Spelling suggestions: "subject:"tool weak"" "subject:"tool were""
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Automatiserad fotografering av verktygsförslitning med robot / Automated photography of tool wear using a robotMörk, Albin January 2023 (has links)
Vid skärande bearbetning av material för att framställa olika produkter med önskade egenskaper orsakas förslitningar av verktygen som är viktiga att fotografera och analysera för att uppskatta livslängden. Detta kräver erfaren personal med precision som är svår att upprepa där automation kan vara en lösning för att avlasta personal från ett monotont arbete. Syftet med studien är att bidra med kunskap om hur man kan fotografera förslitningen av verktyg med hjälp av automation och ge förslag på en lösning. För att komma med ett lösningsförslag har en nulägesanalys genomförts med hjälp av observationer och intervjuerhos Sandvik Coromant, litteratursökning för att undersöka vad som gjorts inom området redan och simuleringar. Resultatet blev ett konstruktionsförslag för en kamerafixtur och cykeltider för att fotografera samtliga förslitningsområden för de testade verktygen i ett simuleringsprogram. Om lösningsförslaget ska implementeras i verkligheten kommer den behöva testas för att med säkerhet kunna fotografera med tillräckligt bra fokus och ljussättning samt att kamerafixturen inte blir för skakig vid rörelse med roboten. / The use of cutting tools in cutting processing cause tool wear which need be analysed and photographed to predict tool life. To analyse the tool wear you need technicians with experience with precision that is hard to repeat in which automation could be a solution. The purpose of this study is to contribute with knowledge on how you could photograph tool wear using automation and suggest a solution. This was done with a current situation analysis with the use of observation and interview of the technicians at Sandvik Coromant. A literature study was conducted to gather information about what has been done earlier in this field. Later a suggestion on the design of the camera fixture was made and simulated in a simulation program with the robotic cell to ensure it is possible to implement in real life. The result from the study suggests that the camera fixture with the current robotic cell is capable of automatically photograph the tool wear of the tested tools. If the suggested camera fixture should be implemented in real life it needs to be tested with the camera to confirm it gets good enough focus and lightning inside the CNC-machine. It also needs to be tested so it does not wobble to much with the usage of the robot.
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Tool Degradation Characterization in the Friction Stir Welding of Hard MetalsThompson, Brian Thomas 30 July 2010 (has links)
No description available.
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Vibration Assisted Drilling of Carbon Fiber Reinforced Polymer and Titanium Alloy for Aerospace ApplicationHussein, Ramy January 2019 (has links)
The physical and mechanical characteristics of carbon fiber reinforced polymers (CFRP) and Ti6Al4V make them widely used in the aerospace industry. The hybrid structure of CFRP/ Ti6Al4V material has been used in the new generation of aircraft manufacturing. The drilling process of these materials is often associated with unfavorable machining defects such as delamination, burr formation, reduced surface integrity, and tensile residual stresses. These machining defects are attributed to high thermal load, continuous chip morphology, and poor chips evacuation efficiency. Vibration-assisted drilling (VAD) uses an intermittent cutting process to control the uncut chip thickness and chip morphology. VAD has potential advantages include low thermal load, high chips evacuation effectiveness, and longer tool life.
This thesis presents an experimental investigation into the effect of VAD machining parameters on the cutting energy, CFRP delamination, surface integrity, geometrical geometry, Ti6Al4V burr formation, induced residual stresses, and tool wear during the drilling process of CFRP, Ti6Al4V, and CFRP/Ti6Al4V stacked materials. Moreover, a kinematics model is developed to link the observed results to the independent machining parameters (i.e., cutting speed, feed rate, modulation amplitude, and modulation frequency). The experimental work covers a wide range of machining parameters using four levels of frequencies (83.3, 125, 1500, and 2150 Hz).
The VAD results show up to 56 % reduction in the cutting temperature with a significant enhancement in the CFRP entry and exit delamination, geometrical accuracy, surface integrity, and burr formation. The use of VAD also generates compressive stresses, hence improving the part fatigue life. / Thesis / Doctor of Philosophy (PhD)
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Development of a Surface Roughness Prediction & Optimization Framework for CNC TurningBennett, Kristin S. January 2024 (has links)
Computer numerical control (CNC) machining is an integral element to the
manufacturing industry for production of components with requirements to meet several
outcome conditions. The surface roughness (Ra) of a workpiece is one of the most
important outcomes in finish machining processes due to it’s direct impact on the
functionality and lifespan of components in their intended applications. Several factors
contribute to the creation of Ra in machining including, but not limited to, the machining
parameters, properties of the workpiece, tool geometry and wear. Alternative to traditional
selection of machining parameters using existing standards and/or expert knowledge,
current studies in literature have examined methods to consider these factors for prediction
and optimization of machining parameters to minimize Ra. These methods span many
approaches including theoretical modelling and simulation, design of experiments,
statistical and machine learning methods. Despite the abundance of research in this area,
challenges remain regarding the generalizability of models for multiple machining
conditions, and lengthy training requirements of methods based solely on machine learning
methods. Furthermore, many machine learning methods focus on static cutting parameters
rather than consideration of properties of the tool and workpiece, and dynamic factors such
as tool wear.
