Abstract: A low density abradable seal produced by depositing metallic particles onto a binder coated substrate and then heat treating the coated substrate to produce a porous coating structure having excellent erosion and oxidation resistance and abradability characteristics.

Abstract: A method of making a high void porous sheet by sintering metallic coated hollow carbonaceous particles and sheets made by such method.

Abstract: Abradable seal composite structure having a porous, abradable ceramic surface layer which is resistant to high temperature oxidation and a metallic bottom layer capable of being bonded to a metallic substrate, with at least two intermediate layers consisting of ceramic/metal mixtures. The intermediate layer next to the ceramic layer has the highest ceramic content, with the remaining intermediate layers having progressively lower ceramic content and correspondingly higher metallic contents. The composite is made by laying up the layers in wet paste form and then drying them, after which the composite can be heated to bond it to the metallic substrate.