ZrO_2陶瓷坯体的凝胶注模工艺研究

Gel-casting process of ZrO_2 ceramic body

为了能以凝胶注模成型技术制备出成品率较高且性能优良的ZrO_2发热元件,有必要研究凝胶注模工艺对ZrO_2陶瓷坯体性能的影响。因此,以d50=3. 221μm的Y_2O_3稳定ZrO_2粉(YSZ粉)为原料制备ZrO_2料浆,研究引发剂APS用量(体积分数分别是0. 5%、0. 7%和0. 9%)、催化剂TEMED用量(体积分数分别是0. 3%、0. 5%、0. 7%和0. 9%)和固化温度(分别是30、40、50和60℃)对料浆固化时间的影响,料浆固含量(体积分数分别为50%、51%、52%、53%和54%)对坯体干燥收缩率、体积密度和抗弯强度的影响,以及脱泡时间(分别为5、10、15和20 min)对坯体体积密度的影响,并从实际情况出发选择适宜的凝胶注模工艺。结果表明:随着料浆固含量的增大,坯体的干燥收缩率减小,体积密度增大,但抗弯强度却逐渐降低;通过控制引发剂APS用量为0. 7%(φ)、催化剂TEMED用量为0. 5%(φ)、固化温度为50℃、脱泡时间为15 min等工艺因素,在料浆固含量为54%(φ)时可以制备出体积密度为4. 01 g·cm-3、常温耐压强度为29. 2 MPa的氧化锆坯体。

In order to fabricate excellent performance zirconia heating element by gel-casting with high yield,it is necessary to research the effect of gel casting process on the properties of ZrO2 ceramic billets.ZrO2 slurry was prepared using Y2 O3 stabilized ZrO2 powder( d50= 3. 221 μm) as raw material. Effects of evocating agent APS additions( 0. 5%,0. 7%,and 0. 9%,by volume),catalyst TEMED dosages( 0. 3%,0. 5%,0. 7%,and 0. 9%,by volume),and curing temperatures( 30,40,50,and 60 ℃) on curing time of the slurry,solid contents( 50%,51%,52%,53% and 54%,by volume) on drying shrinkage,bulk density and bending strength of the green body,as well as defoaming times( 5,10,15 and 20 min) on the bulk density of the green body were investigated. And the appropriate gel-casting process was adopted considering the actual situation finally. The results indicate that with the solid content of the slurry increasing,for the greed body,the drying shrinkage decreases,the bulk density increases,but the bending strength decreases gradually. With 0. 7% APS,0. 5% TEMED,50 ℃ of curing temperature,and 15 min of defoaming time,54% of solid content,the zirconia green body with bending strength of 29. 2 MPa and bulk density of 4. 01 g·cm-3 can be obtained.