Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 134-139). Also available on the Internet.

Thesis (Ph. D.)--McMaster University, 2003. / Advisor: Mohamed Elbestawi. Also available via World Wide Web.

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2006. / Paul Griffin, Committee Member ; Hamid Garmestani, Committee Member ; Thomas Kurfess, Committee Member ; Steven Liang, Committee Member ; Shreyes Melkote, Committee Chair.

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2006. / Dr. Richard F. Salant, Committee Member ; Dr. Shreyes N. Melkote, Committee Member ; Dr. Francis M. Kolarits, Committee Member ; Dr. Jane C. Ammons, Committee Member ; Dr. Thomas R. Kurfess, Committee Chair.

Thesis (M.S.)--Ohio University, June, 2002. / Title from PDF t.p. Includes bibliographical references (leaves 136-137)

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: South Africa holds the second largest share of the world’s titanium mineral deposits. However, there is no capacity for the development of titanium metal, mill products or components. It is at these stages of development that most of the value is added. For this reason, the Department of Science and Technology (DST) has been undertaking a research-led industrialisation initiative. The aim of this initiative is to establish a titanium industry strategy within South Africa. This research comes at a time when the demand for titanium, particularly from the commercial aerospace and biomedical sectors is growing rapidly. A South African industrial strategy framework has been developed by the DST to deliver titanium related competencies across the entire titanium value chain. One of the key building blocks within the strategy framework is targeted at the machining of titanium metal. This is a core competence required for the manufacture of finished titanium products. This research is fully aligned with the Advanced Manufacturing Technology Strategy (AMTS) and its objective of improving industry competitiveness via the development of advanced manufacturing technologies, as well as to the objectives of the Titanium Centre of Competence (TiCoC), whose mission is to develop and commercialise the technology building blocks required for the establishment of a titanium industry in South Africa. In order to implement the titanium industry strategy successfully in South Africa, all research being conducted in this field needs to be transferred to industry as well as protected. This is the focus of this thesis and is achieved through the development of technology transfer (TT) strategy as well as an intellectual property (IP) strategy for titanium machining. Without a TT strategy, the technological developments which are made might not be successfully implemented into industry as intended. An IP strategy is equally as important as, without one, entire research and development projects can be lost to those seeking to take advantage of incorrectly protected IP. To develop the TT and IP strategies, substantial information on the basics of these fields was considered. Titanium machining relevant information, such as contract details, industrial partnerships as well as the level of development which the research had achieved upon starting this study was also considered. Together this information created a solid foundation for decision making with regards to how both IP and TT should be handled for the titanium machining research initiative. Each new technology developed, along with its respective IP needs to be considered individually, as the scenarios for both its protection and transfer into industry will be in some way unique. As such, the strategies developed within this report attempt to provide a general outline for the decision making process for any situation which might arise. Ultimately both strategies are represented within this thesis. In order to take the research presented