Em decorrência ao grande crescimento e evolução dos processos de usinagem e a demanda para adequação ambiental, novos fluidos de corte tem sido aplicados. Uma comprovação de sua eficiência em refrigerar a peça, e a ferramenta melhorando a produtividade do processo ainda é necessária. O presente trabalho propõe o estudo e o desenvolvimento de um sistema para avaliar a eficácia de fluidos de corte em operações de usinagem. Inicia-se com uma abordagem matemática da modelagem do processo de dissipação de calor em operações de usinagem. Em seguida prossegue-se com uma investigação de diferentes maneiras de solução do modelo proposto. Experimentos práticos foram realizados no laboratório de Otimização de Processos de Fabricação - OPF. A partir dos dados obtidos foi realizada uma análise assintótica das equações diferencias parciais que governam o modelo. Finalizando, o modelo selecionado foi aplicado no fresamento do aço AISI 4340 endurecido usinado sob alta velocidade. / Due to the rapid growth and development of machining processes there has been a demand for environmental sustainability and news cutting fluids have been applied. A reliable assessment of their efficiency in cooling the workpiece, tools and improving productivity is still a requirement. The present thesis presents a theoretical study and a proposal of a system to assess the effectiveness of cutting fluids applied to machining operation. It begins using a mathematical approach to model the heat propagation during machining operations. Then, it continues with an investigation into different ways to solve the proposed theorical model. Machining experiments using realistic cutting operations were also conducted at the Laboratory for Optimization of Manufacturing Processes - OPF. From the experimental data, was carried out an asymptotic analysis of partial differential equations, which govern the mathematical model. Finally, the selected model will be applied to a milling operation using High Speed Machining (HSM) technique on hardened steel AISI 4340.

In the nanoscale metrology industry, there is a need for low-cost instruments, which have the ability to probe the structrure and elemental composition of thin films. This dissertation, describes the research performed to design and simulate a miniature Cylindrical Mirror Analyzer, (CMA), and Auger Electron Spectrometer, (AES). The CMA includes an integrated coaxial thermionic electron source. Electron optics simulations were performed using the Finite Element Method, (FEM), software COMSOL. To address the large Secondary Electron, (SE), noise, inherent in AES spectra, this research also included experiments to create structures in materials, which were intended to suppress SE backgound noise in the CMA. Laser Beam Machining, (LBM), of copper substrates was used to create copper pillars with very high surface areas, which were designed to supress SE’s. The LBM was performed with a Lumera SUPER RAPID‐HE model Neodymium Vanadate laser. The laser has a peak output power of 30 megawatts, has a 5x lens and a spot size of 16 μm. The laser wavelength is in the infrared at 1064 nm, a pulse width of 15 picoseconds, and pulse repetition rate up to 100 kHz. The spectrometer used in this research is intended for use when performing chemical analysis of the surface of bulk materials and thin films. It is applicable for metrology of thin films, as low as 0.4 nm in thickness, without the need to perform destructive sample thinning, which is required in Scanning Tranmission Electron Microscopy, (STEM). The spectrometer design is based on the well known and widely used coaxial cylinder capacitor design known as the Cylindrical Mirror Analyzer, (CMA). The coaxial tube arrangement of the CMA allows for placing an electron source,which is mounted in the center of the inner cylinder of the spectrometer. Simulation of the electron source with an Einzel Lens was also performed. In addtion, experiments with thin film coatings and Laser Beam Machining to supress Secondary Electron emission noise within the Auger electron spectrum were completed. Design geometry for the miniature CMA were modeled using Computer Aided Design, (CAD). Fixed Boundary Conditions, (BC), were applied and the geometry was then meshed for FEM. The electrostatic potential was then solved using the Poisson equation at each point. Having found the solution to the electrostatic potentials, electron flight simulations were performed and compared with the analytical solution. From several commercially available FEM modeling packages, COMSOL Multiphysics was chosen as the research platform for modeling of the spectrometer design. The CMA in this design was reduced in size by a factor of 4 to 5. This enabled mounting the CMA on a 2 ¾ in flange compared to the commercial PHI model 660 CMA which mounts onto a 10 in flange. Results from the Scanning Electron Microscopy measurements of the Secondary Electron emission characteristics of the LBM electron suppressor will also be presented.

