Flash-sintering Of Barium Titanate Ceramics

In recent years.Flash sintering has become a highly attractive technology.It has been used in ion conductor,electrical conductors,insulators and all kinds of ceramic material,such as semiconductors,etc.A lot of studies about flash sintering have shown that the sintering temperature of flash sintering was lower compared with the conventional sintering.Flash sintering occurs in a few seconds.It can decrease the temperature and time of sintering significantly.BaTiO3 ceramics has been widely used because of its good iron voltage electric properties,but the traditional sintering temperature of barium titanate ceramics is very highly.The purpose of this paper is to study the flash-sintering of BaTiO3 ceramics.Studing the effects of different flash-sintering parameter on BaTiO3 ceramics,and decreasing the sintering temperature of barium titanate ceramics.In this paper,the dog bone shape blanks made of two kinds of powder,they were sintered in two modes of constant temperature and warming.And studied the impact of current on the flash,found that there is a safe current range,the current exceeds this limit will make the sample breakdown,or even blow.According to the experimental results,lOmA/mm2 was chosen as the best experiment current.For barium titanate,the firing temperature can be decreased from 1400? to about 700?.The study of micron BaTiO3 found that it is difficult to sinter compact,so the use of extended steady-state time and secondary sintering technology.The results show that the relative density can reach 92%after the secondary sintering of 450 V/cm,and the BaTiO3 ceramics are more compact.Therefore,the firing of BaTiO3 ceramics can be improved from the following aspects:fine grain size,increase the electric field strength,improve the flash furnace temperature,prolong the steady state residence time and multiple sintering.The study of nanometer BaTiO3 found that nano-powder easily agglomerate,by adding 5wt%of polyacrylic acid amine,effectively solve this problem.The BaTiO3 powder was compared with that of the barium titanate,and the nanometer BaTiO3 powder was compared with the nanometer BaTiO3 powder before and after the dispersion.It was found that the nanometer BaTiO3 powder was more easily sintered and dispersed than the micron BaTiO3 powder under the same conditions After the nano-BaTiO3 than the dispersion of nano-BaTiO3 more easily sintered,indicating that different powder flashing effect is significantly different.And the dispersion of nano-BaTiO3 ceramics for a variety of electrical properties of the measurement.By studying the micro-BaTiO3.it is found that it is difficult to sinter dense,so the extended steady-state time and the second sintering technology.The results show that the relative density can reach 92%and the BaTiO3 ceramic is denser after sintering at 450 V/cm.Therefore,the BaTiO3 ceramics can be improved from the following aspects:refining the grain size,increasing the electric field strength.improve the flash temperature,prolong the steady state residence time and sintering.