Chem-Braze Abradable Seal Attachment to Aircraft Gas Turbine Compressor Components

摘要

Manufacturing methods were established for bonding an abradable seal surface onto the stationary compressor element (e.g., case shroud) of small gas turbine engines utilizing an easily replaceable Chem-Braze bond system. Continuing work initiated under Army contract DAAG46-78-C-0062, bonded specimens were prepared and evaluated in vibration and rub incursion tests. Tooling was fabricated for bonding a seal to Army supplied engine hardware, and NDI methods were established for inspecting bond integrity. Chemical stripping techniques for removing Chem-Braze attached seals were optimized to permit efficient refurbishment of severely worn seals. An economic analysis indicated significant cost savings for attaching abradable seals to compressor blade tip-shrouds using the improved Chem-Braze system compared to attachment with gold-nickel braze. The Chem-Braze system has been used successfully to bond abradable seals to titanium, cobalt, nickel and iron base alloys; however, attempts to use Chem-Braze to bond seals to selected aluminum and magnesium alloys were not successful. (Author)