抄録
Directionally solidified single crystal eutectic ceramics have many advantages as high temperature structural materials because of strength temperature dependence, high creep resistance, and good oxidation resistance. However, it is difficult to perform very high temperature fatigue tests in air. For that reason, little information of long-term durability and very high temperature fatigue reliability is available. This study newly developed a very high temperature tensile fatigue testing methodology using a locally heated, cold-gripped, round-bar type specimen and determined high cycle fatigue strength characteristics for Al_2O_3/YAG and Al_2O_3/GAP eutectic ceramics at temperatures greater than 1500°C in air. Temperature dependence and materials comparison show that single crystal eutectic ceramics also have good very high temperature fatigue durability compared to representative high temperature structural ceramics and ceramic matrix composites.
