Dissertations / Theses on the topic 'Manufactures – Defects'
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Lawrence, James Andrew. "The prediction of bubble defects in castings." Thesis, University of Greenwich, 2004. http://gala.gre.ac.uk/6219/.
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Objective of this research was to develop models that capture the entrainment, breakup and transport of gas bubbles in solidifying TiAl castings. The candidate has reviewed the literature, programmed in FORTRAN code, and validated a number of competing techniques for two phase flow relevant to the filling of moulds. He has developed a hybrid (Donor-acceptor/ Level Set) method, which captures the characteristics of gas bubbles based on the surface tension —fluid inertia balance on the free surface. He has demonstrated the ability of this method to reproduce observed phenomena. The candidate also conducted an experimental campaign in Birmingham University under the supervision of Dr R.A. Harding to provide real casting data for his simulations. KAP Edited extract from RD3 MPhil/PhD form: "This research was carried out at the University of Greenwich in conjunction with the University of Birmingham as part of a larger EPSRC- funded project concerned with the development of a casting process route for the production of gamma-TiAl components. Focus of the research was the development of a model of entrained bubbles in the metal casting process. This model comprises the combination of several physical phenomena coupled within the PHYSICA multi-physics framework. The key areas the research has touched on are, surface tension modelling and free-surface modelling using the finite volume technique. A model has been developed that simulates bubble formation during the filling of castings due to surface entrainment and subsequent motion. Once entrained these bubbles tend to solidify in the casting where the rate of solidification is too fast for escape by buoyancy. This problem is particularly acute in thin blade sections of TiAl, where sufficient superheat cannot be maintained during the casting process. Mould filling techniques have to be modified accordingly to improve the mechanical integrity of components. Two phase systems with a sharp, well-defined interface governed by surface tension are required to be modelled. The Level Set Method (LSM) is such a method, used to maintain the position of the interface as it moves through a fixed computational grid. The interface is moved or distorted by the advection equation. In this case two numerical methods are used in differencing: Van-Leer and Donor Acceptor. The Donor Acceptor method is of use when modelling highly dynamic surfaces, such as those encountered during the metal pouring phase in castings, or when fuel sloshes in a fuel tank. This method is best for capturing the entrapment of large bubbles of gas by surface folding. A process directly related to the moving surface. However, the LSM, which allows many surface properties to be calculated, cannot be used in conjunction with the Donor Acceptor method which uses heuristics to sharpen the interface in each compu6tational cell. Once bubbles are formed, their existence and motion are governed by the action of surface tension, therefore the mathematically more rigorous Van-Leer differencing scheme is used in conjunction with the LSM. Bubbles are then tracked using the freesurface method. The tracking limit is determined by the fineness of the mesh used. Sub grid bubbles or bubbles that only occupy a small number of cells can no longer be tracked in a continuum Eulerian simulation. Lagrangian particle tracking is then necessary. The original work in this research can be described as the coupling of the formation of bubbles using the Donor Acceptor method, with the LSM / Van-Leer technique for their subsequent motion and behaviour. This involves: • Modelling the initial free-surface dynamics with the Donor Acceptor technique. • Modelling bubble formation using the Donor Acceptor technique. • Using Results from bubble formation database to "re-start" the simulation with the inclusion of surface tension. • Tracking bubbles as a free-surface, computing their subsequent break up or coalescence • Once the bubbles reach a minimum size for a given mesh, continue tracking using the Lagrangian particle tracking technique. The model was applied to: • Simple validation experiments to test the correctness of the coding • Sloshing/collapsing column experiments to evaluate bubble formation • Simple geometry situations where the combined model is used with Bubble Formation/Tracking Surface Tension • Model the filling of the flat plate experimental setup Future work (not completed ...) • Develop criteria for switching between the Eulerian (free surface) and Lagrangian (particle tracking) scheme • Compare with Experimental Data obtained at the University of Birmingham • Run 3D Cases representing real geometries with HT and solidification • Model the counter-gravity filling process"
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Bogen, Daniel J. "Effects of Manufacturing Defects on the Corrosion of Additively Manufactured AlSi10Mg." Youngstown State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1596641889374996.
