摘要
用通常的混合氧化物工艺,在(Ba-Pb)TiO_3固溶体系统中,以 La_2O_3和 Nb_2O_5为复合施主掺杂物,以一定比例的 Al_2O_3—SiO_2—过量 BaCO_3和 Mn^(2+)离子为改性添加物,并以分段保温、快速升温的烧结过程,获得了居里温度为180±5℃、室温电阻率为50Ω·cm、电阻率突变为10~4的 PTCR 材料。用该材料加工的圆片发热元件组装成的冷起动器性能达到上海桑塔纳轿车和北京吉普213生产线的国产化要求。本文还研究了此材料制备过程中的化学组成、制备工艺、电气性能和微观结构之间的关系。
PTCR material bated on(Ba-Pb)TiO_3 solid solution was prepared by using themixed oxide method.La_2O_3 and Nb_2O_5 were added as co-donor,Al_2O_3-SiO_2-excessBaCo_3 and Mn ion with a fixed ratio were selected as the additives,multi-stagesoaking and fast heating procedure were used in sintering process.The property ofa typical sample is as follows:T_c:180±5℃;ρ_v at room temperature:50Ω.cm;Δρ_v(ρ_(vmax)/ρ_(vmin)):10~4.Manifold heaters used for Shanghai Sontana and Beijing Jeep213 were assembled with the heating elements made of the above PTCR material,and exhibit a quite good performance.In the experiment,the relation between composition,process,microstructureand property of the PTCR material was studied.The samples doped with Sb_2O_3exhibit a quite low resistivity at room temperature and those co-doped with La_2O_3and Nb_2O_5 can form a good PTCR anomaly:the additives to form liquid phase du-ring sintering can improve the performance of the sintering behavior and grainboundary property;the introduction of Mn ion changes the resistivity at room tem-perature and enhances largely PTCR anomaly;multi-stage soak and fast heatingprocedure produce a suitable microstructural development and are beneficial to PTCReffect;sintering in N_2 atmosphere and post-treating in air reduce the resistivity atroom temperature but exhibit no substantial improvement of PTCR anomaly of thesamples under the studied condition.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1992年第1期42-49,共8页
Journal of Inorganic Materials
关键词
电阻
汽车材料
PTCR
发热元件
PTCR effect
Donor
Acceptor
Microstructure
Liquid phase additives
