Multi-beam engineering microscopy - A versatile tool for optimal materials design

Engineering microscopy is a term we use to refer to a suite of versatile techniques for spatially resolved characterisation of material structure and properties for the purpose of optimising design, performance and durability of structures and technological systems. The range of tools that can be used for this purpose includes beams of photons (including X-rays), electrons, neutrons, and ions. Different modes of imaging include absorption and emission, spectroscopy, and scattering that can be used in full field or scanning regimes. The approaches that collect information in the form of 2D images can also be extended to 3D characterisation by serial sectioning or reconstruction tomography. An important additional mode of near-surface property evaluation arises through the use of nanoscale contact tip sensors, such as AFM, nanoindentation, electrochemical probes, etc. Crucial underpinning for multi-beam microscopic characterization is provided by multi-scale materials modelling. The lecture will provide an overview of flavours of engineering microscopy and highlight the exciting opportunities presented by the combination of techniques in the form of so-called correlative microscopy. Examples of multi-modal correlative microscopy will include partially stabilized zirconia, biomaterials such as flax fibres and human dental tissues, and also advanced engineering alloys and ceramics″.</p

A study of phase transformation at the surface of a zirconia ceramic

Yttria Partially Stabilized Zirconia (YPSZ) is one of the most important engineering ceramic materials in that it displays a whole host of outstanding structural and functional properties. Of particular importance for load-bearing applications is the remarkable fracture toughness of YPSZ that arises from its ability to undergo martensitic transformation, a phase transformation that is dependent on stress, temperature, time, humidity, grain size, and the proximity of an interface. The present study was aimed at revealing the influence of the thermal ageing on the tetragonal to monoclinic phase transformation in the near-surface regions of YPSZ. In order to perform qualitative and quantitative characterisation of the phase composition, three principal microscopic techniques were employed: atomic force microscopy, depth resolved Raman micro-spectroscopy, and synchrotron X-ray diffraction. Satisfactory consistency was achieved between the results obtained using different techniques. Moreover, the data obtained in this way displayed complementarity that provided valuable input for the development of thermodynamic modelling of the complex inter-dependence between phase state and processing history of zirconia ceramics