Orientador: Eduardo Carlos Bianchi / Banca: Rosemar Batista da Silva / Banca: Gilmar Ferreira Batalha / Resumo: Este trabalho teve o propósito de contribuir com informações sobre a aplicação de fluidos de corte na operação de retificação plana de aço, em especial do ano ABNT 4340 temperado e revenido. Desta forma testados e comparados três métodos de lubri-refrigeração, os quais são: MQL (Mínima Quantidade de Lubrificante), convencional e otimizado. Os testes foram realizados em retificadora plana universal, utilizando um rebolo de cBN Vitrificado. Os fluidos de corte utilizados para os testes foram: emulsão com diluição a 5% para os métodos convencinal e Otimizado, enquanto que para MQL utilizou-se fluido sintético. A fim de obter uma análise comparativa dos desempenhos entre os três métodos, o parâmetro profundidade de corte foi variado em três valores (0,02mm;0,05mm e 0,08mm). Os outros parâmetros de corte, os quais foram mantidos constantes. Como variáveis de saída foram analisadas: força tangencial de corte, rugosidade, desgaste diametral do rebolo, relação G, dureza por microindentação, tensão residual superficial da pela e imagens obtidas no Microscópio Eletrônico de Varredura foram também obtidas para analisar a superfície das peças usinadas. Os resultados indicaram que a técnica MQL, permite obter menor desgaste diametral do rebolo, no entanto há prejuízos quanto ao acabamento superficial (rugosidade) em profundidades de corte até 0,05mm, acima deste valor o método MQL mostrou-se incapaz de realizar a lubrirefrigeração de forma eficaz. Já o método otimizado permitiu obter os melhores resultados de rugosidade, menor desgaste diametral do rebolo e induziu menor tensão residual superficial, mas em profundidade de corte de 0,02mm apresentou os maiores valores de força de corte tangencial comparados aos outros métodos. Por fim, o método convencional apresentou resultados medianos em quase todas as variáveis de saída analisadas / Abstract: This work aims to investigate the comparative efficiency of three different colling and lubrificatins system e applied to surface grinding operation. Systems compared are MQL (Minimal Quantify Lubrification), conventional and conventional optimized. Grinding tests were performed on universal grinding machine using a vitrified cBN grinding wheel for grinding, steel samples of ABNT4340 (grade SAE4340) hardened and tempered to 55HRc. The cutting fluid used for testing was soluble oil at 5% for methods and conventional and conventional optimized and synthetic fluid for MQL technique tested. In order to obtain a comparative analysis of performance among the three methods, the depth of cut parameter was varied in three values (0,02mm, 0,05 mm, 0,08mm), the other cutting parameters were kept constant. Which one output variables investigated were: tangential cutting force, surface roughness, wheel diametrical wear, G ratio, workpiece microhardness and surface residual stress. Images obtained by scanning electron microscopy of the ground surface were used to analyze machined surfaces. The results indicated that the MQL technique allowed to prolong tool life of wheel, however there is damage on the surface finish of machined surfaces (roughness) at depths of cut up values to 0.05 mm. Above this value the MQL method proved did not provide efficiente lubrification and cooling functions. Conventional optimized method showed the best results of roughness, residual stress and least wear of wheel, bur in depth of cut 0.02 mm gave the highest values of tangential cutting force compared to other methods under conditions investigated. Finally, the conventional coolant method presented relatively satisfatory results for most output variables analyzed / Mestre

Made available in DSpace on 2014-06-11T19:28:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-06Bitstream added on 2014-06-13T19:36:43Z : No. of bitstreams: 1 moia_dfg_me_bauru.pdf: 2028523 bytes, checksum: a4957573090c9f2211022b6a4fceb9b6 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O processo de retificação confere à peça o acabamento final, minimizando as irregularidades superficiais através de interações entre os grãos abrasivos de uma ferramenta (rebolo) e peça retificada. O desgaste do rebolo devido ao atrito entre o rebolo e a peça retificada torna a ferramenta inadequada para nova utilização, sendo necessária a realização do processo de dressagem do rebolo para remoção e ou avivamento dos grãos gastos de sua superfície de corte, de forma e deixá-lo em condições para novo uso. O presente trabalho tem como objetivo classificar a condição do rebolo durante a operação de dressagem utilizando o sinal de emissão acústica (EA) e estatísticas derivadas desse sinal, por meio de redes neurais artificiais. Nos experimentos realizados usou-se um rebolo de óxido de alumínio instalado em uma retificadora plana, um sistema de aquisição de sinais e um dressador de ponta única de diamante. O processamento digital de sinais foi obtido através do