Abstract
Cold spin tests of 3DC/C disk were conducted to elucidate feasibility for the turbine disk of ATREX engine. The fracture speed of the 3DC/C disk was 516 m/s, and this speed satisfied the condition of turbine system in ATREX engine. The fly-out of the fiber-bundles from 3 DC/C disk occurred before the total fracture of the disk and the shaft vibration simultaneously increased. The fly-out behavior was characterized by the delamination of the fiber-bundles from the surface of the 3DC/C disk. The effective preventive methods for fly-out behavior were concluded as to use fine fiber texture and increase inter-bundle bonding strength. Enhancement of the inter-bundle bonding strength by partial Si conversion was shown to be effective to improve the onset speed of fly-out behavior. The machinability of 3DC/Cs for turbine blade was also examined and the tip radius could be machined with 0.5 mm and it remained its shape until 470 m/s.
