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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 13 of 13 for “"Surface hardening"”.
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Controlled Surface Layer Deposition for Steel Surface Hardening
… and 5% H2-N2 (nitridation), were used for surface hardening. The coarse Ti particles (≤50 μm) were suspended in ethanol using the charging agent poly(diallyldimethylammonium chloride) (PDADMAC). EPD: The present work demonstrated the importance of assessing the electrophoretic mobilities of …
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Influence of surface hardening on single crystal nickel-based superalloys
… thesis is concerned with the influence of two surface hardening procedures, mechanical shot peening (MSP) and deep cold rolling (DCR), on the microstructures of single crystal nickel-based superalloys. These alloys have excellent high temperature properties, and consist of a randomly …
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Effect of surface hardening conditions on susceptibility of fasteners to hydrogen embrittlement
… testing, microstructure review, and fracture surface examination allows the determination of susceptibility thresholds. It is shown that core hardness is the primary consideration for susceptibility. However, the fastener surface is prone to failure before the bulk section, up to the case …
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Optimisation of the oxygen diffusion process for surface hardening of the Ti-6A1-4V alloy
A well established method of surface hardening for titanium alloys is through solid solution strengthening by alloying with oxygen. This is achieved through a two step oxygen boost diffusion hardening (OBDH) process. During the oxidation step, the formation of a thick adherent rutile TiO2 layer …
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Development of a plasma source ion implantation facility for the modification of materials' surfaces
… ions are implanted into materials to modify surface properties, achieving surface hardening, increased wear and corrosion resistance. Plasma Source Ion Implantation is alos used for doping semiconductors and could form an essential step in the manufacture of multilayered wafers. This thesis …
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In Vitro Study Comparing Treatments for Incipient Enamel Lesion Remineralization
… Fluoride (SDF; Advantage Arrest™) on enamel surfaces affected by incipient caries lesions. Methods: Caries-free permanent teeth, extracted for orthodontic or surgical purposes, were obtained from the Pediatric Dentistry Department at UIC College of Dentistry. Enamel samples (4 mm x 5 mm) were …
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Multi-component boron coatings on low carbon steel AISI 1018
Boronizing and metalizing are thermo-chemical surface hardening treatments in which boron and metal atoms diffuse into the metal substrate forming metallic boride layers, providing complex properties of B-Me-Fe system. To study multi-component boron coatings on low carbon steel AISI 1018, the …
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Laser surface modification of steel
… presented work is an investigation of the laser surface modification of H13 tool steel using pulse laser processing mode. Initial screening experimental designs conducted lead to more optimised detailed designs. A carbon dioxide (CO2) laser system with 10.6 μm wavelength was used. In the …
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Memory efficient approaches of second order for optimal control problems
… of the optimal control problem of laser surface hardening and other optimal control problems.
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Development of quantitative techniques for the study of discharge events during plasma electrolytic oxidation processes
Plasma electrolytic oxidation, or PEO, is a surface modification process for the production of ceramic oxide coatings upon substrates of metals such as aluminium, magnesium and titanium. Two methodologies for the quantitative study of electrical breakdown (discharge) events observed during plasma …
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Wear of fine pearlite, nanostructured bainite and martensite
… mechanisms change, for example from severe sub-surface deformation leading to sticking in the case of pearlite, to brittle detachment of material in the martensitic state. The nanostructured bainite, on the other hand, undergoes reaustenitisation at the surface that leads to the formation of a …
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Effects of Laser Shock Peening on Residual Stress, Texture and Deformation Microstructure of Ti-6Al-4V Alloy
Laser shock peening (LSP) is a novel surface treatment process that generates deep compressive residual stresses and microstructural changes and thereby dramatically improves fatigue strength of critical metal aircraft engine parts. In the past, researchers have evaluated the mechanical effects of …
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Ανάπτυξη μεθοδολογίας υπολογισμού της κατανομής και του βάθους διείσδυσης σκλήρυνσης λόγω διεργασίας σκλήρυνσης μέσω λείανσης (grind - hardening)
… έχει υποστεί Σκλήρυνση μέσω Λείανσης (Grind-Hardening). Η διεργασία Σκλήρυνσης μέσω Λείανσης είναι μία νέα επιφανειακή θερμική κατεργασία η οποία χρησιμοποιεί την θερμότητα που αναπτύσσεται στην ζώνη λείανσης για την θερμική κατεργασία του κομματιού. Η παρούσα διατριβή επικεντρώνεται στην …