software MATLAB. Os ensaios foram realizados com diferentes graus de recobrimento e profundidade de dressagem. A partir dos dados obtidos de EA puro, calculou-se o valor médio quadrático (RMS), bem como mais duas estatísticas, as quais já foram empregadas com sucesso em trabalhos de detecção de queima, no processo de retificação. Essas estatísticas também se mostraram bons indicadores para o monitoramento da operação de dressagem. Uma rede neural perceptron multicamadas (MLP) foi utilizada com o algoritmo de aprendizado Levenberg-Marquardt, cujas entradas foram as duas estatísticas mencionadas e o valor RMS de EA. Os resultados mostram que o método empregado foi capaz de classificar as condições do rebolo no processo de dressagem, identificando o rebolo como afiado (com capacidade de corte) e rebolo se afiação (com perda de capacidade de corte), viabilizando a redução do tempo e custo dessa operação e minimizando a remoção excessiva / The grinding process gives the piece a final finish by minimizing surface irregularities through interactions between the abrasive grains of a tool (wheel) and the part to be ground. The wear of the grinding wheel due to excessive friction between the grinding wheel and ground workpiece makes the tool unsuitable for further use; it is imperative the accomplishment of the process of dressing the grinding wheel to remove or resharpen the worn grains of its surface in order to make if suitable for use again. The present study aims to classify the condition of the grinding wheel during operation using acoustic emission (AE) signal and statistics derived from this sinal through artificial neural networks. In the experiments an aluminum oxide grinding wheel installed to a surface grinding machine was used along with a data acquisition system and a single point diamond dresser. The digital processing of these data was obtained using the MATLAB software. Tests were performed with different overlap ratio and depth of cut. The root mean square value of the AE signal as well as two other statistics were obtained from the raw acoustic emission signal, which have been successfully used in grinding burn detection. These statistics were also good indicators for monitoring the dressing operation. A multilayer perceptron neural network (MLP) was used with the learning algorithm Levenberg-Marquardt, whose inputs were the statistics previously mentioned and dressing conditions. The results show that the method used was able to classify the conditions of the grinding wheel in the process of dressing, identifying the wheel as sharp (cutting capacity) and dull (with loss of cutting capacity), enabling the reduction of time and cost of operation and minimizing the excessive removal of the wheel abrasive material

Orientador: Paulo Roberto de Aguiar / Banca: Carlos Elias da Silva Junior / Banca:m Eduardo Carlos Bianchi / Resumo: O processo de retificação confere à peça o acabamento final, minimizando as irregularidades superficiais através de interações entre os grãos abrasivos de uma ferramenta (rebolo) e peça retificada. O desgaste do rebolo devido ao atrito entre o rebolo e a peça retificada torna a ferramenta inadequada para nova utilização, sendo necessária a realização do processo de dressagem do rebolo para remoção e ou avivamento dos grãos gastos de sua superfície de corte, de forma e deixá-lo em condições para novo uso. O presente trabalho tem como objetivo classificar a condição do rebolo durante a operação de dressagem utilizando o sinal de emissão acústica (EA) e estatísticas derivadas desse sinal, por meio de redes neurais artificiais. Nos experimentos realizados usou-se um rebolo de óxido de alumínio instalado em uma retificadora plana, um sistema de aquisição de sinais e um dressador de ponta única de diamante. O processamento digital de sinais foi obtido através do software MATLAB. Os ensaios foram realizados com diferentes graus de recobrimento e profundidade de dressagem. A partir dos dados obtidos de EA puro, calculou-se o valor médio quadrático (RMS), bem como mais duas estatísticas, as quais já foram empregadas com sucesso em trabalhos de detecção de queima, no processo de retificação. Essas estatísticas também se mostraram bons indicadores para o monitoramento da operação de dressagem. Uma rede neural perceptron multicamadas (MLP) foi utilizada com o algoritmo de aprendizado Levenberg-Marquardt, cujas entradas foram as duas estatísticas mencionadas e o valor RMS de EA. Os resultados mostram que o método empregado foi capaz de classificar as condições do rebolo no processo de dressagem, identificando o rebolo como "afiado" (com capacidade de corte) e rebolo "se afiação" (com perda de capacidade de corte), viabilizando a redução do tempo e custo dessa operação e minimizando a remoção excessiva / Abstract: The grinding process gives the piece a final finish by minimizing surface irregularities through interactions between the abrasive grains of a tool (wheel) and the part to be ground. The wear of