Institute for Materials Research

FACULTY OF ENGINEERING

 

Non-Ferrous Metallurgy Research

Research areas are categorised into the following areas:

Non-Ferrous Metallurgy
Aluminium Alloys - contact Dr R.F. Cochrane
  • Determination of microstructural evolution and structure-property relationships in spray-cast ES2X and SS7X alloys.
TEM bright field image (a) of theta prime and omega precipitates and dark field image (b) of omega phase precipitates in peak aged (T6) spray cast ES20 aluminium alloy.
Intermetallics - contact Dr R.F. Cochrane
  • production by mechanical alloying and rapid solidification
  • order-disorder reactions
Titanium Alloys - contact Dr C. Hammond
  • superplastic deformation
Tungsten Alloys - contact Prof. D.V. Edmonds
  • microstructure-property relationships: the effect of interfacial segregation and precipitation upon mechanical properties.

Optical micrograph of tungsten heavy alloy (W-5wt%Ni-5wt%Fe) showing spheroidal tungsten particles in a Ni-W-Fe matrix. A corresponding fracture surface (inset) shows interface fracture between particle and matrix and featureless tungsten-tungsten separation.

Electron micrograph of tungsten heavy alloy (W-5wt%Ni-5wt%Fe). Despite the inhomogeneous nature of this microstructure, TEM foils for examination by high-resolution transmission electron microscopy can be prepared and in this case reveal precipitation at the tungsten particle/matrix interface.
Uranium Alloys - contact Prof. D.V. Edmonds
  • Facilities and techniques for the metallographic preparation of depleted uranium (DU) alloys have been established. Solid state transformations in a range of uranium alloys and the deformation metallography of the resulting microstructures have been extensively studied.
Bright field TEM micrograph of water-quenched U-6wt%Nb alloy shows banded martensite containing an array of transformation twins.
Davy Fastcast - contact Prof. D.V. Edmonds
  • The design of a new generation of twin-roll casters for the high-productivity casting of thin strip or sheet of aluminium alloys directly from the melt has resulted from a collaborative research programme between the Universities of Oxford and Leeds and Kvaerner Davy.
Commercial twin-roll casters for producing aluminium alloy sheet recently installed at (a) Finspag Aluminium, Sweden and (b) Eurofoil, Luxembourg [images courtesy of Kvaerner Davy].
Extractive Metallurgy - contact Dr A. Jha
Specialised Characterisation Techniques
HREM - contact Dr R.M. Brydson
The application of high resolution electron microscopy (HREM) and analysis using EELS and EDX to investigate metal/ceramic interfaces and grain boundary phases/segregation in monolithic materials.
High Resolution Electron Spectroscopic Imaging (ESI) - contact Dr R.M. Brydson
Application to rapid imaging of precipitate distributions and reaction interphases in materials.Electron spectroscopic image (EELS) of an interface in a coated SiC fibre reinforced Ti alloy
Surface Analysis - contact Dr R.M. Brydson
  • XPS/UPS/AES/SIMS of coatings and interfaces
  • Dynamic SIMS of multilayered structures
Non-Destructive Testing - contact Dr R.F. Cochrane
  • acoustic emission
  • image processing
Thermal Analysis - contact Dr R.F. Cochrane
novel applications of DSC, DDSC, DTMA and thermoresistometry in the quantitative study of the kinetics of phase transformations in conventional materials and those processed by non-equilibrium routes such as rapid solidification and mechanical alloying.
Modelling
Flow Effects on Solidification - contact Dr A.M. Mullis
Fluid flow with in the parent melt can have a profound influence on the microstructure and properties of metallic components. Yet because of buoyancy driven convection it is almost impossible to study solidification free from the disturbing influence of flow in the terrestrial laboratory. For this reason a number of microgravity (10-6 g) experiments are planned for the Materials Science Laboratory aboard the International Space Station (ISS). This work, which is part of the as part of the European Space Agency’s (ESA) Microgravity Applications Programme, is being supported at Leeds by developing simulations of the effect of flow on growing crystals and by experiments in our Electromagnetic Levitation System.The images below show phase-field simulations of crystals growing into a flowing melt. In each case the flow is directed from the top right corner towards the bottom left corner. As in these simulations the incoming fluid is cooler than growing solid growth of both the primary and secondary dendrite arms is promoted into the flow. In each case the crystal is shown within the same size box to enable quantitative comparison of the effect.
watch the crystal grow (avi) watch the crystal grow (avi) watch the crystal grow (avi)
Semi-solid Forming and Rheology - contact Dr A.M. Mullis
Semi-solid forming is a generic term for a range of metallurgical forming operations in which the metal is processed as a slurry, that is a much containing both the solid and the parent liquid. Such semi-solid metal slurries have very complex rheological properties, being both shear thinning and thixotropic. Work at Leeds is aimed at using Monte-Carlo models of the interactions between particles as a means of calculating the degree of ordering within the semi-solid, and hence the viscosity, as a function of the processing parameters (shear rate, solid fraction etc.).
Electronic Structure - contact Dr R.M. Brydson
Modelling of unoccupied electronic states using cluster-based multiple scattering calculations and the interpretation of electron energy loss near-edge structure (ELNES) for the extraction of bonding information
Damage Processes - contact Dr R.F. Cochrane
  • composite materials
Composite Materials
Metal Matrix Composites - contact Dr R.F. Cochrane
  • semi-solid processing and casting;
  • intermetallic and nano-sized ceramic phases;
  • phase transformation in MMCs;
  • in-situ development of microstructure;
  • electronic packaging materials;
  • deformation and fracture
Academic Staff
Dr. R.F. Cochrane
 Prof. R. Brydson
Prof. D.V. Edmonds
Dr. C. Hammond
Prof. A. Jha Dr. A.M. Mullis
Research Staff
Postgraduate Students