Cutting fluids are mainly used for cooling, lubricating, and chip removing. The use of minimum/minimal quantity lubrication (MQL) in machining processes not only reduces the cost of cutting fluids but also has the potential to alleviate the environmental impact. In addition, the MQL technique could be a viable choice to decrease the damage to the miniature machines due to the near-dry lubrication. Therefore, the objective of this study is aimed at the mechanical performance of MQL for micro-grinding of SK3 steels based on surface finish and tool life. In this study, it is observed that tool breaks in dry grinding or air blow grinding, and it is also found that workpiece surface is burned in dry grinding. However, these phenomena are not observed in MQL grinding. The reason is that the use of MQL reduces the friction between the tool and workpiece and improves the chip removal in micro-grinding. The use of MQL in micro-grinding also leads to better surface roughness and the tool life is more than seven times compared to dry grinding. Experimental results show that the best surface finish is achieved in MQL grinding when the use of cutting fluids is 1.88 ml/hr with the air flow rate of 30 l/min among the lubrication conditions in this study.

Surface integrity is of great significance in grinding performance since grinding process is often used as a finishing step. For metallic materials, residual stresses play an important role in surface integrity for its strong effect on fatigue life, corrosion resistance, and part distortion. For ceramic materials, the surface damage induced by grinding process could greatly affect the mechanical strength and surface finish of the component. The functional behavior of machined components can be enhanced or impaired by the grinding process. Because of this, understanding the surface integrity imparted by grinding is very important. The use of fluid is common in grinding process, however, the high cost and environmental impact of the conventional flood cooling is very undesirable. The minimum quantity lubrication (MQL) have been introduced in industry for about two decades as a promising alternative to conventional flood cooling for economical and environmental advantages. A comprehensive understanding of the MQL effect on the process performances and surface integrity is of great value to the implementation of MQL technique in industrial situation. Grinding-induced residual stress prediction has been a topic of research since the 1970’s while the studies of MQL grinding is still on the early stage with experimental investigations. A comprehensive study and quantitative description of MQL effect on the residual stress generation in grinding is highly demanded. On the other hand, although there has been significant research in the area of surface damage in ceramic grinding, there are still opportunities for advancing predictive methods. Therefore, the objectives of the current research are set as follows: (1) develop a method of predicting residual stress based on an analytical description of the grinding process under MQL condition, (2) develop a method of predicting surface finish and damage in ceramic grinding, and (3) validate the model with experimental data. The research will first focus on predicting residual stresses in MQL grinding based on first principles. This includes predictive models of grinding forces, and grinding temperature stemmed from grinding kinematics and dynamics principles as part of the overall modeling effort. The effect of MQL on both lubrication and cooling aspects has been integrated into these models. The mechanical and thermal output parameters will serve as the basis for determining the loading history which generate residual stresses. The research will also aim at surface roughness modeling in ceramic grinding. A ductile-brittle mixed surface generation is predicted based on the nature of ceramic materials and grinding kinematics. The crack system developed from indentation fracture mechanics approach will be utilized in evaluating the brittle mode surface generation. The modeling techniques will be applied to a range of grinding conditions and materials. This research would aid in evaluating various surface integrities in grinding of metallic and ceramic materials with little experimental efforts. The output could be used to machine these materials effectively to order to improve the functionality of the component.

It has been reported that minimum quantity lubrication (MQL) provides better tool life compared to flood cooling under some drilling conditions. In this study, I evaluate the performance of uncoated HSS twist drill when machining AISI 1018 steel using a newly developed lubricant designed for MQL (EQO-Kut 718 by QualiChem Inc.). A randomized factorial design was used in the experiment. The results show that a tool life of 1110 holes with a corresponding flank wear of 0.058 mm was realized.