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Bhamidipati, Kanthi Latha. "Detection and elimination of defects during manufacture of high-temperature polymer electrolyte membranes." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/43616.
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Defect generation and propagation in thin films, such as separation membranes, can lead to premature or catastrophic failure of devices such as polymer electrolyte membrane fuel cells (PEMFC). It is hypothesized that defects (e.g., air bubbles, pin-holes, and holes) originate during the manufacturing stage, if precise control is not maintained over the coating process, and they propagate during system operation. Experimental and numerical studies were performed to detect and eliminate defects that were induced during slot die coating of high-viscosity (1 to 40 Pa-s), shear-thinning solutions. The effects of fluid properties, geometric parameters and processing conditions on air entrainment and coating windows (limited set of processing conditions for which defect-free coating exists) were studied. When smaller slot gaps and coating gaps were used, relatively small bubbles were entrained in the coated film. The air bubble sizes increased as the viscosity of the coating solution decreased. A semi-empirical model correlating the maximum coating speed to a solution's material properties, geometric parameters and processing conditions was developed. Such a predictive model will enable engineers to determine the maximum coating boundary for shear-thinning and Newtonian solutions within certain constraints. Smaller coating gaps and low-viscosity solutions produced higher coating speeds. The surface tension property of the coating solution provided stability to the coating bead. Therefore, solutions with higher surface tension could be processed at higher coating speeds.
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González, Bautista Javier, and Sánchez Alberto Guerrero. "Reducción de defectos en el proceso de fabricación para el bastidor de automóvil." Thesis, Universidad de las Américas Puebla, 2010. http://catarina.udlap.mx/u_dl_a/tales/documentos/lmnf/gonzalez_b_j/.
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Tammas-Williams, Samuel. "XCT analysis of the defect distribution and its effect on the static and dynamic mechanical properties in Ti-6Al-4V components manufactured by electron beam additive manufacture." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/xct-analysis-of-the-defect-distribution-and-its-effect-on-the-static-and-dynamic-mechanical-properties-in-ti6al4v-components-manufactured-by-electron-beam-additive-manufacture(cb034391-b61f-4e16-91cd-7ad3c9ec6312).html.
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Selective electron beam melting (SEBM) is a promising powder bed Additive Manufacturing technique for near-net-shape manufacture of high-value titanium components. An extensive research program has been carried out to characterise in 3D the size, volume fraction, and spatial distribution of the pores in model samples, using X-ray computed tomography (XCT), and correlate them to the SEBM process variables. The average volume fraction of the pores (97.5 %) where fatigue cracks would initiate based on the relative stress intensity factor of all the pores. In contrast, crack growth was found to be insensitive to porosity, which was attributed to the much higher stress concentration generated by the crack in comparison to the pores. Some crack diversion was associated with the local microstructure, with prior β grain boundaries often coincident with crack diversion.
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Eidt, Wesley Earl. "Defect Modeling and Vibration-Based Bending Fatigue of Additively Manufactured Inconel 718." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1590502861855386.
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Yorgason, Robert Ivan. "Heteromorphic to Homeomorphic Shape Match Conversion Toward Fully Automated Mesh Morphing to Match Manufactured Geometry." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6414.