The main contribution of this research was to develop a prediction and optimization
model framework to minimize Ra for finish turning that combines theoretical and machine
learning methods, and can be practically utilized by CNC machine operators for parameter
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decision making. The presented research work was divided into four distinct objectives.
The first objective of this research focused on analyzing the relationship between the
machining parameters and Ra for three different materials with varying properties (AISI
4340, AISI 316, and CGI 450). This was followed by the second objective that targeted the
development of an Ra prediction framework that utilized a kinematics-based prediction
model with an ensemble gradient boosted regression tree (GBRT) to create a multi-material
model with justified results, while strengthening accuracy with the machine learning
component. The results demonstrated the multi-material model was able to provide
predictions with a root-mean-square error (RMSE) of 0.166 μm and attained 70% of testing
predictions to fall within limits set by the ASME B46.1-2019 standard. This standard was
utilized as an efficient evaluation tool for determining if the prediction accuracy was within
an acceptable range.
The remaining objectives of this research focused on investigating the relationship
between tool wear and Ra through a focused study on AISI 316, followed by application
of the prediction model framework as the fitness function for testing of three different
metaheuristic optimization algorithms to minimize Ra. The results revealed a significant
relationship between tool wear and Ra, which enabled improvement in the prediction
framework through the use of the tool’s total cutting distance for an indicator of tool wear
as an input into the prediction model. Significant prediction improvement was achieved,
demonstrated by metrics including RMSE of 0.108 μm and 87% of predictions were within
the ASME B46.1-2019 limits. The improved prediction model was used as the fitness
function for comparison performance of genetic algorithm (GA), particle swarm
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optimization (PSO), and simulated annealing (SA), under constrained and unconstrained
conditions. SA demonstrated superior performance with less than 5% error between the
optimal and experimental Ra when constrained to the experimental data set during
validation testing. The overall results of this research establish the feasibility of a
framework that could be applied in an industrial setting for both prediction of Ra for
multiple materials, and supports the determination of parameters for minimizing Ra
considering the dynamic nature of tool wear. / Thesis / Master of Applied Science (MASc) / The surface quality produced on a workpiece via computer numerical control
(CNC) machining is influenced by many factors, including the machining parameters,
characteristics of the workpiece, and the cutting tool’s geometry and wear. When the
optimal machining parameters are not used, manufacturing companies may incur
unexpected costs associated with scrapped components, as well as time and materials
required for re-machining the component. This research focuses on developing a model to
indirectly predict surface roughness (Ra) in CNC turning, and to provide operators
guidance regarding the optimal machining parameters to ensure the machined surface is
within specifications. A multi-material Ra prediction model was produced to allow for use
under multiple machining conditions. This was enhanced by comparing three different
optimization algorithms to evaluate their suitability with the prediction framework for
providing recommendation on the optimal machining parameters, considering an indicator
for tool wear as an input factor.
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Testování nástrojů pro víceosé frézování na obráběcích centrech / Testing of cutting tools for multi-axis machining at machining centresDvořáček, Jan Unknown Date (has links)
The thesis is focused on testing of the cutting tools for machining on five axis machine tools and possibility of implementation of designed experiments in this area. The theoretical section focuses attention on analysis of specific features during five axis machining, including chip cross section and particularity of tool testing under high speed cutting conditions with consideration of dynamic stability of cutting tools. In the thesis force loading of the tool is discussed as well as its measurement process, considering force development caused by tool wear and data analysis. Description of designed experiment and its application to the area of tool testing is included as well. All theoretical predictions are followed by experimental verifying by extensive number of experimental tests, including evaluation of cutting tool condition, influence of hard coatings on cutting power of the tools, etc. For each of testing conditions are designed specific methods of processing of gathered data as well as evaluation of power of the cutting tools. Gathered data were processed by means of statistical evaluation and by statistical methods of designed experiments. The thesis contains also the extensive number of records and analysis, documented by means of light microscopy as well as electron microscopy.
