The diploma thesis Technology of CNC production of aluminium alloy part is based on the particular specification of the company FP cz s.r.o. The core of the work lies in the proposal of production technology of the given part made from aluminium alloy which is machined by two universal CNC lathes with operating system FANUC. There is an introduction to the issue of characteristics and machinability of aluminium and its alloys because of coherence of the thesis. Practical part is focusing on the particular proposal of production technology which consists of the casting analysis, method of clamping on the chosen machines, choice of tools and verification of the production. There can be achieved effective production and significant time reduction with proposed technology.

The master thesis deals with the use of the Sinumerik 840D control system for programming of blanks for gear manufacturing. The first part of the thesis is focused on analysis of machinability of the material followed by experimental testing of machinability of material 16MnCr5. An experimental evaluation of the effect of cutting parameters was carried out to force load of semi roughing cutting tool CoroTurn 300. In the next part of the thesis there is a technical documentation of gearing parts, for which a NC program is created. Finally, the possibilities of using the Sinumerik 840D control system are listed and demonstrated by workshop-oriented programming of the considered components for the SP 280 SY turning center.

Metal matrix composites have seen a rise in demand within the last decade. Aluminum alloy reinforced with silicon carbide particles is a type of particle metal matrix composite that has seen applications in the aerospace, ground transportation, and electronics industry. However, the abrasive SiC particles have made this material difficult to machine through conventional machining strategies. This research will focus on using computer aided manufacturing with trochoidal tool paths to maximize machining productivity and extend the tool life of CVD diamond coated end mills. The focus of this research will be on AlSiCp with a high volume fraction of reinforcement (30%) to expand the potential applications of this pMMC. The cutting experiments are divided into three parts: cutting test, confirmation test, and endurance test. Taguchi method will be used to perform an analysis of variance and signal-to-noise ratio to optimize a combination of material removal rate, average cutting forces, and surface roughness. The optimal cutting conditions were found to be 254 mm/min, 30°, and 9500 r/min for MRR+AvgFxy+Ra, 1524 mm/min, 30°, and 9500 r/min for MRR+AvgFxy, and 1524 mm/min, 90°, and 9500 r/min. The cutting conditions for MRR+AvgFx+Ra was not considered for the endurance tests as the machining productivity was too low to be considered a feasible option in the industry. It was concluded that trochoidal milling under wet cutting conditions produced nearly half the tool wear as previous research with conventional milling strategies. However, the longer the CVD diamond coated end mills were engaged in the AlSiCp workpiece, the more dominant the abrasive wear mechanisms appear and cause tool damage. It was concluded that square end mills may not be suitable for machining AlSiCp and that future research should focus on varying the tool geometry or utilizing ball end mills.

This thesis covers some aspects of hard part turning of carburised steels using a poly‑crystalline cubic boron nitride (PCBN) cutting tool during fine machining. The emphasis is on the influence of the steel cleanliness and the characteristics of non‑metallic inclusions in the workpiece on the active wear mechanisms of the cutting tool. Four carburising steel grades suitable for automotive applications were included, including one that was Ca‑treated. A superior tool life was obtained when turning the Ca-treated steel. The superior machinability is associated with the deposition of lubricating (Mn,Ca)S and (CaO)x-Al2O3-S slag layers, which are formed on the rake face of the cutting tool during machining. Moreover, the transfer of work material to the rake face crater is characteristic in hard part turning of clean steels. It can be because of the lack of sulfides that protect the cutting edge when turning machinability treated steels. This corresponds to the more pronounced crater wear caused by the low‑sulfur steels than that of the steels with higher sulfur contents. It was also concluded that the composition of the non‑metallic inclusions in the Ca‑treated steel is a more important factor than the inclusion number and size, in hard part turning using a PCBN cutting tool. Also, a 3D analysis after electrolytic extraction was found to give a more precise characterisation of non‑metallic inclusions than the conventional 2D analysis by SEM‑EDS. In turn, better correlations to machinability and mechanical properties can be obtained. Hence, the use of this technique is beneficial for future material development. Finally, the challenge for future metallurgy is to manufacture high‑performance steels with improved combined properties of mechanical strength and machinability. / <p>QC 20150422</p>

