Polyimides are ubiquitous in the electronics, space science, and research industries due to their thermal stability, ease of use, lifetime, and high dielectric strength. These properties, along with the propensity of polyimides to absorb water vapour, has led to both their use as a common sensing element in humidity sensors, and additional challenges when utilising polyimides in solid state electronic devices. Consequently, a substantial amount of literature has been produced regarding the transport properties of water vapour in polyimide films. This has been found to be a complex process dependent on the morphology and chemistry of the particular polyimide in question. Accordingly, as part of an industrial collaboration with Honeywell Inc. several tools and probing techniques were developed to map and quantify the transport properties and characteristics of such materials. The material of focus is a particular form of polyimide which is used as a sensing element by Honeywell in their capacitance based humidity sensors. The cure procedures and preparation have been varied to understand the relationship between water transport and processing procedure. Importantly, methods and equipment have been developed to measure and characterise the subtle difference in water transport resulting from variations in the preparation procedure. in-situ techniques to characterise transport have included the use of capacitance measurements, Attenuated Total Refectance Infra -Red spectroscopy (ATR-FTIR), Quartz Crystal Microbalance (QCM), and Neutron Refectivity. Other techniques to characterise the polymer have included Transmission Electron Microscopy(TEM) and Atomic Force Microscopy(AFM). The use of Attenuated Transmission Reflectance Infrared Spectroscopy (ATR-FTIR) has indicated a chemical interaction between the polar elements of polymer backbone and the water molecule. Permporometry and an analysis of the TEM images indicate a transport length scale ∼ 0.2nm, similar to the size of a water molecule. Density profles ftted to Neutron Refectivity measurements reveal a dense skin layer on the surface of the polymer, the characteristics of which vary with the sample curing procedure. The neutron refectivity technique was then used in time of fight mode (ToF) to map the ingress of vapour into the polymer, pushing the time resolution further than has previously been achieved. However, the box-car averaging technique which was used to gain sufficient counts of neutrons was found to obscure the longer timescale transport effects. The QCM procedures outlined have provided Honeywell with a cost effective method of raw material measurements of transport properties for a range of materials. QCM measurements indicate dual diffusion coefficients, skin, and bulk, when Fickian transport models are applied to the system. The transport timescales were found to be thickness independent in the range studied (60nm-1.1µm), consequently diffusion is not the rate limiting factor in this system. Thus, the key factors such as time and length scales of this diffusion system have been characterised with the customisation of a host of techniques. The distribution of water vapour within the samples is shown to be uniform in the bulk layer of the sample, and the rate limiting step in the transport of water vapour is demonstrated to be constant on all polyimide thin films. It is also indicated that oxygen plasma etching can be used to reduce the hystersis effect in this form of polyimide with some indication that such treatment impacts on the chemical interactions between the polyimide films and water vapour.

The EU-funded SATIN project sought to provide a multimodal interface to aid product designers in judging the quality of curved shapes. This thesis outlines a research programme designed to assist in the exploration of fundamental issues related to this project, and provide a means to evaluate the success of such interfaces more generally. Therefore, three studies were undertaken with the aim of exploring the value of haptic and sound feedback in the perception of curve shape differences, and through the knowledge gained provide an evaluative framework for the assessment of such interfaces. The first study found that visual, haptic, and visual-haptic perception was insufficient to judge discontinuities in curvature without some further augmentation. This led to a second study which explored the use of sound for conveying curve shape information. It was found that sine waves or harmonic sounds were most suited to for this task. The third study combined visual-haptic and auditory information. It was found that sound improved the perception of curve shape differences, although this was dependent upon the type of sonification method used. Further to this, data from studies one and three were used to identify gradient as the active mechanism of curve shape differentiation and provided a model for the prediction of these differences. Similarly performance data (response time, accuracy, and confidence) were analysed to produce a model for the prediction of user performance at varying degrees of task difficulty. The research undertaken across these studies was used to develop a framework to evaluate multimodal interfaces for curve shape exploration. In particular a ‘discount’ psychophysical method was proposed, along with predictive tools for the creation of perceptual and performance metrics, plus guidelines to aid development. This research has added to fundamental knowledge and provided a useful framework through which future multimodal interfaces may be evaluated.