Manufacturing by mechanical machining has historically benefited from the use of cutting fluid. Cutting fluids help to reduce temperature, friction, flush away chips, and hence prolong tool life and improve machining performance. However, uncontrolled use of cutting fluid raises concern in respect of cost and environmental burden. For these reasons, dry machining is used in conjunction with high speed machining to reduce cycle times and simultaneously deliver a greener process. However, for some workpiece materials full implementation of dry machining is not economically viable due to the absence of the essential cooling and lubricating functions delivered by cutting fluids. The most feasible bridging technology is minimum quantity lubrication (MQL) where a very small flow rate of coolant/lubricant is delivered to the cutting zones. In terms of machinability, the application of MQL is promising. However, most studies conducted on MQL focused on the feasibility of MQL application and show-casing the technical benefits. No studies had been identified in literature systematically investigating the relationship between cutting conditions and MQL with the goal of optimising the process. Moreover, the presumed environmental benefits of MQL have not been systematically assessed because Life Cycle Analysis (LCA) derived evaluation models do not explicitly model the impact of machining conditions such as feedrates, cutting velocities and depth of cut.The motivation for this PhD work was to select the optimum machining process variables for maximising effectiveness of MQL, to explore process improvements and to assess the environmental credentials of the process in relation to other forms of cutting environments. In this work, high speed, end milling tests on tool steel were undertaken and 1) Taguchi methods were used to optimise the process, 2) the sensitivity of tool wear to nozzle position was evaluated and 3) the environmental burden of dry, MQL and flood coolants were evaluated based on direct energy needs and process outputs. A fluid soaking device was used to assess the amount of fluid collected or presumed to be delivered to the cutting zone for different nozzle orientations.The Taguchi process optimisation suggested that in HSM the size effect, brought about by a low chip thickness, should be considered in the search for an optimum process window for HSM. A significant and novel finding of this PhD was the dominance of MQL nozzle positioning. The study clearly showed that when machining hardened steel at a high cutting speed and RPM the tool life could be significantly increased by 50% by adjusting the position of the nozzle toward the rake face in relation to the end-milled face. The work opens up new science and provides recommendations as to where to align the nozzle when end milling tool steel at high cutting speeds. The fluid trapping and the blade-wiping angle are key parameters that influenced the effective delivery of MQL when high spindle revolutions per minute are used. These results from the fluid soaking device were found to correlate strongly with observed machining performance evaluations.In terms of modelling, the PhD developed an improved and more generic direct energy model that can be used to determine the environmental burden for direct electrical energy requirements and the energy embodied in other process material outputs. This model addresses the system boundary and activity that within the control of the manufacturing plant. The model was used to evaluate the environmental performance of dry, flood and MQL fluids. The impact of these results and models in optimising environmental performance was also illustrated.The work in this PhD is important to industry in that it contributes to the optimisation of MQL and gives an assessment of the environmental impact. The PhD developed new and significantly important machining science in the positioning of nozzles in MQL machining at higher speeds.

