Aluminium oxide
Data sheet
| Property | Unit | Tempereture | A-976 | A- 995 | ||||
|---|---|---|---|---|---|---|---|---|
| Al2O3-Content | % | 97,6 | 99,5 | |||||
| Color | - | white | white | |||||
| Density | g/cc | R.T. | 3,76 | 3,86 | ||||
| Flexural resistance | MPa | R.T. | 296 | 310 | ||||
| Compressive strength | MPa | R.T. | >1720 | >2070 | ||||
| Hardness | Rockwell 45N | 75 | 81 | |||||
| Porosity | % Proz. Wasseraufn. | Vakuumdicht 0 | Vakuumdicht 0 | |||||
| Thermal Conductivity | W/m °K | R.T. | 26,8 | 29,3 | ||||
| Thermal Expansion- coefficient | 10-6/°C | 25°-200°C | 6,9 | 6,9 | ||||
| 200°-400°C | 7,8 | 7,8 | ||||||
| 400°-600°C | 8,5 | 8,3 | ||||||
| 600°-800°C | 8,8 | 9,0 | ||||||
| 800°-1000°C | 9,0 | 9,4 | ||||||
| Max. Operating temp. | °C | 1650 | 1725 | |||||
| Dielectric Resistance | D.C. volts/mil | R.T. | 1100 | 800 | ||||
| D.C. kvolts/mm | 43,3 | 31,5 | ||||||
| Temperature coefficient | °C | >1000 | >975 | |||||
| Specific Contact resistance | ohm-cm | 25°C | >1014 | >1014 | ||||
| 300°C | 1,0*1012 | 2,0*1011 | ||||||
| 600°C | 2,3*1010 | 6,0*108 | ||||||
| 1000°C | 5,0*1018 | 2,5*106 | ||||||
| Dielectricity constant | 25°C | 300°C | 500°C | 25°C | 300°C | 500°C | ||
| 10MHz | 9,53 | 9,91 | 10,14 | 9,58 | 9,92 | 10,20 | ||
| 1000MHz | 9,00 | - | - | 9,30 | - | - | ||
| 8500MHz | 9,04 | 9,32 | 9,54 | 9,37 | 9,61 | 9,82 | ||
| Dielectrical Loss factor (Tan Δ) | 25°C | 300°C | 500°C | 25°C | 300°C | 500°C | ||
| 10MHz | 4*10-5 | 1,6*10-4 | 5,2*10-4 | 3*10-5 | 9*10-5 | 4*10-4 | ||
| 1000MHz | 3*10-4 | - | - | 1,4*10-4 | - | - | ||
| 8500MHz | 4,5*10-4 | 4*10-4 | 7,2*10-4 | 9*10-5 | 1,4*10-4 | 2,5*10-4 | ||
| Loss factor (K'tan Δ) | 25°C | 300°C | 500°C | 25°C | 300°C | 500°C | ||
| 10MHz | 3,8*10-3 | 1,58*10-3 | 5,27*10-3 | 2,9*10-3 | 8,9*10-3 | 4,08*10-3 | ||
| 1000MHz | 2,7*10-3 | - | - | 1,3*10-3 | - | - | ||
| 8500MHz | 4,07*10-3 | 3,73*10-3 | 6,87*10-3 | 8,4*10-4 | 1,35*10-4 | 2,45*10-3 | ||
Regarding the property values given in the tables the preliminary remark about DIN 40685 applies analogously, whereby the given values only apply for the test specimens on which they were measured. A transfer to other forms is only permission under certain conditions. The given values are consequently only to be understood as standard values.