the grinding wheel due to excessive friction between the grinding wheel and ground workpiece makes the tool unsuitable for further use; it is imperative the accomplishment of the process of dressing the grinding wheel to remove or resharpen the worn grains of its surface in order to make if suitable for use again. The present study aims to classify the condition of the grinding wheel during operation using acoustic emission (AE) signal and statistics derived from this sinal through artificial neural networks. In the experiments an aluminum oxide grinding wheel installed to a surface grinding machine was used along with a data acquisition system and a single point diamond dresser. The digital processing of these data was obtained using the MATLAB software. Tests were performed with different overlap ratio and depth of cut. The root mean square value of the AE signal as well as two other statistics were obtained from the raw acoustic emission signal, which have been successfully used in grinding burn detection. These statistics were also good indicators for monitoring the dressing operation. A multilayer perceptron neural network (MLP) was used with the learning algorithm Levenberg-Marquardt, whose inputs were the statistics previously mentioned and dressing conditions. The results show that the method used was able to classify the conditions of the grinding wheel in the process of dressing, identifying the wheel as sharp (cutting capacity) and dull (with loss of cutting capacity), enabling the reduction of time and cost of operation and minimizing the excessive removal of the wheel abrasive material / Mestre

O presente trabalho trata da análise experimental de um sistema de monitoramento baseado na técnica de fusão de sensores, aplicado em uma retificadora cilíndrica externa. A fusão é realizada entre os sinais de potência e emissão acústica para obtenção do parâmetro FAP (Fast Abrasive Power) através do método desenvolvido por Valente (2003). Através da simulação de problemas encontrados nos processos de retificação (falha de sobremetal, colisão, desbalanceamento e vibração), foram captados os sinais de potência e emissão acústica e a partir destes gerado o parâmetro FAP, comparando seu desempenho, na detecção dos problemas, com os outros dois sinais. Para a análise foram construídos os gráficos das variações dos sinais em relação ao tempo de execução do processo e os mapas do FAP e acústico. O sistema de monitoramento avaliado tem como característica baixa complexidade de instalação e execução. Os dados experimentais revelam que o FAP apresenta uma velocidade de resposta maior que a potência e levemente amortecida em relação à emissão acústica. O nível do seu sinal é igual ao da potência mantendo-se homogêneo durante o processo, ao contrário da emissão acústica que pode ser influenciada por diversos outros parâmetros, tais como geometria da peça, distância do sensor, montagem do sensor, entre outros, que independem da interação ferramenta-peça. O resultado é uma resposta dinâmica e confiável, associada à energia do sistema. Estas características são interessantes para o monitoramento de processos de retificação (excluindo a dressagem) sendo superiores àquelas apresentadas isoladamente pelos sinais de potência e emissão acústica. / The present study deals with an experimental analysis of a monitoring system based on a sensor fusion strategy applied to a cylindrical grinding machine. It comprises a fusion of the power and acoustic emission signals and has as main goal to obtain the FAP (Fast Abrasive Power) using the method developed by Valente (2003). Initially, the power and acoustic emission signals were captured under operational dysfunction conditions during the grinding process (stock imperfection, collision, unbalancing e vibration). Then, based on these signals, the FAP parameter was generated and its capability in characterizing operational dysfunctions evaluated against the performance of an individual analysis of the power and acoustic emission signals. For this analysis, FAP and acoustic maps plus plots showing the FAP signals vs. working time were implemented. The experimental data revealed that the FAP presents a faster response than the power signal and a slightly dumped response when compared against the acoustic signal. The signal level of the FAP is similar to the power signal and is homogenous during the machining process. On contrary to the FAP, the acoustic emission signal may be affected by parameters that are not related to the tool-workpiece interactions, workpiece geometry and sensor positioning. The dynamic response of FAP is reliable and linked to the energy of the system. Finally, it should be highlightened that the monitoring system based on the FAP parameter presents low complexity in both implementation and execution. Such characteristics are superior to those observed when using either the power or acoustic emission signals and highly valuable in a system designed to monitor grinding processes.

