High Temperature Properties of SiC Fiber Reinforced SiC Matrix Composites for Turbine Rotor Application

Bladed disks made of continuous SiC fibers and SiC matrix have been developed using combined process of Chemical Vapor Infiltration (CVI) followed by Polymer Impregnation and Pyrolysis (PIP) in previous works. The temperature at the bladed section of the disk is estimated to increase up to 1400 °C in the advanced gas-generator of AMG program. However, the conventional SiC fiber such as Nicalon did not obtain the high temperature properties enough to meet the requirements of the bladed disk. In this study the high temperature properties of the CMCs with high graded SiC fibers have been investigated. The CMCs with Hi-Nicalon type S fiber with CVD BN coating showed the excellent creep rupture properties. Concurrently, the CMC disk with high fiber volume fraction has been made from Tyranno ZMI fiber due to the advantage of the weaving property. And the maximum peripheral speed of the CMC disks increased 30% more than first developed one. Finally, the CMC bladed disk was rotated at 1400 °C by the hot gas stream up to 20,000 rpm successfully.