烧结工艺对透明氧化铝陶瓷性能的影响

Effect of sintering process on properties of transparent alumina ceramics

以Isobam600AF为分散剂,Isobam104为胶黏剂,采用注凝成型工艺和真空无压烧结技术,通过改进两步烧结法制备了透明氧化铝陶瓷,探究了不同烧结温度和保温时间对氧化铝陶瓷晶粒尺寸、致密度、光学性能和力学性能的影响.结果表明:该烧结工艺可有效控制晶粒尺寸长大和提高相对密度,进而提高其光学性能和力学性能.在烧结过程中,当温度升高到一定范围时,致密化过程开始,且致密化速率随着温度的升高和保温时间的延长先增加后降低,在两步烧结1 400℃保温3 h时致密化速率达到最快.因此,坯体的致密化过程是非线性的,且具有一个最高致密化速率温度和保温时间点.

Using Isobam600 AF as dispersant and Isobam104 as adhesive, transparent alumina ceramics were prepared by improved two-step sintering method using gelcasting process and vacuum pressureless sintering technology. The effects of different sintering temperatures and holding time on the grain size, density, optical and mechanical properties of alumina ceramics were investigated. The results showed that the sintering process can control the growth of grain sizes and improve the relative density of ceramics effectively, so as to improve their optical properties and mechanical properties. During the sintering process, when the temperature rise to a certain range, the densification process start, and the densification rate first increase and then decreases with the increase of temperature and holding time. The densification rate reaches the fastest value in the condition of the second sintering step holding at 1 400 ℃ for 3 hours. Therefore, the densification of the green body is a nonlinear process with a maximum densification rate temperature and holding time point.