Role of CaO in Alumina Based Castables with Oxides or In-situ Formed Non-oxides Bonding
As an important binding agent,calcium aluminate cement (CAC) has been widely used in castables.However,in Al2O3-SiO2 system castables,the introduction of CaO will lead to significant decrease of high temperature properties especially the hot modulus of rupture (HMOR).Adopting tabular alumina,α-Al2O3 ultrafine,microsilica,CAC and Si powder as main materials,alumina based ULC castables and in situ non-oxide bonded corundum castables were prepared by vibrating casting and in-situ nitridation sintering.Effect and mechanism of CaO on HMOR of two kinds of castables was investigated by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM).Compared with alumina based ULC castables,negative effects caused by CaO in the castables bonded by in situ non-oxide phases obviously reduce.The reason can be attributed to formation of in situ non-oxide bonded phases such as β-SiAlON,O-SiAlON and α -Si3N4,leading to modification of microstructure.And another reason is the solid solution of Ca2+ in the SiAlON structure.
YU Renhong DU Penghui ZHOU Ningsheng WANG Huifang
High Temperature Materials Institute, Henan University of Science and Technology, Luoyang 471003,China
国际会议
The 6th International Symposium on Refractories (第六届国际耐火材料会议)
郑州
英文
532-535
2012-10-18（万方平台首次上网日期，不代表论文的发表时间）