【摘要】 以MgO、Y2O3复合稳定的部分稳定氧化锆(Mg,Y-PSZ)为主要原料,添加一定量采用溶胶-凝胶法制备的Al2O3-ZrO2复合粉,成型烘干后经1750℃×2 h烧成制备定径水口。矿物组成、微观结构及微区成分分析显示,随复合粉加入量的增加,烧成制品中立方相ZrO2含量下降,单斜相含量相对增加;定径水口烧成后,复合粉中的氧化锆形成柱状增强结构,氧化铝与稳定剂MgO反应生成镁铝尖晶石。结果表明:选择合适的Al2O3-ZrO2复合粉添加量能提高制品的力学强度和断裂韧性,改善气孔结构并降低气孔率,从而使水口具有良好的抗侵蚀性和抗热震稳定性,在连铸现场试验取得了理想的使用效果。更多还原

【Abstract】 Using ZrO2 partially stabilized by MgO and Y2O3( Mg,Y-PSZ) as the main material,adding a certain amount of Al2O3-ZrO2 composite powder prepared by sol-gel method,the metering nozzle has been produced fter molding,drying,and sintering at 1750 ℃ for 2 h. It is shown from the mineral phase analysis,microstructure and micro-area composite analysis that,the content of c-ZrO2 in nozzles was decreased with the increasing amount of the composite powder,compared with that of relatively increasing m-ZrO2; After sintering,ZrO2 introduced by the composite powder formed a kind of columnar structure to enhance the substrate,while Al2O3 reacted with the stabilizer MgO to generate magnesia aluminate spinel. The results of the experiment demonstrated that,with a reasonable amount of Al2O3-ZrO2 composite powder addition,the nozzles showed enhanced mechanical strength and fracture toughness,as well as improved pore structure and lower porosity,which was benefited to the nozzles with better erosion resistance and thermal shock resistance,and therefore it performed well in the casting tests.更多还原