Staff Profile

Professor Lesley Cornish

Biography

Works

Research areas: Alloy development, especially in platinum-based systems, steels, aluminium alloys, magnesium alloys, VC-WC-Co hardmetals, shape memory alloys, TiAl. Materials characterization: SEM, XRD, metallography. Experimental derivation and calculation of phase diagrams, especially in platinum systems.

P rof. Lesley Cornish has been associated with Wits for over 25 years, and in that time she has taught all years of the undergraduate metallurgical engineering course, lectured post graduate students, and supervised MSc and PhD students to completion. She has a wide range of interests within physical metallurgy and materials engineering, and specialises in phase equilibria and characterisation. She has also worked for the Unitied Kingdom Atomic Energy Authority, and Mintek. She is a Professor (Physical Metallurgy) in the School of Chemical and Metallurgical Engineering. Her other responsibilities include: Assistant Dean Research for the Faculty of Engineering and the Built Environment Director: African Materials Science and Engineering Network (AMSEN)

NRF Rating (South Africa): B2 Best paper/ poster presentation using any analytical technique, (Electron) Microscopy Society of Southern Africa Conference: 1995, 1997, 1998, 2000. Vice Chancellor's Teaching Award 1998. Best published paper using electron microscopy, 1999, 2004, 2006, 2007, 2008, 2010. Materials Science International Team Certificate for many contributions and scientific collaboration, 2006, 2007, 2009. Part of the team that was a R&D Magazine 2011, R&D 100 Winners, for Novel platinum/chromium alloy for the manufacture of improved coronary stents (Life Sciences); Primary developer: National Energy Technology Laboratory, USA; by Boston Scientific Corporation Inc. and Carpenter Specialty Alloys, Minitubes ZAC Technisud, Accellent Inc., for work done whilst at Mintek. Corrosion Institute of Southern Africa Research Award 2011, for the University of the Witwatersrand to advance corrosion research an capacity building in South Africa, together with Dr Abe Mngomezulu, CEO, Mintek, for collaboration for the application to the SARChI for a Chair in corrosion. National Science and Technology Forum “Eskom Research Capacity Award, 2013.

Funding: Mintek, CSIR, NRF, DST, RISE-Carnegie. Publications: Over 250: >100 in refereed journals; >170 in conference proceedings; >25 phase equilibria reviews in books; Chapter in ASM Metallography Handbook 2004; Chapter in Gas Turbines 2011, plus ~60 technical reports. Group: Currently supervising or co-supervising 12 post graduate students, with 27 MScs and 16 PhDs already graduated.

TEM study of Pt-based superalloys

Dr LH Chown, Prof. L.A. Cornish, Dr A. Douglas, Prof. J. Neethling, Prof. M.J. Witcomb and Prof. K. Preussner

• A suite of alloys is being developed to enable applications at high temperatures in aggressive environments. The alloys are based on the Pt-Al system and have similar precipitates to the Ni-based superalloys, although there is a variation in the precipitates. Studies to date have focused on the Pt-Al systems as well as selected ternary systems. More work is needed on the quaternary and higher systems, so that the dislocation movements and precipitate stability can be understood. The work is necessary so that the alloys? behaviour at high temperature can be optimized, and the best alloying additions and heat treatments confirmed.

Effect of additional elements on the microstructure and properties of Pt-based superalloys

Dr LH Chown, Prof. L.A. Cornish, Prof. M.J. Witcomb, Mr. M.B. Shongwe and Mr. B. Odera.

• There are still a number of proposed additions that are planned to be made to the suite of alloys being developed to enable applications at high temperatures in aggressive environments. Each addition needs to be studied in a systematic way in terms of the amount of the addition, the combination with other additions, the effects of varying amounts, and the effect of heat treatement. The techniques will include: metallography, (SEM with EDS), XRD, image analysis, DTA, hardness tests, compression testing, tensile tests and high temperature fatigue.

Phase diagram studies for systems needed to develop and extend a Pt-based alloy thermodynamic database for high temperature and aggressive applications

Prof. L.A. Cornish, Dr LH Chown, Prof. M.J. Witcomb and Mr. B. Odera

• A thermodynamic database is being built based on Pt-Al-Cr-Ru. Since there is very little reliable information available on the component binary and ternary systems, an extensive study is being made on these systems. A number of projects are available to allow further study on a number of systems, including: Pt-Cr, Cr-Ru, Pt-Nb-Ru and Pt-Co-Nb. Phase equilibria studies are necessary on both experimental and computational aspects. The latter will be done using mainly the Thermo-Calc program. Experimental techniques will include: metallography (optical and SEM with EDX), XRD, image analysis and high temperature DTA / DSC

Optimising hard metals, and utilising

Publications

1. T. Carter and L.A. Cornish, Hydrogen in Steels, Engineering Failure Analysis, 8 (2001) 113-121.

 

2. L.A. Cornish, B. Fischer and R. Voelkl, Development of Platinum Group Metal Based Superalloys for High Temperature Use, Materials Research Society Bulletin, (by invitation) 28, 9 (2003) 632-638.

 

3.T. Biggs, M.B. Cortie, M.J. Witcomb and L.A. Cornish, Platinum alloys for shape memory applications, Platinum Metals Review, 47 (2003) 142-156.

4.            J.K. Odusote, L.A Cornish, L.H. Chown and R.M. Erasmus, Isothermal Oxidation Behaviour of a Two-phase ?/?? Precipitation-hardened Quaternary Pt-based Alloy in Air at 1350oC, Oxidation of Metals, 78 (1-2) (2012) 123-143.

5. O.P. Oladijo, N. Sacks, L.A. Cornish and A.M. Venter, Effect of substrate on the 3 body abrasion wear of HVOF 17wt% Co coatings, International Journal for Refractory Metals and Hard Metals, 35 (2012) 288-294.

6. R.M. Genga, L.A. Cornish and G. Akdogan, Effect of Mo2C additions on the properties of SPS manufactured WC-TiC-Ni cemented carbides, International Journal of Refractory Metals and Hard Materials, 41 (2013) 12-21.

7. J.K. Odusote, L.A. Cornish, L.H. Chown and R.M. Erasmus, Assessment of the oxidation behaviour of a Pt-based alloy for high temperature applications, J. Materials Engineering and Performance, 22 (11) (2013) 3466-3475.

8. I.A. Mwamba, L.A. Cornish and E. van der Lingen, Effect of platinum group metals on microstructure and high temperature oxidation behaviour of Ti-47.5 at.% Al, Corrosion Engineering and Technology, 49(3) (2014) 180-188.

9. B.O. Odera, L.A. Cornish, M.J. Papo and G.O. Rading, Experimental Solidification Projection, Liquidus Surface Projection and Isothermal Section at 1000°C for the Pt-Cr-V System, J. Phase Equilibria and Diffusion, 35(4) (2014) 476-489.

10. K.D. Njoroge, G.O. Rading, J.M. Kihiu, M.J. Witcomb and L.A. Cornish, The impact of interstitial carbon on dislocation motion in the α-Fe lattice, International Journal of Computational Engineering Research, 4(12) (2014) 5 - 9.