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The modern engineering design process includes computer software packages that require approximations to be made when representing geometries. These approximations lead to inherent discrepancies between the design geometry of a part or assembly and the corresponding manufactured geometry. Further approximations are made during the analysis portion of the design process. Manufacturing defects can also occur, which increase the discrepancies between the design and manufactured geometry. These approximations combined with manufacturing defects lead to discrepancies which, for high precision parts, such as jet engine compressor blades, can affect the modal analysis results. In order to account for the manufacturing defects during analysis, mesh morphing is used to morph a structural finite element analysis mesh to match the geometry of compressor blades with simulated manufacturing defects. The mesh morphing process is improved by providing a novel method to convert heteromorphic shape matching within Sculptor to homeomorphic shape matching. This novel method is automated using Java and the NX API. The heteromorphic to homeomorphic conversion method is determined to be valid due to its post-mesh morphing maximum deviations being on the same order as the post-mesh morphing maximum deviations of the ideal homeomorphic case. The usefulness of the automated heteromorphic to homeomorphic conversion method is demonstrated by simulating manufacturing defects on the pressure surface of a compressor blade model, morphing a structural finite element analysis mesh to match the geometry of compressor blades with simulated manufacturing defects, performing a modal analysis, and making observations on the effect of the simulated manufacturing defects on the modal characteristics of the compressor blade.
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Acharya, Pradip. "DETECTION AND SEGMENTATION OF DEFECTS IN X-RAY COMPUTED TOMOGRAPHY IMAGE SLICES OF ADDITIVELY MANUFACTURED COMPONENT USING DEEP LEARNING." OpenSIUC, 2021. https://opensiuc.lib.siu.edu/theses/2834.
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Additive manufacturing (AM) allows building complex shapes with high accuracy. The X-ray Computed Tomography (XCT) is one of the promising non-destructive evaluation techniques for the evaluation of subsurface defects in an additively manufactured component. Automatic defect detection and segmentation methods can assist part inspection for quality control. However, automatic detection and segmentation of defects in XCT data of AM possess challenges due to contrast, size, and appearance of defects. In this research different deep learning techniques have been applied on publicly available XCT image datasets of additively manufactured cobalt chrome samples produced by the National Institute of Standards and Technology (NIST). To assist the data labeling image processing techniques were applied which are median filtering, auto local thresholding using Bernsen’s algorithm, and contour detection. A convolutional neural network (CNN) based state-of-art object algorithm YOLOv5 was applied for defect detection. Defect segmentation in XCT slices was successfully achieved applying U-Net, a CNN-based network originally developed for biomedical image segmentation. Three different variants of YOLOv5 which are YOLOv5s, YOLOv5m, and YOLOV5l were implemented in this study. YOLOv5s achieved defect detection mean average precision (mAP) of 88.45 % at an intersection over union (IoU) threshold of 0.5. And mAP of 57.78% at IoU threshold 0.5 to 0.95 using YOLOv5M was achieved. Additionally, defect detection recall of 87.65% was achieved using YOLOv5s, whereas a precision of 71.61 % was found using YOLOv5l. YOLOv5 and U-Net show promising results for defect detection and segmentation respectively. Thus, it is found that deep learning techniques can improve the automatic defect detection and segmentation in XCT data of AM.
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Ngo, Austin. "Effects of Build Orientation and Post Processing on the Mechanical Properties of Additively Manufactured AlSi10Mg." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1588623582368507.
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Tsui, Mabel W. "A critical analysis of pharmaceutical manufacturers' product liability claims under the Australian consumer law: Interpretation, operation and reform." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/98526/4/Mabel_Tsui_Thesis.pdf.
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This thesis examines the adjudication of pharmaceutical product liability claims under the Australian Consumer Law. Recognising the seminal role that policy and principles have in the interpretation of legislation, this thesis encourages the adoption of a principled approach in the adjudication of statutory pharmaceutical product liability claims in Australia. The principles can be used to critique the current adjudication of pharmaceutical product injury claims while also guiding the determination of future claims. This thesis demonstrates a step forward in streamlining the law in this area, thus fulfilling its objective to reform product liability law in Australia.
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Farnworth, N. R. "Product liability in the vehicle manufacturing industry : The history and development of product liability in the USA, Europe and the UK and its effect in particular on a commercial vehicle manufacturer." Thesis, University of Bradford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376680.
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Van, der Horst Frank. "South African automotive industry: globalisation, re-structuring and world-class manufacture." University of the Western Cape, 2002. http://hdl.handle.net/11394/7900.