<p>U radu je izvršeno eksperimentalno istraživanje procesa obrade<br />glodanjem u cilju saznanja o obradivosti legure aluminijuma dobijene<br />sa dva različita tipa livenja. Izvršeno je modeliranje funkcija<br />obradivosti preko izmerenih karakteristika stanja procesa: sila<br />rezanja, hrapavosti obrađene površine, temperature u procesu rezanja<br />i faktora sabijanja strugotine. Modeliranje funkcija obradivosti je<br />izvršeno pomoću faktornog plana eksperimenta, kao i primenom<br />veštačkih neuronskih mreža i fazi logike. Optimizacija ulaznih<br />parametara procesa obrade glodanjem sprovedena je pomoću Taguči<br />metode. Proces glodanja simuliran je pomoću metoda konačnih<br />elemenata.</p> / <p>In this work an experimental research of the milling process were performed<br />in order to find out the machinability of aluminum alloys which are obtained<br />with two different types of casting procedure. Modeling of machinability<br />functions is performed through the measured process state characteristics:<br />cutting force, surface roughness, temperature in the cutting zone and chip<br />compression ratio. Modeling of the machinability functions was performed<br />using a full factorial experiment and through the model of artificial neural<br />networks and fuzzy logic. Optimization of process input values in defined<br />models is performed through Taguchi methods. The process of milling is<br />simulated with finite element method.</p>

L’introduction massive des alliages de titane pour les pièces de structures aéronautiques a soulevé de nouvelles problématiques d’usinage. Du fait que les matériaux réfractaires présentent de faibles propriétés thermiques leur mise en forme par usinage à sec est difficile. L’objectif industriel est d’améliorer la productivité de l’usinage des alliages de titane afin d’en réduire les coûts. Des travaux concernant la coupe du Ti6Al4V α+β, du Ti54M et du Ti6Al4V traité β ont été réalisés pour mettre en évidence les différences d’usinabilité entre ces trois matériaux. Ces travaux mettent en avant une forte influence du comportement orthotrope et de l’hétérogénéité de la microstructure lamellaire, ainsi que de la taille des grains du Ti6Al4V traité β sur la mise en forme par coupe. L’étude sur l’usure des outils par diffusion montre que le principal élément de diffusion est le titane et que par conséquent aucune différence n’est observée entre les trois matériaux. Pour confirmer que la diffusion est le mode d’usure principal, des essais de perçage instrumentés avec un système de mesure de température sans fil ont été effectués. Les températures à l’arrière de l’arête de coupe atteignent des températures supérieures à 500°C pour de faibles vitesses de coupe. A cette température le phénomène de diffusion est thermiquement activé et confirme les hypothèses évoquées précédemment. Enfin, pour avoir une compréhension des différences d’usinabilité mises en évidence lors des travaux expérimentaux, une recherche sur le comportement des matériaux (Johnson-Cook) et la mise en place d’une simulation numérique ont été réalisées. Les simulations réalisées à l’aide des lois de comportement identifiées précédemment modélisent précisément l’usinage du Ti6Al4V α+β et du Ti54M. L’hétérogénéité du Ti6Al4V traité β ne permet pas une bonne modélisation de la formation du copeau. Une modélisation polycristalline serait plus adaptée. / The massive introduction of titanium alloys onto the aeronautical structures parts has raised new problems in the machining process. Because of their low thermal properties (refractory materials), they are considered as difficult to cut material. The industrial aim is therefore to improve the productivity of the titanium alloy’s machining and to reduce their costs. Some research on Ti6Al4V α + β, Ti54M and β-treated Ti6Al4V cutting was carried out to point out machinability’s differences between these three materials. This work highlights a strong influence of the orthotropic behavior and the heterogeneity of the lamellar microstructure as well as the grain size of the β-treated Ti6Al4V on cutting. The study on the tool wear diffusion shows that the main diffusion element is titanium and therefore no difference is observed between those three materials. To check that diffusion is the main wear mode, instrumented drilling tests with a wireless temperature measurement device were performed. Temperatures behind the cutting edge reach temperatures above 500 °C for low cutting speeds. At this temperature the phenomenon of diffusion is thermally activated. Finally, in order to have an understanding of the machinability consistencies, a research on the materials’ behavior (Johnson-Cook) and the implementation of a numerical simulation were realized. The simulations carried out, using the previously identified behavior’s laws, model precisely the machining of the Ti6Al4V α+β and Ti54M. The heterogeneity of the β-treated Ti6Al4V does not allow a good modeling of the chip formation. Polycrystalline modeling would be more appropriate.