Sustainable manufacturing is making products from processes which have minimal environmental impact, energy and resource efficient, economically viable and safe for consumers and society as whole. Achieving sustainability in manufacturing would mean infusing sustainability methods on product process and system level. On the process level, machining technology is one of the most widely extended processes in the industry. One way to attain sustainability in this technology is by adopting efficient management of Metal Working Fluids (MWF). In this purpose to reduce the amount of MWF starts Minimum Quantity Lubrication (MQL), where very small quantity of fluid is applied to the cutting zone with maximum precision. Moreover, addition of nanoparticles to these ´minimum quantity lubricants´ further enhances its tribological properties leading to higher reduction in friction and temperature in the machining process.The main objective of this thesis is to study the performance of cooling-lubricating fluids and these fluids modified with nanoparticles, how the use of this new lubricants improves the results obtained in material process technologies, particularly in turning. This project is being supported by the company LetsNano AB, providing the lubricants enhanced with nanoparticles and the funding, and Accu-Svenska AB, providing base oil and MQL technology.The experiments are carried out at Kungliga Tekniska Högskolan (KTH), at Institutionen för Industriell Produktion (IIP) laboratory. The turning process was tested with two different workipiece materials: hardened steel (Toolox® 44) provided by SSAB, and grey cast iron (Scania case study material). Two different tooling systems, due to the different materials. One provided by Mircona AB, and the other given directly by Scania, provided by Sandvik AB and Cermatec AB. The MQL system is a high-performance booster provided by Acuu-Svenska AB. The lubricant is a vegetable oil that will also be the base for the Nanofluids (NF). This Nanofluids and produced and developed by LetsNanoAB.The study revealed an encouraging potential of moving from conventional (dry) cooling techniques to the vegetable oil based MQL. Machining performance of MQL was encouraging as in most of the cases the systematic reduction in tool wear reveals a better machinability. The contribution of this work for Scania could help them to take the decision and move to more sustainable machining processes. To prove the potential of the nanotechnology in this kind of processes further study is needed, and it is going to be tested at IIP facilities in near future. The implementation of this technology brings more challenges that should considered a study of the hazards of the technology (emissions, fire and explosion, noise, skin…) necessary safety measures (cleaning, operator instruction, skin protection…) and modifications in the machine tools system beyond the process only. This could also be a next step in the further study of this research. / Hållbar tillverkning gör produkter från processer som har minimal miljöpåverkan, energi och resurseffektiv, ekonomiskt genomförbar och säker för konsumenterna och samhället som helhet. Att uppnå hållbarhet i tillverkningen skulle innebära infusion av hållbarhetsmetoder på produktprocess och systemnivå. På processnivå är bearbetningsteknologi en av de mest utbredda processerna inom branschen. Ett sätt att uppnå hållbarhet i denna teknik är genom att anta effektiv hantering av metallbearbetningsvätsko (MWF). I detta syfte för att minska mängden MWF startas Minimalsmörjning (MQL), där mycket liten mängd vätska appliceras på skärzonen med maximal precision. Dessutom ökar tillsatsen av nanopartiklar till dessa "minimala smörjmedel" ytterligare sina tribologiska egenskaper vilket leder till högre minskning av friktion och temperatur i bearbetningsprocessen.Huvudsyftet med denna avhandling är att studera prestanda av kylsmörjande vätskor och dessa vätskor modifierade med nanopartiklar, hur användningen av de här nya smörjmedlen förbättrar resultaten som erhållits i materialteknik, särskilt vid vridning. Projektet stöds av företaget LetsNano AB, vilket ger smörjmedlen förbättrad med nanopartiklar och finansieringen, och Accu-Svenska AB, som erbjuder basolja och MQL-teknik.Experimenten utförs vid Kungliga Tekniska Högskolan (KTH) vid Institutionen för Industriell Produktion (IIP). Vridprocessen testades med två olika material: Härdat stål (Toolox® 44) som SSAB levererade och grått gjutjärn (Scanias fallstudiematerial). Två olika verktygssystem, på grund av olika material. En som tillhandahålls av Mircona AB och den andra som ges direkt av Scania, tillhandahållen av Sandvik AB och Cermatec AB. MQL-systemet är en högpresterande booster som tillhandahålls av Acuu-Svenska AB. Smörjmedlet är en vegetabilisk olja som också kommer att vara basen för Nanofluiderna (NF). Dessa Nanofluider och produceras och utvecklas av LetsNanoAB.Studien avslöjade en uppmuntrande potential att flytta från konventionell (torr) kylningsteknik till den vegetabiliska oljebaserade MQL. Maskinens bearbetningsförmåga var uppmuntrande, eftersom i de flesta fallen den systematiska minskningen av verktygsslitaget visar bättre bearbetning. Arbetet med detta arbete för Scania kan hjälpa dem att fatta beslut och flytta till mer hållbara bearbetningsprocesser. För att bevisa nanoteknikens potential i denna typ av processer krävs ytterligare studier, och det kommer att bli testat vid IIP-anläggningar inom en snar framtid. Genomförandet av denna teknik ger fler utmaningar som bör övervägas en studie av farorna med tekniken (utsläpp, brand och explosion, buller, hud ...) nödvändiga säkerhetsåtgärder (rengöring, operatörsinstruktion, skydd mot huden ...) och modifikationer i verktygsmaskinerna system utöver processen bara. Detta kan också vara nästa steg i den fortsatta studien av denna forskning.

