Non-oxide silicon-based ceramics, such as silicon nitride(Si_3N_4) or silicon carbide(SiC) are the leading candidate materials to displace Ni-based superalloys for high temperature structural components in the next generation gas turbine engines. However, siliconbased ceramics will be corroded by the water vapor at high temperatures to form volatile substances, leading to degeneration of structural components in its application. For practical applications, it is necessary to fabricate gas-tight environmenta...