Die Schleifbearbeitung ist häufig ein abschließender Bearbeitungsschritt, dessen Misserfolg zu hohen wirtschaftlichen Verlusten führt. Um im Vorfeld stabile Prozessparameter und optimale Schleifbahnen finden und den Bearbeitungsablauf simulativ testen zu können, werden Modelle benötigt, die die Zusammenhänge über physikalische Gesetzmäßigkeiten abbilden. In dieser Arbeit sind speziell für das Werkzeugschleifen charakteristische Eigenschaften systematisch untersucht und ein Gesamtmodell des Schleifprozesses aufgebaut worden. Die untersuchten Haupteinflüsse sind dabei die aufgrund der starken Geometrieänderung durch den Nutenschleifprozess zeitlich veränderlichen dynamischen Eigenschaften des Werkstücks und die Anregung durch die Rotation und Topographie der Schleifscheibe. Analysiert werden darüber hinaus der Materialabtrag und die Schleifkräfte in Abhängigkeit der Prozessparameter. Die Ergebnisse der Untersuchung dienen als Basis zum Aufbau effizienter, überwiegend auf physikalischen Gesetzmäßigkeiten beruhender Einzelmodelle. Mit dem gekoppelten Gesamtmodell lassen sich Schleifbearbeitungen an einseitig eingespannten und lang auskragenden Werkstücken hochdynamisch und bis zu einigen Minuten abbilden. Es können die Schleifkräfte sowie die Geometriefehler der geschliffenen Werkstücke aufgrund ihrer Durchsenkung berechnet und eine Abschätzung der Werkstücktemperatur durchgeführt werden. Darüber hinaus lässt sich das Schleifmodell zur Anpassung der Schleifbahn nutzen um die Geometriefehler zu reduzieren und die Effizienz der Bearbeitung zu steigern. Durch die physikalisch begründeten Modelle ist die systematische Untersuchung des Schleifens und der Wechselwirkungen möglich, wodurch das Verständnis des Schleifprozesses erweitert wird. / As final machine processing mostly grinding is used so failure of this production step leads to high economic losses. To avoid instable process condition, to adapt the grinding wheel path, and to simulate grinding setups in advance, efficient and physically based models are need. In this work especially the tool grinding process is analysed and characteristically effects are investigated to build up an overall grinding model. The main effects are thereby the time variant dynamical properties of the workpiece due to strong geometry changes during the flute grinding process and the excitation due to the rotation and topography of the grinding wheel. Additionally analysis of the contact conditions and grinding forces in dependency of the predefined process parameters are carried out. Based on the results of these investigation efficient models are build up to represent the behaviour mostly by physical laws. With the coupled model, grinding processes of one-sided clamped and long cantilevering workpieces can be simulated high dynamically over several minutes. It is possible to predict grinding forces and geometry errors of the ground flute due to deformation of the workpiece. Additionally the temperature of the workpiece can be estimated. Furthermore the grinding wheel path can be adapted and tested to reduce geometrical errors and to increase the efficiency of the manufacturing process. With these physically based models systematically investigations of the grinding process and the interaction are possible. With this simulation the understanding of grinding can be enhanced which is important to adapt the manufacturing process.

