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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Behavior of cutting tool coating material Ti1-xAlxN at high pressure and high temperature / Faser i Ti1-xAlxN-ytbeläggningar vid högt tryck och hög temperatur

Dilner, David January 2009 (has links)
The high pressure and high temperature (HPHT) behavior of Ti1-xAlxN coatings on cutting tool inserts have been of interest for this diploma work. A literature study of HPHT techniques as well as measurement methods has been done. A diamond anvil cell (DAC) would be a good device to achieve high pressure and high temperature conditions on small samples. Another way to obtain these conditions would be a cutting test, which has been performed on a Ti1-xAlxN coated cutting tool insert with x = 0.67. Also a cubic press could be used to apply HPHT on a     Ti1-xAlxN sample or a large volume press on a whole cutting tool insert. To measure hardness on thin coatings a nanoindentor could be used, which have been done on heat-treated Ti0.33Al0.67N and TiN samples. X-ray diffraction (XRD) is a suitable method to measure phase composition of a sample and was performed on the cutting tested insert as well as on an untreated reference insert. Three ways to continue this project have been outlined all starting with more comprehensive cutting tests.
102

Process and machine improvements and process condition monitoring for a deep-hole internal milling machine

Wilmot, Wessley January 2017 (has links)
Milling is a widely used cutting process, most commonly applied to machining external surfaces of workpieces. When machining operations are required within hard to reach areas of components, or deep within the bore of components, alternative methods of metal removal are generally employed. Typically when milling at extended reaches, difficulties may increase exponentially when trying to achieve distances several meters into a component. Essentially every topic of the milling process becomes difficult and more convoluted. Firstly to generate a stable cutting condition, and ultimately for an operator to be able to understand the cutting conditions, when all normal senses to interpret the machining stability are removed. The aim for the research is, to enable the operation of high slenderness ratio internal milling operations to become a viable technology, by detailing the measures required, to obtain a stable cutting condition. The process needs to be monitored for degradation of the tooling due to wear, and to prevent catastrophic machine damage from tool breakage or machine component failure. This research addresses the lack of knowledge available for milling with extended reaches, and the knowledge gained to overcome the real difficulties that exist for this process. Initial experiments are conducted on a prototype machine to gain experience of the internal machining operation and the many issues that it faced. Establishing requirements of the process via investigation of the tooling and necessary auxiliary equipment, it becomes possible to consider countermeasures to address the errors generated by torsional twisting of the milling arm. A system for applying a counter torque to reduce torsional deflection errors has been employed to successfully reduce the unavoidable issue over such long distances. For the process to become manageable for an industrial operator without a high level of specialist knowledge, the application of tool condition monitoring (TCM) and process condition monitoring (PCM) had to be applied. This addresses a void in available literature and research with respect to internal machining, and enables the process to become practical for an industrial environment. For this reason the research project will concentrate on the application of TCM and PCM onto the machining system. The completion of the research resulted in the process becoming satisfyingly stable, and with a resulting accuracy that satisfies the requirements of the component. Performance of the final system rivalled or achieved better results than had been experienced by the project sponsor.
103

Compósitos de alumina com adições de NbC, TaC e TiC para aplicação em ferramentas de corte / Alumina composites with additions of NbC, TaC and TiC for application in cutting tools

TONELLO, KAROLINA P. dos S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:36:00Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:33Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
104

Compósitos de alumina com adições de NbC, TaC e TiC para aplicação em ferramentas de corte / Alumina composites with additions of NbC, TaC and TiC for application in cutting tools

