Scanning Electron Microscopy (SEM)

Characterization and chemical/crystallographic analysis of surfaces or fracture surfaces of bulk specimens with the aid of

  • secondary or backscattered electron imaging (SE/BSE),
  • energy dispersive X-ray analysis (EDX),
  • electron backscattering diffraction patterns (EBSD).

By several special in situ-techniques and equipments in the SEM one can observe:

  • the fracture behaviour during tensile or compressive test,
  • thermal phase transformations,
  • processes of degradation and migration under thermal / electric loading

General assumptions for investigation:

  • samples must be electrically conductible or sputtered with a conductive layer,
  • biological samples must be dehydrated and fixed,
  • maximal size of specimen 75 mm x 75 mm x 25 mm; <=10 mm x 10 mm x 10 mm recommended.

SEM imaging

can be used e.g. for

  • grain size determination on powders, etched surfaces, and section specimen
  • pore distribution on sinter materials
  • characterization of fracture surfaces (failure diagnostics)
  • general inspection of samples from technology, biology, and medicine

In situ-techniques

Loading of specimen under direct SEM observation can be performed by strain, bending, oscillate bending or electric current. The methods in particular serve for proof and observation of crack initiation and propagation, surface defects, and migration processes.

Some illustrative examples