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An experimental investigation into tool wear in micro-drilling of aluminium, aluminium/copper metal alloys and carbon fibre reinforced compositesCheng, Ming-Yi January 2017 (has links)
Limitation of conventional machining equipment has become a growing concern over the past two decades due to the demands for greater machining accuracy in today’s manufacturing. The development of micro-machining has therefore attracted significant attention; it signifies the advancement of national economy as well as the level of accuracy manufacturing industry could achieve. While the connection between tool lifespan, cost of machining and throughput is well established, the factor of tool lifespan appears to have more significance since the miniaturization of tool could lead to further performance concerns such as its lack of strength and durability. On the other hand, raising feed rate and spindle rotation speed are the two common approaches for increasing manufacturing throughput. Such approaches tend to cause an increase in the thrust force subjecting the tool to greater stress, which is the main cause of tool wear and even tool failure. Through literature review and preliminary experiments, it was found that spot-drill is often done prior to micro-drilling since it prepares a pre-drill countersunk hole that helps the alignment of tool for subsequent micro-drilling. Although such pre-drill step does improve the micro-drilling operation, the fundamental issue of tool diameter difference still remains. Often the tool used for pre-drill has a bigger diameter than the one for micro-drilling although a significant difference is always something to be avoided. This is because the difference has to be picked up by the tool used for micro-drilling and is directly linked to the wear caused by increased thrust force. In this research the operation of micro-drilling is investigated via mathematical models. Such operation is further broken down into various steps and stages so more detailed description can be achieved. The findings are then further enhanced by simulation based on the 3D model of micro-drilling. Three materials were selected for this research: Al 6061T, Al/Cu metal alloy panel and Carbon fibre reinforced composites. Such a selection enables the study of individual characteristics of different materials and the variation in respective thrust forces. Finally, Conclusions present the summary of the main findings from micro-drilling process analysis based on research and investigation shown in earlier chapters. By combining actual measurements on micro-drilling and mathematic model this research hopefully would improve the understanding towards micro-drilling processes.
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Optimizacija procesa elektroerozivne obrade savremenih inženjerskih materijala / Optimization of electrical discharge machining of advanced engineering materialsRodić Dragan 12 September 2019 (has links)
<p>Predmet istraživanja ove disertacije predstavlja unapređenje, modelovanje i optimizacija procesa elektroerozivne obrade (EDM) savremenih inženjerskih materijala. Prvo su predstavljene dve inovativne metode: EDM u dielektrikumu sa pomešanim prahom i EDM sa pomoćnom elektrodom, a zatim i njihova kombinacija. Za generisanje matematičkih modela primenjene su metodologija odzivne površine i alati veštačke inteligencije. U nastavku su postavljeni optimizacioni procesi određivanja ulaznih parametara sa jednom i više funkcija cilja koji su rešeni primenom klasičnih metoda optimizacije. U završnom osvrtu sprovedena je verifikacija dobijenih modela i optimalnih ulaznih parametara elektroerozivne obrade.</p> / <p>The subject of the research of this dissertation is the improvement, modeling and optimization of the electrical discharge machining (EDM) of advanced engineering materials. First, two innovation methods are presented: EDM in powder mixed dielectric fluid and EDM with assisted electrode and that their combination. The method of response surface and artificial intelligence tools were applied to generate mathematical models. The optimization problems of determining the input parameters with single and multiple target functions are solved by the application of classical optimization methods. Finally, verification of the obtained models and optimal input parameters of electrical discharge machining was carried out.</p>
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Determinação da vida de brocas utilizadas em implantodontia e influência das condições de corte / Life Twist Drills Used in Implantodology and Influence of the Cutting ConditionsCarneiro, Marcelo Bertolete 25 September 2009 (has links)
Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The aim of this work is to determine the life of twist drills used for dental implantology when
drilling bovine tibia bones and to study the influence of the cutting conditions. The inputs
variables considered were the cutting tool material, the feed velocity and the spindle speed.
