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Karen M Steel - One of the best experts on this subject based on the ideXlab platform.

  • influence of coal thermoplastic properties on coking pressure generation part 2 a study of binary coal blends and specific additives
    Fuel, 2010
    Co-Authors: John J Duffy, Merrick R Mahoney, Karen M Steel
    Abstract:

    A number of coal blends and pitch/coal blends were evaluated using rheometry, thermogravimetric analysis and microscopy to confirm and further elucidate the coking pressure mechanism previously proposed by Duffy et al. (2007) [1]. We confirm that blending a low rank, high fluidity, low coking pressure coal, with a high rank, low fluidity, high coking pressure coal can significantly reduce the coking pressure associated with the latter. Interestingly, blending does not necessarily result in a fluidity that is midway between that of the two coals; sometimes the fluidity of the blend is less than that of the low fluidity coal, especially when the coals are significantly different in rank. This occurs because the increase in complex viscosity (η*) through resolidification of the low rank, high fluidity coal counteracts the reduction in η* resulting from softening of the high rank, low fluidity coal. It has also been confirmed that the η* of the resultant blend can be estimated from the η* of each component coal using a logarithmic additivity rule commonly employed for polymer blends. Polarised light microscopy has indicated that the degree of mixing between coals of different rank is minimal, with fusion restricted to the particle surface. It is therefore inappropriate to think of such a coal blend in the same way as a single coal, since each component coal behaves relatively independently. This limited fusion is important for understanding the coking pressure mechanism for blends. It is proposed here that the lower rank coal, which softens at lower temperature, is able to expand into the interparticle voids between the high rank coal that is yet to soften, and these voids can create channels for volatiles to traverse. Then, and importantly, when the high rank coal begins to expand, the pore structure developed in the Resolidified structures of the low rank coal can facilitate removal of volatiles, while the Resolidified Material may also act as a suitable sorbent for volatile matter. This is considered to be the primary mechanism by which coal blending is able to alleviate coking pressure, and applies to addition of inert Material also. Addition of a coal tar pitch was found to increase fluidity but also to extend the thermoplastic range to lower temperatures. This caused an increase in the swelling range, which was accompanied by a long plateau in η*, a feature which has previously been observed for certain high fluidity, high pressure coals. Elasticity and η* at the onset of expansion were also higher for both the pitch impregnated coals and the high pressure blends, which supports previous findings for singly charged high pressure coals, and confirms the potential use of such criteria for identifying potentially dangerous coals/blends. © 2009 Elsevier Ltd. All rights reserved.

Franco S.d. - One of the best experts on this subject based on the ideXlab platform.

  • Analysis Of Surface Topography In Electrical Discharge Machining Of Abnt M2 High Speed Steel [análise Da Topografia Da Superfície Usinada Por Descargas Elétricas Do Aço-rápido Abnt M2]
    2015
    Co-Authors: Rodrigues J.r.p., Cruz C., Franco S.d.
    Abstract:

    The electrical discharge machining is an exceptional procedure for machining complex shapes into electric conductor Materials, mainly for those of high hardness, difficult of machining by traditional processes. At each discharge, a crater is formed in the Material and a small crater is formed in the electrode. From every molten Material produced in each discharge, only 15%, or less is removed through the dielectric liquid. The remaining of molten Material solidifies forming a wrinkled surface. The characteristics of the obtained surface, as overlap of craters, globules of sullage, "chimneys", bubbles (formed when trapped gases are released through the Resolidified Material), are revealed through an analysis by scanning electron microscopy. The proposed study aimed to examine the effect of several dielectric fluids, on the surface topography and Material removal rate, in workpiece of high speed steel (ABNT M2), during the electrical discharge machining

  • Analysis Of Surface Topography In Electrical Discharge Machining Of Abnt M2 High Speed Steel [análise Da Topografia Da Superfície Usinada Por Descargas Elétricas Do Aço-rápido Abnt M2]
    2015
    Co-Authors: Rodrigues J.r.p., Cruz C., Franco S.d.
    Abstract:

