| Al2O3-ZrO2-C slide gate material with basic ZrO2 is preparated with sintered Al2O3 ,Al2O3 powder , ZrO2 and C as raw material ,Al and Si as additives,which is mixed, pressedafter deposited for 24 h , and sintered in deoxidizein ambience in different temperature for8 h.Samples aren't dealt with asphaltum soakage for convenient analysis and contrast.Test results show that it is preparated with Al2O3 as main raw material, appropriateZrO2 carrier, fitting additives and right temperature, whose performance of resistanceability to corrosion and thermal shock resistance performance is excellent.It appears to craze during sintering for Aptly hydrated aluminium carbide as reactionoffspring when Al is as additive, so sole Al isn't as additive in it. When Si is as additive,its offspring structure is continuous , well-proportioned, and little bulk effect, so Si ispreferred as additive in it.When t-ZrO2 and part steady 7% m-ZrO2 as raw material is added, its thermal shockresistance performance is excellent, for t-ZrO2 shows low dilatability and part steady m-ZrO2 expanded uniformity so that bulk effect disperses in wide range of temperature.While nano ZrO2 powder is added 3% in the same time, the effect is better.When nano ZrO2 powder is added in slide gate, the rate of thermal expansion dropsremarkably and obvious curvilinear inflexion on thermal expansion in about 800℃advances to appear, for smaller crystal partical Leads to decrease translated temperaturefrom t-ZrO2 to m-ZrO2. There is gently section where translation from t-ZrO2 to m-ZrO2happens, so it increases observably in thermal shock resistance performance. Accoding tothermal expansion curviline and XRD graph, it confers that crystal partical of nano ZrO2hasn't observably grown in test sintering temperature, especially in lower one. The hugespecific surface area of nano ZrO2 in slide gate leads to its distributing in tiny reunitedsystem and absorbing part thermal stress, so that thermal shock resistance performance ofslide gate increares. |