<p>Process planning as a function for competitiveness is often neglected. However, as an intermediary between product development and manufacturing, it holds a key function in transforming product specifications and requirements into a producible process plan. Demands and requirements should be met concurrently as manufacturing costs and lead times are minimised. The focus of this thesis is the act of process planning, where the use of better methodologies, computer-aids and performance measurements are essential parts. Since process planning has the function of transforming demands and requirements, changing customer and regulative requirements are vital to regard. Since environmentally benign products and production increases in importance, the research presented in this thesis includes a CNC machining cost model, which relates machining costs to energy consumption.  The presented results in this thesis are based on quantitative and qualitative studies in the metal working industry.</p><p> </p><p>This thesis has contributed to an enhanced understanding of process planning to achieve better performance and important areas for improvements. Despite a 50 year history of computerised process planning aids, few of these are used in the industry, where manual process planning activities are more common. Process planning aids should be developed around the process planner so that non-value adding activities, such as information management and documentation are minimised in order to allow more resources for value adding activities, such as decision making. This thesis presents a study of systematic process planning in relation to perceived efficiency. This correlation could however not be verified, which opens up for further studies of other possible explanations for process planning efficiency. Process planning improvements in the industry are difficult to make, since there is little focus on process planning activities and limited knowledge about actual performance hereof. This means that measures taken regarding process planning development are difficult to verify.</p> / NFFP4

Process planning as a function for competitiveness is often neglected. However, as an intermediary between product development and manufacturing, it holds a key function in transforming product specifications and requirements into a producible process plan. Demands and requirements should be met concurrently as manufacturing costs and lead times are minimised. The focus of this thesis is the act of process planning, where the use of better methodologies, computer-aids and performance measurements are essential parts. Since process planning has the function of transforming demands and requirements, changing customer and regulative requirements are vital to regard. Since environmentally benign products and production increases in importance, the research presented in this thesis includes a CNC machining cost model, which relates machining costs to energy consumption.  The presented results in this thesis are based on quantitative and qualitative studies in the metal working industry.   This thesis has contributed to an enhanced understanding of process planning to achieve better performance and important areas for improvements. Despite a 50 year history of computerised process planning aids, few of these are used in the industry, where manual process planning activities are more common. Process planning aids should be developed around the process planner so that non-value adding activities, such as information management and documentation are minimised in order to allow more resources for value adding activities, such as decision making. This thesis presents a study of systematic process planning in relation to perceived efficiency. This correlation could however not be verified, which opens up for further studies of other possible explanations for process planning efficiency. Process planning improvements in the industry are difficult to make, since there is little focus on process planning activities and limited knowledge about actual performance hereof. This means that measures taken regarding process planning development are difficult to verify. / NFFP4

This thesis illustrates analysis of the influence of the non-machining processes on product quality by experimental design and statistical analysis. For the analysis objective / dishwasher production in Arcelik Dishwasher plant is examined. Sheet metal forming processes of dishwasher production constitutes the greatest portion of production cost and using the Pareto analysis technique / four pieces among twenty six pieces are determined to be investigated. These four pieces are the U Sheet, L Sheet, Inner Door and Side Panel of the dishwasher. By the help of the flow diagrams production process of the determined pieces are defined. Brainstorming technique and cause&amp / effect diagrams are used to determine which non-machining process parameters can cause pieces to be scrapped. These parameters are used as control factors in experimental design. Taguchi&amp / #8217 / s L16(215) orthogonal array, Taguchi&amp / #8217 / s L16(215) orthogonal array using S/N transformation and 28-4 fractional factorial design are used on purpose. With repetitions and confirmation experiments the effective parameters are determined and optimum level of these parameters are defined for the improvements on scrap quantity and quality of production.

