Technical Ceramics
The OXAL brand ceramics made by BRISK Tábor have excellent properties thanks to the high curing temperature. Several types of alumina ceramics with a 90 – 99.7% content of Al2O3 are made for various applications. Various advanced production technologies allow the production of even the most demanding, very difficult and complex parts.
The OXAL brand ceramics made by BRISK Tábor have excellent properties thanks to the high curing temperature. Several types of alumina ceramics with a 90 – 99.7% content of Al2O3 are made for various applications. Various advanced production technologies allow the production of even the most demanding, very difficult and complex parts. Many products are produced using isostatic pressing with subsequent grinding or turning, based on the mass production of spark plug insulators.
Overview of the typical characteristics of OXAL alumina ceramics
Al2O3 content 95%
Volume mass 3.7 g/cm3
Water absorption – less than 0.05%
Bending strength 300 MPa
Compression strength 2000 MPa
Hardness 78 HRC – Mohs 9
Maximum working temperature 1600°C
Thermal conductivity 20W/mK at 100°C
Specific resistance 5.107 Ω x m at 700°C
Electric strength 30kV ef/mm at 20°C
Dielectric constant 12 at 10MHz and 20°C
IGNITION ELECTRODES AND IONISATION PROBES
Ignition electrodes and ionisation probes are used for the ignition of gaseous fuel in gas appliances. They operate on the principle of ignition by jumping of a high voltage spark. Here, the centre electrode must not be permanently in the flame. The ignition electrode and ionisation probe are placed together in the combustion chamber of the gas appliance – gas boilers, water heaters, gas stoves, etc.
The ignition electrodes can be used as ionisation probes and vice-versa. But it is always necessary to respected their location, i.e. the ignition electrode must be outside the flame, and only the central electrode of the ionisation probe must be in the flame. The ignition electrodes and ionisation probes are made from high quality materials. The insulator is made of OXAL ceramics with a high content of Al2O3. The characteristic feature of this ceramic material is high mechanical strength and resistance to thermal and electrical stress (electrical insulator strength is 18 kV). The centre electrode is made of special refractory material – Kanthal, which is resistant to high temperature and electrochemical corrosion.
IONISATION PROBES
Are used as combustion sensors in gas devices. The centre electrode is permanently in the flame. The rest of the parts of the probe must be positioned in the burner space in such a way that they are not subjected to natural cooling.