in this thesis further, the development of an IP portfolio is suggested allowing for decisions to be made with regards to technology specific IP outputs. For the technology transfer further implementation of tests for validation purposes at the industrial partners is recommended, in order to begin to develop an understanding of their environments and capabilities. / AFRIKAANSE OPSOMMING: Suid-Afrika beskik oor die wereld se tweede grootste titaaan mineraalafsetting, maar daar is geen kapasiteit vir die ontwikkeling van titaan metaal, milj produkte of komponente nie. Dit is op hierdie stadium van ontwikkeling waar die meeste waarde toegevoeg word. Om hierdie rede is die Departement van Wetenskap en Tegnologie (DWT) besig met ‘n navorsingsgedrewe industrialisering inisiatief. Die doel van hierdie inisiatief is om 'n titaan bedryfstrategie in Suid-Afrika te vestig. Hierdie navorsing vind plaas op ‘n tydstip waar die vraag na titaan, veral vanuit die kommersiële ruimte- en biomediese sektore, vinnig groei. 'n Suid-Afrikaanse industriële strategie raamwerk is ontwikkel deur die DWT om titaan verwante vaardighede te lewer oor die hele titaan waardeketting. Een van die belangrikste boustene binne die strategiese raamwerk is gemik op die bewerking van titaan metaal. Dit is die kernbevoegdheid wat benodig word vir die vervaardiging van voltooide titaan produkte. Hierdie navorsing is ten volle belyn met die “Advanced Manufacturing Technology Strategy” (AMTS) en sy doelwit van verbetering van die bedryfsmededingendheid via die ontwikkeling van gevorderde vervaardigingstegnologie, asook die doelwitte van die “Titanium Centre of Comptetence” (TiCoC), wie se missie dit is om die tegnologiese boustene wat nodig is vir die vestiging van 'n titaan bedryf in Suid-Afrika te ontwikkel en te komersialiseer. Ten einde die titaan bedryf strategie suksesvol in Suid-Afrika te implementeer, moet alle navorsing in hierdie veld beskerm word en daarna na die bedryf oorgeplaas word. Dit is dan die fokus van hierdie tesis, wat bereik word deur die ontwikkeling van ‘n IP strategie asook ‘n tegnologie oordragstrategie vir titaan masjinering. Sonder die nodige intellektuele eiendom (IP) beskermingstrategie, kan hele navorsing- en ontwikkeling projekte verloor word deur diegene wat voordeel wil trek uit IP wat nie korrek beskerm is nie. ‘n Tegnologie oordragstrategie is ewe belangrik aangesien, in die afwesigheid hiervan, die ontwikkelings wat gemaak word, dalk nie suksesvol geïmplementeer sal word in industrie soos bedoel nie. Om die IP strategie te ontwikkel, is omvattende inligting oor die basiese beginsels van IP beskerming en bestuur oorweeg. Tersaaklike inligting oor titaan verwerking soos, kontrak besonderhede, industriele venootskappe asook die vlak van ontwikkeling wat die navorsing alreeds bereik het met die aanvang van hierdie studie, is in ag geneem. Saam het hierdie inligting ‘n stewige fondament geskep vir besluitneming ten opsigte van die toepassing en die hantering van beide IP asook die oordrag van tegnologie in die titaanverwerking navorsings inisiatief. Elke nuwe tegnologie wat ontwikkel word, tesame met die betrokke IP benodighede, moet individueel oorweeg word, aangesien die scenario vir beide die IP beskerming en oordrag van die tegnologie na industrie unieke aspekte sal hê. As sodanig poog die strategie wat ontwikkel is binne hierdie verslag, 'n algemene raamwerk te bied vir die besluitnemingsproses vir enige situasie wat mag ontstaan. Beide strategieë is in hierdie tesis aangespreek. Die rigting vir toekomstige werk dui daarop dat ‘n IP portfolio saamgestel moet word wat voorsiening maak vir tegnologies-spesefieke besluite ten opsigte van IP uitsette. Ten opsigte van tegnologie oordrag, word verder aanbeveel dat toetse vir die validasie by venote in industrie ingestel word, ten einde begrip te ontwikkel vir hulle omgewings en vermoëns.