Aufbauend auf einer Analyse ausgewählter methodentheoretischer Ansätze der Produktionsstättenplanung und des Umweltmanagements wird eine Methode des planungsintegrierten Umweltschutzes bei der Produktionsstättenplanung entwickelt. Sie besteht zum Einen aus einer umweltbezogenen Analyse und Bewertung, basierend auf der Ökobilanzierung, die an die Belange der Produktionsstättenplanung angepasst und integriert wird. Zum Anderen erfolgt das Entwerfen umweltverträglicher Lösungen. Hierzu wird das Konzept des planungsintegrierten Umwelschutzes zu heuristischen Regeln operationalisiert und den Planungsaktivitäten Funktionsbestimmung/Dimensionierung/Strukturierung/Gestaltung zugeordnet. Es erfolgt abschließend der beispielhafte Einsatz der Methode in einer Branchenstudie zur spanenden Metallbearbeitung.

Detta examensarbete har utförts på uppdrag av Koenigsegg Automotive AB, som utvecklar, tillverkar och säljer högpresterande sportbilar. Företaget erbjuder fälgar tillverkade helt i kolfiberkomposit, som ger betydande viktbesparingar i jämförelse med traditionella metallfälgar. Efter tillverkningen kräver fälgarna viss bearbetning vid anläggningsytan mellan fälg och däck. Syftet med examensarbetet har varit att undersöka möjligheten att utföra bearbetningen av fälgarna in-house i Ängelholm, och målet har varit att konstruera en maskin för detta ändamål. Projektet inleddes med en litteratursökning, där svårigheter och möjligheter gällande bearbetning av kolfiberkompositer undersöktes. Till följd av de undersökningar som gjordes, valdes bearbetningsmetoden svarvfräsning och ett antal konstuktionskoncept genererades. Genom ett antal utvärderingar utvecklades ett speciellt koncept vidare till ett komplett produktförslag. Produktförslaget är komplett med analyser, beräkningar samt tillverkningsunderlag, som ger uppdragsgivaren bättre insikt i sina möjligheter. Även underlag som tillåter en framtida CE-märkning har tagits fram. Projektet har följt Fredy Olssons konstruktionsmetod. / The following thesis has been performed in cooperation with Koenigsegg Automotive AB, which develops, manufactures and sells high-performance sportscars. Koenigsegg offers rims made completely from carbon fiber composite, which yields substantial benefits in stiffness and weight compared to their traditional metal counterparts. After the manufacturing of the rims, some trimming is necessary in the contact surface between rim and tire. The purpose of this thesis has been to examine the possibility of performing the necessary trimming in-house in Ängelholm, by designing a special tool. The project began with a literature study, where possibilities and difficulties of machining carbon fiber composites were examined. As a result of the study, the manufacturing process turn-milling was chosen, and a number of concepts were generated. Through a series of evaluations, one concept was further developed to a final product. The suggested product is complete with calculations, analyses and drawings, which gives Koenigsegg a better insight of future possibilities. A solid foundation for future CE-marking has also been produced. The project has followed Fredy Olssons methods of Engineering Design.

