Additive manufacturing has developed radical through the years. Sandvik has invested in the area by building a center specific for additive manufacturing. Due to problems with the material- and product properties and high production costs no products have been used with additive manufacturing method. These aspects have improved over the years and therefore the master thesis was made with an objective: to compare two different produced blades with focus on the aspects of material- and product properties and production costs. One of the blades was produced through additive manufacturing (AM) and the other blade was produced in today’s production at Sandvik Coromant in Gimo. If the blade can be produced through AM there is a possibility to lower the production costs and improve the degree of design freedom. The material that will be used is SS2230 (50CrV4) which are used in conventionally produced blades and 1.2709 which are used in AM produced blades.   The investigation consisted of five different tests (flow rate, pressure force, vibration, fatigue and keyhole wear) and a study on production aspects with focus on value stream mapping, investments and production costs. The main objective in the result was to compare each test between the two different produced blades, not to investigate the optimal value. Therefore, was the test designed to have continuity with as small deviation as possible between the tests. This resulted in choosing values which were not optimal for the blades but focused on continuity and deviation.   The coolant channels flow rate improved with 35% on the AM produced blades but pressure force, fatigue and keyhole wear resistance did not deviate much from conventionally produced blades. Fatigue tests were made twice with two different inserts because the result from the first test differentiated too much from the expected results on both blades. Production costs will be higher with AM but on a long-term may an investment improve the degree of design freedom on a product and a possibility to produce towards costumer (just in time). This will need an expensive investment with a bigger perspective on the timeframe. The value of the product may increase but the production costs will increase too.

Phase field models have played an important role in shaping our understanding of a variety of micro structural phenomena in materials. Their attractive features include (a) their ability to capture instabilities in microstructures, and (b) their ability to handle topological transitions { such as splitting or coalescence { gracefully. Therefore, we have chosen to use a phase field model in our study of instabilities in cylindrical pores in nanoporous membranes which eventually lead to their failure. Our study is motivated by recent studies on thermal stability of nanoporous membranes of alumina, titania and zirconia. The key feature in our model is its ability to incorporate surface discussion as the mechanism for mass transport. We first benchmark the model through a critical comparison of our results on early stages of surface evolution during Rayleigh instability and grain boundary grooving with those from linear theories of these phenomena. We have then used longer simulations (which go beyond early stages, and therefore, can incorporate non-lineare effects) to study instabilities in a hollow cylinder in three different systems: single crystal or amorphous solid (which fails through Rayleigh instability), a model sys-tem with parallel grain boundaries (which fails through grain boundary grooving), and a polycrystal (whose failure depends on a combination of grain growth and grooving). In all the cases, the surface energy is assumed to be isotropic, and the operative mechanism for mass transport is assumed to be surface discussion.

The thesis in question deals with the influence of geometry of the cutting tool with a non-null angle r and of the cutting conditions on change of cutting tool’s overall deformation during the process of cutting-off and grooving. When conducting the experiments the loading of cutting tool was measured, there was created a simple 3D model of the cutting tool based on measured data, the deformation analysis of the cutting tool by the simulation programme ANSYS was performed and on the grounds of established facts there was made a conclusion on attributes of the cutting tool during the process of cutting-off and grooving.

This thesis covers matters related to high-speed digital cameras and their usage in various spheres of human activities, mainly in research of chip forming. Thesis summarises important knowledge needed for creation of high-speed recordings and choice of suitable lenses. Focus is taken on creation of high-speed recordings of chip forming process in turning operation outside grooving by using of different types of chipformers. Main goal is to verify its functionality in specific value range of feed per revolution.

