Preparation And Properties Of Nanometer ZrO₂ Powders By Microwave Drying And Pyrolysis

As a kind of energy saving and environmental protection heating technology,microwave heating technology has attracted much attentions from domestic and foreign researchers because of its unique overall heating characteristics,selective heating characteristics,fast and efficient advantages.It is widely used in the drying,preparation and sintering of some materials.Zirconia has excellent physical and chemical properties,with high temperature,thermal conductivity,wear resistance,good thermal shock resistance,etc.It is an important structural and functional ceramics.However,the preparation of the traditional nano-zirconia powder is not only high energy consumption,but also easy to agglomerate in the process,and can not get high property nano-powder.Therefore,the preparation process of zirconium oxide powder urgently needs to be improved.In this paper,the nano-zirconia precursor containing 80% water was used as raw material,and the raw materials were dried and pyrolyzed by microwave heating,and they were compared with the samples made by traditional drying and pyrolysis process,those samples were analyzed by particle size analysis,XRD,SEM to characterize the property of the samples,and finally determined the best microwave drying and pyrolysis process.The problem of long preparation period,poor dispersibility and easy agglomeration in the preparation of nanometer zirconia by pyrolysis in the traditional heating process was solved.The main results of this paper are as follows:Respectively,the raw materials was dried directly,anhydrous ethanol processed before dried and by microwave.The results show that the dispersion of the raw materials dried by microwave was the best,the particle size is about 100 nm,and the drying time is only 30 min,which was shorter than the drying time of the other two processes,the microwave drying method greatly saved the drying time,improved the efficiency.The dried materials were pyrolyzed by traditional resistors and microwave materials workstation at different temperatures.The optimum pyrolysis process of the two methods was determined.The optimum pyrolysis process of traditional resistance was 450? for 30 min.Which has small particle size and good dispersibility,and the particle size is about 200 nm.The sample pyrolyzed at 500? for 1min by microwave heating was smaller than other particles at different temperatures,about 50 nm in size,and the particles were evenly distributed.Compared with the traditional pyrolysis process,the microwave pyrolysis samples have smaller particle size,better dispersibility and no obvious agglomeration.The time for the pyrolysis process was also significantly reduced.