This document shows the method used to develop an innovative machining process used for manufacturing of a threaded tube.

Orientador: Manoel Cleber de Sampaio Alves / Banca: Marcos Valério Ribeiro / Banca: Ana Lúcia Piedade Sodero Martins Pincelli / Banca: Ivaldo Domênico Valarelli / Banca: José Victor de Candido de Souza / Resumo: Dentre as novas tecnologias para melhorar a qualidade e o uso da madeira, encontra-se o tratamento térmico. Temperaturas de 120 a 200˚C são aplicadas a madeira provocando transformações químicas e físicas alterando suas propriedades. Há muitas pesquisas relacionadas a esse tipo de tratamento, porém poucos trabalhos se dedicam especificamente a usinagem dessa madeira tratada. Neste trabalho é apresentado e avaliado um dos processos mais utilizados na indústria madeireira, o processo de fresamento periférico e frontal, com a influência do tratamento térmico nas madeiras de Pinus elliottii e Corymbia citriodora. O objetivo principal foi conhecer a influência desse tratamento no processo de fresamento analisando os parâmetros: rugosidade média, potência consumida, vibração, emissão sonora, temperatura de corte e imagens dos cavacos. As temperaturas usadas no tratamento térmico foram de 120, 140, 160, 180 e 200˚C durante cinco horas em condições normais do ambiente. Para a usinagem foi utilizada uma fresadora CNC, fresa de metal duro com recobrimento de nitreto de titânio-alumínio e 6 arestas de corte. Foram realizados três tipos de corte: fresamento periférico concordante e discordante, e fresamento frontal. Os ensaios foram realizados seguindo um delineamento fatorial de combinações. A qualidade superficial piorou com o aumento da temperatura de termorretificação, comparada as amostras testemunhas. O consumo de potência diminuiu com o aumento da temperatura de tratamento e o Pinus elliottii consumiu menor potência. A espécie de Corymbia citriodora provocou maior temperatura de corte na ferramenta e o corte discordante o menor valor. O corte concordante proporcionou maiores valores para a variável vibração / Abstract: Among the technologies for improving the quality and the use of wood, there is heat treatment. Temperatures of 120 to 200˚C are applied to wood causing chemical and physical transformations changing its properties. There are many researches related to this kind of treatment, but few studies specifically dedicated to this machining treated wood. This work presents and rated one of the processes most commonly used in the wood industry, the peripheral and face milling process, with the influence of heat treatment in the woods of Pinus elliottii and Corymbia citriodora. The main objective was to understand the influence of this treatment in the machining process by analyzing the parameters: average roughness, consumed power, vibration, noise emission, cutting temperature and chip images. The temperatures used in heat treatment were 120, 140, 160, 180 and 200˚C for five hours under normal environmental conditions. For machining was used a CNC milling machine, hard metal milling with covering titanium-aluminum nitride and 6 cutting edges. There were three types of cutting: concordant and discordant peripheral milling and face milling. Assays were performed following a factorial design combination. Surface quality deteriorated with increasing treatment temperature compared to control samples. The power consumption decreased with increasing treatment temperature and Pinus elliottii consume less power. The species Corymbia citriodora caused higher cutting temperature in the tool and the dissenter cutting the lowest value. The concordant court gave higher values for the variable vibration / Doutor

Orientador: Marcos Valério Ribeiro / Banca: José Vitor Candido de Souza / Banca: Amauri Hassui / Resumo: As ligas de níquel possuem uma composição química com elevado teor de elementos de liga, os quais são responsáveis por suas propriedades mecânicas e térmicas; porém estas características dificultam demasiadamente sua usinagem, levando a ocorrência de alguns problemas durante o processo. O objetivo deste trabalho é o estudo da usinagem por torneamento cilíndrico externo da liga a base de níquel Nimonic 80A, visando a otimização da usinagem desta liga, buscando proporcionar aumentos reais de produtividade sem a necessidade de investimentos em novos meios de produção. Além disto, resultados deste trabalho devem oferecer informações mais detalhadas a respeito do comportamento desta liga em relação a usinagem por torneamento. Os ensaios de usinagem foram realizados em um corpo de prova da liga, considerando os parâmetros de usinagem: velocidade de corte (75 e 90 m/min), profundidade de usinagem (0,8 e 1,6 mm) e avanços (0,12; 0,15 e 0,18 mm/v). Os ensaios foram realizados em um torno CNC e ferramentas com pastilha de metal duro. Após cada etapa do torneamento foram realizadas as medidas do comprimento de corte, do desgaste das ferramentas (através de uma lupa (8x)) e a rugosidade das peças (avaliada em cada fase do processo), com o auxílio de um rugosímetro portátil. Por meio de microscopia óptica, foi possível observar o desgaste das ferramentas de corte para cada condição avaliada. Microscopicamente, observou-se que, apesar da grande variação do comprimento de corte para os diversos testes, o mecanismo predominante de desgaste nas ferramentas foi sempre o mesmo (abrasão no flanco). Os valores de rugosidade Ra e Ry, para as condições avaliadas foram sempre superiores aos valores teóricos. Após análise dos resultados foi possível concluir que o melhor desempenho para esta faixa de trabalho testada foi obtido para ap=0,8mm; f=0,15mm/volta e vC=75m/min, o que resultou em um maior comprimento de corte (1811 m). / Abstract: The nickel alloys have a chemical composition with high tenor of alloy elements which are responsible for your mechanical and thermal properties, however these characteristics hinder your too much machining, taking the occurrence of some problems during the process. The objective of this work is the study of the machining by external cylindrical turning of the nickel based alloy Nimonic 80A, seeking the machining optimization of this alloy looking for to provide real increases of productivity without the need of investments in new production means. Besides, the results of this work should offer more detailed information regarding the behavior of this alloy in relation to machining by turning. The machining experiences were accomplished in a specimen of the nickel alloy, considering the machining parameters: cutting speed (75 and 90 m/min), cutting depth (0,8 and 1,6 mm) and feed rate (0,12; 0,15 and 0,18 mm/v). The valuations were accomplished in a CNC lathe and tools with of hard metal inserts. After each stage of the turning the measures of the cutting length were accomplished, of the waste of the tools through a magnifying glass (8x) and the roughness of the specimen evaluated in each phase of the process, with the aid of a portable roughness meter. Through light optical microscopy it was possible to observe the wear of the cutting tools for each appraised condition. Aided by microscopy was observed that, in spite of the great variation of the cutting length for the several tests, the predominant mechanism of tool wear was always the same (abrasion in the flank). The roughness values, Ra and Ry, for the appraised conditions were always superiors to the theoretical values. After analysis of the results it was possible to end that, the best acting for this work strip tested it was obtained for ap=0,8mm: f=0,15mm/rev and VC=75m/min, what resulted in a larger cutting length (1811 m). / Mestre

