Cold sintering process (CSP) is usually used for low temperature sintering of high temperature (< 1000) ceramics. There are many sintering methods for high-temperature composite ceramics. Common methods include hot pressing sintering, hot isostatic pressing and spark plasma sintering. These methods usually achieve densification of high-temperature composite ceramics under high temperature and high pressure, which can meet the sintering requirements of composite ceramics with high melting points. However, these methods increase energy consumption and usually require high experimental equipment. Therefore, it is of great significance to explore the low-temperature sintering technology of composite ceramics with high melting point and high sintering temperature (≥1000).
The Chang Aimin research team of the Materials Physics and Chemistry Laboratory, Xinjiang Institute of Physics and Chemistry, Chinese Academy of Sciences, has been committed to the research and application of thermal ceramic materials and devices for many years. The research team used the combination of cold sintering technology and traditional solid-phase reaction sintering process, starting from the composite ceramic phase structure, selecting scheelite CaCeNbWO8 with tetragonal phase and perovskite LaMnO3 with orthogonal phase to composite to achieve high melting point and high sintering temperature Densification of 0.3CaCeNbWO8-0.7LaMnO3 composite ceramic material (relative density as high as 94.5%), and the relationship between the phase structure, microscopic morphology and aging properties of the composite ceramic material was studied. In-situ X-ray diffraction data (HT-XRD) was used to analyze the effect of phase transition on electrical properties; X-ray photoelectron spectroscopy (XPS) was used to analyze the effect of Ce4+ to Ce3+ in composite ceramics on electrical properties; the ceramic material is 200- The 800 temperature range shows good negative temperature coefficient characteristics, and the aging rate is less than 2%. It is expected to be used as a high temperature thermistor material for temperature measurement and monitoring in high temperature environments.