Density and electrical properties of cordierite based ceramics as function of compaction pressure

Abstract

Mechanical activation is widely used and relatively inexpensive procedure for sintering process sample preparation. However, the influence of pressure, which is used for compaction, has not been completely investigated. Cordierite, 2MgO⋅2Al2O3⋅5SiO2, is a very actual hightemperature ceramic material, due to its characteristics. Based on our previous investigation, the mechanical activation of the starting mixtures with 5.00 mass% TiO2 was performed in a high energy ball mill during 10 minutes. Compaction pressure varied from 0.5 to 6t/cm2 (49 MPa - 588 MPa). Sintering process was performed at 1350oC for 4h in air atmosphere. The phase composition of activated and sintered samples was analyzed by the X-ray diffraction method. Scanning electron microscopy was performed to analyze the microstructure of both compacted and sintered sample. Non-isothermal sintering up to 1400oC, with a constant heating rate, was investigated by thermal shrinkage change with dilatometer. In this paper we research green bodies and sintered samples compaction pressure influence electrical properties.