Esta Dissertação tem por objetivo estudar o comportamento de diferentes materiais sob a ação de desgaste micro-abrasivo. Como parte do trabalho, foi projetada e construída uma máquina de ensaio desgaste por micro-abrasão por esfera rotativa fixa, com configuração mecânica com diferenças em relação às observadas na literatura (Gee et al., 2005). Como corpos-de-prova, foram utilizadas pastilhas intercambiáveis de metal duro (classe P20) e aço ferramenta M2. As esferas foram de aço AISI 1010 cementado e aço AISI 52100 temperado e revenido. Durante os ensaios, foi inserida entre a esfera e o corpo-de-prova uma pasta abrasiva preparada com carbeto de silício preto, com tamanho médio de partícula de 5 µm. Inicialmente, foram realizados ensaios preliminares, com a finalidade de analisar não só o comportamento do equipamento, mas também estudar a transição entre os modos de desgaste que podem ocorrer durante o desgaste micro-abrasivo. A transição entre os modos de desgaste foi estudada em função da carga normal e dos materiais utilizados durante o ensaio. Os resultados obtidos indicaram boa reprodutibilidade do equipamento e coerência com resultados da literatura. Em seguida, em ensaios denominados definitivos, foram pesquisadas as atuações dos modos de desgaste abrasivo e a obtenção do regime permanente de desgaste. Os resultados mostraram que, com a variação da distância de deslizamento, houve alterações nas ocorrências dos modos de desgaste abrasivo. Por outro lado, em alguns ensaios, o coeficiente de desgaste tendeu a permanecer constante, o que caracteriza a obtenção do regime permanente de desgaste. Entretanto, em outros, o coeficiente de desgaste teve uma evolução aleatória com a distância de deslizamento, fornecendo indicativos de que o desgaste não entrou em regime. / This work presents a study on the behavior of different materials under the action of micro-abrasive wear. A micro-abrasive wear testing machine with fixed sphere was designed and constructed, presenting a mechanical configuration with differences with respect to those found in the literature (Gee et al., 2005). M2 tool steel and WC-Co P20 were used as testing specimen materials. Ball materials were cemented AISI 1010 steel and quenched and tempered AISI 52100 steel. During the tests, an abrasive slurry, prepared with black silicon carbide (SiC) particles (average particle size of 5 µm), was supplied to the contact between the specimen and the ball. Initially, preliminary tests were conducted to study the wear mode transitions that can occur during the micro-abrasive wear and to analyze the operational conditions of the equipment. The wear mode transitions were evaluated as a function of the applied normal load and of the materials used. The results indicated good reproducibility and qualitative agreement with those found in the litarature. Later, a new set of tests was conducted, which analyzed the evolution of the abrasive wear modes and the achievement of steady state wear as a function of sliding distance. The results indicated a continuous variation in the abrasive wear modes with sliding distance. Additionally, in some tests, the wear coefficient tended to stabilize in constant value, which characterizes the achievement of steady state regime. However, in other tests, the wear coefficient presented a non constant evolution of wear coefficient with the sliding distance, which denotes that the constant regime of wear was not obtained.

O ensaio de desgaste micro-abrasivo por esfera rotativa vem conquistando elevada aceitação em universidades e centros de pesquisa, sendo amplamente adotado em estudos envolvendo desgaste abrasivo de materiais. Dois modos de desgaste abrasivo podem ser observados neste tipo de ensaio: rolamento resulta quando as partículas abrasivas rolam sobre a superfície do corpo-de-prova, enquanto riscamento é observado quando as partículas abrasivas deslizam sobre o mesmo; o tipo do modo de desgaste abrasivo apresenta uma significante influência sobre o comportamento de um sistema tribológico. Diversos trabalhos envolvendo coeficiente de atrito durante ensaios de desgaste abrasivo estão disponíveis na literatura, mas somente uma pequena parcela dedicaram-se ao estudo do coeficiente de atrito desenvolvido em ensaios de desgaste micro-abrasivo conduzidos por esfera rotativa. Adicionalmente, pesquisas preliminares reportaram que os resultados são dependentes da variação de pressão, ocasionada pela condução de ensaios sob condições de força normal constante. Logo, o propósito desta Tese de Doutorado é pesquisar a relação entre coeficiente de atrito e modos de desgaste abrasivo em ensaios desgaste micro-abrasivo por esfera rotativa, em condições de força normal constante e pressão constante. Ensaios ball-cratering foram conduzidos com esferas de aço AISI 52100 e um corpo-de-prova de aço-ferramenta AISI H10. A pasta abrasiva foi preparada com partículas de carbeto de silício (SiC) preto (tamanho médio de partícula de 3 m) e água destilada. Diferentes valores de força normal constante e pressão constante foram definidos para os experimentos. As forças normal (N) e tangencial (T) foram monitoradas continuamente durante os ensaios e a relação entre T/N foi calculada para fornecer uma indicação do coeficiente de atrito atuante no sistema tribológico esfera / partículas abrasivas / corpo-de-prova. Em todos os casos, análises por Microscopia Óptica das crateras de desgaste revelaram somente a presença de desgaste abrasivo por riscamento. Entretanto, observações mais detalhadas, conduzidas por Microscopia Eletrônica de Varredura, indicaram que diferentes níveis desgaste abrasivo por rolamento atuaram ao longo dos riscos, fenômeno nomeado de micro-rolling abrasion (microrolamento). Além disso, os resultados obtidos mostraram, também, que: i) a distância de deslizamento apresenta significante influência sobre a transição entre os modos de desgaste abrasivo, ii) para os valores de força normal constante e pressão constante adotados, o coeficiente de atrito manteve-se, aproximadamente, na mesma faixa de valores e iii) o coeficiente de atrito é independente da taxa de desgaste. / The micro-scale abrasive wear test by rotative ball has gained large acceptance in universities and research centers, being widely used in studies on the abrasive wear of materials. Two wear modes are usually observed in this type of test: rolling abrasion results when the abrasive particles roll on the surface of the tested specimen, while grooving abrasion is observed when the abrasive particles slide; the type of wear mode has a significant effect on the overall behaviour of a tribological system. Several works on the friction coefficient during abrasive wear tests are available in the literature, but only a few were dedicated to the friction coefficient in micro-abrasive wear tests conducted with rotating ball. Additionally, recent works have identified that results may also be affected by the change in contact pressure that occurs when tests are conducted with constant applied force. Thus, the purpose of this work is to study the relationship between friction coefficient and abrasive wear modes in ball-cratering wear tests conducted at constant normal force and constant pressure. Micro-scale abrasive wear tests were conducted with a ball of AISI 52100 steel and a specimen of AISI H10 tool steel. The abrasive slurry was prepared with black silicon carbide (SiC) particles (average particle size of 3 m) and distilled water. Two constant normal force values and two constant pressure values were selected for the tests. The tangential and normal loads were monitored throughout the tests and their ratio was calculated to provide an indication of the friction coefficient. In all cases, optical microscopy analysis of the worn craters revelated only the presence of grooving abrasion. However, a more detailed analysis conducted by SEM has indicated that different degrees of rolling abrasion have also occurred along the grooves. The results have also shown that: i) the sliding distance presents an important role on the wear mode transition, ii) for the selected values of constant normal force and constant pressure, the friction coefficient presented, approximately, the same range of values and ii) the friction coefficient was independent of the wear rate.

