Abstract

The characteristics of Al_2TiO_5 ceramics were influenced by the additives and the heat treatment that controls the microcrack behavior at grain boundaries. The effect of additives on Al_2TiO_5 ceramics were investigated in terms of mechanical properties and thermal expansion at high temperature. The Al_2TiO_5 were synthesized at 1500°C, 1550°C and 1600°C for 2h by reaction sintering. The formation of Al_2TiO_5 phase was increased by additives that enhanced the volume of the microcrack that can lead to low thermal expansion. The mechanical properties of the stabilized Al_2TiO_5 ceramics were increased remarkably at 1100°C, 1200°C and 1300°C due to the oneset of mechanical healing of grain-bondary microcracks at a high temperature. The amount of microcrack was decreased at lower sintering temperature that causes the increase of mechanical properties at high temperature.

• Keywords: Al_2TiO_5;Thermal stability;Low thermal expansion;Grain-boundary microcrack;High temperature strength;Thermal hysteresis;