Mounting is the critical first step in any preparation process. The goal is to retain the true structure of the sample. To obtain this goal a variety of mounting techniques are employed in the MetLab. For example bakelite is typically used for general metallic samples, whereas fragile samples require vacuum infiltration with epoxy before sectioning and polishing..
Above: Bakelite hot press (top right), vacuum infiltration (top left), high-pressure infiltration/cure (bottom left), and sample ready for polishing (bottom right).
Above: Vacuum infiltration of epoxy by first pulling a vacuum on the sample then introducing the epoxy while the sample is under vacuum (left). After vacuum infiltration sample cups are placed in a pressure chamber and put under 1000 psi pressure for approximately 8 hours until the epoxy is cured (right).
Bakelite Resin
Used mainly for metallic samples where cracking or coatings are not an issue
Mounted at 170 degrees C at 30kN of pressure
Two Part Cold Mount Epoxy
Epoxy contains a fluorescent dye providing observation of pre-existing cracks and open porosity
Critical samples are vacuum infiltrated and high pressure cured at 1000 psi to remove voids and to fill the smallest cracks
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