Patent ID: 6190604
Filing Date: 2001-02-20
Classification: B22F,B28B,C04B,C22C

Abstract:
A process for preparing a preform with a high volume fraction of SiC particles by use of an apparatus comprising:a bottom die;a top mold with a cavity, placed on the bottom die;an upper punch for pressing a material for said preform in said cavity;and two water-absorbers, one being inserted between said bottom die and said-top mold, the other being placed on the top mold, wherein a slurry prepared by mixing SiC particles with binders in deionized water and ball milling the mixture, is introduced in said cavity and pressed by said punch while the water is absorbed in said absorbers or drained through a gap between said bottom die and said mold;said process comprising the steps of:mixing SiC particles with an inorganic binder, an organic binder and a coagulant in distilled water and ball milling the resulting suspension to give a slurry;pressing the slurry in said apparatus to give a primary preform;drying said primary preform; andcalcining said primary preform.