防冰用钛酸钡系正温度系数材料制备与性能研究

Preparation and Properties of Barium Titanate System Positive Temperature Coefficient Materials for Ant-Icing

覆冰对电网威胁巨大。开发适于防冰的正温度系数材料与绝缘子结合,使绝缘子的发热功率受温度控制,对提升绝缘子防冰能力具有重要意义。以BaCO3、TiO2为原料,分别掺杂15. 0%(摩尔分数,下同)的Sn4+、32. 4%的Sr4+作为居里点移动剂取代Ti元素和Ba元素,又分别以Y3+、Mn2+作为电子施主和电子受主,均在1 150℃和1 350℃进行预烧与二次烧结,制备出Ba(Ti0. 850Sn0. 150) O3和(Ba0. 676Sr0. 324) TiO3两种正温度系数材料,两种材料的居里温度均在0℃附近,低温区体积电阻率分别在105Ω·m数量级和103Ω·m数量级,Ba(Ti0. 850Sn0. 150) O3在居里点附近体积电阻率阶跃达2个数量级,(Ba0. 676Sr0. 32 4) TiO3在居里点附近温度上升25℃时,体积电阻率约增大一倍。两种材料居里点、低温体积电阻率和PTC效应满足被选作防冰材料的基本要求。

Insulator icing threatens the safe operation of power grid. It is of great significance to develop a positive temperature coefficient material suitable for ant-icing and to combine it with insulator so that the heating power of insulator can be controlled by temperature. Using BaCO3 and TiO2 as raw materials,15. 0%( mole fraction) Sn4+and 32. 4%( mole fraction) Sr4+were doped respectively as Curie point mobile agent to replace Ti and Ba. Y3+and Mn2+were used as electron donor and electron acceptor,respectively. The first and second calcinations of the materials were carried out at 1 150 ℃ and 1 350 ℃,respectively. Two kinds of positive temperature coefficient materials Ba( Ti0. 850Sn0. 150) O3 and( Ba0. 676 Sr0. 324) TiO3 were prepared. The Curie pointof the two materials was near 0 ℃ and the volume resistivity in the low temperature area were 105Ω·m and 103Ω·m,respectively. When the temperature near Curie point increased by 25 ℃,the volume resistivity of( Ba0. 676 Sr0. 324) TiO3 only doubled. Positive temperature coefficient effect of Ba( Ti0. 850 Sn0. 150) O3 is more obvious than that of( Ba0. 676Sr0. 324) TiO3. The Curie point,volume resistivity at low temperature and positive temperature coefficient effect of the two materials meet the basic requirements of being selected as anti-icing materials.