Alguns espelhos usados em câmeras de satélite devem apresentar qualidade superficial elevada. Eles são normalmente fabricados em ZERODUR®, um material vitrocerâmico, por meio de processos abrasivos. Observou-se que a qualidade da superfície do material deteriora-se algum tempo após a usinagem, necessitando assim de retrabalho. A causa mais influente desse fenômeno é o crescimento de trincas devido à corrosão sobtensão. Estas trincas são geradas pelas condições impostas nos processos convencionais de lapidação e polimento. Este trabalho apresenta um estudo sobre a usinabilidade do ZERODUR® utilizando torneamento de ultraprecisão com ferramenta de diamante de ponta única como uma alternativa a estes métodos tradicionais. Amostras de ZERODUR® foram submetidas a testes de indentação e riscamento a fim de se estudar as propriedades mecânicas do material, a transição dúctil-frágil e os mecanismos de remoção de material. Com base nesses testes, foi delineado um experimento fatorial do tipo 23 para avaliar a influência das seguintes variáveis de usinagem: profundidade de corte, nos níveis 0,4 e 0,2 \'mü\'m, taxa de avanço, nos níveis 0,3 e 0,1 \'mü\'m/rev e ângulo de saída da ferramenta, nos níveis -5º e -20º. As amostras do experimento foram usinadas em um torno de ultraprecisão com a ferramenta de diamante de ponta única. A qualidade superficial de cada combinação foi avaliada por microscopia eletrônica de varredura e perfilometria óptica interferométrica. Os resultados dos experimentos foram analisados estatisticamente, por meio de análise de variância (ANOVA). Para os intervalos das variáveis testadas verificou-se que o ângulo de inclinação da ferramenta é o que mais afeta a qualidade superficial. Ângulos com inclinações mais negativas (-20º) proporcionaram as melhores qualidades superficiais (em torno de 200 nm). Nos resultados não houve evidência de que o corte do material tenha ocorrido dentro do regime dúctil. Porém, a rugosidade superficial encontrada em algumas combinações de corte sugere que o torneamento de ultraprecisão pode ser uma alternativa ao processo lapidação que antecede o polimento. Este trabalho de caráter exploratório contribui com estimativas de alguns parâmetros ótimos para usinagem do ZERODUR®, fornecendo subsídios para pesquisas futuras sobre este tema. / Some mirrors used in satellite cameras must present a high surface quality. They are usually made of ZERODUR®, a brittle glass ceramic, by means of abrasive processes. It was observed that the surface quality of the material deteriorates some time after the machining, thus requiring rework. The most influential cause of this phenomenon is the crack growth due to stress corrosion. These cracks are generated by the conventional machining processes of lapping and polishing. This work presents a study on the machinability of ZERODUR® using ultraprecision turning with single-point diamond tool as an alternative to these traditional methods. ZERODUR® samples were subjected to indentation and nano-scratching tests in order to study the ductile-brittle transition and material removal mechanisms. After that, a \'2 POT.3\' factorial experiment was designed in order to assess the influence of three machining parameters on the resulting surface roughness, which are: depth of cut (tested at levels 0,4 and 0,2 \'mü\'m), feed rate (tested at levels 0,3 and 0,1 \'mü\'m/rev) and rake angle of the cutting tool (tested at levels -5º e -20º). The samples were turned with single-point diamond tool using different combinations of the parameters at the levels described above. The surface quality of each sample was evaluated using an interferometric optical profiler and a scanning electron microscope (SEM). The results of the experiments were statistically evaluated by means of Analysis Of Variance (ANOVA). For the ranges tested, it was found that the rake angle of the tool was the most influential parameter. The angle of -20º provided the best values for surface quality, which were around 200 nm. There was no evidence that the cut of the material occurred in the ductile regime, however, the obtained surface roughness showed that the ultraprecision turning may be a feasible alternative for the lapping process of optical components. This exploratory research contributes to the existing knowledge by providing estimates for optimal parameters of ZERODUR® machining, furnishing empirical basis for future research in this field.

