以石灰石和工业氧化铝为原料研究了煅烧温度及配料组成对纯铝酸钙水泥性能的影响。结果表明,当 w Al2O 低于 376%时,随配料组成中 w Al2O 的增加, A 矿物的形成量增加,水泥的凝结时间延长且强度降低;...以石灰石和工业氧化铝为原料研究了煅烧温度及配料组成对纯铝酸钙水泥性能的影响。结果表明,当 w Al2O 低于 376%时,随配料组成中 w Al2O 的增加, A 矿物的形成量增加,水泥的凝结时间延长且强度降低;随煅烧温度提高,水泥的凝结 3 C 2时间延长但强度提高,尤其是 3d, 强度;掺少量 BaO , 7d ZnO 可缩短水泥的凝结时间但强度降低。展开更多
目的:研究3种复合树脂粘固剂与铸造纯钛的粘接强度。方法:用牙科铸钛的方法制作直径分别为4mm和5mm的钛棒,切割成长度为4mm的小钛片。2种规格的钛片配对粘接面用400～1200目碳化硅砂纸在流水下打磨抛光,使之呈均匀一致的平面。50μm氧...目的:研究3种复合树脂粘固剂与铸造纯钛的粘接强度。方法:用牙科铸钛的方法制作直径分别为4mm和5mm的钛棒,切割成长度为4mm的小钛片。2种规格的钛片配对粘接面用400～1200目碳化硅砂纸在流水下打磨抛光,使之呈均匀一致的平面。50μm氧化铝喷砂,另一组表面不喷砂作为对照,分别使用Super-BondC&B、Panavia F、Rely X Unicem 3种复合树脂粘固剂粘接。扫描电镜观察喷砂前后铸造纯钛的表面形态。复合树脂粘接剂固化后经37℃恒温水浴24h以及5000次5～55℃冷热循环,测试剪切强度。用SAS的ANOVA过程对各组数据进行分析。结果:喷砂前后纯钛与Panavia F的剪切强度最高,分别为(26.62±3.40)MPa、(23.71±5.28)MPa;5000次冷热循环后,喷砂组的铸造纯钛与Panavia F的剪切强度最高(27.12±8.68)MPa;未喷砂的铸造纯钛与Super-Bond C&B、Rely X Unicem的粘接强度最低,并且有12.5%的脱落率。结论:本实验结果表明喷砂可以提高Super-Bond C&B、Panavia F、Rely X Unicem的粘结力和粘结耐久力。不喷砂时,Panavia F与铸造纯钛之间能获得较高的粘接强度和良好的粘接耐久性,喷砂以后优势不再明显。展开更多
Two kinds of pure calcium aluminate cement(CAC)prepared by the sintering method and the electric melting method,respectively were analyzed in terms of the particle size,XRD patterns and hydration characteristics;and t...Two kinds of pure calcium aluminate cement(CAC)prepared by the sintering method and the electric melting method,respectively were analyzed in terms of the particle size,XRD patterns and hydration characteristics;and their effects on the hydration heat and construction performance of the cement-based castables were discussed.It is found that(1)the electric fused CAC contains 50.67%CA and 44.89%CA_(2),while the sintered CAC contains 74.57%CA and 22.97%CA_(2);in addition,compared to the sintered CAC,the electric fused CAC contains more C_3A,C_(12)A_7,and a small amount of amorphous phase;(2)the electric fused CAC(d_(50)of 7.93μm)has much smaller particle size than the sintered CAC(d_(50)of 12.51μm);(3)in the early stage of hydration,the exothermic peak of the electric fused CAC appears earlier and the heat flow rate is higher than that of the sintered CAC;the dormant period of the sintered CAC is relatively short and the main exothermic peak appears earlier than that of the electric fused CAC;(4)for cement-based castables,there is no obvious exothermic peak in the early hydration stage,but the temperature of the castables slightly increases;among them,the initial hydration temperature of the electric fused CAC-based castable is higher;and the main exothermic peak of the sintered CAC-based castable appears later than that of the electric fused CAC-based castable;(5)the exothermic heating on-site occurrs earlier,which is related to the higher environmental temperature(about 30°C);the on-site electric fused CAC-based castable begins to show more cracks during the exothermic peak stage.展开更多
文摘以石灰石和工业氧化铝为原料研究了煅烧温度及配料组成对纯铝酸钙水泥性能的影响。结果表明,当 w Al2O 低于 376%时,随配料组成中 w Al2O 的增加, A 矿物的形成量增加,水泥的凝结时间延长且强度降低;随煅烧温度提高,水泥的凝结 3 C 2时间延长但强度提高,尤其是 3d, 强度;掺少量 BaO , 7d ZnO 可缩短水泥的凝结时间但强度降低。
文摘目的:研究3种复合树脂粘固剂与铸造纯钛的粘接强度。方法:用牙科铸钛的方法制作直径分别为4mm和5mm的钛棒,切割成长度为4mm的小钛片。2种规格的钛片配对粘接面用400～1200目碳化硅砂纸在流水下打磨抛光,使之呈均匀一致的平面。50μm氧化铝喷砂,另一组表面不喷砂作为对照,分别使用Super-BondC&B、Panavia F、Rely X Unicem 3种复合树脂粘固剂粘接。扫描电镜观察喷砂前后铸造纯钛的表面形态。复合树脂粘接剂固化后经37℃恒温水浴24h以及5000次5～55℃冷热循环,测试剪切强度。用SAS的ANOVA过程对各组数据进行分析。结果:喷砂前后纯钛与Panavia F的剪切强度最高,分别为(26.62±3.40)MPa、(23.71±5.28)MPa;5000次冷热循环后,喷砂组的铸造纯钛与Panavia F的剪切强度最高(27.12±8.68)MPa;未喷砂的铸造纯钛与Super-Bond C&B、Rely X Unicem的粘接强度最低,并且有12.5%的脱落率。结论:本实验结果表明喷砂可以提高Super-Bond C&B、Panavia F、Rely X Unicem的粘结力和粘结耐久力。不喷砂时,Panavia F与铸造纯钛之间能获得较高的粘接强度和良好的粘接耐久性,喷砂以后优势不再明显。
文摘Two kinds of pure calcium aluminate cement(CAC)prepared by the sintering method and the electric melting method,respectively were analyzed in terms of the particle size,XRD patterns and hydration characteristics;and their effects on the hydration heat and construction performance of the cement-based castables were discussed.It is found that(1)the electric fused CAC contains 50.67%CA and 44.89%CA_(2),while the sintered CAC contains 74.57%CA and 22.97%CA_(2);in addition,compared to the sintered CAC,the electric fused CAC contains more C_3A,C_(12)A_7,and a small amount of amorphous phase;(2)the electric fused CAC(d_(50)of 7.93μm)has much smaller particle size than the sintered CAC(d_(50)of 12.51μm);(3)in the early stage of hydration,the exothermic peak of the electric fused CAC appears earlier and the heat flow rate is higher than that of the sintered CAC;the dormant period of the sintered CAC is relatively short and the main exothermic peak appears earlier than that of the electric fused CAC;(4)for cement-based castables,there is no obvious exothermic peak in the early hydration stage,but the temperature of the castables slightly increases;among them,the initial hydration temperature of the electric fused CAC-based castable is higher;and the main exothermic peak of the sintered CAC-based castable appears later than that of the electric fused CAC-based castable;(5)the exothermic heating on-site occurrs earlier,which is related to the higher environmental temperature(about 30°C);the on-site electric fused CAC-based castable begins to show more cracks during the exothermic peak stage.
