放电等离子超快速烧结氧化铝力学性能和显微结构研究

Mechanical Properties and Microstructure of Al_2O_3 Ceramics Superfast Densified by SPS

本文介绍用放电等离子超快速烧结方法制备的氧化铝陶瓷的力学性能和显微结构特征．超快速烧结的升温速率为600℃／min，在烧结温度不保温，迅即在3min内冷却至600℃以下．与保温时间为2h的无压烧结相比，可降低烧结温度和提高样品密度．力学性能研究结果表明，用放电等离子超快速烧结方法制备的纯氧化铝陶瓷的抗弯强度高达800MPa以上，比通常氧化铝陶瓷的抗弯强度高出一倍．用SEM研究了在不同温度下超快速烧结的纯氧化铝陶瓷的显微结构特征．

Al2O3 ceramics were successfully superfast densified by spark plasma sintering (SPS) underthe conditions of heating rate as high as 600℃/min, no holding time at the sintering temperaturefrom 1350 to 1700 ℃ and then fast cooling to 600℃ within 3 minutes. It showed that Al2O3ceramics could reach to a higher density at a lower sintering temperature by SPS, as comparedwith by normal pressureless sintering. The bending strength of pure Al2O3 ceramics super fastdensified by SPS at the temperature range of 1400~1550 ℃ was as high as about 800 MPa, whichis an excellent datum being of more than a double of the bending strength for normal pure Al2O3ceramics. SEM micrographs showed that the intragranular fracture was a preponderant fracturemode in these Al2O3 ceramics being of very high bending strength.