Este estudo teve por objetivo analisar os aspectos estéticos, físicos, mecânicos e de qualidade da superfície usinada da madeira de árvores de Eucalyptus grandis, Eucalyptus urophylla e Eucalyptus dunnii aos 18 anos, tendo como objetivo a sua aplicação na indústria moveleira. Para tanto, foram coletadas três árvores de cada espécie da Estação Experimental de Ciências Florestais (EECF) da ESALQ/USP, localizada em Anhembi-SP. Os ensaios de massa específica aparente, densidade básica, variação dimensional e módulos de ruptura e elasticidade foram realizados de acordo com a NBR 7190/96. Para a análise de qualidade da superfície usinada foram avaliados 48 corpos de prova de cada espécie, aplainados em 7 diferentes velocidades de avanço. Em cada corpo de prova foram feitas 3 leituras, em diferentes posições, com rugosímetro. Foram realizadas análise de variância e testes de médias para cada parâmetro avaliado. Posteriormente, executaram-se as correlações de Pearson entre resultados dos diferentes ensaios. Com base nos resultados obtidos, concluiu-se que as três espécies estudadas apresentam características compatíveis para uso na indústria moveleira, com diferentes aplicações; a madeira de Eucalyptus urophylla apresentou o melhor desempenho em relação à maioria dos parâmetros analisados, o que indica a possibilidade de sua aplicação em grande parte dos componentes de um móvel; o Eucalyptus grandis foi a espécie que apresentou melhor desempenho nos ensaios de variação dimensional, porém apresentou restrições quanto ao uso estrutural e altos valores de coeficiente de variação nos resultados; o Eucalyptus dunnii apresentou maior retratibilidade e pior desempenho em relação à qualidade da superfície usinada, qualificando-se dentre as três espécies estudadas, como a menos indicada para uso em movelaria; as três espécies apresentaram importantes variações das características físicas ao longo do raio; os melhores resultados em relação à qualidade da superfície usinada foram obtidos com baixa velocidade de avanço; pela análise descritiva, os parâmetros de densidade e massa específica aparente são bons indicadores de estabilidade dimensional, desempenho mecânico e qualidade de superfície usinada; os resultados obtidos nas análises e os da bibliografia apontam uma alta variabilidade tecnológica da madeira das três espécies de eucalipto, recomendando a seleção e usos da madeira de clones. / The objective of this work was to analyze the aesthetics aspects, surface quality, physical and mechanical properties of Eucalyptus grandis, Eucalyptus dunnii and Eucalyptus urophylla wood with 18 years-old, aiming to give technical information its best application in furniture production. The material for the tests were three trees of each species, collected at Experimental Campus of Forestry Science from ESALQ/USP at Anhembi/SP. For the physical and mechanical tests the NBR 7190/96 was used. For the surface quality, 48 samples of each species were processed in 7 different forward velocities. In each sample, 3 tests in different positions were done using reliefmeter. Data were evaluated through analysis of variance, tests of comparison of means and Pearson correlation test between the different tests. It was concluded that the three studied species are suitable for furniture production, in different applications; the Eucalyptus urophylla had the best results for most of the realized tests, being suitable for most of the furniture components; the Eucalyptus grandis had the best results on shrinkage test, suitable for rigid joints or the ones with glued pieces and big dimension components, although it had the higher variation coefficient values and the species is not suitable for structure components, due to the low values on the mechanical tests; the Eucalyptus dunnii had the worst results for furniture production, comparing to the other studied, due to it\'s low performance at the shrinkage tests and at the surface quality test;. the three species had important variation trend of physical characteristics for the values on the radial direction, from the pith to the sapwood; the best results for the quality surface were due to the low forward velocity; the basic density and specific gravity parameters have good correlation with the studied characteristics: shrinkage, mechanical performance and surface quality; the results obtained on the analysis and the ones on the references show high technological variability on wood of the three species studied, so it is recommended the selection and use of wood from clones.