The aim of this research is to understand the failure modes and mechanisms of adhesive materials used to flip-chip bond a silicon die onto a polyimide substrate. The bonding material investigated in this research is called Anisotropic Conductive Film (ACF). This is a promising interconnection material and has gained extensive interest in the electronics packaging industry. Both the experimental and finite element analysis (FEA) methods were used in order to investigate the behaviour of the ACF materials when subjected to certain manufacturing and environmental testing conditions. The manufacturing condition investigated was a subsequent solder reflow process on an ACF flip-chip bonded device. The environmental testing condition investigated was the moisture test. For the manufacturing condition, both experimental and modelling results demonstrate the impact of a subsequent reflow process on the behaviour of the ACF joint. Typical failures observed after this process were cracks at the pad/particle interface. This failure mode was more sever with a higher peak reflow temperature. This was also found using FEA where high tensile stresses were predicted in these regions. FEA modelling was also used to help identify the mechanisms leading to these failures. This is primarily due to the Coefficient of Thermal Expansion (CTE) miss-match in the materials and the elastic/plastic deformation behaviour of the conductive particle. Important design variables that can minimise these failures are the Young’s Modulus and CTE of the adhesive and the height of the hump on the die. For the environmental testing condition, an autoclave test at 121°C, 100%RH and pressure of 2atm was used. More than 85% of the ACF joints failed during the first 24 hours of testing. The failure mode observed was cracking along the interface between the adhesive and substrate and pad. A macro-micro modelling approach was used to help identify the mechanisms leading to these failures. It was found that most of the damage is caused by moisture diffusion and associated swelling. Important design variables that will help minimise this mode of failure are: Coefficient of Moisture Expansion (CME) and Young’s Modulus of the adhesive and the height of the bump on the die.

Additive manufacturing (AM) techniques provide engineering design flexibility not available when manufacturing is constrained by the tool-path restrictions of conventional subtractive techniques such as turning, milling and grinding. AM techniques allow the manufacture of complex form, light weight components with optimised geometries and topographies, including internal and re-entrant features. These features may greatly enhance the components functional capability. The design flexibility may allow a reduction in assembly part count, with a corresponding reduction in assembly time. Additionally, the ability to use high performance engineering metals in the AM process, such as 316 stainless steel, titanium Ti6Al4V and cobalt chrome provide the aerospace, medical and automotive industries with a new manufacturing toolbox using familiar raw materials. These quality-driven industries are fully aware of the potential of AM and are actively engaged and invested with the AM industry and research community. The complex features and design freedom providing great potential for these industries also presents challenges for surface measurement and characterisation. Surface measurement is vital to assure compliance with designed sealing, bearing, flow and adhesion properties of the component. Parts manufactured using AM are not exempt from the stringent quality requirements applicable to other manufacturing processes and so surface texture requirements will be incorporated into drawings and design specifications, imposed by customers onto suppliers. There will need to be a common language and approved standards. Compliance verification will be mandatory. If a feature is specified on a drawing then these industries will require verification that the component complies with design requirements. Traditionally, line-of-sight measuring devices were able to follow the tool pathways to access and measure these surfaces. With the advent of additive processes, new techniques will need to be developed. X-ray computed tomography (CT) has been used successfully for dimensional and defect detection as it allows the measurement of internal and re-entrant features. Thus far, there has been little research on the application of CT for the measurement of surface texture. This thesis reports on the development of a novel technique, detailing the first extraction of areal surface texture parameters per a recognised standard (ISO 25178-2) from CT scans of AM components. Industry will require reproducibility of measurements and so an interlaboratory comparison was performed to compare CT measurement results using this technique from four laboratories. The repeatability and accuracy of surface measurements is also vital for industrial applications and so the influence on extracted surface texture parameter values of selected CT measurement and reconstruction factors has been investigated. Extraction of true 3D data from CT requires the generation of new surface characterisation parameters to take full advantage of the technique and a new parameter has been developed to enable the true surface of re-entrant surfaces to be characterised. The additive process itself is complex and verification of consistent additive machine performance is vital for production. A series of small, inexpensive, surfacespecific measurement artefacts has been developed and built to characterise the build chamber and provide production process verification. This series of inter-related experimental investigations were chosen to be industrially relevant, to be linked closely to component function and be used as practical measurement and surface characterisation techniques. This work is intended, as far as possible, to not be machine-specific, but to be applicable to all CT machines and all metal powder bed fusion (PBF) AM machines. As AM and CT machine capability improves, as it inevitably will, the techniques and applications presented here are designed to evolve with these changes.