A tendência da fabricação de moldes e matrizes é utilizar a tecnologia de usinagem HSM (High Speed Machining), pois esta pode produzir superfícies com melhor qualidade. Isto é possível, pois pode-se aumentar o número de passes laterais de um molde, sem que haja perdas de tempo de ciclo de usinagem, melhorando assim a qualidade do produto. No entanto, com a crescente utilização desta tecnologia, o perfil gerado de uma superfície usinada com uma fresa de ponta esférica, é alterado. Isto ocorre porque, normalmente, é possível medir-se a rugosidade em duas direções, obtendo-se em cada uma delas um valor de rugosidade máxima: um é o pico (crista) entre passes laterais e o outro é a altura de crista entre avanços por dente sucessivos. Cada um deles tem maior importância em função dos parâmetros utilizados. Estudar os fatores que alteram o perfil de rugosidade se faz, portanto, necessário. O objetivo deste trabalho é verificar experimentalmente como os parâmetros de usinagem: avanço por dente, passe lateral, diâmetro da ferramenta, ângulo de inclinação do eixo axial da ferramenta de corte e direção de corte (unidirecional ou bidirecional) influenciam o perfil de rugosidade e a rugosidade máxima, além de criar um modelo matemático que possa prever estas alterações. Foi mostrado neste trabalho que o perfil de rugosidade para corte unidirecional é diferente do corte bidirecional, e que, à medida que a relação entre avanço por aresta e passe lateral cresce, a rugosidade máxima também aumenta. Mas, ao se inclinar o eixo axial da ferramenta e aumentar o diâmetro da fresa esférica a rugosidade máxima diminui. Em resumo, este trabalho visa mostrar quais são os fatores que influenciam o acabamento de superfícies usinadas com fresas de topo esférico em condições, cuja relação entre o passe lateral e avanço por dente são típicas da HSM. / The trend in molds and dies manufacturing is the use of the HSM (High Speed Machining) technology, since it is able to produce surfaces with a better quality. This is possible because the number of radial passes, can be increased without lossing in the machining cycle times, enhancing the product quality. But with the arising utilization of this technology, the generated profile in a surface machined with a ball nose end milling cutter is changed. This happens because, it is usually possible to measure the surface roughness in two directions, getting in each of them a maximum surface roughness value: one of them is the peak to valley height between radial passes and the other one is the same parameter between successive feed per tooth. Each of them has major importance depending on the used cutting parameters. To study the factors that change the surface roughness profile is, therefore, necessary. The goal of this work is experimentally verify how the cutting parameters: feed per tooth, radial pass, tool diameter, spindle inclination angle and cutting direction (unidirectional or bidirectional) influences the surface roughness profile and the peak to valley roughness, besides of creating a mathematical model able to predict these changes. It was showed in this work that the surface roughness profile generated in a unidirectional cut is different of the profile generated in a bidirectional cut and that, as the ratio between feed per tooth and radial pass increases the same happens with the peak to valley surface roughness. But when the spindle is tilt and the ball nose cutting tool diameter is bigger the surface roughness decreases. This work aims to show which are the factors that influences the finishing of surfaces milled with ball nose end milling cutters using conditions whose ratio between the radial pass and feed per tooth are typical of HSM.