Chemical processing metallurgy.
The primary objective of metallographic examinations is to reveal the constituents and structure of metals and their alloys by means of a light optical microscope. the proper selection and preparation of the specimen is of major importance in obtaining reliable results.
In most cases this means cutting, mounting & polishing. This must be performed in such a manner as not to introduce any unwanted morphologies in the process. We therefore follow the guidance of ASTM E3 Standard guidance for preparation of metallographic specimens.
Microsection Thickness
Microsection Thickness evaluation provides a visual of the coating system where individual layers can be measured. Micrographs can be incorporated into the laboratory report.
Photographic reports can be provided for optical microscopy methods such as intergranular attack where accurate scales and measurements can be added to enhance the micro-graphs. The software can be used to measure any visible elements within a micro-graph. for Example, indent depth, scratch depth, pitting, heat affected zone and alpha case.
Test Methods include:
- ISO 2808
- ISO 1463
- ASTM B487
Inter Granular Attack & End Grain Pitting
IGA (Inter Granular Attack) is a form of corrosion occurring at grain boundaries within a metal, where grain boundaries are more susceptible to corrosion.
EGP (End Grain Pitting) is localised corrosion resulting in a cavity or pit extending from the surface into the metal.
IGA (Inter Granular Attack) and EGP (End grain Pitting) can occur during various stages of processing. To assess the impact during processing test pieces require treating and analysing. Alongside analysis for IGA and EGP we can supply test pieces ready for processing.
Materials susceptibility to corrosion can differ from alloy to alloy… or batch to batch depending on conditions during manufacture. Testing a materials susceptibility to IGA and EGP can be conducted to ensure suitability of material for intended purpose or further processing.
We can provide micrographs showing evidence of IGA and EGP.
Test Methods include:
- ASTM F 2111
- BATS 2525
- BATS 2545
