Metallurgical examination of hot gas path components assessed for remaining service life includes characterizing the type of damage and quantifying the extent of material degradation so that an informed and cost effective repair or replacement decision can be made.
Analysis can include investigation of:
Liburdi has developed techniques which have become the recognized industry standard with the issue of "Gas Turbine Blade Life Assessment and Repair Guide" co-authored by Liburdi and published by EPRI. We continue to develop advanced techniques for correlating microstructural and coating changes with service exposure which, along with effective use of Finite Element Technology, enhances the value of the information derived from the components.
Unlike hot section components such as turbine blades and vanes, discs operate in a relatively cool environment, free of oxidation attack, but at very high stress loads. This environment requires a different approach to determining disc life.
Liburdi has developed and successfully applied a detailed mechanical design methodology by modelling the blade/disc assembly and using finite element stress analysis to determine stress concentration, stress relaxation algorithms and ultimately the service life expectancy of the disc. This results in a Disc Design Life based on modern Finite Element analysis as an alternative to stated component life which may be based on original estimates using decades old methods..