O ensaio de desgaste micro-abrasivo por esfera rotativa vem conquistando elevada aceitação em universidades e centros de pesquisa, sendo amplamente adotado em estudos envolvendo desgaste abrasivo de materiais. Dois modos de desgaste abrasivo podem ser observados neste tipo de ensaio: rolamento resulta quando as partículas abrasivas rolam sobre a superfície do corpo-de-prova, enquanto riscamento é observado quando as partículas abrasivas deslizam sobre o mesmo; o tipo do modo de desgaste abrasivo apresenta uma significante influência sobre o comportamento de um sistema tribológico. Diversos trabalhos envolvendo coeficiente de atrito durante ensaios de desgaste abrasivo estão disponíveis na literatura, mas somente uma pequena parcela dedicaram-se ao estudo do coeficiente de atrito desenvolvido em ensaios de desgaste micro-abrasivo conduzidos por esfera rotativa. Adicionalmente, pesquisas preliminares reportaram que os resultados são dependentes da variação de pressão, ocasionada pela condução de ensaios sob condições de força normal constante. Logo, o propósito desta Tese de Doutorado é pesquisar a relação entre coeficiente de atrito e modos de desgaste abrasivo em ensaios desgaste micro-abrasivo por esfera rotativa, em condições de força normal constante e pressão constante. Ensaios ball-cratering foram conduzidos com esferas de aço AISI 52100 e um corpo-de-prova de aço-ferramenta AISI H10. A pasta abrasiva foi preparada com partículas de carbeto de silício (SiC) preto (tamanho médio de partícula de 3 m) e água destilada. Diferentes valores de força normal constante e pressão constante foram definidos para os experimentos. As forças normal (N) e tangencial (T) foram monitoradas continuamente durante os ensaios e a relação entre T/N foi calculada para fornecer uma indicação do coeficiente de atrito atuante no sistema tribológico esfera / partículas abrasivas / corpo-de-prova. Em todos os casos, análises por Microscopia Óptica das crateras de desgaste revelaram somente a presença de desgaste abrasivo por riscamento. Entretanto, observações mais detalhadas, conduzidas por Microscopia Eletrônica de Varredura, indicaram que diferentes níveis desgaste abrasivo por rolamento atuaram ao longo dos riscos, fenômeno nomeado de micro-rolling abrasion (microrolamento). Além disso, os resultados obtidos mostraram, também, que: i) a distância de deslizamento apresenta significante influência sobre a transição entre os modos de desgaste abrasivo, ii) para os valores de força normal constante e pressão constante adotados, o coeficiente de atrito manteve-se, aproximadamente, na mesma faixa de valores e iii) o coeficiente de atrito é independente da taxa de desgaste. / The micro-scale abrasive wear test by rotative ball has gained large acceptance in universities and research centers, being widely used in studies on the abrasive wear of materials. Two wear modes are usually observed in this type of test: rolling abrasion results when the abrasive particles roll on the surface of the tested specimen, while grooving abrasion is observed when the abrasive particles slide; the type of wear mode has a significant effect on the overall behaviour of a tribological system. Several works on the friction coefficient during abrasive wear tests are available in the literature, but only a few were dedicated to the friction coefficient in micro-abrasive wear tests conducted with rotating ball. Additionally, recent works have identified that results may also be affected by the change in contact pressure that occurs when tests are conducted with constant applied force. Thus, the purpose of this work is to study the relationship between friction coefficient and abrasive wear modes in ball-cratering wear tests conducted at constant normal force and constant pressure. Micro-scale abrasive wear tests were conducted with a ball of AISI 52100 steel and a specimen of AISI H10 tool steel. The abrasive slurry was prepared with black silicon carbide (SiC) particles (average particle size of 3 m) and distilled water. Two constant normal force values and two constant pressure values were selected for the tests. The tangential and normal loads were monitored throughout the tests and their ratio was calculated to provide an indication of the friction coefficient. In all cases, optical microscopy analysis of the worn craters revelated only the presence of grooving abrasion. However, a more detailed analysis conducted by SEM has indicated that different degrees of rolling abrasion have also occurred along the grooves. The results have also shown that: i) the sliding distance presents an important role on the wear mode transition, ii) for the selected values of constant normal force and constant pressure, the friction coefficient presented, approximately, the same range of values and ii) the friction coefficient was independent of the wear rate.

