CaO-MgO-Al2O3-SiO2 corrosion behavior of SrZrO3-La2Ce2O7 composite ceramics

摘要

In this work, the corrosion behavior, interaction products, and the corrosion mechanism of (1-x)SrZrO3-xLa2Ce2O7(x = 0.3, S7L3; x = 0.5, S5L5; x = 0.7, S3L7) composite bulks after CaO-MgO-Al2O3-SiO2 (CMAS) attack at 1250 degrees C for 1, 4, and 12 h were investigated, respectively. The molten CMAS and the bulks rapidly interacted and generated a dense reaction layer, which mainly composed of La-Ce apatite, Ce2Zr2O7.04, ZrO2 with some Ce, Ca, Si, Mg, and Al elements preventing CMAS from continuous penetration effectively. The formation of CMAS self-crystallizing products such as Ca2Al2SiO7 gehlenite and Mg-Al spinel with high melting points increased the viscosity of CMAS. The elements in the ceramic also diffused into the molten CMAS and formed Ce2Zr2O7.04 and La2Ce2O7, increasing the melt viscosity and blocking the penetration channel of the molten CMAS. The S5L5 bulk has the best corrosion resistance against CMAS attacks.