In surface mount technology (SMT) electronics assembly, the solder paste is printed onto the PCB's surface through a stencil and the components are later placed over the solder paste deposits. Since 2007, the use of extremely small SMT components for assembly of SMT devices has been widespread, and achieving consistent print deposits for fine pitch (the distance between the leads of the components) components has become a real challenge. The majority of the defects at the printing stage, such as skipping and bridging, were found to be related to the quality of the solder paste. These defects are usually carried over to the reflow process, causing defective final products. Hence, it is important to monitor the quality of the solder paste. Conventional techniques for monitoring the quality of solder pastes during the production and packaging stage are usually based on the viscosity measurements of the solder pastes from the viscometer and rheometer. One of the potential limitations of viscometer- and rheometer-based measurements is that the collection and preparation of the solder paste samples can irreversibly alter the structure and flow behaviour of the sample. Due to the sample preparation process (removal, preshear/ pre-mixing), repeatability issues were often encountered when taking measurements using a viscometer or rheometer. Secondly, rheological measurements and the interpretation of rheological data comprise a very technical and time consuming process, which requires professionally trained research and development (R&D) personnel. Finally, the monitoring/inspection process usually employs random sampling technique from the production batch. Hence, measurement may not represent the actual quality of the whole production batch. This would mean that the conventional solder paste quality control that has been employed in the industry as a benchmark for printability (i.e. checking the viscosity of the paste before being despatched to the customers), would need to be re-evaluated for its feasibility and other possible methods of solder paste quality control would need to be considered. This has brought the ultrasound technique into context as it can offer a non-destructive evaluation of the quality of the solder paste in terms of viscosity. Also, it can be used at different stages of paste production and processing. It is for these reasons that materials suppliers that formulate and produce solder pastes, as well as solder paste consumers (especially contract electronics manufacturers), are keen to see the development of simple, easy-to-use and accurate techniques for the rheological characterisation of solder pastes. This thesis concerns the study of a non-destructive ultrasonic technique for characterising the rheological properties of solder pastes and, specifically, the use of through-mode microsecond ultrasonic pulses for evaluation of viscoelastic properties of solder paste materials. In this study, a wide range of flux systems and solder alloy particle distributions used in the industry are investigated to determine the correlation of the ultrasound attenuation and velocity to the viscosity of the solder paste and their correlation to paste printing performance. The work is part of a bigger study aimed at the development of an on-line quality control technique for paste manufacture based on both conventional rheological tests and ultrasound measurements. Results from the work on the comparative study of standard fluids and both commercial and newly formulated solder pastes and flux vehicle systems have been used to demonstrate the utilisation of the ultrasound technique for on-line, non-destructive measurement of the viscosity of non- Newtonian materials such as solder pastes. The study also found that the viscosity of the solder paste is governed by the intermolecular forces between the solder particles and the flux. The strength of these intermolecular forces depends on the probability of these particles rubbing up against one another while the paste is being sheared. Provided that the right correction factor for a particular shear rate is used, the ultrasound viscosity results obtained were found to be comparable to the rheometer viscosity results or to the viscosity provided by the solder paste manufacturer. The ultrasound technique produced consistent results and was also proven to work at low temperatures. The ultrasound technique may be used to help solder paste manufacturers to add the correct amount of flux or solder particles to their paste in order to reach a desired viscosity. Otherwise, it can be used as a quick go/no-go monitoring tool in the production line for predicting printing quality. Based on the foregoing, it can be concluded that the ultrasound technique is a viable alternative to using a rheometer.

