Abstract:

Ceramic slurry of 78 mass% solid loading was prepared using photosensitive acrylic resin and dispersant SP-710 as the liquid phase,Al₂O₃ powder (d₅₀=2.38 μm) and TiO₂ powder additive as the solid phase.Alumina ceramics were prepared by DLP,sintering for 4 h at 1 450,1 500,1 550 or 1 600 ℃,respectively.The effects of the TiO₂ addition (0,1%,2%,3% and 5%,by mass) on the properties of the ceramics were studied.The results show that the addition of TiO₂ can improve the sintering of Al₂O₃ ceramics,significantly improve the densification,and reduce the sintering temperature.With the optimum TiO₂ addition of 3 mass% and the optimum sintering temperature of 1 600 ℃,the obtained Al₂O₃ ceramics have shrinkage of 15.7%,15.8% and 23.8% at the x axis,the y axis,and the z axis,respectively,the porosity of 2.41%,the bulk density of 3.74 g·cm^-3 and the three-point bending strength of 251.1 MPa.Compared with the undoped alumina ceramics,the doped alumina ceramic has increased bulk density by 0.56 g·cm^-3,decreased apparent porosity from 20.19% to 2.41%,and the three-point bending strength increases by 2.5 times.Therefore,the density and strength of DLP prepared ceramics can be improved effectively by adding an appropriate addition of TiO₂,and the performance of the DLP prepared ceramics is close to that of the pressed samples.Thus,it is hopeful to apply DLP in refractories field.

Key words: digital light printing, alumina ceramics, strength, bulk density, sintering aid

摘要：

以光敏丙烯酸树脂与分散剂SP-710为液相,以d₅₀=2.38 μm的Al₂O₃粉和添加剂TiO₂粉为固相,制备了固含量为78%(w)的Al₂O₃陶瓷浆料。采用数字光固化成型技术(DLP)打印Al₂O₃陶瓷素坯,经1 450、1 500、1 550、1 600 ℃保温4 h烧后,分析TiO₂加入量(质量分数分别为0、1%、2%、3%、5%)对Al₂O₃陶瓷试样性能的影响。结果表明:TiO₂的加入可促进Al₂O₃陶瓷的烧结,显著提高致密性,降低烧结温度,并确定TiO₂最优掺量为3%(w),烧结温度最优为1 600 ℃,此时试样在x轴、y轴、z轴的收缩率分别为15.7%、15.8%与23.8%,显气孔率为2.41%,体积密度为3.74 g·cm^-3,三点弯曲强度为251.1 MPa,与未添加TiO₂的Al₂O₃陶瓷对比,体积密度提高了0.56 g·cm^-3,显气孔率由20.19%降低为2.41%,三点弯曲强度增大为原来的2.5倍。因此,加入适量TiO₂,可以有效提高DLP打印陶瓷体的致密度与强度,使打印试样的性能接近压制成型的试样,有望使打印工艺应用于耐火材料领域。

关键词: 数字光固化成型技术, Al₂O₃陶瓷, 强度, 体积密度, 烧结助剂