石英陶瓷在精密平台中的应用

分析研究了分别采用钢、铝、氧化铝陶瓷、石英陶瓷四种材料的精密直线电机驱动平台的温升、热变形、变形受室温变化的影响、到达热平衡时间等情况。结果表明:有较小导热系数的石英使得热量不易传递,温升明显减小;由于较小的热膨胀系数使得平台热变形较小,同时石英由热膨胀引起的内应力及受室温变化引起的变形变化远小于铝、钢与氧化铝;导热系数小的石英热量传递速度慢,到达热平衡的时间长。精密直线电机驱动平台中,运动平台受直线电机初级部件发热影响最大,所以精密平台应选择导热系数、热膨胀系数小、对温度变化不敏感的材料,石英是此类平台比较理想的陶瓷材料。

Application of silica ceramic in precision stage

The temperature rise, deformation, deformation via room temperature change and the time of reaching heat balance of the motion table in precision linear motor driven stage made of steel, aluminum, alumina ceramic and silica ceramic are analyzed. The results show that the temperature rise of silica ceramic with small heat conductivity coefficient decreases clearly. Because of the small thermal expansion coefficient, the deformation of silica ceramic table is small. The thermal stress and deformation of silica ceramic table due to room temperature change are smaller than those of aluminum,steel and alumina ceramic tables. The heat conduction of silica ceramic is slow, so the time of reaching heat balance is long. As a result of the motion table being badly influenced by the primary section of the linear motor in precision linear motor stage, precision stage should choose the material with small heat conductivity coefficient, small thermal expansion coefficient and insensitive to temperature change. Silica ceramic is the suitable ceramic material for these stages.