In popular culture, the integration of mankind and technology is often a tale of experiments gone wrong. For a biohacker, however, “going wrong” is an integral part of the project to update the human body. This study takes aim at the subculture of biohacking through the lens of technology and gender. More specifically, the intersection of gender and class in masculinist and queer constructions of identity. Additionally the study examines the entanglement of risk, gender and the body in grinder practice. Transcripts from the internet forum biohack.me were downloaded and relevant parts were selected. Through discourse analysis, articulations were read in relation to gender, class and the corporeal. The reader is provided with an outline of a “grinder subject”. This is identified as the a product of an cyber culture built on an ideology of DIY and freedom of information. It presumes an essence of humanity, uninformed by gender and body politics, just waiting to be hacked. Masculinist constructions of such a discourse includes an underdog “man-of-action hero” as a rebellion against established elites, and a technological martyrdom. The study informs the reader on an ongoing identification process regarding the integration of body and technology, beyond traditional spaces such as the research hospital. The study confirms well-established feminist views on discourses about the body and technology as implicitly gender marked as masculine. Additionally, a reluctance to discuss politics of the body as well as a indifferent or negative view of queer voices in such a situation. A rebellion against institutionalised bio-power might theoretically blend well with a corporeal feminist critique on gender, but is instead trumped by fear of ridicule and ambitions of mainstream acceptance. However, the study observes a a glimmer of traditionally marginalised and queer folk speaking up about their experiences within a context of grinding. This also questions the notion that discussions of the body and technology assert a binary gender system. A feminist theoretical view on grinder practices requires a analysis of the body open to scrutiny, modification and harm. In discussing “aftercare”, a collective/individual management of risk emerges as a gendered cyborg concept, and the body as an essential agent in the grinder project. This is articulated through encouragement and concern when presented with failed grinder projects.This further supports the entangling of the body and the biohacker subject as a corporeal and gendered agent.

Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-07-10T18:48:53Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação completa.pdf: 8076647 bytes, checksum: 5dc16e9ca5f10026afed3fda08fda16b (MD5) / Made available in DSpace on 2017-07-10T18:48:53Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação completa.pdf: 8076647 bytes, checksum: 5dc16e9ca5f10026afed3fda08fda16b (MD5) Previous issue date: 2016-05-12 / Minerais industriais em faixas ultrafinas (< 10 μm) têm suas propriedades potencializadas em relação ao mesmo mineral com maior granulometria. Os materiais ultrafinos são utilizados em diversos seguimentos industriais; por exemplo: materiais cerâmicos, papel e celulose, fármacos, polímeros e tintas. A produção de ultrafinos ocorre em moinhos de alta energia. Dentre estes, o moinho planetário de bolas destaca-se pelas altas taxas de redução de tamanho e pelo fato de poderem ser alimentados via seco ou via úmido em regime contínuo (escala industrial) ou por batelada. A produção de ultrafinos é limitada pelo consumo de energia e pela necessidade de controle das condições operacionais, tamanho, morfologia e composição das partículas. Para otimização das variáveis do processo, usam-se ferramentas computacionais embasadas em modelos matemáticos, tais como os modelos de balanço populacional (MBP), dada pela equação da moagem por batelada, e modelos energéticos. Este trabalho teve por objetivo estudar modelos cinético e energéticos, sendo o primeiro uma solução analítica da equação da moagem por batelada utilizado para descrever as distribuições de tamanhos de partículas, e o segundo dado pela relação energia-tamanho, que prevê uma taxa de redução de tamanho ilimitada, e pela relação tempo-tamanho, que está fundamentada na taxa de moagem () e no limite de moagem. Os modelos foram aplicados em duas centenas de curvas granulométricas resultantes de ensaios de moagem executados anteriormente em alíquotas de calcário e quartzo (duas procedências) com massa e granulometria controladas. Os tempos de moagem variaram de 2 a 960 minutos com velocidades de revolução de 100 a 300 rpm. Os ajustes dos modelos cinético e energéticos foram avaliados considerando os seguintes fatores: coeficiente de determinação (R2), erro padrão (EP), erro de ajuste () e índice de dependência (ID). O modelo cinético apresentou, para a maioria das condições de moagem testadas, grande incerteza associada a alguns de seus parâmetros ( > 10%), tornando os ajustes insatisfatórios segundo os critérios utilizados. Os fatores de avaliação para o modelo cinético só foram adequados para o quartzo de uma procedência, na faixa de 38x75 μm, satisfazendo a condição de compensação estabelecida. No caso dos modelos energéticos, os ajustes obtidos para a relação