The aim of diploma thesis is a comparison of flame and fusion laser cutting of thin metal sheets for ACO Industries k. s. company, where the experimental part was also realized. After consultation with company, the thesis was extended by data samples, which were cut by compressed air for comparison with other two gases. The optimization design of cutting parameters was created by Taguchi method. Afterwards the surface roughness of samples was measured. Based on Ra and Rz5 parameters, the samples were classified to classes based on their accuracy according to ISO 9013 standard. According to results the fusion method of laser cutting is more suitable method, especially for its good quality of cutting edge, which is not affected by the oxidic layer. Fusion method uses cutting speed two times higher than the flame method, which leads to decrease of time and financial consumption of the process despite of its higher hourly rate. In case of laser cutting of material by compressed air the quality of cut is insufficient in comparison with fusion or flame cutting method.

AISI 4140 alloy steel has been a very common material to be investigated in automotive and aerospace industries for several decades. AISI 4140 alloy steel is chromium, molybdenum, and manganese containing low alloy steel. It has high fatigue strength, abrasion and impact resistance, toughness, and torsional strength. The functional performance is largely determined by the surface states after machining. The aim of the present study is to explore the polishing methods and surface analysis after machining AISI 4140 alloy steel in different cutting speeds and cooling conditions. The surface analysis includes surface roughness, hardness and residual stresses. Compared to traditional polishing, an innovative experimental work was conducted on electro-polishing technology for removing surface layer before subsurface residual stress measurement. The results of this work show that the electro-polishing method is a significant approach for the residual stress analysis. High cutting speed and cooling conditions can improve the surface quality to achieve lower surface roughness, higher microhardness and more compressive residual stresses after machining AISI 4140 alloy steel.

This diploma thesis is focused on comparison of plasma and oxygen - acetylene cutting. A literature review of this issue is included in the work. For technological - economic evaluation, there were proposed a sample part to assess how optimal the cutting process is. Observed resulst and there comparison are stated in conclusion.

O planejamento de processos é uma atividade essencial nas diversas etapas do ciclo de manufatura, em particular nas indústrias que produzem peças através de processos de usinagem. O uso de sistemas CAPP tem implicado em uma evolução nos sistemas de planejamento. A determinação da máquina, da ferramenta e das condições operacionais adequadas visando a otimização das diversas operações é fundamental para o sucesso do processo produtivo e da empresa, podendo ser melhorado pelo uso do CAPP. Estudam-se, assim, os fatores que influenciam esse tipo de processo, propondo-se um modelo de sistema protótipo para o seu planejamento, de forma a se ter no final uma especificação teórica da profundidade de corte, do avanço e da velocidade de corte, considerando aspectos como a usinabilidade do material da peça, os tempos de fabricação secundários e auxiliares, e a própria logística aplicada ao fluxo de peças no chão-de-fábrica através da definição quanto à máquina empregada ser ou não gargalo além de considerações sobre a disponibilidade de carga-máquina. Procurou-se elaborar um critério de otimização que considere não apenas o intervalo de máxima eficiência como proposto por vários autores, mas discuta a aplicação de seus limites e as restrições do sistema máquina-ferramenta-peça. Além do planejamento teórico o sistema possui um módulo de ensaios práticos visando refinar os valores teóricos da velocidade de corte adotada para garantir a sua perfeita aplicação com a máquina e a ferramenta adotados. A proposta do sistema é semi-generativa, unindo soluções algorítmicas e baseadas em conhecimento, com uma interface simples e amigável ao usuário. / Process planning is an essential activity in the several stages of the manufacturing cycle, particularly in industries which produce parts by means of machining processes. The use of CAPP systems has implied in a planning systems evolution. The determination of machine, tooling and suitable operational conditions looking at the optimization of the several operations is fundamental to the success of the productive process and of the enterprise, and can be improved by use of CAPP systems. It was studied the factors which influence this kind of process and it was proposed a prototype system model for this planning and for obtaining a theoretical specification of the depth of cut, feed and cutting speed, taking into consideration aspects like machinability of the part material, secondary and auxiliary manufacturing times, and the logistics applied to the flow of parts at the shop-floor through the definition of the used machine to be or not a production neck beyond considerations on the availability of machine capacity. It was proposed an optimization criterion which considers not only the maximum efficiency interval as quoted by many authors but also discuss the application of its limits and the restrictions of the system machine-tool-part. Besides the theoretical planning the system has a practical testing module intended to refine the theoretical values of the adopted cutting speed to guarantee its application to the defined machine and tooling. The system approach is semi-generative, with algorithmic and knowledge based solutions, with a simple and user-friendly interface.

