中文摘要：

采用放电等离子烧结技术制备La1-x SrxMnO3（x=0~0.4）热控陶瓷,重点研究了烧结温度和Sr含量对其物相组成、致密度、微观结构、导电性能和辐射特性的影响。随着烧结温度的升高,La1-x SrxMnO3陶瓷的密度和致密度逐渐增大,在1 100℃时其相对密度〉97%且物相单一。适量Sr含量对La1-x SrxMnO3陶瓷的物相无明显影响,而且随着Sr含量的增加,Mn4＋浓度逐渐增大,由此促进了Mn3＋-O2--Mn4＋双交换作用,导致其导电性增强。随着温度的升高,La1-xSrxMnO3陶瓷发生从金属态向绝缘态的相转变,由此导致其红外辐射率逐渐增大,Sr含量x=0.1时辐射率变化幅度达0.33,表现出明显的可变辐射率特征和良好的辐射特性。

英文摘要：

Sr-doped lanthanum manganite （La1 -x Srx MnO 3 ）thermal control ceramics were prepared by spark plasma sintering （SPS）and the effects of sintering temperature as well as Sr doping on crystalline phase,relative density,microstructure,electrical conductivity and emissivity were investigated.With the increasing of sin-tering temperature,the density and relative density were increased and single-phased La1 -x Srx MnO 3 ceramics with a high relative density （〉97%）were obtained at 1 100 ℃.The ratio of Mn4＋/Mn3 ＋ in the ceramics was increased with increasing Sr doping content,leading to the enhancement in electrical conductivity.With the increasing of temperature,the phase transition from metal to insulator occurred and the infrared emissivity increased,indicating good variable-emittance and high emissivity at the appropriate Sr doping content of x =0.1.