Sun, 27 June, 2021
July 2021: PhD Vacancy with TWI Ltd and Sheffield Hallam University
PhD applications are now open for a new topic with global engineering, materials and joining technologies experts TWI, and the Materials and Engineering Research Institute (MERI) at Sheffield Hallam University.
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Watch a TWI Webinar: Extreme High-Speed Laser Application (EHLA) Technology
PhD Studentship Topic
Extreme High-Speed Laser Application (EHLA) Coatings
Background to this PhD opportunity
Protecting components against wear and corrosion has no trivial solution, with standard coating processes, such as hard chrome plating or thermal spraying having their drawbacks in terms of health and environmental concerns, coating quality or process efficiency.
Laser metal deposition (LMD) could be an attractive alternative, offering high integrity coating potential with significant material performance benefits over conventional processes with which it competes. LMD is already used in a limited number of cases, however its principal drawbacks are its slow coverage rate and the relatively high heat that has to be used, which can be an issue in some crack-sensitive materials.
This project proposes to develop a fundamental understanding for TWI of a completely new LMD technology, using a recently developed extreme high-speed laser (EHLA) nozzle design. This understanding will start from 15 years of existing LMD processing expertise at TWI, and apply the experience gained to a number of relevant industrial needs.
The EHLA nozzle is capable of applying coatings up to in 300 µm thickness, and can also work at traverse speeds of up to 100 m/min. This represents an entirely new capability, and takes LMD from coverage rates of ~10-40 cm2/min to rates possibly up to 250 cm2/min. This is achieved by introducing the powder stream into the line of the laser beam, causing it to melt prior to reaching the melt pool, thus reducing the laser energy input into the substrate component, which in turn reduces dilution.
What are the research aims and objectives...?
- A developed fundamental understanding of the EHLA process and the relationships between process inputs and process outputs.
- A developed knowhow in thin-coating capability to state-of-the-art level relevant to industrial applications.
- Strengthened expertise in LMD, with a UK-unique new offering in the form of an EHLA system.
- Application driven benchmarking of EHLA coatings against end-use quality and performance requirements, with reference to competing manufacturing methods.
Funding for doctorate
TWI and Sheffield Hallam University fund this position. The studentship will provide successful Home/EU students with a minimum stipend of £16k/year and will cover the cost of tuition fees. Overseas applicants are welcome to apply, with total funding capped at £24k per year.
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