Orientador: Alessandro Roger Rodrigues / Resumo: A microusinagem é um dos processos de fabricação capaz de produzir produtos ou geometrias de precisão e complexidade com detalhes menores que 1 mm. Contudo, para um melhor desempenho do processo de usinagem associado à qualidade do produto, entender a interação peça-ferramenta é fundamental. Esta pesquisa determinou a influência do tipo de corte e do avanço da ferramenta no desgaste da fresa (ferramenta), na energia específica de corte (processo) e na rugosidade (peça), ao empregar a operação de microfresamento de topo no aço COS AR60 de grãos ultrafinos. Os ensaios foram realizados em um centro de usinagem Romi D600 com a adaptação de um cabeçote de alta rotação (60 krpm) sem aplicação de fluido de corte. Microfresas de topo reto (Ø 800 µm) com substrato de metal duro e revestidas com TiAlN foram aplicadas nos testes. A profundidade de usinagem e a velocidade de corte foram mantidas constantes em 160 µm e 60 m/min, respectivamente. Foram variados o avanço por dente (3 e 10 µm/z) e o tipo de corte (simétrico em cheio e em face e assimétrico concordante e discordante). Análise de Variância (ANOVA) com intervalo de confiança de 95% foi aplicada a cada uma das três réplicas. Os resultados indicaram que os níveis de desgaste e a redução do diâmetro da microfresa são influenciados pelo avanço da ferramenta e tipo de corte. As maiores reduções no diâmetro (≈11%) foram devido ao impacto periódico da aresta de corte na peça e não pelo efeito de sulcamento (≈4%). Além disso, para o pe... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Micro-machining is one of the processes feasible for generating geometries or parts with precision and complexity regarding dimensions smaller than 1 mm. However, the achievement of enhanced machining performance and product quality requires a prior understanding on the tool-workpiece interface. This research detemined the influence of cutting type and cutting feed on wear (tool), specific cutting force (process) and surface roughness (workpiece) when cutting the ultrafine-grained steel COS AR60 under end milling strategy. Machining tests were performed in a CNC machining centre Romi D600 provided with a high-speed spindle (60kpm) without cutting fluid application. TiAlN coated carbide endmill (Ø 800 μm) was used for straight cut with 60 m/min cutting speed, 160 μm depth of cut and feed per tooth of 3 and 10 μm. Analysis of Variance (ANOVA) with confidence interval of 95% was applied to the three runs of each cutting sets. The results have shown that tool wear levels and tool effective diameter are influenced by tool feed and cutting type. Hence, intermittent impact of tool’s cutting edges into the workpiece (≈11%) during cutting revealed to be the major cause of tool wear when compared to cutting mechanism dominated by ploughing (≈4%). Regarding experimental sets with cutting length of 98,018 m there was a predominance of tool edge chipping over abrasion and adhesion when performing face cutting with ploughing at 4.2%. On the other hand, if ploughing increases to 14.3% the m... (Complete abstract click electronic access below) / Mestre

