|About this Abstract
||Materials Science & Technology 2019
||Failure Analysis: Industry Specific Failures
||The Little Plane that Could: Failure Analysis of a Robust Turbine Engine
||Dale Alexander, Richard Baron, Mark Lewis, Casey Smith, Pierce Umberger, Ellen Wright
|On-Site Speaker (Planned)
Delayed evaluation of engine health monitoring data revealed a significant step increase in compressor section engine vibration occurring approximately 30 operational hours earlier in a small commercial aircraft turbine engine. This prompted an engine borescope examination that revealed a stage 1, High-Pressure Turbine (HPT1) blade sustained a separation of its outboard airfoil. Several other HPT1 blades experienced damage.
This presentation describes the macroscopic, microscopic, fractographic, and metallurgical evaluations performed to understand the root cause of the HPT1 blade separation. Comparison of this separation to upstream compressor section blade damage was also performed. The directionally-solidified, nickel-base superalloy HPT1 blades had internal cooling channels with engine-supplied air to lower blade temperatures and maintain mechanical integrity in the hot gas path environment. Leading-edge impact damage, caused by an engine ingested foreign object, was ultimately determined to have breached the separated blade’s cooling channel resulting in overheating, blade metal creep, and failure.