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Magister Commercii - MComPolitical and economic sanctions between 1970 and 1994 isolated the inward-oriented economy of South Africa from global trends. A variety of factors, such as a challenging new global competitive environment, production overcapacity, falling protectionist tariff barriers in a period of liberalisation, world-class manufacture and globalisation, are contributing to the reform of the economy and the automotive industry. The South African automotive industry therefore faces a major reform in trade policy. The South African government introduced the Motor Industry Development Plan (MIDP) in 1995, to create the necessary levels of competitiveness, promote world class manufacture practices, increase levels of investments and exports that would consequently lead to the successful reconstruction and development of this sector of the South African economy. Subsequent research has shown that the successful adoption of world-class manufacture (or lean production) processes in the South African automotive industry is necessary not only for survival, but also for increased competitiveness of the industry and the improved economic performance of automotive firms. However, complicated links exist between the adoption of world-class manufacture for improved levels of operational competitiveness. for firm-level success, on the one hand, and long-term sustainability of the industry, on the other hand. Combined firm level economic success and long-term sustainability of the industry depend on factors such as international trends, connectivity to global value chains, modern technological capabilities, lean production and enterprise systems, substantial investments, increased exports, world-wide quality standards, as well as customer satisfaction, human resource development, advanced education, skills development, worker participation, government policy and institutional support. This is borne out by a recent study of the auto component sector, utilising a lean , production 'market driver' toolkit. The study found that although component manufacturers significantly improved their operational competitiveness, they have not necessarily experienced improved economic performance levels. More important is connectedness and integration into global value chains, via intermediaries, mergers and acquisitions. The changing political economy of automotive value chains is also important in shaping fum-level operational success and industry sustainability. In this research paper, we review global automotive industry trends which influenced the introduction of the government's visionary MIDP. We then discuss their impact on the performance of the South African assembly and component sectors at industry and finn level. This leads to a series of recommendations for improved performance to world-class manufacture, world-wide quality standards and global competitiveness
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van, der Horst Frank A. "South African automotive industry: Globalisation, re-structuring and world-class manufacture." University of the Western Cape, 2002. http://hdl.handle.net/11394/7901.
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Magister Commercii - MComPolitical and economic sanctions between 1970 and 1994 isolated the inward-oriented economy of South Africa from global trends. A variety of factors, such as a challenging new global competitive environment, production overcapacity, falling protectionist tariff barriers in a period of liberalisation, world-class manufacture and globalisation, are contributing to the reform of the economy and the automotive industry. The South African automotive industry therefore faces a major reform in trade policy. The South African government introduced the Motor Industry Development Plan (MIDP) in 1995, to create the necessary levels of competitiveness, promote worldclass manufacture practices, increase levels of investments and exports that would consequently lead to the successful reconstruction and development of this sector of the South African economy. Subsequent research has shown that the successful adoption of world-class manufacture (or lean production) processes in the South African automotive industry is necessary not only for survival, but also for increased competitiveness of the industry and the improved economic performance of automotive firms. However, complicated links exist between the adoption of world-class manufacture for improved levels of operational competitiveness. for firm-level success, on the one hand, and long-term sustainability of the industry, on the other hand. Combined firm level economic success and long-term sustainability of the industry depend on factors such as international trends, connectivity to global value chains, modern technological capabilities, lean production and enterprise systems, substantial investments, increased exports, world-wide quality standards, as well as customer satisfaction, human resource development, advanced education, skills development, worker participation, government policy and institutional support. This is borne out by a recent study of the auto component sector, utilising a lean , production 'market driver' toolkit. The study found that although component manufacturers significantly improved their operational competitiveness, they have not necessarily experienced improved economic performance levels. More important is connectedness and integration into global value chains, via intermediaries, mergers and acquisitions. The changing political economy of automotive value chains is also important in shaping fum-level operational success and industry sustainability.
