Type 4 (hardened)
yellow / Au 75.1
palladium-free, copper-free
| Composition: | Au 75.1 / Ag 13.6 / Pt 8.3 / Zn 2.5 / Ta 0.2 / Ir 0.1 / In 0.1 / Mn 0.1 |
| Standard: | DIN EN ISO 22674 and DIN EN ISO 9693 |
| Colour: | yellow |
| Melting range °C: | 1080–955 |
| Soft annealing: | 15 mins at 750 °C / quench in water |
| Hardening: | 15 mins at 500 °C / air |
| Preheating temperature °C: | 700 |
| Casting temperature °C: | 1230 |
| Further heating after melting (secs): | electr.: 20–30 inductive: 5–8 flame: 5–8 |
| Casting crucible: | Graphite/ceramic |
| Density g/cm3: | 16.9 |
| CTE 25°C–500°C (µm/mK): | 15.6 |
| CTE 25°C–600°C (µm/mK): | 15.8 |
| Soldering before firing: | Orplid Ceramic solder CF 950 |
| Soldering after firing: | Orplid solder CF 720 |
| Vickers hardness (HV 5/30): | w: 125 a: 190 g/b: 150/125 |
| 0.2% proof stress (MPa): | w: 190 a: 455 g/b: 275/210 |
| Elongation at break (%): | w: 9 a: 7 g/b: 7/12 |
| Spruing: | Following the rules for dental applications (see General Instructions for Use) |
| Investment: | Phosphate-bonded investment materials |
| Preheating: | 700 °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 50–125 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 without vacuum. Afterwards, always clean in a preheated acid bath, e.g. Neacid, (for 10 mins) or sandblast with 50–110 µm aluminium oxide. Pressure should not exceed 2 bar. Clean thoroughly 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 |