Facilities to prepare samples for microscopic investigation, such as grinding, polishing and etching, are present. Materials can be embedded in a resin (under vacuum) or in a hot mounting press. Samples for microscopic examination cannot be larger than approximately 25 x 25 x 25 mm due to the dimensions of the sample cups for embedding. There are only limited means at HE Tubing to cut small samples out of a large object.
- Zeiss Discovery V12
- Magnification up to 100x
- Zeiss Observer Z1
- Magnifications from 25x to 1000x
Both microscopes have a camera connected to a PC for live images and to take snapshots. With the AxioVision software image analysis can be performed.
Examples of microscopic investigations
- Determine microstructure (determine different phases, effect of heat treatment)
- Determine the grain size of the microstructure (according to ASTM E112)
- Size and number of precipitates, inclusions or porosities in the material
- Determining the fraction of a phase (duplex stainless steel: ratio austenite/ferrite; coverage of a surface with a coating (based upon contrast differences)).
- Determine the presence of hydrogen cracking or other welding defects
- Determine the weld penetration depth