Inconel 617 is a nickel-based superalloy whose properties include corrosion and oxidation resistance in high temperature environments. Due to their material properties, Inconel alloys are commonly used in aerospace applications where resistance to high pressure and temperature is required. These properties also cause the material to be hard to machine due to high temperatures in the cutting zone and its tendency to work harden. This paper focuses on improving the surface integrity and tool life for turning of Inconel 617 for use in next-generation nuclear applications. Various machining parameters are tested to improve the finish and tool life such as the feed rate, cutting speed, and depth of cut. While the machining of popular Inconel grades, such as Inconel 718, have been highly studied and understood, Inconel 617 lacks the knowledge base and research to define how the alloy behaves in machining and how it compares to other grades. Tests on tool coatings confirmed that commercially available coatings are durable enough to withstand the machining of this superalloy in finish turning and determined that AlTiN coatings provide the longest tool life. The investigations performed uncovered the relationship between cutting parameters and their influence on the surface integrity and tool life. MQL deposition was tested and found to be comparable and at times better than conventional flood coolant and may be considered a replacement for coolant after more improvement. This work details the knowledge and experimental procedure used to understand the machining of this superalloy. / Thesis / Master of Applied Science (MASc) / The purpose of this research is to develop an understanding of the machining of Inconel 617 for next-generation nuclear reactors. Canada’s plan to phase out coal-fired plants and deploy new nuclear reactors is contingent on being able to manufacture the necessary components. Inconel 617 is slated to be used in these high temperature, corrosive environments due to its high strength in elevated temperatures and its resistance to corrosion. However, since the material is a recent addition to the list of compatible materials, not much research has been performed on the manufacturing of this superalloy. Factors like cutting speed, coolant, and tooling were investigated and understood with the aim of improving the cost and time associated with manufacturing these nuclear grade components.

Made available in DSpace on 2014-06-11T19:31:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-09-28Bitstream added on 2014-06-13T20:41:15Z : No. of bitstreams: 1 fernandes_ub_dr_bauru.pdf: 2660962 bytes, checksum: fc9e67e750b58c50d6c4a294d57f31a5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A operação de retificação cilíndrica interna de precisão tem sido empregada na fabricação de componentes de responsabilidade na indústria metal-mecânica em geral. As modernas retificadoras CNC aprimoraram este processo no que diz respeito ao posicionamento e à rigidez do sistema máquina-peça-ferramenta, possibilitando a obtenção de peças de elevada precisão com baixos valores de tolerâncias dimensionais. Todavia, tem-se observado nos últimos anos uma crescente conscientização quanto à toxidade dos fluidos de corte empregados na lubrificação e refrigeração da peça. Paralelamente, criou-se nos últimos anos uma rígida legislação, visando evitar uma depredação desenfreada do meio ambiente. Diante de tal conjuntura, as indústrias iniciaram uma busca a métodos alternativos de lubri-refrigeração que empregassem menores quantidades. Dentre todas as técnicas existentes à de Mínima Quantidade de Lubrificação (MQL) vem ganhando cada vez mais destaque. Tal técnica pode ser entendida como um elo de ligação entre os métodos de lubri-refrigeração convencional e a usinagem a seco. Pretende-se ainda avaliar o desempenho de um novo bocal de aspersão de fluido de corte, baseando-se no modelo desenvolvido por Webster , adequado a operação de retificação cilíndrica interna. Logo, tem-se neste trabalho, o intuito de associar estas novas tendências por meio do estudo do comportamento da operação de retificação cilíndrica interna de mergulho a alta velocidade no processo de acabamento de um aço endurecido, utilizando-se a técnica de Mínima Quantidade de Lubrificação (MQL), o modelo otimizado e ainda o modelo convencional.A análise dos dados que servirão para a avaliação dos métodos de lubri-refrigeração empregados será feita por meio dos valores de rugosidade , desvio de circularidade , micro-estrutura e micro-dureza . Espera-se, com este... / Plunge cylindrical grinding has been widely employed in the manufacture of components by the metal and mechanical industry in general. Modern CNC grinding machines improve this process in terms of the positioning and rigidity of the machine-workpiece-tool system, allowing for the fabrication of high precision workpieces with low dimensional deviations. However, over the last few years, increasing awareness has been shown regarding the toxicity of the cutting fluids employed in the lubrication and cooling of the workpiece. Concomitantly, increasingly strict legislation has been passed in recent years, aiming to prevent inrestrained destruction of the environment. This situation has prompted the industry to seek alternative lubrication and cooling methods that use lower quantities of fluids. Among the existing techniques, the Minimum Quantity Lubrication (MQL) method has gained increasing prominence. This technique can be considered a combination of the conventional cooling and dry grinding methods. An evaluation was made of the performance of a new cutting fluid dispersion nozzle, based on Webster's model, suitable for the plunge cylindrical grinding operation. The purpose of this work is to examine these new trends in a study of the behavior of highrotation plunge cylindrical grinding in the finishing operation of hardened steel, using the MQL technique, the optimized nozzle model, and the conventional model. The lubrication and cooling methods employed here are evaluated based on an analysis of the roughness, circularity deviation, microstructure, and microhardness data. The results of this study le to the conclusion that the optimized lubrication and cooling method provide the best results and that the MQL system in cylindrical grinding produced unsatisfactory results, requiring further studies aimed at solving the problems that were identified.