The work discussed in this thesis is aimed at examining the formation of freeze layers and refractory wear on water-cooling elements within direct smelting processes through the use of computational modelling techniques. The motivation of performing this work is to examine the cooling of regions of the Smelt Reduction Vessel of the HIsmelt process closer to the molten bath material. HIsmelt is a novel process for the production of pig iron which has been under development by Rio Tinto and is now being ommercialised. The previous work performed in this are has been reviewed with particular focus on the refractory wear mechanisms as the solidification algorithms have been thoroughly implemented within the Computational Fluid Dynamics (CFD) framework PHYSCIA used within this work. The governing equations along with the Finite Volume discretisations of these equations are set out within this thesis. Some comment is made about the solution methods used, and how boundary conditions are implemented. The Free-surface flow and Solidification governing relationships are also described as these are important for investigating the formation of freeze layers. The implementation of the refractory wear mechanisms are discussed in some detail. The three mechanisms implemented are for the penetration of slag into the refractory, the corrosion of the refractory by this penetrated slag; and the erosion of the refractory by the bulk flow of slag within the furnace. To be able to reasonably predict refractory wear, it is necessary to make the properties of the materials within the system temperature dependent. During the pilot plant trials at the HIsmelt® Research and Development facility, located in Kwinana Western Australia, accretions formed on the end of the solids injection lances. These accretions have been termed Elephant's Trunks. With the imminent construction of the Development Plant which injects the iron bearing feeds at an elevated temperature rather than at ambient temperatures used on the pilot plant, the formation of these pipe-like accretions under both the cold and hot injection conditions have been examined. This work provides confidence that the freeze layers predicted from the model will reflect those formed within the furnace. To evaluate the effectiveness of the refractory wear mechanisms, data from experimental and the HIsmelt pilot plant have been modelled. Sections of refractory samples from an induction furnace test and a rotary slag test have been modelled. The results are in agreement with the profile and affected regions of the sectioned refractory test pieces. A part of the HIsmelt pilot plant Smelt Reduction Vessel (SRV) has been modelled for the period of campaign 8-1 & 8-2 (just over 20 days). The predicted wear is in agreement with the measurements taken after the vessel had been cooled. To bring together freeze layer formation with the refractory wear mechanisms, a water-cooled element was modelled for the sloping slag section. The results show the growth of a small freeze layer that is consistent with the small freeze layer seen on the upper cooling panels of the pilot plant SRV. This model is an ideal tool to evaluate different water-cooling strategies for HIsmelt and other similar direct smelting processes. This work has developed models that predict the formation of freeze layers and refractory wear within direct smelting processes. The models have focused on slag-refractory interactions and further work would be needed to extend the refractory wear models to account for metal-refractory interactions. To examine spalling, stress calculations could be performed to determine when this may occur.

Environmental concerns have brought attention to the requirement for more efficient and renewable processes for chemicals production. Lignin is the second most abundant natural polymer, and might serve as a sustainable resource for manufacturing fuels and aromatic derivatives for the chemicals industry after being depolymerised. In this work, two main approaches were investigated with the aim of treatment of lignin with a mediator, 2,2’-azinobis(3-ethylbenthiazoline-6-sulfonic acid) diammonium salt (ABTS), in 1-ethyl-3-methylimidazolium ethyl sulfate, ([C2mim][C2SO4]). In the first approach, laccase from Trametes versicolor (LTV) was used to treat organosolv lignin, using [C2mim][C2SO4] as a co-solvent in the presence of ABTS. LTV was shown to possess catalytic activity for the degradation of organolsov lignin in systems containing ionic liquid and syringaldehyde was found to be a major product obtained from the process. ABTS alone has been evaluated for its reaction with lignin by means of cyclic voltammetry (CV). Here, the non-phenolic lignin model compound veratryl alcohol and three types of lignin (organosolv, Kraft and lignosulfonate) were specifically examined. The presence of either veratryl alcohol or organosolv lignin increased the second oxidation peak of ABTS under select conditions, indicating the ABTS-mediated oxidation of these molecules at high potentials in [C2mim][C2SO4]. Furthermore, CV was applied as a quick and efficient way to explore the impact of water in the ABTS-mediated oxidation of both organosolv and lignosulfonate lignin. Higher catalytic efficiencies of ABTS were observed for lignosulfonate solutions either in sodium acetate buffer, or when [C2mim][C2SO4] (15% v/v) was present in an aqueous solution, whilst there was no change found in the catalytic efficiency of ABTS in neat [C2mim][C2SO4]-lignosulfonate mixtures relative to ABTS alone. In contrast, organosolv showed an initial increase in oxidation, followed by a significant decrease on increasing the water content of a [C2mim][C2SO4] solution. Despite enhanced lignin solubility in ionic liquids, the yields of small molecules attributed to depolymerisation in ionic liquids are often quite low. Since depolymerisation approaches examined herein are thought to proceed via free-radical mediated mechanisms, two different stable radicals 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ABTS were assessed for the rapid monitoring of radical activity of lignin-related compounds in ionic liquid systems. While these assays are successful in aqueous and organic solvent systems, the presence of the ionic liquids complicates the assay procedure, requiring further developmental work.

