Speaker
Mr
Lehlohonolo Lisema
(Wits)
Description
Previously we have shown that implantation of the hexagonal allotrope of boron nitride with light ions (e.g. He+, Li+, B+) produces a surface layer containing nanoparticles of the much harder cubic allotrope, as revealed by Raman spectroscopy, X-ray diffraction and electron microscopy. We now show that the irradiated layer is measurably harder when interrogated by micro-indentation which probes a layer comparable to the ion range. The hardness value increases reproducibly with the ion fluence, confirming that the latter is responsible for it. There are possible implications for the surface hardening of BN components after they have been configured in the easily machinable hexagonal form. Some aspects of the hardening mechanism are discussed.
Main supervisor (name and email)<br>and his / her institution
Prof. T.E. Derry, Trevor.Derry@wits.ac.za
University of the Witwatersrand
Co-supervisor Dr. Morgan Madhuku, Madhuku@tlabs.ac.za
iThemba LABS (Gauteng)
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
MSc
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Primary author
Mr
Lehlohonolo Lisema
(Wits)
Co-authors
Dr
Emily Aradi
(University of Huddersfield)
Dr
Morgan Madhuku
(iThemba LABS)
Dr
Ronald Machaka
(CSIR)
Mr
Thabang Magabe
(Wits)
Prof.
Trevor Derry
(University of the Witwatersrand)
