QUB PhD Project Proposal for International Students
Title: Using Knowledge driven high value manufacturing of silicon
Project Description:
Figure 1: MD simulation results of nanometric cutting
Single point diamond machining (SPDM) technology which employs diamond (the hardest naturally-occurring material
realized to date) as a cutting tool to cut a workpiece is the most productive manufacturing process ranged in terms of
quality and efficiency. Machining a brittle material using using SPDT is a complex process and, while several
experimental and analytical studies presented to date aid in the understanding of several critical processes of machining,
the current knowledge is still sparse. There is a pressing need to incorporate an appropriate simulation-based approach
in the manufacturing research of silicon, owing primarily to the number of uncertainties in the current experimental
research that includes wear of the cutting tool, poor controllability of the nano-regime machining scale (effective thickness
of cut), and coolant effects (interfacial phenomena between the tool, workpiece/chip and coolant), etc. This project will
help in developing an understanding on how the stresses manifest during fracture in the brittle range, or
dislocations/amorphisation in the ductile range, which are crucial to understanding the brittle–ductile transition in general
and silicon in particular.
The aim of this project would be to develop a theoretical understanding based on molecular dynamics simulation for
understanding (i) the wear of diamond and (ii) material removal mechanics in order to optimise the whole process. After
this is accomplished, the next step will be to make use of the MD data to be fed to the FEA, in order to scale the models
to compare with experiments. The simulation models will be validated with the world’s topmost energy organisation based
in Paris who are funding this project. Upon completion, the project will help to obtain answers to the following important
research questions:
1. Whether the ductile response of silicon is a function of high pressure phase transformation or dislocations – this
would help to establish precision engineering as an alternative process to form and synthesize amorphous or
metastable phases of brittle materials, having their own mechanical, electrical, and optical properties different
from their respective pristine state.
2. How does the wear mechanism of diamond takes place during SPDM?
Key Skills Required for the post:
This project will be driven by the use of numerical modelling using LAMMPS and ABAQUS. It is a heavy
prerequisite that student is versed with the skills of programming, and have good background in
manufacturing/physics/mechanics.
Key Transferable Skills that will be developed during the PhD:
MD simulation, FEM simulation, Programming skills, Manufacturing technologies
First/Lead Supervisor
Dr. Saurav Goel, School: Mechanical and Aerospace Engineering
sgoel.diamond@gmail.com or s.goel@qub.ac.uk
(Contact me asap with your CV)
Second Supervisor
Dr. Adrian Murphy, School: Mechanical and Aerospace Engineering
a.murphy@qub.ac.uk