Woven engineering fabrics generally serve as advanced composite preforms and are an important class of engineering material. This thesis focuses on improving the accuracy of Computer Aided Engineering (CAE) tools for simulating the deformation of such materials during the press-forming manufacture process. Specifically, this has involved better understanding: (i) the material behaviour during deformation and (ii) the extent and influence of material variability on forming behaviour. To this end, the use of a novel fabric shear test, the BBE test, capable of characterising the shear-tension coupling of engineering fabrics has been used for the first time in an extensive characterisation program, involving three different woven engineering fabrics. Results show a strong dependence of shear compliance on in-plane tension. Wrinkling behaviour during shear has also been characterised using two new analysis methods, a transmitted backlighting technique and a tracer line analysis technique. The onset of wrinkling is clearly shown to be an increasing function of the in-plane tension applied to the deforming fabric. Variability of fibre orientation, otherwise known as ‘tow meander’ can degrade the final mechanical properties of a textile composite part and can also influence measurements of the fabric’s shear compliance. Accordingly, variability of tow orientation in a pre-consolidated textile composite and three engineering fabrics has been characterised using two different image processing methods: a simple manual method and a semi-automated method. The latter has been found to be a promising tool in terms of increasing accuracy and in reducing manual effort during the characterisation process. Modelling tow meander has also been conducted using a numerical code, VarifabGA, that has been developed during the course of this work. The code has allowed the effects of tow meander on shear compliance to be investigated in numerical simulations using a technique of assigning an initial fibre orientation to each element in a Finite Element (FE) mesh before conducting shear test simulations. The experimentally measured shear-tension coupling has also been modelled by enhancing a pre-existing Non-Orthogonal Constitutive Model (NOCM). A comparison between model predictions and experimental results of the sensitivity of this shear-tension coupling has shown that the model provides good results. Finally, a novel geometrically complex 3D forming tool of a kart wheel has been designed and manufactured for use in experimental and numerical forming studies. The part provides a challenging modelling problem with which to demonstrate the use of the new computational tools developed during the course of this work.