energiatamanho foram melhores para aquelas situações em que os diâmetros característicos não apresentaram uma estabilização em seu decrescimento. Por sua vez, a relação tempo-tamanho mostrou ajustes compatíveis com as situações em que foi observado um estado estático de decrescimento dos diâmetros característicos, atingindo o limite de moagem. A partir dos ajustes da relação tempo-tamanho foi possível determinar uma constante k’ que caracterizasse a resistência à fragmentação do material em função das condições de moagem estudadas. Os valores dessa constante mostraram que materiais mais resistentes à fragmentação possuem os menores valores de k’, que variaram entre 0,96 e 2,6 g/J para o calcário e entre 0,06 a 0,53 g/J para o quartzo. Concluiu-se, que o modelo cinético foi incompatível com a moagem ultrafina, devida a presença de eventos significativos de aglomeração e interações mecânicas multipartículas, confirmados pela variação do índice de uniformidade () com o tempo de moagem. Os modelos energéticos se complementam na descrição dos resultados experimentais. Logo um modelo intermediário que considere uma taxa de redução de tamanho como uma função potência, com um expoente e um parâmetro (l) que represente o limite de moagem, seja o mais recomendado para a representação dos processos de moagem ultrafina de minerais industriais. / Industrial minerals in ultrafine ranges (< 10 μm) have their properties potentiated compared to the same mineral with larger particle size. The ultrafine materials are used in several industries; for example, ceramics, paper and cellulose, pharmaceuticals, polymers and paints. The production of ultrafine occurs in high energy mills. Among these mills, the planetary ball mill stand out by high rates and can be fed dry or wet in continuous (industrial scale) or batch operation. The production of ultrafine is limited by the energy consumption and the need to control of the operating conditions, size, morphology and composition of the particles. Computational tools based on mathematical models are used in the optimization and control of process variables, such as the population balance models (MBP), given by equation milling batch, and energetic models. This work has as objective to study kinetic and energetic models, the first is a analytical solution for the batch grinding equation used to describe particle size distributions; the second given by the energy-size relations, which predict a size reduction rate unlimited, and by the time-size relations, which are based on the milling rate () and grinding limit. The models were applied to two hundred of particle sizes distributions curves resulting from grinding tests performed previously in aliquots of limestone and quartz (two origins) with control of mass and particle size. The milling times range 2 - 960 min with revolution speeds of 100 to 300 rpm. The fits of the kinetic and energetic models were evaluated considering the following factors: coefficient of determination (R2), standard error (SE), fit error (ε) and dependency index (ID). The kinetic model showed uncertainty associated with some of its parameters (ε > 10%) for most of the grinding conditions tested, resulting in unsatisfactory fits to the criteria used. The evaluation factors for the kinetic model were only suitable for one quartz, in the range of 38x75 μm satisfying the compensation condition. In the case of energetic models, the fits to the energy-size relation were better for those situations where the characteristic diameters did not show a stabilization in its decrease. On the other hand, the sizetime relation shown compatible fits with the situation where was observed a decrease static state of the characteristic diameters reaching the grinding limit. From the fits of the time-size relation was possible to determine a constant ′ that characterizes the resistance to fragmentation of the material depending on the grinding conditions studied. The values of this constant showed that materials more resistant to fragmentation have the smaller ′ values, ranging between 0.96 and 2.6 g/J for the limestone and from 0,06 to 0.53 g/J to quartz. It was concluded that the kinetic model was incompatible with ultrafine grinding, due to the presence of significant events of multi-particle interactions and agglomeration, which was confirmed by variation in the uniformity index (′) in milling time function. Energetic models complemented each other for description of the experimental results. Ready an intermediate model which consider a size reduction rate as a power function with an exponent η and a parameter (l) representing the grinding limit is the most recommended for the representation of the ultrafine grinding processes of industrial minerals.

This master's thesis deals with vibrodiagnostics and its use for monitoring of the vibration transmission during grinding of large shafts at Siemens Electric Machines s.r.o. based in Drásov. Diagnostic system for machine tools testing was designed as well as a measurement methodology, which is used to detect the vibration transfer from the grinding spindle to the workpiece. Influences that affect the quality of the ground surface were determined, based on evaluation of measured data. The last part is dedicated to a proposal of a diagnostic and measuring system.

