Preparation And Properties Of Oxidized Antistatic Ceramics

With the rapid development of science and technology,electrostatic widespread in many industries,such as national defense,military,aerospace,petrochemical,electronic components,and so on,and it has serious harm.Antistatic material has the function of static dissipation,which can release the static electricity safely.As a new type of antistatic material,antistatic ceramics have been widely studied due to its advantages of abrasion resistance,corrosion resistance and high safety performance.However,the antistatic ceramics produced at present have many problems such as unstable anti-static performance,complex preparation process and high cost.Oxidized antistatic ceramics not only have simple preparation method and low production cost,but also have controllable range of surface resistivity from conducting electrostatic to antistatic at room temperature,which can be applied to different antistatic fields.In this paper,dry pressing molding technology and atmospheric sintering method were used to prepare three kinds of oxidized anti-static ceramics:Al₂O₃ doped ZnO,ZrO₂ doped AZO（2 wt.%Al₂O₃ doped ZnO）and Nb₂O₅ doped ZrO₂.The influences of sintering temperature,doped material content and holding time on the relative density,mechanical properties and anti-static properties of ceramics were studied.The results obtained are as follows:（1）It was obtained from characterization analysis of Al₂O₃ doped ZnO ceramics that the density,bending strength and hardness of ceramics increased first and maximize at 1475℃,then decreased when the sintering temperature increased.The surface resistivity of the ceramic which Al₂O₃ doping amount from 2 wt.%to 10 wt.%were in the range of 10³Ω/□to10⁷Ω/□which sintered from 1400℃to 1500℃,they all achieved the requirement of anti-static performance and it have controllable range of surface resistivity from conducting electrostatic to antistatic.The experiment with the 8 wt.%amount of Al₂O₃ doped can get the best performance when sintering at 1475℃,the shrinkage rate is 14.5%,the relative density is98.3%,the bending strength is 143.2 MPa,and the vickers hardness is 295.4 HV0.3.（2）2 wt.%Al₂O₃ doped ZnO ceramics with good electrical conductivity were used as the matrix material,the ZrO₂ component is added to improve the mechanical properties of the materials.At the same time,the surface resistivity of the ceramics can be adjusted by controlling the doping amount of ZrO₂.By analyzing the ceramic XRD phase,it was found that the tetragonal phase ZrO₂ appeared when the ZrO₂ doping amount was 3 wt.%,and the content of the tetragonal phase ZrO₂ gradually increased with the increase of the ZrO₂ doping amount.The result showed that the surface resistivity of the ceramic which ZrO₂ doping amount from 1 wt.%to 15 wt.%were in the range of 10⁵Ω/□to 10⁸Ω/□which sintered from 1250℃to 1500℃,they all achieved the requirement of anti-static performance.The experiment with the 1 wt.%amount of ZrO₂ doped can get the best performance when sintering at 1450℃,the shrinkage rate is 17.6%,the relative density is 97.6%,the bending strength is 154.5 MPa,and the vickers hardness is 357.5 HV0.3.（3）Nb₂O₅ doped ZrO₂ antistatic ceramics were prepared by using ZrO₂ as ceramic matrix material.By the analysis of XRD phase,it was found that when the doping amount of Nb₂O₅ was lower than 3 wt.%,the ceramic phase was single and only the tetragonal phase ZrO₂ was present.When the doping amount of Nb₂O₅ was 4 wt.%and 5 wt.%,the tetragonal phase ZrO₂ was transformed into monoclinal phase ZrO₂,and the second phase Nb₂Zr₆O₁₇appeared,which reduced the density and mechanical properties of ceramics.The result showed that the surface resistivity of the ceramic which Nb₂O₅ doping amount from 1 wt.%to5 wt.%were in the range of 10⁵Ω/□to 10¹⁰Ω/□which sintered from 1200℃to 1350℃,they all achieved the requirement of anti-static performance.The experiment with the 1 wt.%amount of ZrO₂ doped can get the best performance when sintering at 1350℃,the shrinkage rate is 21.9%,the relative density is 97.7%,the bending strength is 506.2 MPa,and the vickers hardness is 1880.0 HV0.3.