230
Further heating after melting (secs): electr.: 20–30
inductive: 5–10
flame: 5–10
Casting crucible: Graphite/ceramic
Density g/cm3: 14.2
CTE 25°C–500°C (µm/mK): 16.1
CTE 25°C–600°C (µm/mK): 16.2
Soldering before firing: Orplid Ceramic solder CF 950
Soldering after firing: Orplid solder CF 720
Vickers hardness (HV 5/30): w: -
a: 230
g/b: 210/230
0.2% proof stress (MPa): w: -
a: 500
g/b: 460/580
Elongation at break (%): w: -
a: 3
g/b: 4/5
Spruing: Following the rules for dental applications (see General Instructions for Use)
Investment: Phosphate-bonded investment materials
Preheating: 850 °C, 30 to 120 mins until end temperature, depending on size of mould
Casting: 1230 °C, possibly increase by 20°C–30°C for resistance-heated vacuum pressure casting. Graphite crucible or open flame with ceramic crucible
Finishing: With carbide burs and/or ceramic-bonded stones. Always grind in one direction only! Sandblasting at a flat angle, using 110–125 µm aluminium oxide. Pressure should not exceed 2 bar
Cleaning: Steam jet cleaning or boiling in distilled water
Oxide firing: 5 mins at 800°C with vacuum. Afterwards, always clean in a preheated acid bath, e.g. Neacid, (for up to 5 mins), or sandblast with 50-110 µm aluminium oxide, at up to 2 bar pressure; clean with a steam jet
Soldering before firing: Orplid Ceramic solder CF 950
Soldering after firing: Orplid solder CF 720
Firing: For highly expanding ceramic materials