초록 ▼

Porous ceramic greenware comprising finely divided ceramic filler, finely divided metal, and polyolefin controls shrinkage in fired shape. In a preferred embodiment the metal and ceramic filler are bound together with the clean burning polyolefin and a plasticizer. After molding the mixture into the

Porous ceramic greenware comprising finely divided ceramic filler, finely divided metal, and polyolefin controls shrinkage in fired shape. In a preferred embodiment the metal and ceramic filler are bound together with the clean burning polyolefin and a plasticizer. After molding the mixture into the final shape, the plasticizer is removed to introduce porosity into the shaped article. Next the article is heated to decompose the polyolefin which can exit as a gas through the pore openings. Finally, the article is fired to a high temperature to oxidize the metal to metal oxide which becomes sintered with the ceramic filler particles to form a sintered porous article where the oxidized metal bonds the filler particles together in the desired shape.

대표청구항 ▼

Homogeneous precursor composition for forming a sintered porous ceramic article comprising (a) 5 to 90 wt. % of a finel divided solid metal capable of forming an oxide by heating in air and selected from the group consisting of Al, Zn, Fe, Cu, Si, Ti, Mg, Ba, Ta, U, Cr, Co, V, Mn, Ni, Sn, Zr, Th, Ge

Homogeneous precursor composition for forming a sintered porous ceramic article comprising (a) 5 to 90 wt. % of a finel divided solid metal capable of forming an oxide by heating in air and selected from the group consisting of Al, Zn, Fe, Cu, Si, Ti, Mg, Ba, Ta, U, Cr, Co, V, Mn, Ni, Sn, Zr, Th, Ge, T1, Pb, Mo, W, the rare earth metals and mixtures thereof, (b) 5 to 90 wt. % of a finely divided ceramic filler which is an oxide of a metal selected from the group listed in part (a), and (c) remainder of a particle binding effective amount of a nonaqueous polymer binder system which is capable of being removed when the composition is heated in the pressure of air or oxygen, said binder being present in at least 4% by weight of the composition and comprising a mixture of (1) a polymer which is capable of being oxidized away when the composition is heated and (2) a plasticizer for the polymer.