| 摘要 |
<p>Insulating refractory ceramic materials contain spheroidal voids larger than normal pores. The voids are created by admixing to the ceramic raw material round particles of pref. a hydrocarbon which volatilises at the firing temp. This material can be used for different thermal insulations, but is esp. suitable for articles produced by extrusion, because it does not show any texture (nonuniform density, varying orientation of grains) inherent in the known extruded products (such texture reduces the resistance to thermal shocks). If the material contains up to 50 vol.% of voids its compressive strength is not excessively reduced, whilst its heat-insulating properties are greatly improved and its weight is correspondingly diminished. The pref. applications include oxygen-blasting tuyeres, protective sheath for thermocouples or pressure-measuring devices, etc.</p> |
