原料组成对多微孔方镁石-镁铁铝复合尖晶石陶瓷显微结构与性能的影响

Effect of Raw Material Composition on Microstructures and Properties of Microporous Periclase-Composite Spinel (Mg(Fe, Al)_(2)O_(4)) Ceramics

利用原位分解合成法,以轻烧MgO、Fe2O3和Al(OH)3为原料,成功制备了多微孔方镁石-镁铁铝复合尖晶石陶瓷,并研究原料组成对其显微结构与性能的影响。研究结果表明:当理论镁铁铝复合尖晶石含量为0%(质量分数,下同)时,试样中颈部连接形成较少,耐压强度较低;当理论镁铁铝复合尖晶石含量为4%~16%时,试样中生成的液相量增多,物质运输速率加大,形成的颈部连接较多,耐压强度较高;当理论镁铁铝复合尖晶石含量为24%时,试样中镁铁铝复合尖晶石生成带来的体积膨胀增多,增大颗粒间距,颈部连接的形成减少,试样的耐压强度减小。同时,当理论镁铁铝复合尖晶石含量为12%~16%时,多微孔方镁石-镁铁铝复合尖晶石陶瓷具有较高的显气孔率(22.3%~24.6%)、较低的体积密度(2.75~2.80 g/cm^(3))和较高的耐压强度(100.6~123.1 MPa)。

In the work,microporous periclase-composite spinel(Mg(Fe,Al)2O_(4))ceramics was successfully prepared using calcined MgO,Fe 2O_(3) and Al(OH)3 as raw materials by in-situ decomposition synthesis.Meanwhile,the effects of raw material on its microstructures and properties were studied.The results show that when the periclase-composite spinel(Mg(Fe,Al)2O_(4))content is 0%(mass fraction,the same below),less neck connection form in the sample as well as the compressive strength is low.When the theoretical periclase-composite spinel(Mg(Fe,Al)2O_(4))content is 4%~16%,the content of the liquid increases and the mass transport accelerates.Then,lots of neck connections form and the compressive strength is high.When the theoretical periclase-composite spinel(Mg(Fe,Al)2O_(4))content is 24%,the expansion amounts caused by the formation of composite spinel increase so the inter-particle pore size increases and the neck connections decrease.Therefore,the compressive strength of the sample decreases.When the theoretical periclase-composite spinel(Mg(Fe,Al)2O_(4))content is 12%~16%,microporous periclase-composite spinel(Mg(Fe,Al)2O_(4))ceramics has excellent comprehensive properties,the apparent porosity of 22.3%~24.6%,the bulk density of 2.75~2.80 g/cm^(3),the compressive strength of 100.6~123.1 MPa.