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Florêncio, Marcelo Akyama. "A responsabilidade pelo produto do proprietário da marca sob a perspectiva do Código de Defesa do Consumidor." Pontifícia Universidade Católica de São Paulo, 2012. https://tede2.pucsp.br/handle/handle/5998.
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Previous issue date: 2012-10-22The objective of this work is to describe potential and limits of a product liability for trademark owner and licensor. Research starts with exposure of business history and formation of consumer society in order to contextualize the consumer law and product liability. It examined the evolution of doctrine of product liability and implied warranties that served as a reference to Directive 85/374/EEC and liability set out in Consumer Protection Code of Brazil. Remains on investigate a trademark law. This reaches conclusion trademark owner is liable by products based by reasoning in profit, increasing its goodwill in their capacity to withstand the damages distributions in the price, in fact that is more accessible to consumers, and ensuring product quality in case of problems that compromise the intended purpose
O objetivo deste trabalho é delinear as potencialidades e os limites de uma responsabilidade pelo produto do titular da marca ou quem com ele se assimile. Inicia-se a pesquisa pela exposição da evolução da organização dos meios de produção e da formação da sociedade consumo de forma contextualizar o direito do consumidor e a responsabilidade pelo produto. Em seguida explora-se o conhecimento do direito do consumidor, da consolidação da doutrina do strict product liability e das implied warranties como modelos jurídicos que serviram de referência para a Diretiva da CEE 85/374 e para o sistema de responsabilidade previsto no nosso Código de Defesa do Consumidor. Continua-se a exposição da evolução da organização dos meios de produção, com o objetivo de evidenciar a marca e em seguida investigar a doutrina jurídica marcária. Percorrido esse caminho científica alcança-se a conclusão de que o proprietário da marca ou quem com ele se assimile responde pelos produtos em raciocínio lastreado no proveito econômico tirado por este sujeito quando a marca lhe valoriza o seu estabelecimento comercial por meio do aumento do seu goodwill, na sua condição econômica de suportar a dano, de diluí-lo no preço, no fato de que é o sujeito mais acessível ao consumidor no caso de danos e porque se enquadra no conceito de fornecedor e integra a cadeia de fornecimento, no caso de problemas que comprometem a finalidade do produto ou lhe diminua o seu valor
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Ariaeipour, Ali. "La responsabilité du fait des produits défectueux en droit des affaires internationales et comparé (droit européen, droit français et droit iranien)." Thesis, Lyon 3, 2012. http://www.theses.fr/2012LYO30018.
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Responsabilité du fait du produit c’est le nom, donné à un domaine de droit concernant la responsabilité des personnes qui s’occupent à fabriquer et vendre ou distribuer par d’autres moyens des produits pour les différents sorts des dommages causés aux consommateurs et même aux tierces personnes par les défauts de sécurité de ces produits. Cette responsabilité est une responsabilité sans faute qui va au-delà distinction traditionnelle entre la responsabilité contractuelle ou extra-contractuelle. Il existe différents modèles de la responsabilité du fait des produits défectueux dans le monde. Parmi eux le droit américain et le droit européen de la responsabilité du fait des produits sont particulièrement significatifs. Aux Etats-Unis la section 402A de la seconde restatement of torts déterminait le régime de la responsabilité du fait des produits. En 1998 l’institut de droit américain a publié la troisième restatement of torts sous le nom de la responsabilité du fait des produits, ce qui est censé de remplacer la section 402A de la seconde restatement of torts. En Europe, la directive communautaire numéro (85/374/CEE) du conseil du 25 juillet 1985 relative au rapprochement des dispositions législatives, réglementaires et administratives des États membres en matière de responsabilité du fait des produits défectueux constitue le droit spécial des états membres en matière de la responsabilité du fait des produits défectueux. Cette directive a été transposée en droit français par la loi du 19 mai 1998 sous la forme des articles 1386-1 à 1386-18 du code civil français. La faute constitue la seule base légale de la responsabilité civile des vendeurs et des fabricants des produits défectueux en droit iranien. Pour résoudre les conflits de lois et des juridictions qui résultent de l’exportation de produits au niveau international on peut mettre œuvre les conventions et les règlements internationales qui ont été élaborées en la matière ainsi que le droit commun des conflits des lois et des juridictions des paysProducts liability is the name of a field of law concerning the liability of