The outputs variables monitored were the number of drilled holes, the workpiece
temperature, the thrust force and the tool wear. The tests were carried out in a CNC machine
center and the cutting parameters were varied following a 23 experimental design. Three
types of uncoated tool materials were used, a martensitic stainless steel (M340/Böhler), an
austenitic stainless steel (AISI 316L) and a ceramic (zircon stabilized with Y2O3). The tool
lives were expressed by the number of drilled holes considering a limit of the workpiece
temperature of 47ºC, used as the end of tool life criterion. The temperatures were monitored
by using three thermocouples of the type T (cupper-constantan) inserted in the work material
samples, positioned very close to the drill wall. The thrust force was measured with a Kistler
rotating dynamometer. A data acquisition board and a computer were used for automation of
the measurement system. A mixture of 20% of car radiator fluid and water was applied as
coolant (irrigation) with a flow rate of 160 ml/min. The results showed that the martensitic
stainless steel outperformed the austenitic stainless steel and the ceramic material. The
lowest temperatures and a conformity state at the clinic standard for thrust force values were
obtained with the highest cutting parameters (45 mm/min and 2500 rpm). It was observed
that the higher feed velocity promoted a temperature drop, while the higher spindle speed
decreased the thrust force. / O objetivo deste trabalho é determinar a vida de brocas para implantodontia através de
furação em tíbia bovina e estudar a influência das condições de corte utilizadas. As variáveis
de entrada do trabalho foram o material de ferramenta, a velocidade de avanço e a rotação.
E as variáveis de saída monitoradas foram o número de furos realizados, a temperatura
próxima à parede óssea, a força de avanço e o desgaste das ferramentas. Os testes foram
executados em um Centro de Usinagem variando os parâmetros de corte seguindo um
planejamento experimental 23. Três tipos de materiais de ferramenta não revestidos foram
utilizados, um aço inoxidável martensítico (M340/Böhler), um aço inoxidável austenítico
(AISI 316L) e um cerâmico (zircônia estabilizada com Y2O3). A vida da ferramenta foi
expressa pelo número de furos realizados considerando como critério de fim de vida a
temperatura na peça igual a 47ºC. As temperaturas foram monitoradas pelo uso de três
termopares do tipo T (cobre-constantan) inseridos no corpo-de-prova e posicionados
próximo à parede do furo. A força de avanço foi medida com um dinamômetro rotativo
Kistler. Uma placa de aquisição de dados e um computador foram utilizados para a
automação do sistema de medição. Uma mistura de 20% de líquido de arrefecimento
automotivo foi utilizada como refrigerante (irrigação) a uma vazão de 160 ml/min. Os
resultados mostraram que o aço inoxidável martensítico superou o aço inoxidável
austenítico e o material cerâmico. Menores temperaturas e um estado de conformidade aos
padrões clínicos para valores de força de avanço foram obtidos com os maiores parâmetros
de corte (45 mm/min e 2500 rpm). Observou-se que velocidade de avanço alta promove
principalmente a queda da temperatura, enquanto a rotação elevada à queda na força de
avanço. / Mestre em Engenharia Mecânica
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Testování a analýza protahovacího stroje / Testing and Analysis of a Broaching MachineDvořák, David January 2020 (has links)
This master's thesis deals with the broaching technology. Theoretical part includes the essay about the technology, tools and machines used for broaching. Theoretical part also describes the analysis of the broaching machine testing. Practical part is focused on the collecting, comparing and analysis of the data. These data have been collected during and after the broaching process. The supplier of the new analysed broaching machine is Stenhoj Hydraulik and the older machine has been made by Arpini. The measurements show that the increased number of broached pieces influence the cutting force and the quality of the surface due to wear of the tool which has been also monitored. The measuring dimension through the ball is almost constant. In the conclusion we evaluated the economical aspect of the results.
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Testování nástrojů pro víceosé frézování na obráběcích centrech / Testing of Cutting Tools for Multi-Axis Machining at Machining CentresDvořáček, Jan January 2017 (has links)
The thesis is focused on testing of the cutting tools for machining on five axis machine tools and possibility of implementation of designed experiments in this area. The theoretical section focuses attention on analysis of specific features during five axis machining, including chip cross section and particularity of tool testing under high speed cutting conditions with consideration of dynamic stability of cutting tools. In the thesis force loading of the tool is discussed as well as its measurement process, considering force development caused by tool wear and data analysis. Description of designed experiment and its application to the area of tool testing is included as well. All theoretical predictions are followed by experimental verifying by extensive number of experimental tests, including evaluation of cutting tool condition, influence of hard coatings on cutting power of the tools, etc. For each of testing conditions are designed specific methods of processing of gathered data as well as evaluation of power of the cutting tools. Gathered data were processed by means of statistical evaluation and by statistical methods of designed experiments. The thesis contains also the extensive number of records and analysis, documented by means of light microscopy as well as electron microscopy.
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