Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 144-148).

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 133-142). Available also in a digital version from Dissertation Abstracts.

Title from title page (viewed April 28, 2010) Graduate School of Engineering. Dept. of Mechanical and Industrial Engineering. Includes bibliographical references.

QC 351 A7 no. 03 / The problems connected with the utilization of large high -resolution telescopes are concentrated into two principal areas. The first concerns the physical properties of the mirror disc; the second involves the pro- cessing of the mirror in the optical shop. This technical report concerns, 1) the design of a new type of opti- cal polisher, one with a stationary mirror platform, and, 2) the casting of large discs made up of a new type of glass. This new glass, designated type RZ by Owens -Illinois, has a zero coefficient of thermal expansion at 25° Centigrade. A proposal for research in these two areas has already been made. This research has been supported, in part, under Contract ONR -2173- (12) by the Advanced Research Projects Agency and administered by the Office of Naval Research.

Orientador: Eduardo Carlos Bianchi / Banca: Gilberto de Magalhães Bento Gonçalves / Banca: Luciana Montanari / Resumo: Uma técnica utilizada para substituir o método de lubri-refrigeração convencional é a mínima quantidade de lubrificante (MQL). Este método utiliza de uma mistura de óleo e ar à elevada pressão, reduzindo a quantidade de fluído de corte necessário para a usinagem. Entretanto, em diversos estudos feitos na área de retificação com MQL, nota-se que há a necessidade de aperfeiçoamento dessa técnica com relação à limpeza da zona de corte do rebolo. Devido à dificuldade do baixo fluxo de fluído, em remover os resíduos superficiais acumulados, cavados aderem à superfície da ferramenta abrasiva, preenchendo os poros do rebolo e prejudicando o processo. Sendo assim este trabalho busca promover uma técnica de limpeza para o rebolo do tipo CBN, na retificação cilíndrica de aço ABNT4340 temperado e revenido, com a utilização de MQL. Através de um dispositivo, foi colocado em contato na superfície periférica do rebolo, bastões retangulares compostos dos materiais: Teflon, Óxido de alumínio e Carbeto de silício. As variáveis de saída do processo analisadas foram o comportamento da força tangencial de corte, rugosidade, emissão acústica, relação G (volume de material removido/volume do rebolo desgastado), fotos em microscópio eletrônico de varredura, microdureza e circularidade. O método MQL com o dispositivo, foi comparado com as seguintes condições de lubri-refrigeração: Convencional; MQL sem limpeza com local de ar. Com base nos resultados obtidos, o método de limpeza utilizando o dispositivo juntamente com o bastão de carbeto de silicone, comprovou em algumas condições a obtenção de melhores resultados e ausência de danos térmicos, se comparado aos outros métodos / Abstract: A technique used to replace the method of conventional lubrification and cooling is the minimum quantity lubricant (MQL). This method uses a mixture of oil and air to the high pressure, reducing the amount of fluid required for machining. However, in various studies in the field of grinding with MQL, it is noted that there is a need for improvement of this techique with respect to cleaning the cutting zone of the wheel. Due to the difficulty of low fluid flow, to remove the accumulated surface residue, chips adhere to the surface of the abrasive tool, filling the pores of the wheel and impairing the process. Thus, this work seeks to promote a clening technique for the type CBN wheel, the grinding cylindrical AISI 4340 steel hardened and tempered, with the use of MQL. Through a device was placed in contact on the peripheral surface of the grinding wheel, rectangular rods compounds materials: Teflon, aluminum oxide and silicon carbide. The output variables of the process were analyzed the behavior of the tangential cutting force, surface roughness, acoustic emission, G ratio (volume of material removed/volume of wheel worn), in photos scanning electron microscope, hardness and roundness. The method MQL with the device was compared with the followin conditions of lubrication and cooling: Conventional; MQL without cleaning; MQL and cleaning air nozzle. Based on the results obtained, the cleaning method using the device with the bat silicon carbide, proved in some conditions to obtain better results and no thermal damage, compared to other methods / Mestre

Production of micro-scale components is an important emergent field. One underdeveloped area is the production of micro-scale 3D surfaces, which has important applications in micro-optics and fibre optic sensors. One particular application is the production of micro-lenses. With scales of less than 200 ??m these lenses can improve light coupling efficiencies in micro-optic systems. However, current lens production techniques have limitations in accuracy and versatility. Creating these surfaces through mechanical micro-grinding has the potential to improve the precision and variety of profiles that can be produced, thus improving transmission efficiencies and leading to new applications. This work presents a novel micro-grinding method for the production of microscale asymmetric, symmetric and axisymmetric curved components from brittle materials such as glasses. A specialised micro-grinding machine and machining system has been designed, constructed and successfully tested and is presented here. This system is capable of producing complex profiles directly on the tips of optical fibre workpieces. A five degree of freedom centring system is presented that can align and rotate these workpieces about a precision axis, enabling axisymmetric grinding. A machine vision system, utilising a microscope lens system and sub-pixel localisation techniques, is used to provide feedback for the process, image processing techniques are presented which are shown to have a sensing resolution of 300 nm. Using these systems, workpieces are centred to within 500 nm. Tools are mounted on nanometre precise motion stages and motion and infeed are controlled. Tooling configurations with flat and tangential grinding surfaces are presented along with control and path generation algorithms. The capabilities and shortcomings of each are presented along with methods to predict appropriate feed rates based on experimental data. Both asymmetric and axisymmetric flat and curved micro-profiles have been produced on the tips of optical fibres using this system. These are presented and analysed and show that the system, as described, is capable of producing high quality micro-scale components with submicron dimensional accuracy and nanometric surface quality. The advantages of this technique are compared with other processes and discussed. Further development of the system and technique are also considered.

No description available.

No description available.

No description available.

No description available.