In the first part of this thesis is discussed of the possibilities of surface grinding. There are described various methods for grinding and describe their characteristics. Furthermore, there is shown the marking of grinding wheels and is discussed of their composition and of calculating the cutting forces. In the second part of this thesis the experiment is performed. On the samples of various materials are monitored parameters of roughness after grinding, which is used by conventional grinding BPH 300 and horizontal lathe from company TDZ Turn.

Syftet med denna studie är att undersöka vad det är som får spelarna att stanna kvar i spelet under en spelsession. Spelmarknaden kan delas upp i två typer av spel, antingen Open World-spel där användaren fritt kan ströva omkring i en virtuell värld och ges en betydande frihet i att välja hur denne skall nå sina mål eller linjära spel där användaren styrs av start och slutscener. Det är mycket vanligt i designen av den andra varianten (linjära spel) att användaren själv, aktivt väljer att starta nästa omgång. För att begränsa omfattning på denna studie har studien gjorts på linjära spel där användaren aktivt väljer att påbörja en ny omgång och exempel på speltyper som ofta inkluderas i linjära spel är MOBA, Battle Royal eller Första Personskjutare. Detta beslut har gjorts för att kunna jämföra resultatet med andra studier om binge-beteende. Binge är ett begrepp många inte har hört idag men som det talas allt mer om. Begreppet används ofta för att beskriva konsumenter som sträcktittar på TV-serier men har även börjat appliceras på flera aktiviteter då man gör något överdrivet under en period.  För att svara på frågeställningen ”Vilka faktorer uppmuntrar användaren till ett bingebeteende?” Har jag valt att se på problemet från två olika vinklar och delat upp detta i två arbetsfrågor ”Vilka externa faktorer utanför spelets design påverkar användaren?” och ”Vilka implementerade funktioner påverkar användaren?” Resultatet från intervjustudien visar att den sociala miljön som datorspel erbjuder, men som också skapas av användaren själv genom att man bygger en social umgängeskrets i spelmiljön påverkar användaren att fortsätta spela. Under intervjuerna gav intervjupersonerna exempel på att om man blir ombedd att spela en omgång till av kompisarna eller att man har så roligt tillsammans att man inte vill avbryta så leder det till att man fortsätter spela trots att kan från början inte har planerat det.    Studien visade även på en stor betydelse av den implementerade designimplementationen grinding, förmågan att genom att spela längre låsa upp nya saker, gå upp i level eller klättra i ett rankat tävlingssystem.  En slutsats efter denna intervjustudie är att det finns bingebeteende i relation med datorspel, exakt i vilken form och till vilken grad det uppkommer beror på hur man definierar binge. Det går även påvisa att grinding och den sociala aspekten i spelen bidrar i hög grad till att spelsessionerna blir längre än vad personerna först planerade. / The purpose of this study is to investigate what causes the players to remain in the game during a game session. The gaming market can be divided into two types of games, either Open World games where the user can freely roam in a virtual world and is given considerable freedom in choosing how to achieve their goals or linear games where the user is guided by start and end scenes. It is very common in the design of the second type (linear games) that the user himself, actively chooses to start the next round. To limit the scope of this study has the study has been focused on linear games where the user actively chooses to start a new round and examples of game types that are often included in linear games are MOBA, Battle Royal or First-Person Shooter. This decision has been made to compare the results with other studies on binge behavior. Binge is a concept many have not heard about today but as it is more and more common. The term is often used to describe consumers who is watching an excessive amount of TV series but has also started to apply to several activities when doing something exaggerated during a period. To answer the question "What factors encourage the user’s binge behavior?" Have I chosen to look at the problem from two different angles and divided this into two work issues "What external factors outside the game's design affect the user?" And "What implemented functions affect the user?" The result of the interview study shows that the social environment that computer games offers, but which is also created by the user himself by building a social circle in the gaming environment, affects the user to continue playing. During the interviews, the interviewees gave for example that you have so much fun playing together that you do not want to interrupt, this will lead to them continuing to play. The study also showed a great importance of the design implementation grinding, the ability to, by playing longer, unlocking new things, increasing in levels or climbing in a ranked system. One conclusion after this interview study is that there is a binge behavior in relation to computer games, exactly in what form and to what degree it occurs depends on how one defines binge. It is also possible to demonstrate that grinding and the social aspect of the games greatly contribute to the fact that the gaming sessions are longer than the people first planned