Materials Testing

Background

Materials testing laboratoryThe reliability and performance of gears is greatly influenced by material quality and condition. The most common mode of failure is fatigue and is dependant on:

  • Steel composition, cleanliness, grain size, hardenability and heat treatment;
  • Post heat treatment finishing processes such as shot blasting, shot peening, grinding and superfinishing;
  • The effect of lubricants and lubricant additives.

The Materials Laboratories at Design Unit support industrial gear research and consultancy projects in three main areas:

  • Metallography and evaluation of material properties.
  • Quality control (eg gear manufacture and heat treatment).
  • Characterisation and analysis of gear failures.

Facilities

A range of up-to-date laboratory equipment is used to study the metallurgy of gears and the factors affecting fatigue performance. The facilities available include:

  • Sectioning, mounting and polishing equipment for metallographic sample preparation;
  • Video imaging and analysis software connected to stereo and reflected light microscopes;
  • Micro- and macro-Vickers testers for hardness and case depth measurement;
  • X-ray diffraction equipment for measurement of residual stress and retained austenite;
  • Barkhausen Noise analysis for detection of grinding burn;
  • Glow discharge optical emission spectroscopy (GDOES) for chemical analysis;
  • Eddy Current crack detection equipment.

Design Unit also has access to the University's scanning electron microscopes fitted with EDX analysers, an optical profilometer for characterisation of surface topography.