Research On Ultra-fast High-temperature Sintering Technology To Prepare YSZ Ceramic And LaFeO₃ Nano-Materials

Ultra-fast high-temperature sintering technology（UHS）is a new sintering technology in recent years,the UHS have high heating rate,short sintering time,simple structure,low environmental pollution and low energy consumption,the technology is still in the laboratory using stage at present,in the synthesis process of ceramic sintering and nanomaterials on further development of space,as a kind of low consumption and fast sintering method,It is of great significance to develop and perfect UHS technology.In this paper,the UHS device was mainly designed and built.By optimizing the heating mode of the device,the gradient yttrium oxide stabilized zirconia（YSZ）ceramic material was prepared,and the lanthanum ferrite nanomaterial was prepared with self-made quartz crucible.The main three aspects are as follows:1.Based on the concept of traditional ultra-fast high-temperature sintering technology,UHS device was successfully built by designing and optimizing device parameters.The device can achieve high temperature sintering at 3000℃,the limit rate can reach 600℃/s,under the condition of 1500℃can be used for a long time,10seconds can achieve ceramic dense sintering,the overall structure has good stability and modification conditions.2.By expanding UHS technology,asymmetric gradient YSZ ceramics can be prepared in a few seconds,greatly reducing energy consumption.The porosity,density and grain size of gradient YSZ ceramics prepared at different sintering temperatures were studied.The results show that during the UHS gradient sintering process stabilized at 2000℃for 15 seconds,a dense layer with a relative density of 95%is formed at the bottom of the ceramic,and the rest are porous structures with a relative density of less than 95%.The grain size decreases from 3.5μm to 1.5μm,and the gradient characteristics of the microstructure are consistent with the distribution of temperature gradient in the thermal field.This gradient sintering technique provides a fast and simple method for the preparation of asymmetric gradient ceramics.3.Perovskite nanomaterials under different conditions were prepared by controlling temperature point and constant temperature time.The material can be heated from room temperature to 800°C within 30 seconds and stabilized for 40 seconds,and then cooled to room temperature for about 6 seconds.During the rapid cooling process,the structural characteristics of nanomaterials with different constant temperature time can be retained.The microstructure evolution is characterized by mossbauer spectrum and X-ray diffraction technology.It was found that the superparamagnetic micro-oxide nanoclusters gradually evolved into a transition state of lanthanum ferrite crystals,during which the Fe³⁺of iron oxide gradually changed from 100%to 0%in total iron content,and completely transformed into pure phase lanthanum ferrite nanomaterials（37.62nm）.This work supplements the basic research on the application of UHS.The application of this method in non-carbon based nanomaterials is also extended.