Exploiting graphene and nanodiamond to enhance wear resistance of carbide-basedMaterials by Spark Plasma Sintering
Dr V Garcia-Rocha
Prof SL Evans
No more applications being accepted
Funded PhD Project (European/UK Students Only)
(a) Scientific Excellence
Structural ceramics and their composites play an essential role in engineering. There is a need to find sustainable manufacturing processes to avoid climate change and at the same time ensure the performance and longevity of materials. This is exceptionally challenging, but advanced composites engineering can play an important role. Exploring ways of combining the right materials using environmentally friendly processing and manufacturing technologies has proven to be the pathway to follow.
Tungsten carbide- cobalt (WC-Co) ceramic composite’s wear and corrosion resistance have been enhanced, typically by tuning Co content and incorporating high hardness phases such as ZrO2, B4C particles, and graphite or other free-carbon sources to compensate for W dissolution into the cobalt binder. Most recently nanodiamond particles have been used to improve both. In addition, novel rapid consolidation techniques such as Spark Plasma Sintering have played an important role in achieving full density and restricting grain growth. Recently bioinspired self-monitoring ceramics by using graphene networks (Rocha et al. Nature Comm, 2017) have been demonstrated. The unique strategy of using graphene networks to design layered ceramic composites with improved toughness and electrical conductivity can now be applied to build nanodiamond–graphene networks, which in turn could host a WC-Co matrix.
(b)Feasibility of completion in 3.5 years
This project will develop a fundamental understanding of the system nanodiamond, graphene and tungsten carbide which have been shown to be a promising ceramic composite for cutting tools. While its processing by crude milling of the raw powders have been previously studied there is comparatively little information on bottom-up approaches using wet chemistry processing by engineering the initial composition of the composite combined with novel sintering techniques such as Spark Plasma Sintering. This will be followed by measuring the mechanical, thermal and electrical behaviour of these composites. The data produced in this way will not only be useful for developing novel approaches of processing ceramics composites and its manufacturing but also allow developing new composites for producing cutting tools with improved lifetime.
This project will use a range of state of the art of wet chemistry methods and novel casting and sintering technologies such as freeze casting and Spark Plasma Sintering which has been recently commissioned at Cardiff University. In addition, collaboration with the Centre of Advanced Structural Ceramics at Imperial College London will be around the use of the semi-pilot facility for producing large amounts of graphene oxide. A wide range of mechanical tests such as hardness, fracture strength, fracture toughness and wear of the composites will be measured at the Structural Performance and Tribology laboratories. These properties will be related to microstructural features through the use of scanning electron microscopy (SEM), and Raman spectroscopy among others. Nanodiamond characterization facilities will be available at the Cardiff Diamond Foundry.
Applicants should be able to demonstrate a suitable background in materials science through a relevant qualification in engineering materials, materials chemistry, materials physics or related discipline. Applicants are expected to hold a first or upper-second class degree or a lower second plus a distinction in a Masters degree.
The supervisory team at Cardiff University will ensure regular progress meetings and it will be leaded by Dr V.G. Rocha who is an expert in carbon-ceramic composites, Prof Evans, expert in deformation and failure of materials and nanocomposites both from the School of Engineering and Prof Williams who is leading authority in synthetic diamond growth from the School of Physics and Astronomy and head of the Cardiff Diamond Foundry.
You should have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK.
Applicants with a Lower Second Class degree will be considered if they also have a master’s degree. Applicants with a minimum Upper Second Class degree and significant relevant non-academic experience are encouraged to apply.
Full awards, including the Tuition fee and maintenance stipend (Approx. £14,777 in 2018/19), are open to UK Nationals and EU students who can satisfy UK residency requirements. To be eligible for the full award, EU Nationals must have been in the UK for at least 3 years prior to the start of the course for which they are seeking funding, including for the purposes of full-time education.
Applications should be made online at: http://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/engineering
Please note the following when completing your online application:
The Programme name is Doctor of Philosophy in Engineering with an October 2019 start date.
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