School of Aerospace, Transport and Manufacturing (SATM)

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Browsing School of Aerospace, Transport and Manufacturing (SATM) by Course name "MSc by Research in Manufacturing"

Now showing 1 - 5 of 5
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    Carbon nano materials based composites for energy storage.
    (Cranfield University, 2022-04) He, Shojun; Ayre, David
    The development of human industrial technology has increased the requirement for electric energy. At present, the rapid development of various smart devices has led to an increasing demand for high-performance batteries. The emergence of various wearable devices has led to a need for flexible electrodes. Aerogels and paper, as two good flexible porous materials, have attracted many scholarly studies in recent years. Combining carbon materials, which have excellent electrochemical properties, with aerogel and paper can result in flexible electrodes with good performance. This research presents a series of aerogel and carbon paper samples prepared using three different production processes. For the aerogel samples, the effects of graphene addition and manufacturing route were investigated. The study resulted in a recommended material and process to produce a porous aerogel sample with high electrochemical cycle stability. For carbon paper samples, the relationship between variables such as surfactant, paper, conductive material and the sample properties was examined. Initial work indicates that carbon paper manufacturing routes are simpler than others reported elsewhere and provide materials that have electrochemical properties with potential for use as electrodes in supercapacitors and other energy storage devices. Of course, cost and environmental protection have also been considered in this project.
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    Creation of a control system for plasma delivery to increase automation and stability.
    (2016-09) Zhou, Hui; Endrino, José L.; Jourdain, Renaud
    Surface figuring of extremely large telescopes (ELT) addresses a highly challenging manufacture issue for the field of ultra precision. [1] High form accuracy and rapid fabrication are needed for ELT primary mirror surface figuring. In Cranfield University, Plasma Figuring (PF) [2] is used as a main method to correct ELT mirror surface figure error. The non-contact based material removal process brings PF to a high level of accuracy (under 1nm RMS level). Some other great features of PF are the capability to work at atmospheric pressure, the low-cost of consumables. Other figuring methods make use of vacuum chamber (ion beam Figuring) which are expensive. On the other hand magnetorheological finishing requires expensive consumables. Although PF is dominant for the surface correction of metre scale surfaces, challenges still exist to improve the automation and stabilization of the plasma source. In the context of ever-increasing dimensions of optical components, there is a need for improving the robustness and securing the performance of the unique Plasma Delivery System (PDS) available in Cranfield. The current PDS is based on an inductive output L-type radio frequency (RF) circuit, Inductively Coupled Plasma (ICP) torch and computer numerically controlled (CNC) motion system. The combination of optical component surface dimensions and the material removal rate of the plasma jet lead to significant processing duration. Based on the existing PDS for our unique Plasma Figuring machine named Helios1200, we designed an enhanced PDS version. The novel design was given the capability to detect phases and automatically tune the impedance of the plasma. The novel control capability is aiming at secure the process determinism, assisting the machine operator by tuning key electrical components of the RF network and monitoring crucial processing parameters. Furthermore, specific assistances were provided during the three identified processing phases (ignition phase, regular operation and critical circumstance) of the plasma processing. Our design addressed particular functions on each phases to ensure an optimum performance during the Plasma Figuring process.
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    Development of hybrid laser arc welding process for automotive structural applications.
