Study On The Zirconia Metering Nozzle Material

This paper presents the characteristics of zirconia ceramic materials,as well as the research and development of metering nozzle refractory at home and abroad.To baddeleyite,zircon andα-Al₂O₃ powder as main raw material,adding a certain amount of binders and additives,according to ZrSiO₄/Al₂O₃ and ZrO₂/CaO different ingredients, prepared zirconia metering nozzle materials.The linear change rate,bulk density, apparent porosity,flexural strength and compressive strength of the samples were tested. The phase composition and microstructure of the samples were analyzed by XRD and SEM.And the influence of sintering temperature and additives added to the material composition,structure and performance is also discussed.The results show that:(1) The system of ZrO₂-Al₂O₃-SiO₂,the main phase of Z1 sample is zircon, zirconia and mullite.The main phase of Z2 and Z3 sample is zirconia,mullite and corundum.The system of ZrO₂-CaO,the main phase of 3# and 6# sample is zirconia solid solution and calcium zirconate.The main phase composition of 4# and 5# sample is zirconia solid solution.(2) The system of ZrO₂-Al₂₃-SiO₂,grain size is increased with increasing sintering temperature.Grain size is increased with the content increased ofα-Al₂O₃ The system of ZrO₂-CaO,grain size is increased with the content increased of CaCO₃.(3) The effects of preparation parameters on the performance of ZrO₂-Al₂O₃-SiO₂ sample were studied.The suitable sintering temperature was 1550℃,and the suitable addition ofα-Al₂O₃ was 45%～54%.(4) The effects of the addition of additives on the performance of ZrO₂-CaO.The sample by adding CaCO₃ had a higher flexural strength,the largest for 37.2 MPa,its adding the appropriate is 9.31%～16.89%;The sample by adding CaCO₃+CaO had a higher compressive strength,the largest for 186 MPa,for its adding the CaCO₃:5.2%～ 9.65%,CaO:2.29%～4.3%.(5) The performance of ZrO₂-Al₂O₃-SiO₂ sample was bettter than ZrO₂-CaO samples.Add the amount of zircon was 55%,α-Al₂O₃ was 45%and an appropriate amount of stabilizer,sintering sample under 1550℃,can be prepared with excellent performance zirconia metering nozzle material.The bulk density was 3.46 g/cm³, apparent porosity was 1.5%,flexural strength was 112.2 MPa,and compressive strength was 435 MPa.