Vibration control requires high dynamic stiffness in mechanical structures for a reliable performance under extreme conditions. Dynamic stiffness composes the parameters of stiffness (K) and damping (η) that are usually in a trade-off relationship. This thesis study aims to break the trade-off relationship. After identifying the underlying mechanism of damping in composite materials and joint interfaces, this thesis studies the deposition technique and physical characteristics of nano-structured HDS (high dynamic stiffness) composite thick-layer coatings. The HDS composite were created by enlarging the internal grain boundary surface area through reduced grain size in nano scale (≤ 40 nm). The deposition process utilizes a PECVD (Plasma Enhanced Chemical Vapour Deposition) method combined with the HiPIMS (High Power Impulse Magnetron Sputtering) technology. The HDS composite exhibited significantly higher surface hardness and higher elastic modulus compared to Poly(methyl methacrylate) (PMMA), yet similar damping property. The HDS composites successfully realized vibration control of cutting tools while applied in their clamping interfaces. Compression preload at essential joint interfaces was found to play a major role in stability of cutting processes and a method was provided for characterizing joint interface properties directly on assembled structures. The detailed analysis of a build-up structure showed that the vibrational mode energy is shifted by varying the joint interface’s compression preload. In a build-up structure, the location shift of vibration mode’s strain energy affects the dynamic responses together with the stiffness and damping properties of joint interfaces. The thesis demonstrates that it is possible to achieve high stiffness and high damping simultaneously in materials and structures. Analysis of the vibrational strain energy distribution was found essential for the success of vibration control.

This thesis presents cutter swept volume generation, in-process workpiece modeling and Cutter Workpiece Engagement (CWE) algorithms for finding the instantaneous intersections between cutter and workpiece in milling. One of the steps in simulating machining operations is the accurate extraction of the intersection geometry between cutter and workpiece. This geometry is a key input to force calculations and feed rate scheduling in milling. Given that industrial machined components can have highly complex geometries, extracting intersections accurately and efficiently is challenging. Three main steps are needed to obtain the intersection geometry between cutter and workpiece. These are the Swept volume generation, in-process workpiece modeling and CWE extraction respectively. In this thesis an analytical methodology for determining the shapes of the cutter swept envelopes is developed. In this methodology, cutter surfaces performing 5-axis tool motions are decomposed into a set of characteristic circles. For obtaining these circles a concept of two-parameter-family of spheres is introduced. Considering relationships among the circles the swept envelopes are defined analytically. The implementation of methodology is simple, especially when the cutter geometries are represented by pipe surfaces. During the machining simulation the workpiece update is required to keep track of the material removal process. Several choices for workpiece updates exist. These are the solid, facetted and vector model based methodologies. For updating the workpiece surfaces represented by the solid or faceted models third party software can be used. In this thesis multi-axis milling update methodologies are developed for workpieces defined by discrete vectors with different orientations. For simplifying the intersection calculations between discrete vectors and the tool envelope the properties of canal surfaces are utilized. A typical NC cutter has different surfaces with varying geometries and during the material removal process restricted regions of these surfaces are eligible to contact the in-process workpiece. In this thesis these regions are analyzed with respect to different tool motions. Later using the results from these analyses the solid, polyhedral and vector based CWE methodologies are developed for a range of different types of cutters and multi-axis tool motions. The workpiece surfaces cover a wide range of surface geometries including sculptured surfaces.

The thesis deals with the optimal pose selection for geometric and elastostatic calibration for industrial robots employed in machining of large parts. Particular attention is paid to the improvement of robot positioning accuracy after compensation of the geometric and elastostatic errors. To meet the industrial requirements of machining operations, a new approach for calibration experiments design for serial and quasi-serial industrial robots is proposed. This approach is based on a new industry-oriented performance measure that evaluates the quality of calibration experiment plan via the manipulator positioning accuracy after error compensation, and takes into account the particularities of prescribed manufacturing task by introducing manipulator test-poses. Contrary to previous works, the developed approach employs an enhanced partial pose measurement method, which uses only direct position measurements from an external device and allows us to avoid the non-homogeneity of relevant identification equations. In order to consider the impact of gravity compensator that creates closed-loop chains, the conventional stiffness model is extended by including in it some configuration dependent elastostatic parameters, which are assumed to be constant for strictly serial robots. Corresponding methodology for calibration of the gravity compensator models is also proposed. The advantages of the developed calibration techniques are validated via experimental study, which deals with geometric and elastostatic calibration of a KUKA KR-270 industrial robot.