Esta Dissertação tem por objetivo estudar o comportamento de diferentes materiais sob a ação de desgaste micro-abrasivo. Como parte do trabalho, foi projetada e construída uma máquina de ensaio desgaste por micro-abrasão por esfera rotativa fixa, com configuração mecânica com diferenças em relação às observadas na literatura (Gee et al., 2005). Como corpos-de-prova, foram utilizadas pastilhas intercambiáveis de metal duro (classe P20) e aço ferramenta M2. As esferas foram de aço AISI 1010 cementado e aço AISI 52100 temperado e revenido. Durante os ensaios, foi inserida entre a esfera e o corpo-de-prova uma pasta abrasiva preparada com carbeto de silício preto, com tamanho médio de partícula de 5 µm. Inicialmente, foram realizados ensaios preliminares, com a finalidade de analisar não só o comportamento do equipamento, mas também estudar a transição entre os modos de desgaste que podem ocorrer durante o desgaste micro-abrasivo. A transição entre os modos de desgaste foi estudada em função da carga normal e dos materiais utilizados durante o ensaio. Os resultados obtidos indicaram boa reprodutibilidade do equipamento e coerência com resultados da literatura. Em seguida, em ensaios denominados definitivos, foram pesquisadas as atuações dos modos de desgaste abrasivo e a obtenção do regime permanente de desgaste. Os resultados mostraram que, com a variação da distância de deslizamento, houve alterações nas ocorrências dos modos de desgaste abrasivo. Por outro lado, em alguns ensaios, o coeficiente de desgaste tendeu a permanecer constante, o que caracteriza a obtenção do regime permanente de desgaste. Entretanto, em outros, o coeficiente de desgaste teve uma evolução aleatória com a distância de deslizamento, fornecendo indicativos de que o desgaste não entrou em regime. / This work presents a study on the behavior of different materials under the action of micro-abrasive wear. A micro-abrasive wear testing machine with fixed sphere was designed and constructed, presenting a mechanical configuration with differences with respect to those found in the literature (Gee et al., 2005). M2 tool steel and WC-Co P20 were used as testing specimen materials. Ball materials were cemented AISI 1010 steel and quenched and tempered AISI 52100 steel. During the tests, an abrasive slurry, prepared with black silicon carbide (SiC) particles (average particle size of 5 µm), was supplied to the contact between the specimen and the ball. Initially, preliminary tests were conducted to study the wear mode transitions that can occur during the micro-abrasive wear and to analyze the operational conditions of the equipment. The wear mode transitions were evaluated as a function of the applied normal load and of the materials used. The results indicated good reproducibility and qualitative agreement with those found in the litarature. Later, a new set of tests was conducted, which analyzed the evolution of the abrasive wear modes and the achievement of steady state wear as a function of sliding distance. The results indicated a continuous variation in the abrasive wear modes with sliding distance. Additionally, in some tests, the wear coefficient tended to stabilize in constant value, which characterizes the achievement of steady state regime. However, in other tests, the wear coefficient presented a non constant evolution of wear coefficient with the sliding distance, which denotes that the constant regime of wear was not obtained.