Producing transparent polycrystalline ceramic, comprises press-molding and sintering ceramic powder in press in single press cycle between pressing elements of the press, and simultaneously and electrically resistance-heating the elements

摘要

The method comprises press-molding and sintering a ceramic powder in a press in a single press cycle between the pressing elements of the press, and simultaneously and electrically resistance-heating the pressing elements during press-molding and sintering the ceramic powder. The pressing elements are heated in consecutive following temperature stages with different reduced heating rates (K/minutes), and are heated in a first temperature stage with a heating rate of = 100 K/minutes. The ceramic powder is used with a primary grain size of = 300 nm. The method comprises press-molding and sintering a ceramic powder in a press in a single press cycle between the pressing elements of the press, and simultaneously and electrically resistance-heating the pressing elements during press-molding and sintering the ceramic powder. The pressing elements are heated in consecutive following temperature stages with different reduced heating rates (K/minutes), and are heated in a first temperature stage with a heating rate of = 100 K/minutes. The ceramic powder is used with a primary grain size of = 300 nm. The heated pressing elements are impacted with a pressure of = 20 MPa during press-molding and sintering. An unpulsed direct current is applied on the heated pressing element during press-molding and sintering. The pressing elements are a press matrix and a press stamp. Pressing plates are used as pressing elements to produce ceramic articles. A hot isostatic pressing (HIP) process connects itself to the press-molding and sintering of the ceramic powder in a resistance-heated HIP device. The produced ceramic articles are polished for final preparation.