    (Cranfield University, 2019-09) Jeyakandan, Subramanian; Ganguly, Supriyo; Suder, Wojciech
    In today’s world, two-wheelers (Motorcycles and Scooters) have become an indispensable part of people’s lives. Customers are demanding high quality product with superior performance of the vehicle. Frame is one of the safety critical part of a two-wheeler which highly contributes to the functional and aesthetic quality of the vehicle. Predominantly, gas metal arc welding (GMAW) process is being used for the manufacturing of frame. Limited depth of penetration and low welding speed of GMAW process significantly hinders the quality and productivity. Moreover, high heat input of this process consequently results in larger distortion. High fusion zone and HAZ area leads to degradation of material properties. Better structural integrity and consistent frame dimensions are required to meet the functional and finish quality requirements of a vehicle. Hence, advanced laser welding processes were investigated as an alternative method to GMAW process in the facets of productivity, heat input, weld bead geometry, aesthetic quality, gap bridgeability and distortion. Typically two- wheeler frame is made of low carbon steel. Thus low carbon steel of S275 grade was used for the evaluation. The outcomes were compared with existing GMAW process to quantify the benefits of laser welding. High power density of autogenous laser welding (ALW) process provided deeper penetration with significant improvement in productivity. When compared with GMAW process, productivity was improved by a factor of 8 times in 2 mm and 4 mm thick plates whereas 3 times improved productivity was achieved in 8 mm thick plates with complete penetration. However, lack of reinforcement and restricted part fit-up tolerance were found to be the critical limitations of ALW process. On the other hand, addition of filler metal using a GMAW arc in hybrid laser arc welding process (HLAW) ensured a better weld geometry and improved gap bridgeability of the process. Moreover, it was provided deeper penetration and significant improvement in productivity which is comparable to ALW process and far higher than GMAW process. Both HLAW and ALW processes produced ~75% and ~85% less distortion than GMAW process respectively. Moreover, HLAW process improved the productivity with considerably less increase in hardness than ALW process. For instance, in 2 mm thick material, productivity was improved by 8 times than GMAW process with 55% and 17% increase in average fusion zone hardness in ALW and HLAW processes respectively. Moreover, substantial reduction in fusion zone and HAZ width was obtained in both HLAW and ALW processes. In mechanical strength standpoint, all three welding processes produced weld region stronger than base material. Therefore, fracture was occurred in the base material during tensile test. Overall, HLAW process combines the advantages of both individual processes and eliminates the limitations of them. Hence, hybrid laser arc welding process can be considered as the future of welding in the automobile sector.
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    Fabrication of micro-scale features on titanium alloys through micromilling.
    (2018-04) Dickins, Andrew; Goel, Saurav; Giusca, Claudiu
    Structured surfaces are of high interest in the manufacturing world, allowing for functionality to be applied to materials through nothing more than a change in the surface topography or an application of a surface coating. Applications for these surfaces range greatly, including, optical surfaces for antireflective surfaces, thermal structures to assist in heat dispersion and anti-fouling surfaces to reduce organisms from adhering to components. Hydrophobic structures, such as the one that have been examined on the lotus leaf under SEM, generate high droplet contact angles and roll off. The manipulation of surface wettability is of particular interest in areas such as the medical sector for self-cleaning applications or controlling cell adhesion on the surface of an implant. This work investigates the generation of micron level hydrophobic features on two Titanium alloys, Ti-6Al-4V alpha-beta alloy and Ti-30Nb beta alloy, with the aim of identifying how accurately surface structures can be produced through micromilling as well as experimentally testing how successfully these surfaces function after being fabricated. On each alloy, nine different 5mm x 5mm test pillars are machined using micromilling, half of each pillar is machined with 200μm wide and 30μm deep channels, generating a hydrophobic groove structure, and the other half being flat machined. Across these nine pillars the feedrate, spindle speed, axial depth of cut and tool step over were varied to optimise these parameters in terms of structure generation, channel bottom surface roughness and tool to workpiece interaction in an attempt to determine how effective micromilling is as at structuring the surface of beta Titanium alloys. Tool condition was assessed qualitatively using SEM imaging and an independent assessment was carried out to determine the mechanical properties of the beta Titanium alloy being machined.
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    Ultra precision air bearing development for low cost manufacturing.
    (2018-04) Sen, Aroop Kumar; Goel, Saurav; Giusca, Claudiu
    Air bearings today are extensively used in the industry, the manufacturing processes involved in fabricating these bearings are complicated and have major drawbacks. The current research investigates the failure of aerostatic bearings based upon which a manufacturing process is developed which removes the correlation between the bearing surface and the effective gap between these surfaces. This results in low manufacturing errors due to the omission of repeated machining of the bearing surface. The second factor that is novelty towards this research is the application of aluminium coated with hard nickel as suitable alternative to bearing base material instead to the current material for aerostatic bearings. This proposed material solution has low density, good wear resistance and good corrosion resistance. This allows the application of diamond turning instead of precision grinding as the bearing machining process. Reducing on majority of the manufacturing while achieving the form accuracy of the bearing surface. The third novelty factor is the application of bi-conic configuration which would allow self-aligning capability and has a smaller packaging size as compared to any other fluid film mechanical configuration.