O planejamento de processos é uma atividade essencial nas diversas etapas do ciclo de manufatura, em particular nas indústrias que produzem peças através de processos de usinagem. O uso de sistemas CAPP tem implicado em uma evolução nos sistemas de planejamento. A determinação da máquina, da ferramenta e das condições operacionais adequadas visando a otimização das diversas operações é fundamental para o sucesso do processo produtivo e da empresa, podendo ser melhorado pelo uso do CAPP. Estudam-se, assim, os fatores que influenciam esse tipo de processo, propondo-se um modelo de sistema protótipo para o seu planejamento, de forma a se ter no final uma especificação teórica da profundidade de corte, do avanço e da velocidade de corte, considerando aspectos como a usinabilidade do material da peça, os tempos de fabricação secundários e auxiliares, e a própria logística aplicada ao fluxo de peças no chão-de-fábrica através da definição quanto à máquina empregada ser ou não gargalo além de considerações sobre a disponibilidade de carga-máquina. Procurou-se elaborar um critério de otimização que considere não apenas o intervalo de máxima eficiência como proposto por vários autores, mas discuta a aplicação de seus limites e as restrições do sistema máquina-ferramenta-peça. Além do planejamento teórico o sistema possui um módulo de ensaios práticos visando refinar os valores teóricos da velocidade de corte adotada para garantir a sua perfeita aplicação com a máquina e a ferramenta adotados. A proposta do sistema é semi-generativa, unindo soluções algorítmicas e baseadas em conhecimento, com uma interface simples e amigável ao usuário. / Process planning is an essential activity in the several stages of the manufacturing cycle, particularly in industries which produce parts by means of machining processes. The use of CAPP systems has implied in a planning systems evolution. The determination of machine, tooling and suitable operational conditions looking at the optimization of the several operations is fundamental to the success of the productive process and of the enterprise, and can be improved by use of CAPP systems. It was studied the factors which influence this kind of process and it was proposed a prototype system model for this planning and for obtaining a theoretical specification of the depth of cut, feed and cutting speed, taking into consideration aspects like machinability of the part material, secondary and auxiliary manufacturing times, and the logistics applied to the flow of parts at the shop-floor through the definition of the used machine to be or not a production neck beyond considerations on the availability of machine capacity. It was proposed an optimization criterion which considers not only the maximum efficiency interval as quoted by many authors but also discuss the application of its limits and the restrictions of the system machine-tool-part. Besides the theoretical planning the system has a practical testing module intended to refine the theoretical values of the adopted cutting speed to guarantee its application to the defined machine and tooling. The system approach is semi-generative, with algorithmic and knowledge based solutions, with a simple and user-friendly interface.

