An Alternative Low-Cost Process for Deposition of McRally Bond Coats for Advanced Syngas/Hydrogen Turbine Applications

 

Laboratory electro-codeposition process
Laboratory electro-codeposition process
Performer: 
Tennessee Technological University
Website:  Tennessee Technological University
Award Number:  FE0007332
Project Duration:  09/12/2011 – 09/11/2015
Total Award Value:  $466,515.00
DOE Share:  $371,288.00
Performer Share:  $95,227.00
Technology Area:  Hydrogen Turbines
Key Technology:  Hydrogen Turbines
Location:  Cookville, Tennessee

Project Description

The proposed metal chromium-aluminum-yttrium (MCrAlY; where M = nickel [Ni], cobalt [Co] or a mixture of Ni and Co) bond coats will be synthesized via an electrolytic codeposition process, followed by a post-plating heat treatment. In contrast to traditional electro-codeposition processes where sulfate or sulfamate bath is used for Ni/Co deposition, a sulfur-free electrolyte will be employed to control the impurity levels in the MCrAlY coatings. The reduced sulfur (S) levels will be expected to improve oxide scale adhesion. The amounts of Cr, Al, and particularly the Y reservoir, in the MCrAlY bond coat will be optimized to extend the lifetime of the thermal barrier coating (TBC) system. Reactive elements such as Y + hafnium (Hf) or Y + zirconium (Zr) will be co-doped into the MCrAlY coatings by modifying the composition of the CrAlY alloy powder. The composition of the CrAlY+ alloy (where "+" equals Hf or Zr, etc.) will be carefully designed, based on the literature data for model MCrAlY alloys and other types of MCrAlY coatings. Other parameters of the electrolytic codeposition process will be systematically studied using a design-of-experiment approach to provide a fundamental understanding of their synergistic effects and to optimize the coating composition and microstructure.

Project Benefits

This project will utilize a novel coating process to synthesize a nickel/cobalt- chromium-aluminum-yttrium (MCrAlY) bond coat. Turbine materials research seeks to improve coating materials that will allow for higher temperature operation and increased durability leading to increased turbine efficiency and reduced maintenance. Specifically, this project will use electro-codeposition to deposit optimally designed MCrAlY bond coats using a sulfur free electrolyte and analyze the process and resulting bond coats for effects on composition and microstructure.

Contact Information

Federal Project Manager 
Patcharin Burke: patcharin.burke@netl.doe.gov
Technology Manager 
Richard Dennis: richard.dennis@netl.doe.gov
Principal Investigator 
Ying Zhang: yzhang@tntech.edu
 

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