Prof Dermot Brabazon

Biography

Professor Dermot Brabazon (BEng, CEng) graduated from the Department of Mechanical Engineering at University College Dublin in 1995 and continued on at UCD to complete his doctorate in the area of semi-solid metal processing. From 1995 to 2000 he worked with Materials Ireland, a state funded research centre at UCD. Professor Brabazon is a full time lecturer in the School of Mechanical and Manufacturing Engineering at Dublin City University since February 2000. He was appointed Senior Lecturer in 2006, Deputy Head of School in 2007, and Associate Dean for Research in 2009. Prof Brabazon was also conferred with the President’s Award for Research in January 2009 and was appointed as Fellow of the Institute of Mechanical Engineering in 2015.

Research Expertise

Prof Brabazon’s research is focused in the areas of materials and processing technologies and based on the pillars of Near Net Shape Forming, Laser Processing and Separation Science technologies. These overlapping activities are focused toward the development of advanced processing technologies to enable the improved efficiency and quality of production technologies for the benefit of MNC and SME companies, and the broader society. Prof Brabazon is currently Director for the Advanced Processing Technology Research Centre at Dublin City University and a PI within the Irish Separation Science Cluster at DCU, as well as the Water Institute. Professor Brabazon has published over 200 internationally peer reviewed papers and supervised more than 30 research postgraduates to completion. Professor Brabazon’s research group currently includes 7 PhD students and 8 postdoctoral researchers working on development of novel materials, processing, and analytical technologies.

PhD Students

  • PhD Student #1
  • PhD Student #2
  • PhD Student #3

Select Publications

Mechanical stir casting of aluminium alloys from the mushy state: process, microstructure and mechanical properties
  D Brabazon, DJ Browne, AJ Carr      2002      Materials Science and Engineering

Fig. Microstructures of (a) material 1, chill cast Al–4%Si; (b) material 3, Al–4%Si stir cast at 112.84 s−1, 0.36 fs, for a period of 60 s

A comprehensive study was carried out to establish the effects of controlled stirring during solidification on the microstructure and mechanical properties of aluminium alloys, in comparison to conventionally gravity chill cast material. A novel device comprising a grooved reaction bonded silicon nitride rod rotating in a tube-like crucible was used to process aluminium alloys in the mushy state. The stir casting device was specially designed to also enable rheometric study of the alloys in this condition. A factorial design of experiments was used to determine the effect of the process variables shear rate ( ), shear time (ts), and volume fraction solid during shear ( fs) on microstructure and both static and dynamic mechanical properties of the stir cast alloy. Investigation of the microstructure consisted of computer-aided image analysis of the primary phase morphology. A more globular primary phase was achieved at low values of fs, but this was not the optimum morphology for mechanical properties. In all cases, improved mechanical properties and reduced porosity were obtained in the stir cast condition in comparison with conventional casting and in comparison with previous work on stir casting. Comparison with alloy commercially rheocast via electromagnetic stirring, however, showed that the latter had superior mechanical properties. It is proposed that the mechanical stir casting process be considered as an alternative to gravity die casting in cases where very simple and thick walled shapes are required. © 2002 Elsevier Science B.V. All rights reserved.

 

Development and assessment of a new quick quench stir caster design for the production of metal matrix composites
  S Naher, D Brabazon, L Looney      2005      Journal of Materials Processing Technology

Fig (a) Micrograph fromexperiment 1. Processing parameters:stirring speed, 200 rpm;stirring time, 16 s; viscosity, 1 mPa s.

Examination of the liquid and semi-solid stir casting method to produce Al–SiC composites was the focus of this study. A significant part of the work consisted of the design, construction and validation of a specialised quick quench compocaster for this high temperature processing method. Stainless steel was chosen as the main crucible and stirrer material. The machine consisted of a four 45◦ flat bladed stirrer and a crucible in a resistance heated furnace chamber. A linear actuator was integrated to this rig to allow the crucible to be quickly extracted from the furnace for quenching. Stirring speed ranging from 200 to 500 rpm and different shear periods were investigated. Ten percentage volume of 30 J.m sized SiC particles was used. The main research challenge was to get a uniform distribution of SiC in the aluminium matrix. In the compocasting experiments it was found that the uniformity of SiC particles in the aluminium matrix were dependent on shear rate, shear period, cooling rate and volume fraction of primary solid. The quick quench compocaster system was successful in producing cast MMC samples. The use of clean heat-treated SiC particles and the quick quench method was sufficient to produce homogeneous composites. Castings from the liquidus condition were found to result in poor incorporation of SiC particles whereas castings from the semi-solid condition were found to produce a uniform distribution of SiC particles. However, quicker solidification, after cesation of mixing, was found to improve the uniformity of the SiC distribution significantly. Characterization of the MMC samples produced included microstructure recording and image analysis thereof. The matrix phase size, morphology and distribution of SiC particles throughout the stir castings were examined.

http://www.googles.ie/

 

Adsorption and desorption of methylene blue on porous carbon monoliths and nanocrystalline cellulose
  Xiaoyun He, Keith B Male, Pavel N Nesterenko, Dermot Brabazon, Brett Paull, John HT Luong      2013      ACS Applied Materials & Interfaces

The dynamic batch adsorption of methylene blue (MB), a widely used and toxic dye, onto nanocrystalline cellulose (NCC) and crushed powder of carbon monolith (CM) was investigated using the pseudo-first- and -second-order kinetics. CM outperformed NCC with a maximum capacity of 127 mg/g compared to 101 mg/g for NCC. The Langmuir isotherm model was applicable for describing the binding data for MB on CM and NCC, indicating the homogeneous surface of these two materials.

The Gibbs free energy of −15.22 kJ/mol estimated for CM unravelled the spontaneous nature of this adsorbent for MB, appreciably faster than the use of NCC (−4.47 kJ/mol). Both pH and temperature exhibited only a modest effect on the adsorption of MB onto CM. The desorption of MB from CM using acetonitrile was very effective with more than 94 % of MB desorbed from CM within 10 min to allow the reusability of this porous carbon material. In contrast, acetonitrile was less effective than ethanol in desorbing MB from NCC. The two solvents were incapable of completely desorbing MB on commercial granular coal-derived activated carbon.

 

View Full Publication

Menu