Pulsed ytterbium-doped fibre lasers based on a master oscillator power amplifier (MOPA) architecture possess attractive characteristics over their Q-switched diode-pumped solid-state counterparts. These include a relatively low cost of ownership and a flexible operating window with respect to the pulse duration, shape and repetition rate. For micro machining applications, given this inherent large processing window available with respect to the pulse characteristics, the effect of process parameters on particular machining outcomes needs to be investigated. The literature review conducted identified four important gaps in the knowledge surrounding the nanosecond fibre laser machining of materials. These gaps included the optimisation of the nanosecond fibre laser machining during milling operations, with the aim of obtaining both high surface quality and material removal rates, as well as the need for complimentary theoretical and experimental studies on the basic nanosecond laser material interaction for a wide range of engineering materials. In addition, the characterisation of the nanosecond laser machining of bulk metallic glasses, and the investigation of processing conditions leading to crystallisation of their amorphous structure, were identified as knowledge gaps that need to be addressed. The first knowledge gap was the focus of Chapter 3. The particular parameters under investigation in this study were the pulse duration and repetition frequency, the pulse overlap, the scanning strategy and the distance between linear machined tracks when processing aluminium. The results showed that, for each of the pulse durations studied, the specific frequency at which both the highest energy and average power are delivered leads to the maximum material removal rate (MRR) achievable, and to high values of surface roughness. It was also observed that the lowest surface roughness obtained corresponds to a specific frequency range which is common for all pulse durations. Following this, a design of experiments was conducted for a given pulse duration with the aim of identifying an optimum combination of parameters with respect to the attained surface roughness while operating at the frequency resulting in the highest MRR. This optimisation study resulted in a 60% decrease in the achieved surface roughness and also showed that the distance between machined tracks had the highest influence on the surface finish among the parameters considered. In the following chapter, a theoretical model was developed to predict the topographical evolution of the single pulse craters as a result of the time-dependent temperature rise in the processed materials when the laser beam is incident on its surface. In addition to this theoretical study, in an to attempt to understand the laser material interaction on a more fundamental level, single pulse experiments were conducted at varying laser fluence values and pulse durations leading to the formation of single craters on the surface of a number of materials namely, titanium, silicon and silicon carbide. In particular, different pulse lengths were investigated at decreasing values of fluence until no visible effect on the material surface could be observed. Based on this investigation, the fluence corresponding to the ablation threshold for each material at different pulse durations could be found whilst identifying the relationship between the laser processing parameters and the dimensions of the single craters. Scanning Electron Microscopy (SEM) micrographs of the craters were also used to observe phenomena such as melt ejection as a result of varying the process parameters. The experimental results were compared with the theoretical predictions and a good agreement between both set of data was found with respect to the achieved depths and diameters of the craters. The additional knowledge gaps were the focus of Chapter 5. In particular, the characterisation of nanosecond laser machining of a zirconium-based bulk metallic glass (BMG) was conducted using the approach employed in Chapter 4. Similar conclusions were reached with regard to the single pulse material removal behaviour when varying the fluence and pulse duration. In addition, milling of the material with different parametric combinations was implemented to investigate the crystallisation behaviour of the BMG. To complement these experimental tests, the theoretical model reported in Chapter 4 was further developed to predict the heating and cooling rates of the milling process. From this study, it was found that varying the process parameters of the machining of BMG results in a variation in the critical cooling rate (from the melt temperature to the glass transition temperature) which may result in crystallisation of the material.

Nowadays, New Product Development (NPD) has become a business priority in manufacturing companies due to international competition in terms of meeting higher and changing customer requirements, generating high profit at low cost, and maintaining sustainable development and growth. Through literature review and industrial investigations, it has been recognised that NPD is an information and knowledge intensive process. However, in current practice, enterprise knowledge is not properly managed or easily accessible. Many service providers have not followed the good practice of considering business objectives and end users’ requirements as main drivers of knowledge management system development and implementation. This doctoral thesis presents a methodology for the design and development of Knowledge Management (KM) systems to support NPD based on Enterprise Architecture Frameworks (EAFs). The project focuses on IT system specifications generation driven by business and knowledge users’ requirements in the automotive industry. Current EAFs have been developed by researchers and practitioners to help enterprises to design their information systems based on business objectives and user requirements. However, these frameworks are mainly proposed to manage information and data such as finances, resources, management and engineering documents, not for the increasingly important enterprise knowledge, especially tacit and unstructured knowledge. This project aims to extend the capabilities of the latest enterprise architecture frameworks so that not only data and information, but also enterprise knowledge can be managed. A guideline in the form of a flowchart has been developed, which provides a process that can be followed and used by system developers and implementation. The extended EAF has been implemented as easy-to-use folders for the development of a structured knowledge base. A case study in an automotive company proved that the methodology can be used to produce the functional specifications of their IT systems to include knowledge management capability. The system specification can then be used, either to assess a company’s existing information systems and direct its future system development and implementation; or to develop/implement a complete new information system from scratch.