Preparation And Sintering Mechanism Of Zirconia Nanoceramics

Nanoceramics is the future direction of advanced ceramics.In this paper,3Y-TZP nanoceramics was selected as the research object.The microstructure of the material determines its macroscopic properties,so the chemical composition of the material,the design of the microstructure and the control of the sintering mechanism are the key to the preparation of nanoceramics.Y-TZP material has excellent mechanical properties and is widely used in production and life.This paper summarizes the research progress of Y-TZP ceramics and its preparation,composition optimization,superplasticity and abrasion resistance.The application status and prospect of Y-TZP ceramics in dentistry are mainly discussed.The low temperature aging of Y-TZP ceramics The phenomenon limits its application.This paper summarizes the three factors that affect the low temperature aging of Y-TZP ceramics,and put forward several preventive measures to prepare more microscopic nano-TZP ceramic is a solution to protect the material from phase change.Compared with the two-step sintering method and SPS sintering method,it can be seen that the stomata in the two-step sintering has a large scale abnormal growth,and the SPS sintering has the characteristics of high temperature and temperature,and can be used for the grain size and sintering neck size during sintering In addition,SPS technology has a wider pressure range,can achieve the flexibility of sintering pressure control.In classic sintering theory,the contribution of particle rearrangement is limited to only?3%compact shrinkage in early stage and the followed sintering is exclusively dominated by atom-diffusion mechanisms.This viewpoint has been prevailing in academia and rather limited attention has been paid to the behaviors of particle rearrangement during ceramic sintering.However,it was found that the period validity of particle rearrangement had been intensively enhanced to as high as?93%of density in nanoceramic sintering.Moreover,the intensive particle rearrangement showed strong influences on the microstructural development and sintering behaviors during high-density ranges.In present project,spark plasma sintering technique is selected for the investigation of particle rearrangement behaviors using zircoina nanoceramic as examples.By special modes designing,each possible influence from electric filed,heating rate and pressure will be peeled to identify its contribution to the intensive particle rearrangement.Based on these understanding,the kinetic explanations for the intensive particle-rearrangement behaviors of nanoceramic sintering will be proposed.Furthermore,the sintering process of nanoceramics will be divided by the basic densification unit,atom and grain,by which the active stage(s)and contributions of particle rearrangement will be clearly identified.The research findings of present project will be expected to be a supplement to classic sintering theory,as well as providing inspirations for the utilization of particle-rearrangement kinetics in general nanoceramic fabrications.