Hot Isostatic Pressing Rejuvenation of Disks

摘要

Retired field-service Ti-6Al-4V compressor disks and Waspaloy turbine disks from Garrett-AiResearch auxiliary power units were secured for the program test material. They were given a thorough dimensional inspection, nondestructive evaluation (NDE) and metallurgical characterization including mechanical properties and evaluation of microstructures. Baseline low-cycle-fatigue (LCF) lives for these disks were determined by cyclic-spin testing and periodic inspection of new disks. Cleaning and crack bridging techniques were evaluated on the disk materials and reverse-sputter cleaning combined with ion plating was chosen for the preparation of cracked disks prior to hot isostatic pressing (HIP). The HIP parameters were selected for each alloy and the disks were fixtured, protected from excessive oxidation, and HIPped using pressurized argon gas. The Ti-6Al-4V compressor disks were evaluated in the HIPped condition, while the Waspaloy disks were given a post-HIP heat treatment.