Alguns espelhos usados em câmeras de satélite devem apresentar qualidade superficial elevada. Eles são normalmente fabricados em ZERODUR®, um material vitrocerâmico, por meio de processos abrasivos. Observou-se que a qualidade da superfície do material deteriora-se algum tempo após a usinagem, necessitando assim de retrabalho. A causa mais influente desse fenômeno é o crescimento de trincas devido à corrosão sobtensão. Estas trincas são geradas pelas condições impostas nos processos convencionais de lapidação e polimento. Este trabalho apresenta um estudo sobre a usinabilidade do ZERODUR® utilizando torneamento de ultraprecisão com ferramenta de diamante de ponta única como uma alternativa a estes métodos tradicionais. Amostras de ZERODUR® foram submetidas a testes de indentação e riscamento a fim de se estudar as propriedades mecânicas do material, a transição dúctil-frágil e os mecanismos de remoção de material. Com base nesses testes, foi delineado um experimento fatorial do tipo 23 para avaliar a influência das seguintes variáveis de usinagem: profundidade de corte, nos níveis 0,4 e 0,2 \'mü\'m, taxa de avanço, nos níveis 0,3 e 0,1 \'mü\'m/rev e ângulo de saída da ferramenta, nos níveis -5º e -20º. As amostras do experimento foram usinadas em um torno de ultraprecisão com a ferramenta de diamante de ponta única. A qualidade superficial de cada combinação foi avaliada por microscopia eletrônica de varredura e perfilometria óptica interferométrica. Os resultados dos experimentos foram analisados estatisticamente, por meio de análise de variância (ANOVA). Para os intervalos das variáveis testadas verificou-se que o ângulo de inclinação da ferramenta é o que mais afeta a qualidade superficial. Ângulos com inclinações mais negativas (-20º) proporcionaram as melhores qualidades superficiais (em torno de 200 nm). Nos resultados não houve evidência de que o corte do material tenha ocorrido dentro do regime dúctil. Porém, a rugosidade superficial encontrada em algumas combinações de corte sugere que o torneamento de ultraprecisão pode ser uma alternativa ao processo lapidação que antecede o polimento. Este trabalho de caráter exploratório contribui com estimativas de alguns parâmetros ótimos para usinagem do ZERODUR®, fornecendo subsídios para pesquisas futuras sobre este tema. / Some mirrors used in satellite cameras must present a high surface quality. They are usually made of ZERODUR®, a brittle glass ceramic, by means of abrasive processes. It was observed that the surface quality of the material deteriorates some time after the machining, thus requiring rework. The most influential cause of this phenomenon is the crack growth due to stress corrosion. These cracks are generated by the conventional machining processes of lapping and polishing. This work presents a study on the machinability of ZERODUR® using ultraprecision turning with single-point diamond tool as an alternative to these traditional methods. ZERODUR® samples were subjected to indentation and nano-scratching tests in order to study the ductile-brittle transition and material removal mechanisms. After that, a \'2 POT.3\' factorial experiment was designed in order to assess the influence of three machining parameters on the resulting surface roughness, which are: depth of cut (tested at levels 0,4 and 0,2 \'mü\'m), feed rate (tested at levels 0,3 and 0,1 \'mü\'m/rev) and rake angle of the cutting tool (tested at levels -5º e -20º). The samples were turned with single-point diamond tool using different combinations of the parameters at the levels described above. The surface quality of each sample was evaluated using an interferometric optical profiler and a scanning electron microscope (SEM). The results of the experiments were statistically evaluated by means of Analysis Of Variance (ANOVA). For the ranges tested, it was found that the rake angle of the tool was the most influential parameter. The angle of -20º provided the best values for surface quality, which were around 200 nm. There was no evidence that the cut of the material occurred in the ductile regime, however, the obtained surface roughness showed that the ultraprecision turning may be a feasible alternative for the lapping process of optical components. This exploratory research contributes to the existing knowledge by providing estimates for optimal parameters of ZERODUR® machining, furnishing empirical basis for future research in this field.

Performance of indexable insert cutting tools is not only about the performance of cutting inserts. It is also about the cutting tool body, which has to provide a secure and accurate insert positioning as well as its quick and easy handling under severe working conditions. The common damage mechanisms of cutting tool bodies are fatigue and plastic deformation. Cutting tools undergo high dynamic stresses going in and out cutting engagement; as a result, an adequate level of fatigue strength is the essential steel property. Working temperatures of tool bodies in the insert pocket can reach up to 600°C, why the tool steel requires high softening resistance to avoid plastic deformation. Machinability is also essential, as machining of the steel represents a large fraction of the production cost of a cutting tool. The overall aim of the study is to improve the tool body performance by use of an advanced steel grade with an optimized combination of all the demanding properties. Due to the high-temperature conditions, the thesis concerns mostly hot-work tool steels increasing also the general knowledge of their microstructure, mechanical properties and machinability. Knowing the positive effect of sulphur on machinability of steels, the first step was to indentify a certain limit of the sulphur addition, which would not reduce the fatigue strength of the tool body below an acceptable level. In tool bodies, where the demand on surface roughness was low and a geometrical stress concentrator was present, the addition of sulphur could be up to 0.09 wt%. Fatigue performance of the cutting tools to a large extent depended on the steel resistance to stress relaxation under high dynamic loading and elevated temperatures. The stress relaxation behaviour, material substructure and dislocation characteristics in low-alloyed and hot-work tool steels were studied using X-ray diffraction under thermal and mechanical loading.  Different tool steels exhibited different stress relaxation resistance depending on their microstructure, temper resistance and working temperature. Hot-work tool steels showed to be more preferable to low-alloyed tool steels because of their ability to inhibit the rearrangement and annihilation of induced dislocations. High-temperature softening resistance of the hot-work tool steels was investigated during high-temperature hold-times and isothermal fatigue and discussed with respect to their microstructure. Carbide morphology and precipitation were determined using scanning and transmission electron microscopy. Machinability of a prehardened hot-work tool steel of varying nickel content from 1 to 5 wt% was investigated in end milling and drilling operations. Machining the higher nickel containing steels resulted in longer tool life and generated lower cutting forces and tool/workpiece interface temperature. The difference in machinability of the steels was discussed in terms of their microstructure and mechanical properties.