Thermal insulation material based on alumina fibers and its manufacture.

摘要

A heat insulating material, in the form of an anisotropic porous body, contains (by wt.) 70-90% alumina-based fibres and 10-30% aluminosilicate binder, the fibres consisting of 72-97% Al2O3 and 3-28% SiO2 and having an average dia. of up to 2 microns, an aspect ratio (1/d) of 30-130 (pref. 40-90), a strength of at least 600 MPa and a class temp. of 1650 degrees C. The material has a density of 0.15-0.5 g/cm<3>; a linear shrinkage, after 24 h at 1600 degrees C, of up to 2% in the 'strong' direction and up to 4% in the 'weak' direction; a tensile strength of at least 0.15 MPa and a compressive strength of at least 0.2 MPa in its 'strong' direction; an anisotropy of 1.3-4; and a long term service temp. of 1600 degrees C. Also claimed is a process for mfg. the above material.