The use of semiconductor analysis techniques to understand damage susceptibility in Ni-based superalloy aeroblades

Session

Poster Session Three

Authors

Tom Moore (3), Abigail Thomas-Verweij (1), Dr Mike Petty (1), Jane Woolrich (2), Dr Geoff West (3)

Affiliations

1. Loughborough Surface Analysis
2. Rolls Royce plc
3. Warwick Manufacturing Group, University of Warwick

Keywords

Magnetic Sector Secondary Ion Mass Spectrometry (MS-SIMS)

Transmission Electron Microscopy (TEM)

Energy Dispersive X-ray Spectroscopy (EDX)

Ni-based superalloys

Aeroblades

Abstract text

A combination of Magnetic Sector Secondary Ion Mass Spectrometry (MS-SIMS) and electron microscopy is used extensively in manufacturing of semi-conductor components for quality control purposes.  The MS-SIMS proves the ultimate chemical depth sensitivity, whilst Transmission Electron Microscopy allows atomic resolution analysis of site-specific regions.  In this project the possibility of combining the same techniques for applications in aerospace materials is investigated.  Of particular interest is studying the presence of corrosive species as a function of depth in coated Ni-based superalloy turbine blades.

Since the analysis requirements for turbine blades are much different from that of thin-film semi-conductors, a series of trials were devised to enable repeatable results from base metal and sectioned and cleaned test-coupons.  This showed that although the near surface chemistry is dominated by the specifics of the cutting fluid and subsequent cleaning processes, repeatable results could be achieved even on deep craters (>10 µm) on nominally chemically homogeneous materials.  This analysis was subsequently extended to study the effect of roughness, and complex sample geometry on the chemical profiles obtained.  

The combined analysis approach was also applied to coated materials that had been subjected to either laboratory simulated corrosive environments or service conditions.  In this paper the challenges encountered, and the implementation of microscopy techniques used to both guide and provide base-line analysis are discussed.

References