TONELLO, KAROLINA P. dos S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:36:00Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:33Z (GMT). No. of bitstreams: 0 / No presente trabalho foram desenvolvidos compósitos à base de alumina, com adição de carbetos de metais de transição, NbC, TaC e TiC, como reforço. Os carbetos, na forma de partículas, foram adicionados em 1,5% em volume à matriz de alumina durante a moagem em attritor. O processamento foi realizado por moagem em attritor, secagem em rotoevaporadora e desaglomeração em peneira. A dinâmica de oxidação dos carbetos e das composições dos compósitos foi estudada para a definição de parâmetros de sinterização e processamento dos compósitos. A cinética de sinterização foi estudada por dilatometria, com taxa de 10°C/min. até 1600°C em atmosfera de ar sintético, e até 1800°C, em atmosfera de argônio, com esta etapa foi possível verificar que o NbC e o TiC dificultaram a sinterização da alumina e que o TaC auxiliou nos processos de retração. Nas amostras que foram sinterizadas em dilatômetro ao ar foram detectadas fases resultantes de fusão congruente nos compósitos Al2O3/NbC e Al2O3/TaC, foram também observadas evidências de formação de líquido no compósito com adição de TaC. Com base nesses resultados foram estudadas duas técnicas de produção das ferramentas de corte: prensagem uniaxial seguida de sinterização sem pressão e sinterização por prensagem a quente. Todas as amostras foram caracterizadas microestruturalmente e quanto às propriedades mecânicas, tendo-se determinado que as amostras produzidas por prensagem a quente possuem microestrutura mais controlada e propriedades mecânicas superiores às produzidas por sinterização sem pressão. Pelos processos estudados foi observado que os carbetos influenciam diferentemente a sinterização da alumina. De maneira geral a presença destas fases nos contornos de grãos promove alterações na microestrutura modificando o tamanho de grãos da alumina. Foi proposta a hipótese de que esse comportamento é afetado pela formação de uma camada superficial resultante da oxidação dos reforços, com isto, de acordo com os diagramas de fase é possível a formação de soluções sólidas entre alumina e Ta2O5 e Nb2O5 além da formação de fase líquida, estes mecanismos alterariam a mobilidade dos contornos de grão da alumina. Para o processamento das ferramentas de corte foi utilizada prensagem a quente, escolhido pelo critério da microestrutura e propriedades mecânicas. Os testes de usinagem foram realizados com ferramentas de corte de geometria quadrada, em peças de ferro fundido cinzento e vermicular. O tempo de vida útil da ferramenta produzida com o compósito Al2O3/ NbC foi 13% superior quando comparado à uma ferramenta cerâmica comercial no teste de usinagem de ferro fundido cinzento. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
105

Obrábění rotační součásti "těleso" na CNC soustruhu / Machining of rotating Body-part on CNC lathe

Dlouhý, Vít January 2020 (has links)
This master's thesis is focused on the technology fundamentals of machining for the use of the CNC lathe which was used for machining the required parts are made of stainless steel. In the introduction are mentioned the historical milestones related to machine tools. In the following chapter is analyzed machining process and related fact. A follow-up chapter contains the parameters common to a modern machine tool CNC machines. Followed by the practical part with the characteristics of the machined components. The next chapter includes a selection of CNC lathe for production. Continued by selecting the appropriate cutting tool and adjusting the machine for the given component. They were applied a total of three variants of production with the subsequent evaluation. In conclusion, it became established fact, for example, the advantages of the shape tools or the use of more spindles during the machining.
106

Marketingový audit vybrané společnosti / Marketing Audit of a Company

Ermolin, Daniil January 2021 (has links)
The master‘s thesis deals with marketing auditing of company Tungaloy Rus with a special focus on its employees’ satisfaction. The theoretical part of the thesis defines the meaning and importance of marketing audit, as well as the concept of employees’ satisfaction and modern approaches to its measurement. The analytical part of the thesis focuses on performing the marketing audit of company Tungaloy Rus and surveying the satisfaction of its employees. The proposal part of the thesis aims to making a set of recommendations based on the results of the marketing audit and the satisfaction research, which leads to improving the company's marketing activities.
107

Trendy vývoje obráběcích strojů / Trend development of machine tools

Šenkýř, Pavel January 2008 (has links)
This diploma thesis deals with trends of the development of machine tools, and focuses on technologies and machine tools for manufacturing of pressing dies and on manufacturing of cavity of moulds. First, the existing state in the field of these technologies is described and defined, and subsequently, the dissertation concentrates on modern conceptions of this manufacturing.
108

Morfologie vad a opotřebení povlakovaných řezných nástrojů / Morphology of defects and wear of coated cutting tools

Forejt, Miloslav January 2008 (has links)
The thesis focuses on the morphology of defects and cause of wear in coat cutting tools, the description of the chip formation and its effects on the machined area. The experiment drala with the description of the chip form in connection with the cutting properties, type of tools, wear in removable parting cutting tips and the comparison of cutting tips from two leading manufacturers.
109

Optimalizace technologie součásti "nosná deska" ve firmě PROMAT Vsetín / Optimalization technology of production "nosná deska"-part in condition firm PROMAT Vsetín

Juráň, Jaromír January 2008 (has links)
Valorization and analysis of machining technology for the production of aluminium part and consecutively project optimization part production. New advanced cutting tools selection and application of new technologies. The adjustment and simplification of the existing NC program for given CNC machining centre and its final debugging. In the final part, there is an economical and technical evaluation of firm benefits and recommendations into production.
110

Technologie obrábění tvrdých materiálů nástroji s definovanou geometrií břitu / Hard machining with defined geometry edge tools

Bukáček, Zdeněk January 2009 (has links)
This master’s thesis is concerned with subject matter hard machining with defined geometry edge tools. Aim master’s thesis is analysis and parameters evaluation machined surface at hard machining. This master’s thesis contain a characteristic of hard materials, used technology for cutting operation, but also tools and cutting conditions suitable for hard machining. In the conclusion are parameters evaluation machined surface the workpiece.

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