| abstract |
A porous ceramic fiber insulating material and method of making a material having a combination of silica (SiO 2 ) and alumina (Al 2 O 3 ) fibers, and boron-containing powders is the topic of the new invention. The insulative material is composed of about 60 wt % to about 80 wt % silica fibers, about 20 wt % to about 40 wt % alumina fibers, and about 0.1 wt % to about 1.0 wt % boron-containing powders. A specific boron-containing powder used for this invention is boron carbide powder which provide boron-containing by-products, which aid in fusion and sintering of the silica and alumina fibers. The material is produced by forming an aqueous slurry, blending and chopping the fibers via a shear mixer, orienting the fibers in the in-plane direction, draining water from the fibers, pressing the fibers into a billet, heating the fibers to remove residual water, and firing the billet to fuse the fibers of the material. After sintering, bulk density of the new insulation material ranges from 6 to 20 lb/ft 3 . |