persons who are engaged in the business of selling or otherwise distributing products who sell or distribute a defective product for harm to persons or property caused by the defect. They are strictly liable. Their liability is a kind of liability which goes beyond the traditional distinction between the contractual and tortious liability. The United-States of America and European Union have the most developed products liability laws in the world. In the United-States the American Law Institute memorialized precedential rule of strict products liability in tort in §402A of the Second Restatement of Torts, and officially promulgated it in 1965. In 1992, the American Law Institute began working on a new Restatement (Third) of Torts on the specific topic of products liability law, approving the new Restatement in 1997 and publishing it in 1998 as The Restatement (Third) of Torts: Products Liability. In Europe, Council Directive of 25 July 1985 on the approximation of the laws, regulations and administrative provisions of the Member States concerning liability for defective products (85/374/EEC) constitutes specific law of products liability of European Union member states. This directive has been transposed in French law by 19 May 1998 act and formed articles 1386-1 to 1386-18 of civil code. Fault is the only legal basis of Iranian products liability law. For solving conflicts of laws and jurisdictions which arise from international trade of products and determining the applicable law and competent jurisdiction we can implement international conventions and regulations which have been elaborated on this subject as well as traditional rules of conflicts of laws and jurisdictions of the countries
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Chen, Jyh-Chyang, and 陳志強. "Image processing technology applied in checking defects of PLED manufacture." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/93634474187013505348.
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碩士國立中央大學
資訊工程學系碩士在職專班
91
Abstract Ink Jet Printing technology is applied to the manufacturing of substrate of PLED (Polymer Light-Emitting Diode). Compared with the traditional spinning method, the Ink Jet Printing technology can make the huge area, full-color PLED display with lower cost and faster speed. In order to achieve high yield and high throughput of PLED, the defect detection of substrate is very important. After the ink is printed on the substrate, the defects on the substrate can be detected with the vision method. First, the image of the PF (Polyfluoren) solution coated on the substrate is captured with a CCD camera. Secondly, the image is processed offline to find out the defects such as drop-out, half empty cell and empty cell, over-printed. In this research, image processing technology such as bi-level thresholding, particle filtering and analysis, image enhancement, spatial filter and morphology are adapted to checking the detects. Mask image is also produced to detect these defects in the different procedures. LabVIEW IMAQ Vision Builder 6.0 is the tool for analysis.
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Chang, Tzu-Fang, and 張慈芳. "The Judgment on Defects and Claims on Manufacturer Liability in Product Liability Cases." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/70497721814562549612.
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碩士雲林科技大學
應用外語系碩士班
97
With the convenient invention and rapid changing of technical products for a better life, it might go with some potential dangers and disadvantages which may cause personal injury or damages. Customers are usually the disadvantaged minority in purchasing and easily to be ignored or even have difficulties to hold the responsibilities in a lawsuit due to the insufficiency in professional knowledge of product liability law. In addition, many enterprises export products to other countries and with high trading rate, it also arise the importance of product liability concept. More product liability litigations are stress on the awareness of consumers, especially under the free-trading business environment all over the world. As the injured party (the plaintiff) is the minority in the lawsuit during the past decades, consumer protection is not merely a slogan but there are established articles in the Civil Code (Part two Obligation) and Consumer Protection Law in Taiwan to restrain the product manufacturers and secure the consumers. According to the U.S.A Law, the Uniform Commercial Code (U.C.C.) and Common Law have statutes to govern manufacturers/distributors in product liability. The article two (Sale of Goods) of U.C.C. and the Restatement (Second) of Torts § 402A are the major statutes of product liability law. The review of three typical product liability cases in the research could help plaintiffs as well as consumers, who are usually the minority party in litigation, as a guide to have a better understanding how to hold the responsibilities to manufacturers and who should be responsible if a defective product causes personal injury or damage.