Resumo: A operação de retificação cilíndrica interna de precisão tem sido empregada na fabricação de componentes de responsabilidade na indústria metal-mecânica em geral. As modernas retificadoras CNC aprimoraram este processo no que diz respeito ao posicionamento e à rigidez do sistema máquina-peça-ferramenta, possibilitando a obtenção de peças de elevada precisão com baixos valores de tolerâncias dimensionais. Todavia, tem-se observado nos últimos anos uma crescente conscientização quanto à toxidade dos fluidos de corte empregados na lubrificação e refrigeração da peça. Paralelamente, criou-se nos últimos anos uma rígida legislação, visando evitar uma depredação desenfreada do meio ambiente. Diante de tal conjuntura, as indústrias iniciaram uma busca a métodos alternativos de lubri-refrigeração que empregassem menores quantidades. Dentre todas as técnicas existentes à de Mínima Quantidade de Lubrificação (MQL) vem ganhando cada vez mais destaque. Tal técnica pode ser entendida como um elo de ligação entre os métodos de lubri-refrigeração convencional e a usinagem a seco. Pretende-se ainda avaliar o desempenho de um novo bocal de aspersão de fluido de corte, baseando-se no modelo desenvolvido por Webster , adequado a operação de retificação cilíndrica interna. Logo, tem-se neste trabalho, o intuito de associar estas novas tendências por meio do estudo do comportamento da operação de retificação cilíndrica interna de mergulho a alta velocidade no processo de acabamento de um aço endurecido, utilizando-se a técnica de Mínima Quantidade de Lubrificação (MQL), o modelo otimizado e ainda o modelo convencional.A análise dos dados que servirão para a avaliação dos métodos de lubri-refrigeração empregados será feita por meio dos valores de rugosidade , desvio de circularidade , micro-estrutura e micro-dureza . Espera-se, com este... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Plunge cylindrical grinding has been widely employed in the manufacture of components by the metal and mechanical industry in general. Modern CNC grinding machines improve this process in terms of the positioning and rigidity of the machine-workpiece-tool system, allowing for the fabrication of high precision workpieces with low dimensional deviations. However, over the last few years, increasing awareness has been shown regarding the toxicity of the cutting fluids employed in the lubrication and cooling of the workpiece. Concomitantly, increasingly strict legislation has been passed in recent years, aiming to prevent inrestrained destruction of the environment. This situation has prompted the industry to seek alternative lubrication and cooling methods that use lower quantities of fluids. Among the existing techniques, the Minimum Quantity Lubrication (MQL) method has gained increasing prominence. This technique can be considered a combination of the conventional cooling and dry grinding methods. An evaluation was made of the performance of a new cutting fluid dispersion nozzle, based on Webster's model, suitable for the plunge cylindrical grinding operation. The purpose of this work is to examine these new trends in a study of the behavior of highrotation plunge cylindrical grinding in the finishing operation of hardened steel, using the MQL technique, the optimized nozzle model, and the conventional model. The lubrication and cooling methods employed here are evaluated based on an analysis of the roughness, circularity deviation, microstructure, and microhardness data. The results of this study le to the conclusion that the optimized lubrication and cooling method provide the best results and that the MQL system in cylindrical grinding produced unsatisfactory results, requiring further studies aimed at solving the problems that were identified. / Orientador: Eduardo Carlos Bianchi / Coorientador: Paulo Roberto de Aguiar / Banca: Jaime Gilberto Duduch / Banca: Olivio Novaski / Banca: Amauri Hassui / Banca: Luiz Eduardo de Angelo Sanchez / O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp / Doutor

The assessment of MQL technology application in reaming process was elaborated in this diploma work. The evaluation of energy intensity was carried out in terms of specific cutting force during reaming of austenitic stainless steel work piece by using HSS reamers. The comparison of economic costs in the case of the application of MQL technology in production was made. Confrontation of oil mist removal principles. At the conclusion the evaluation of ecological benefits for the environment and the positive influence on the working environment cleanness was defined.

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