National Physical Laboratory

Metallographic preparation, cutting, polishing, etching

Metallographic preparation The metallographic preparation facility underpins many of the materials testing programs at NPL. The facility supports research into a wide range of materials:

  • Polymers and composites
  • Metals
  • Metal Matrix Composites
  • Hardmetals and Cermets
  • Ceramics
  • Electronic interconnects
  • Surfaces for bio-tissue growth
  • Surface preparation for reference materials with Ra<1nm

A full range of sectioning equipment is available for the sectioning of composites, metals, hardmetals, cermets and ceramics. The facility includes:

  • Diamond wire saw for brittle materials such as ceramics to produce thin sections to 20μm
  • Precision cut off machine for metals, ceramics and hardmetals for reproducible parallel slices with positional accuracy to 5μm
  • Semi automatic cut off machines for rough sectioning of samples up to 20 cm
  • The NPL workshop is also available for sectioning of larger samples or for precision cutting using electro-discharge machining (EDM)

A range of automatic and semi-automatic polishing machines are available to ensure rapid and repeatable preparation of either hot or cold mounted specimens up to 50 mm diameter. Specialised techniques and jigs have been developed for the preparation of un-mounted samples. These machines are equipped with depth sensor for grinding to set depths with a 10µm accuracy.

Services, Instruments and Artefacts

  • Sectioning / Sampling of wide range of materials
  • Hot and cold mounting
  • Nickel plating of oxide or corrosion products
  • Automatic polishing for repeatable results
  • Electro polishing
  • Chemical etching
  • Electro etching
  • Thermal etching to 1600º C in inert atmosphere or Argon
  • Sputter coating
  • Plasma etching of ceramics
  • Intereference Film Coating with Iron Oxide, Lead Oxide, Platinum for colour phase contrast.
  • Preparation of samples for Electron Back Scattered Diffraction (EBSD)


Customer Service tel: +44 20 8943 8681

Last Updated: 25 Mar 2010
Created: 2 Sep 2009


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