Submitted by PAULO ROBERTO GOMES ALVES null (pauloalves@grad.itapeva.unesp.br) on 2016-03-19T13:35:12Z No. of bitstreams: 1 ANÁLISE DO ACABAMENTO SUPERFICIAL E DA POTÊNCIA CONSUMIDA NA USINAGEM DE FRESAMENTO FRONTAL E CILÍNDRICO TANGENCIAL DA MADEIRA DE EUCALIPTO.pdf: 4159341 bytes, checksum: 1aece2dc81a26f1c87e9e4d59ff0dd54 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-22T13:52:55Z (GMT) No. of bitstreams: 1 alves_prg_dr_guara.pdf: 4159341 bytes, checksum: 1aece2dc81a26f1c87e9e4d59ff0dd54 (MD5) / Made available in DSpace on 2016-03-22T13:52:55Z (GMT). No. of bitstreams: 1 alves_prg_dr_guara.pdf: 4159341 bytes, checksum: 1aece2dc81a26f1c87e9e4d59ff0dd54 (MD5) Previous issue date: 2016-02-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A expansão tecnológica e de mercado da madeira e produtos derivados de madeira industrializada, fazem com que as pesquisas dos processos que envolvem esse material sejam cada vez mais necessárias. O fresamento é um processo de usinagem muito utilizado na indústria, quando se pretende obter um acabamento superficial de qualidade. O presente trabalho teve por objetivo avaliar o desempenho do processo de usinagem de madeiras das espécies de Corymbia citriodora e Eucalyptus saligna, realizado em centro de usinagem CNC, através da análise do acabamento superficial e da potência consumida em operações de fresamento frontal e cilíndrico tangencial. As madeiras foram usinadas de forma tangencial em movimentos concordante e discordante, com profundidade de corte (ap) de 1,0 mm; de forma frontal nas direções perpendicular e paralelo em relação às fibras com (ap) de 5,0 mm. Como condições de usinagem, empregaram-se quatro velocidades de corte (Vc) 5,9; 8,4; 10,9; 13,4 m/s, e quatro velocidades de avanço (Vf) 3,0; 5,0; 7,0 e 9,0 m/min. Utilizou-se para os ensaios uma fresa helicoidal de metal duro maciço com três dentes e diâmetro de 16,0 mm. Foram analisados os resultados de Rugosidade Média (Ra) obtidos através de rugosímetro e potência consumida captada por sensor de efeito Hall, e verificado a integridade das superfícies fresadas através de microscópio eletrônico de varredura (MEV). Os resultados foram analisados pelo software Minitab e tratados estatisticamente através da análise de variância ANOVA e teste de Tukey. Concluiu-se que as melhores qualidades superficiais registradas ocorreram para as menores velocidades de avanço, maiores velocidades de corte, no fresamento tangencial para o corte discordante, no fresamento frontal para o corte paralelo às fibras da madeira. Para a potência média consumida, o menor valor médio ocorreu para as maiores velocidades de corte e a espécie citriodora, obteve melhor qualidade superficial quando comparado com a espécie saligna. / The technological expansion and market wood and derived from wood products industrialized make research processes involving this material are increasing necessary. Milling is a machining process commonly used in the industry, when applying for a surface finish quality. This study was to evaluate the performance of wood machining process of species Corymbia citriodora and Eucalyptus saligna realized out in CNC machining center, through the analysis of surface finish and the power consumed in tangential front and cylindrical milling operations. The woods were used tangentially on down-milling and up-milling movements, cutting depth of 1.0 mm; the front in parallel and perpendicular directions in relation to the fibers with cutting depth of 5.0 mm. As machining conditions, we used four cutting speeds of 5.9, 8.4, 10.9 and 13.4 m/s, and four feed speeds 3 5, 7 and 9 m/min. It was used for testing a helical cutter solid tungsten carbide tool with three teeth and diameter of 16 mm. The results were analyzed Roughness Average (Ra) obtained from roughness and power consumed captured by Hall effect sensor and the integrity of the machined surfaces obtained by scanning electron microscope. These results were analyzed by Minitab software and statistically analyzed by ANOVA and Tukey test. It is concluded that the best recorded surface qualities were obtained for lower feed rates, higher cutting speeds, the tangential milling cutting for up-milling in front for cutting parallel to the wood fibers. For the average power consumed, the lowest average value occurred for higher cutting speeds and the species citriodora, obtained better surface quality when compared with the species saligna. / CAPES: 00.889.834/0001-08

The optimal choice of cutting conditions, as well cutting tool, has a significant effect on the quality of machined part and is an essential parameter to reduce the cost of production. This thesis describes CNC turning process of disc springs made of 51CrV4 material, especially using new cutting tools and the use of higher cutting speeds. A comparison of four manufacturers of cutting tools in terms of surface quality, tool path and the machined material volume will be introduced. It was experimentally verified that our proposed facility has achieved the best result.

The dissertation thesis is focused on the optimization of control parameters of an EDM machine; the subject of optimization is cutting speed and surface topography. The first part of the thesis contains a research study on the technology of electrical discharge machining with the attention paid to the optimization methods use for control parameters of this process. The second part of the thesis is focused on real application of knowledge gained from studied sources. Here, a design of experiment aim at optimizing the parameters of the EDM machine is designed and carried on to maximize the cutting speed with the highest possible surface quallity. The result of the work is to build adequate regression models and find the optimal setting of machine control parameters.

This master’s thesis deals with the operating production cost in machining process and further optimalization. Individual costs items which are related to machining process are specified. Attention is paid to the time consumption of individual machining methods. The aim of the thesis is to find an optimal combination of cutting speed and durability in order to meet the minimum cost criteria and maximum productivity. The calculations are used for turning the outer cylindrical surface and the face surfaces at a constant cutting speed. The work is accompanied by tables and calculations in Microsoft Excel.

This master’s thesis focuses on analysis of time consumption of machining process, the basic units of operating costs of production,optimization and subsequen tapplication to specific part. It is a turning shaft in two operations, named roughing and finishing turning. The aim is to find the optimum combination of life time of cutting tool and cutting speed, which is the main criterion for optimization in terms of minimum production cost or a maximum of productivity.