Development of heat-resisting alloy for turbine of airplane engine has mainly been focusing on improvement of heat resistant property, and currently its temperature exceeds 1100℃ (2012 ゜F). However, property of strength for lower temperature and higher stress has not been considered so much for advanced single crystal supperalloy with high heart-resisting temperature during alloy design; therefore, air-cooling flow path loaded under such circumstance shows less strength. It is required to get over the reduction in the strength at lower temperature around 750℃ (1382?F) to mount advanced alloy with higher heat-resisting temperature to real machine. Hence, we operate the research on the strength characters of advanced heat-resisting alloy under lower temperature and higher stress.
For airplane engine, the wreck of turbine disk could lead the damage of pressurized cabin or even the danger of crash, so disk is the most critical part and high reliability is required. Although U720Li with great strength in high temperature has been applied to turbine disk for that reasons, U720Li is extremely rare material to obtain and only few researches of U720Li have been operated in Japan. Thereafter, our research focuses on basic analysis of microstructure of U720Li and its creep and fatigue damage properties.
We have a researching group for coating with NIMS (National Institute for Materials Science) in Tsukuba, Ibaraki. Since turbine blade is placed under severe oxidizing conditions because it receives high-pressure combustion gas to rotate, it is necessary to have turbine blade coated for oxidation-resistant. However, almost no research has been run to reveal the relationship between crystallographic anisotropy and oxidation-resistant coating. Hence, we have co-research with NIMS to focus on the influence of oxidation-resistant coating against strength in high temperature with the anisotropic properties of single crystal.
We also have a researching group with JAXA (Japan Aerospace Exploration Agency). Our research points out the microstructure and dynamic interaction with fundamental principles for properties of strength and reliability for structural stocks used for rockets and satellites under a particular circumstance.
・Fracture behavior of hypervelocity collision for ceramics thruster used for planetary exploration spacecraft
・Strength and ductility evaluations for composite bonded structure at extreme low temperature