Study Of Double Function Ring Strontium Titanate Component

The SrTiO₃ double function component is widely applied due to its excellent properties. In this dissertation, the varistor and capacitor mechanism of the SrTiO₃ double function component is analyzed.The main influence factors of property stabilization after soldering tin and current surged are discussed. The mechanism of instability of the components under current surged is analyzed from the point of view of microstructures and the thermal conductivity of components. The mechanism of doping donor and acceptor of the SrTiO₃ ceramics, reductive sintering and re-oxidizing technique for achieving the double function is interpreted. And making use of the theory and knowledge of phase diagram, the mechanism of SiO₂ glass phase of additive to the formation of liquid eutectic activated sintering and improving the components porosity and microstructure has been preliminary discussed. The difference of oxalate decompound and solid phase reaction methods are studied with the purpose of comprehending the conventional electrical properties and stability after soldering tin and current surged. The microstructure of components is analyzed by SEM, the result shows that the methods of powder manufacture are not mainly determining factor in decreasing the porosity rate. The relationship between the various amounts of SiO₂ additive, the components contractibility and the sintering temperature is studied by solid synthesized method. The results of test show that with the increase of added amount of SiO₂, air hole of component decreases and microstructures is more uniform, and crystal granularity presents growing up. At the same time, the SrTiO₃ ceramics contractive rate is related with added amount of SiO₂ and sintering temperature: ceramics contractive rate augments with the increase of added amount of SiO₂ and sintering temperature. It shows that the component begins to contract at about 1050℃, which offers the proof for ceramics sintering. The study shows 0.05mol%～0.1mol% amounts of SiO₂ additive and optimizes process parameters: when the temperature climbs at 1050℃, lowering heating rate to 0.5℃/min and changing the sintering process can effectively improve the porosity of components. The result shows thatΔV/V10mA=0.95%～3.6%,ΔC/C=9.6%～16.4%.