Submitted by Flávio Henrique Manarelli (flaviomanarelli@gmail.com) on 2018-11-01T23:57:49Z No. of bitstreams: 1 Dissertação_Flávio Henrique Manarelli.pdf: 2986064 bytes, checksum: edc4536a4c2ec5e96e1c49c52019885f (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-11-08T19:00:53Z (GMT) No. of bitstreams: 1 manarelli_fh_me_ilha.pdf: 2986064 bytes, checksum: edc4536a4c2ec5e96e1c49c52019885f (MD5) / Made available in DSpace on 2018-11-08T19:00:54Z (GMT). No. of bitstreams: 1 manarelli_fh_me_ilha.pdf: 2986064 bytes, checksum: edc4536a4c2ec5e96e1c49c52019885f (MD5) Previous issue date: 2018-09-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A microusinagem é um dos processos de fabricação capaz de produzir produtos ou geometrias de precisão e complexidade com detalhes menores que 1 mm. Contudo, para um melhor desempenho do processo de usinagem associado à qualidade do produto, entender a interação peça-ferramenta é fundamental. Esta pesquisa determinou a influência do tipo de corte e do avanço da ferramenta no desgaste da fresa (ferramenta), na energia específica de corte (processo) e na rugosidade (peça), ao empregar a operação de microfresamento de topo no aço COS AR60 de grãos ultrafinos. Os ensaios foram realizados em um centro de usinagem Romi D600 com a adaptação de um cabeçote de alta rotação (60 krpm) sem aplicação de fluido de corte. Microfresas de topo reto (Ø 800 µm) com substrato de metal duro e revestidas com TiAlN foram aplicadas nos testes. A profundidade de usinagem e a velocidade de corte foram mantidas constantes em 160 µm e 60 m/min, respectivamente. Foram variados o avanço por dente (3 e 10 µm/z) e o tipo de corte (simétrico em cheio e em face e assimétrico concordante e discordante). Análise de Variância (ANOVA) com intervalo de confiança de 95% foi aplicada a cada uma das três réplicas. Os resultados indicaram que os níveis de desgaste e a redução do diâmetro da microfresa são influenciados pelo avanço da ferramenta e tipo de corte. As maiores reduções no diâmetro (≈11%) foram devido ao impacto periódico da aresta de corte na peça e não pelo efeito de sulcamento (≈4%). Além disso, para o percurso de corte adotado de 98,018 m, com 4,2% da usinagem em sulcamento ou inexistente no corte em face, houve predominância de avarias por lascamento e, para o mesmo percurso, porém, com aproximadamente 14,3% do corte em sulcamento, os fenômenos predominantes no desgaste foram abrasão e adesão. O efeito do sulcamento fez com que os fatores tipo de corte e avanço, bem como suas respectivas interações, fossem significativos sobre a energia específica de corte. Os cortes em cheio e corte concordante com avanço de 3 µm/dente proporcionaram condições mais favoráveis para o microfresamento frontal, com melhor acabamento da peça e menores níveis de desgaste da ferramenta de corte. / Micro-machining is one of the processes feasible for generating geometries or parts with precision and complexity regarding dimensions smaller than 1 mm. However, the achievement of enhanced machining performance and product quality requires a prior understanding on the tool-workpiece interface. This research detemined the influence of cutting type and cutting feed on wear (tool), specific cutting force (process) and surface roughness (workpiece) when cutting the ultrafine-grained steel COS AR60 under end milling strategy. Machining tests were performed in a CNC machining centre Romi D600 provided with a high-speed spindle (60kpm) without cutting fluid application. TiAlN coated carbide endmill (Ø 800 μm) was used for straight cut with 60 m/min cutting speed, 160 μm depth of cut and feed per tooth of 3 and 10 μm. Analysis of Variance (ANOVA) with confidence interval of 95% was applied to the three runs of each cutting sets. The results have shown that tool wear levels and tool effective diameter are influenced by tool feed and cutting type. Hence, intermittent impact of tool’s cutting edges into the workpiece (≈11%) during cutting revealed to be the major cause of tool wear when compared to cutting mechanism dominated by ploughing (≈4%). Regarding experimental sets with cutting length of 98,018 m there was a predominance of tool edge chipping over abrasion and adhesion when performing face cutting with ploughing at 4.2%. On the other hand, if ploughing increases to 14.3% the main wear mechanism observed were abrasion and adhesion. Therefore, there was a significant interaction between specific cutting force and the input parameters of feed per tooth and cutting type. As a result, down-milling and channel-milling at the tool feed of 3 μm/tooth leaded to a valuable cutting performance with better workpiece surface roughness and tool wear at low levels.

This diploma thesis deals with issues in machining of thin-walled components. Its first part describes materials used in the aircraft industry. Then it focuses on issues associated with the prediction of deflections of a rib wall during machining. Later on it focuses on different methods and strategies of thin-walled part milling. The diploma thesis also describes an experiment of manufacturing thin-walled components in the form of ribs and evaluation parameters such as roughness, perpendicularity and straightness deviations, width of the rib and force loading of a cutting tool as measured by various gages. The final part is devoted to a calculation of the specific cutting force and its comparison with its theoretical value.

The main goal of this work is the analysis of manufacturing costs for the component of wheel´s blower. Followed by setting up the size of specific cutting force for milling operation of the titanium alloy Ti-Al6-Mo2-Cr2-Fe-Si, the used tool was a milling cutter which is made out of sintered carbide with conical and spherical face. The final values which are at intervals of 1500 to 1800 MPa were compared with the values of the Sandvik Coromant firm kc = 1690 MPa, for titanium alloy with the strenght in tension Rm = 1050 MPa.

This dissertation thesis is focused on the analysis of specific cutting forces and accompanying effects during machining of the new materials, composite materials. The experimental part is split up to two main chapters. In the first chapter, the development of specific cutting forces is analyzed in detail when cutting conditions are changing. The experimental machining of glass/polyester and carbon/epoxy composites is described for fibers orientations 0 a 90 (ie, the orientation of the fibers in the feed rate direction and perpendicular to the feed rate direction). The influence of the cutting tool flank wear on the specific cutting force is investigated further. The last section compares the values of specific cutting forces when machining with carbide milling tools deposited by different types of coating. The second chapter describes the measurement of sound spectrums generated by cutting process, sound maps creating and finding possible correlations between dominant frequencies of the sound and the specific cutting forces, or the cutting tool flank wear. The measurements are described for the cases of machining steel 15 260.7 and glass-polyester composite material.

Theoretical study describes force analysis and quality of surface when milling. In the experiment the emphasis is on determining forces and surface quality in milling in response to changes in feed rate. Especially determination of specific cutting force kc and cutting force Fc at materials from aluminium alloy AlSi9Cu3, titanium alloy Ti6Al4V and steel C45, the used tool was a milling cutter for high feeds. In the experimental section is furthermore contained statistical evaluation data which demonstrate a certain prediction changes of cutting load and surface roughness when changing feeds.