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Wang, Shih-Hao, and 王士豪. "Defect Formation and Anisotropy in Microstructure of Additive Manufactured Ti-6Al-4V Alloy." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7tswkx.
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碩士國立臺北科技大學
材料科學與工程研究所
105
Additive Manufacturing (AM) is a technique from traditional printing to fabrication of sloid materials. Selective Laser Melting (SLM) is the dominant AM process for metallic materials to date. However, nearly disc-shaped building defect and microstructural anisotropy in the AM metallic materials have been extensively found. The objective of this study was to investigate the generation cause of building defect in SLM Ti-6Al-4V alloy. Moreover, the influences of heat treatment on the microstructural anisotropy was also studied and discussed. The results show that at a given laser power (150 W, 225 W, and 300 W), decreasing the scanning velocity from 658 mm/s to 329 mm/s can lower the porosity. Increasing the laser power from 150 W to 300 W decreases the porosity at a given scanning velocity. However, the effect of scanning velocity is more obvious than that of laser power. Furthermore, raising laser power density from 28 J/mm3 to 152 J/mm3 can decrease the porosity from 1.61 vol% to 0.03 vol%. Building defects whose size is larger than 100 μm can be clearly observed in the specimens manufactured with various SLM parameters. According to the observations on the sample surface and fracture surface, these previous defects are generated due to the balling effect during SLM process. This phenomenon leads to the nearly disc-shaped defects in the SLM specimens. For the microstructural anisotropy, the EBSD results indicate that after 750 °C, 850 °C, 950 °C heat treatments, clear {112 ̅0} preferred orientation is found along the SLM building direction. {0001} preferred orientation can also be observed. Moreover, the columnar grains coarsen with the increase in the heat treatment temperature. After 1050˚C heat treatment, the columnar grains are totally transform into equiaxed grains, and the crystal orientation is more random.
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Nevliudov, I., O. Chala, I. Botsman, O. Klymenko, and M. Vzhesnievskyi. "Automation of Mathematical Modeling of Physical and Technological Processes in the Electronic Devices Manufacture." Thesis, 2021. https://openarchive.nure.ua/handle/document/17949.
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The variant of automation of the mathematical modeling process for forecasting the technological process
parameters of manufacturing nano and microelectromechanical systems is proposed in the paper. For this task realization, a number of defects were identified and the causes of their occurrence were analyzed, as well as physical and technological transformations that occur in the substrates during technological processes. The software for automation of technological parameters forecasting process is developed and described.
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Hunag, Po-Kai, and 黃柏凱. "Using UV curable liquid crystal to manufacture the optical film and study the defect in the manufacturing process." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/68128803820001561911.
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碩士元智大學
化學工程學系
93
A special 2-domain defect was found using UV-curable liquid crystal to manufacture optical film. We changed rubbing parameters to study how the defect.was induced. In the preparation of the UV curable liquid crystal, we found that 2-domain defect would appear for two conditions, one is the anchoring energy(A/K22)<7.6μm-1 under higher pretilt angle(<2.76∘) and the other is anchoring energy(A/K22)<12μm-1 at low pretilt(< 1.5∘). The change of the angle between directional axis of the liquid crystal molecule and extended axis of polarizer could form the optical texture. This optical texture was simulated by the disclination line of liquid crystal molecules. Finally, the optical film with the retardation 142nm±20nm was manufactured using Al3046 alignment film and UV-curable liquid crystal .The optical film could be applied as a compensating film or wide-view film.
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Fournier-Gendron, Hugo. "Sécurité informationnelle des systèmes cyberphysiques et risques à la santé et sécurité : quelle responsabilité pour le fabricant ?" Thèse, 2017. http://hdl.handle.net/1866/21353.
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