Turbine nozzles with slip joints impregnated by oxidation-resistant sealing material and methods for the production thereof

A method for manufacturing a turbine nozzle, comprising:

• assembling the turbine nozzle from a support ring, a slip joint ring having a plurality of slots provided therein, and a plurality of vanes extending from the support ring into the plurality of slots provided in the slip joint ring to define a plurality of slip joints;
• prior to assembling the turbine nozzle, forming a first platinum aluminide bond coat on surfaces of the slip joint ring defining the plurality of slots and forming a second platinum aluminide bond coat on terminal end portions of the plurality of vanes;
• bonding the plurality of vanes to the support ring;
• and
• after bonding the plurality of vanes to the support ring, forming annular seals within the plurality of slip joints and around the terminal end portions of the plurality of vanes, forming comprising:
• dispensing a slurry containing an oxidation-resistant sealing material around the plurality of slip joints in sufficient volume to allow the slurry to flow into the plurality of slip joints by capillary action and contact the first and second platinum aluminide bond coats, while leaving unfilled radial gaps adjacent terminal end portions of the plurality of vanes accommodating relative radial movement between the turbine nozzle vanes and the slip joint ring during operation of the turbine nozzle;
• and
• heat treating the turbine nozzle to thermally decompose organic materials from the slurry and diffuse the oxidation-resistant sealing material into the first and second platinum aluminide bond coats.

A turbine nozzle, comprising:

• a support ring;
• a slip joint ring substantially concentric with the support ring and radially spaced apart therefrom, the slip joint ring having a plurality of circumferentially-spaced slots therein;
• a plurality of vanes fixedly coupled to the support ring and extending radially therefrom into the plurality of circumferentially-spaced slots;
• a plurality of radial slip joints formed between the plurality of vanes and the plurality of circumferentially-spaced slots;
• and
• a silicon-modified aluminide sealing material impregnated into the plurality of radial slip joints, the silicon-modified aluminide sealing material impeding gas flow into the radial slip joints during operation of the turbine nozzle, while fracturing to permit relative radial movement between the plurality of vanes and the slip joint ring;
• wherein the plurality of circumferentially-spaced slots comprises non-penetrating depressions formed in a circumferential surface of the slip joint ring and having floor portions;
• and
• wherein the silicon-modified aluminide sealing material fills annular spaces in the plurality of slip joints to sealingly enclose unfilled radial gaps located between terminal ends of the plurality of vanes and the floor portions of the non-penetrating depressions, the unfilled radial gaps sized and shaped to accommodate relative radial movement between the turbine nozzle vanes and the slip joint ring during operation of the turbine nozzle.