4 year EngD: Cryogenic and CO2 Coolants during machining of next-generation aircraft grade materials (sponsored by AMRC and EPSRC)

This project will evaluate the behaviours and performance of supercritical CO2 cutting fluid media when comparing to traditional emulsion fluids, minimum quantity lubrication (MQL) oils, and combinations of CO2 media and MQL. The aim of the project is to gain a fundamental understanding of these emerging technologies, with a focus on milling, drilling and turning applications. Through this understanding, it is anticipated that further exploitation of the technology can be made into industrial machining processes.

Research will take place at the University of Sheffield’s state-of-the-art Advanced Manufacturing Research Centre, based on the Advanced Manufacturing Park at Catcliffe, near Sheffield.

The project will begin with an investigation into the effects and benefits of different cutting fluids when machining next generation aircraft grade materials. With a tailored design of experiment approach, the effect of the cryogenic media on the workpiece surface and subsurface integrity will be studied.

The AMRC has identified that this fundamental knowledge gap of how the cooling process effects both the cutting tool and workpiece material requires further investigation. Key outputs from this investigation will give rise to operational best practice guides for the application of such emerging cryogenic technologies.

The candidate will also be expected to gain an understanding of how the technology can be used to improve operational efficiency, increase rate of manufacturing and reduce recurring costs. Thus ultimately saving manufacturing costs and retaining capability in the UK to manufacture future aircraft. Cost models will need to be defined for the Cryogenic Machining processes, including the cost of up-front investment to convert machines to have new capability.

The following underpinning science will give the project the best chance of enabling a sustainable and cost effective cryogenic machining capability for machining advanced aerospace alloys:
• Materials science in aerospace alloys
• Chip formation mechanisms in machining
• Understanding of tool wear mechanisms in machining
• Understanding of metrology for machining; tool wear, cutting temperature and surface integrity
• Thermodynamics
• Design of experiments
• Machining dynamics
• Cost modelling


Entry requirements and eligibility
Applicants must have, or expect to get, a 1st or good 2:1 degree (or Masters with Merit) in a relevant science or engineering subject such as Mechanical Engineering, Aerospace Engineering, Materials Science, or Physics.

Due to EPSRC residency requirements, this project is open only to UK and EU applicants who have been resident in the UK for at least 3 years immediately preceding the start of the course.

Candidates must also be able show that their English language proficiency is at a level which allows them to successfully complete the EngD. All applicants require an English language qualification, typically a GCSE or an IELTS test (a score of 7 or above is required, with a minimum of 6 in each component).