Ceramic thermal insulating material

摘要

Ceramic thermal insulating material comprises a structure (2) provided with hollow spaces (3), in which are contained heat insulating filling material (5). Production of the insulating material is also claimed, in which a structure (2) with open hollow spaces (3) or pores is produced, into which a heat insulating filling material is introduced. The structure (2) is a reticular ceramic having a network of ceramic stems (4). The filling material (5) is in the form of hollow spheres, preferably of Al2O3, having a diameter of 50-150 microns and a wall thickness of 10-30 microns. The structure (2) has a heat conductivity of <= 5.5 W/(mK) and a mechanical bending strength of 2-4 MPa. The structure (2) is made of an oxide or non-oxide in form of Al2O3, Al2O3-ZrO2, ZrO2, SiC, SiO2 or Al2O3-SiO2. The structure (2) and filling material (5) are impregnated with a Al2O3 sol and heat treated at more than 1000 deg C, to form a binder phase of Al2O3 between the filling material (5) on one side and the filling material (5) on the structure (2) on the other side.