(Local) Chemical Analysis in the Electron Microscope

Methods

• EDX (Energy Dispersive X-ray Spectroscopy)
  Lateral resolution down to 50 nm; windowless detectors for light elements.
  Fast qualitative and quantitative elemental analysis, spot analyses, and elemental mapping.
• WDX (Wavelength Dispersive X-ray Spectroscopy)
  Highest resolution and detection limits, precise quantification.
• FIB-SIMS (Focused Ion Beam – Secondary Ion Mass Spectrometry)
  Depth profiles, trace elements, isotope-specific analysis, 3D chemical mapping.
• X-ray Fluorescence Analysis (XRF)
  Low-damage, larger analysis volumes, elemental mapping down to trace levels.

Fields of application

Phase characterization and precipitate analysis

• Identification of carbide, nitride, and intermetallic precipitates
• (e.g. Cr carbides in stainless steels, Al-Mg-Si precipitates in Al alloys)
• Analysis of precipitate size, distribution, and chemistry
• Detection of undesired phases (σ-phase, Laves phase, Widmanstätten structures)

Particle, inclusion, and cleanliness analysis

• Chemical assessment of impurities such as non-metallic inclusions
  (MnS, various oxides like Al₂O₃, SiO₂)
• Automated particle size and distribution analysis
• Evaluation of steel cleanliness in line with standards (e.g. DIN/ASTM)
• Investigation of foreign particles in steelmaking, casting, and rolling processes

• Identification of spallation, wear debris, and abrasion particles

   

Local microstructure and microstructural analysis

• Chemical analysis of individual microstructural constituents (heterogeneous materials, e.g. hardmetals/cemented carbides)
• Determination of segregations and microsegregations (e.g. Cr, Mo, Nb)
• Correlative analysis of microstructure vs. chemical composition

• Identification of local corrosion initiators (MnS, intermetallic particles, foreign particles)

   

Coating properties and layer structure

• Analysis of multilayer systems (electroplated coatings, PVD, CVD, thermal spray coatings)
• Determination of layer thicknesses, diffusion zones, and composition gradients
• Detection of elemental enrichments or depleted regions (e.g. Cr-depleted areas)
• Investigation of passive layers, oxides, and corrosion products

Surface modification

• Chemical evaluation of nitrided, carbonitrided, and borided layers
• Analysis of coating adhesion, interfaces, and delamination
• Investigation of local hardness gradients via elemental distributions (C, N diffusion)

Depth profiling & nanoscale analysis (FIB-SIMS)

• Sub-micron depth profiles of coatings, diffusion layers, etc.
• Detection of trace and light elements (e.g. H, Li, B, N)
• Analysis of local contamination in the ppm range
• Investigation of hydrogen embrittlement (H mapping)