High Temperature Mechanical Behavior of MgAl_2O_4-YAG Eutectic Ceramic in Situ Composites by Float Zone Method

摘要

The directionally solidified eutectic MgAl_2O_4-Y_3Al_5O_(12) crystal was prepared at a pressure of 0.4 MPa of ambient nitrogen gas by the high frequency induction heated floating zone furnace. In order to determine the high temperature characteristics, directionally solidified MgAl_2O_4-Y_3Al_5O_(12) eutectic phase has been analyzed with creep test, tensile strength, young modulus and fracture toughness at the various temperatures and the microstructural variations have been studied according to the analysis results. It has been seen that directionally solidified with zone melting MgAl_2O_4-YAG eutectic ceramic which has given the value of 168 MPa below 10~(-6)/s strain rate at 1,700 °C temperature has revealed minimum stress.