PhD, EngD and MSc by research theses (SATM)

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Browsing PhD, EngD and MSc by research theses (SATM) by Course name "MRes in Manufacturing"

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    Predicting service life of steel tubes in building and industrial services.
    (2020-02) Mutyanda, Lovemore; Impey, Susan A.; MacAdam, Jitka
    There is a real need to be able to predict the service life of pipework systems taking account the relevant service conditions. The requirement is to translate corrosion control and corrosion behaviour of small-scale coupons representing small parts of pipes to the behaviour of larger pipework systems (for industrial relevance). The research considered a range of factors influencing corrosion and methods currently used for assessing and determining corrosion rates of pipework systems. Linear Polarization Resistance (LPR) was used to compare results of static and dynamic measurements on carbon steel tubes. The effect of dissolved oxygen, flowrate, surface condition, water chemistry and weld were investigated. Other factors were considered for example; material composition, water (source, composition, hardness), temperature and time. In order to provide recommendations to accurately predict long service life of metal pipework systems from short duration measurements, a range of relevant service conditions were set up with tap water (from two sources) conveyed in open and closed systems. Data was assembled from a range of measurement methods and systems in small scale laboratory tests and flow loops to represent pipework systems. The data generated demonstrated correlation and highlighted that dissolved oxygen and flow rate were the main factors influencing corrosion measurement across length scales in static and dynamic environments. A case study was undertaken to consider issues around monitoring a small pipework system in reality. Corrosion is a dynamic activity and careful attention to a range of influencing factors experienced by a pipe system before and during service and it is important to gather as much relevant information as possible. The use of LPR probes, the probe cleanliness and maintenance, care with handling coupons and a combination of water analysis and LPR measurements are recommended to improve the prediction of service life.
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    Selected area hot machining with a multi-tipped diamond tooling system.
    (2017-09) Dennis, Ashley; Goel, Saurav; Tonnellier, Xavier P.
    An investigation of a novel ultra-precision tool is presented, the hot-milling multi-turret diamond tool. The tool implements micro-Laser Assisted Machining (μ-LAM) upon a multiple diamond fly cutter. Details of its design, both mechanical and optical, are presented- along with proposed modifications to Cranfield University’s Tetraform C machine to allow for its implementation. Relevant experimentation is presented- the modal analysis of the Tetraform C machine and the testing of laser heating on a silicon substrate. FE analyses are carried out and calculations presented to justify design choices. Analytical investigations predicted increased depths of cut by using laser, and indicated that at lower wavelengths of laser light and with lower feed rates that the depth of cut may be significantly increased. A novel method of selecting laser wavelength based upon change in material absorptivity with temperature is investigated which may offer substantial increases in μ-LAM performance