    The electrical discharge machining is an exceptional procedure for machining complex shapes into electric conductor Materials, mainly for those of high hardness, difficult of machining by traditional processes. At each discharge, a crater is formed in the Material and a small crater is formed in the electrode. From every molten Material produced in each discharge, only 15%, or less is removed through the dielectric liquid. The remaining of molten Material solidifies forming a wrinkled surface. The characteristics of the obtained surface, as overlap of craters, globules of sullage, "chimneys", bubbles (formed when trapped gases are released through the Resolidified Material), are revealed through an analysis by scanning electron microscopy. The proposed study aimed to examine the effect of several dielectric fluids, on the surface topography and Material removal rate, in workpiece of high speed steel (ABNT M2), during the electrical discharge machining.3312730Newman, S.T., State of the art electrical discharge machining (EDM) (2003) International Journal of Machine Tools and Manufacture, 43 (13), pp. 1287-1300Kumar, S., Singh, R., Singh, T.P., Sethi, B.L., Surface modification by electrical discharge machining: A review (2009) Journal of Materials Processing Technology, 209 (8), pp. 3675-3687Mahardika, M., Tsujimoto, T., Mitsui, K., A new approach on the determination of ease of machining by EDM processes (2008) International Journal of Machine Tools and Manufacture, 48 (5), pp. 746-760Rodrigues, J.R.P., Cruz, C., Franco, S.D., Assunção, W., Avaliação da geração de microtrincas do aço rápido ABNT M2 no processo EDM com adição de SiC (2008) Acta Scientiarum. Technology, 30 (2), pp. 173-179Simao, J., Lee, H.G., Aspinwall, D.K., Dewes, R.C., Aspinwall, E.M., Workpiece surface modification using electrical discharge machining (2003) International Journal of Machine Tools and Manufacture, 2 (43), pp. 121-128Singh, S., Maheshwari, S., Pandey, P.C., Some investigations into the electric discharge machining of hardened tool steel using different electrode Materials (2004) Journal of Materials Processing Technology, 12 (149), pp. 272-277Tsai, K.M., Wang, P.J., Semi-empirical model of surface finish on electrical discharge machining (2001) International Journal of Machine Tools and Manufacture, 41 (3), pp. 1455-1477Wang, Y.G., Zhao, F.L., Wang, H., A study on the effect of powder on surface quality in EDM finishing (2007) International Journal of Computer Applications in Technology, 29 (2-4), pp. 225-22

Cruz C. - One of the best experts on this subject based on the ideXlab platform.

  • Analysis Of Surface Topography In Electrical Discharge Machining Of Abnt M2 High Speed Steel [análise Da Topografia Da Superfície Usinada Por Descargas Elétricas Do Aço-rápido Abnt M2]
    2015
    Co-Authors: Rodrigues J.r.p., Cruz C., Franco S.d.
    Abstract:

    The electrical discharge machining is an exceptional procedure for machining complex shapes into electric conductor Materials, mainly for those of high hardness, difficult of machining by traditional processes. At each discharge, a crater is formed in the Material and a small crater is formed in the electrode. From every molten Material produced in each discharge, only 15%, or less is removed through the dielectric liquid. The remaining of molten Material solidifies forming a wrinkled surface. The characteristics of the obtained surface, as overlap of craters, globules of sullage, "chimneys", bubbles (formed when trapped gases are released through the Resolidified Material), are revealed through an analysis by scanning electron microscopy. The proposed study aimed to examine the effect of several dielectric fluids, on the surface topography and Material removal rate, in workpiece of high speed steel (ABNT M2), during the electrical discharge machining

  • Analysis of surface topography in electrical discharge machining of ABNT M2 high speed steel
    Brasil, 2015
    Co-Authors: Rodrigues Jrp, Cruz C., Sd Franco
    Abstract:

    Analysis of surface topography in electrical discharge machining of ABNT M2 high speed steel. The electrical discharge machining is an exceptional procedure for machining complex shapes into electric conductor Materials, mainly for those of high hardness, difficult of machining by traditional processes. At each discharge, a crater is formed in the Material and a small crater is formed in the electrode. From every molten Material produced in each discharge, only 15%, or less is removed through the dielectric liquid. The remaining of molten Material solidifies forming a wrinkled surface. The characteristics of the obtained surface, as overlap of craters, globules of sullage, "chimneys", bubbles (formed when trapped gases are released through the Resolidified Material), are revealed through an analysis by scanning electron microscopy. The proposed study aimed to examine the effect of several dielectric fluids, on the surface topography and Material removal rate, in workpiece of high speed steel (ABNT M2), during the electrical discharge machining.331273

  • Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder
    'Universidade Estadual de Maringa', 2015
    Co-Authors: Cruz C., Rodrigues Jrp, Sd Franco, De Assuncao W
    Abstract:

    Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder. It is known that Electrical Discharge Machining (EDM) is a thermal process in which extremely high temperatures (in excess of 1200 degrees C) can occur in the machining area. Consequently, it is easy to understand that during each electric discharge, high temperatures are generated, causing local fusion or even evaporation of the machined Material. In each discharge, a crater is formed in the Material and a small crater is formed in the electrode. Of every melted Material produced in each discharge, only 15% or less is removed using dielectric fluid. The remaining melted Material solidifies, forming a wrinkled surface. The characteristics of the obtained surface - overlap of craters, globules of sullage, chimneys, bubbles (formed when the gases arrested are liberated through the Resolidified Material) - are revealed through an analysis using a scanning electron microscope. The proposed work has as its objective to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2), during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presented significant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM.30217317

  • Analysis Of Surface Topography In Electrical Discharge Machining Of Abnt M2 High Speed Steel [análise Da Topografia Da Superfície Usinada Por Descargas Elétricas Do Aço-rápido Abnt M2]
    2015
    Co-Authors: Rodrigues J.r.p., Cruz C., Franco S.d.
    Abstract:

    The electrical discharge machining is an exceptional procedure for machining complex shapes into electric conductor Materials, mainly for those of high hardness, difficult of machining by traditional processes. At each discharge, a crater is formed in the Material and a small crater is formed in the electrode. From every molten Material produced in each discharge, only 15%, or less is removed through the dielectric liquid. The remaining of molten Material solidifies forming a wrinkled surface. The characteristics of the obtained surface, as overlap of craters, globules of sullage, "chimneys", bubbles (formed when trapped gases are released through the Resolidified Material), are revealed through an analysis by scanning electron microscopy. The proposed study aimed to examine the effect of several dielectric fluids, on the surface topography and Material removal rate, in workpiece of high speed steel (ABNT M2), during the electrical discharge machining.3312730Newman, S.T., State of the art electrical discharge machining (EDM) (2003) International Journal of Machine Tools and Manufacture, 43 (13), pp. 1287-1300Kumar, S., Singh, R., Singh, T.P., Sethi, B.L., Surface modification by electrical discharge machining: A review (2009) Journal of Materials Processing Technology, 209 (8), pp. 3675-3687Mahardika, M., Tsujimoto, T., Mitsui, K., A new approach on the determination of ease of machining by EDM processes (2008) International Journal of Machine Tools and Manufacture, 48 (5), pp. 746-760Rodrigues, J.R.P., Cruz, C., Franco, S.D., Assunção, W., Avaliação da geração de microtrincas do aço rápido ABNT M2 no processo EDM com adição de SiC (2008) Acta Scientiarum. Technology, 30 (2), pp. 173-179Simao, J., Lee, H.G., Aspinwall, D.K., Dewes, R.C., Aspinwall, E.M., Workpiece surface modification using electrical discharge machining (2003) International Journal of Machine Tools and Manufacture, 2 (43), pp. 121-128Singh, S., Maheshwari, S., Pandey, P.C., Some investigations into the electric discharge machining of hardened tool steel using different electrode Materials (2004) Journal of Materials Processing Technology, 12 (149), pp. 272-277Tsai, K.M., Wang, P.J., Semi-empirical model of surface finish on electrical discharge machining (2001) International Journal of Machine Tools and Manufacture, 41 (3), pp. 1455-1477Wang, Y.G., Zhao, F.L., Wang, H., A study on the effect of powder on surface quality in EDM finishing (2007) International Journal of Computer Applications in Technology, 29 (2-4), pp. 225-22

Sinésio Domingues Franco - One of the best experts on this subject based on the ideXlab platform.

  • Análise da topografia da superfície usinada por descargas elétricas do aço-rápido ABNT M2 = Analysis of surface topography in electrical discharge machining of ABNT M2 high speed steel
    Editora da Universidade Estadual de Maringá, 2011
    Co-Authors: Jean Robert Pereira Rodrigues, Claudionor Cruz, Sinésio Domingues Franco
    Abstract:

    A usinagem por descargas elétricas é um processo excepcional para usinagem de formas complexas em materiais condutores elétricos, principalmente para aqueles de alta dureza, difíceis de serem usinados por processos tradicionais. Em cada descarga, uma cratera é formada no Material e uma pequena cratera é formada no eletrodo. De todo Material fundido produzido em cada descarga, só 15%, ou menos, são removidos através do fluido dielétrico. O restante do Material fundido solidifica-se formando uma superfície rugosa. As características da superfície obtida, sobreposição de crateras, glóbulos de impurezas, “chaminés”, bolhas (formadas quando os gases presos são liberados através do Material resolidificado), são reveladas através de uma análise por microscopia eletrônica de varredura. O trabalho proposto tem por objetivo estudar o efeito de vários fluidos dielétricos, sobre topografia da superfície e taxa de remoção de Material (TRM), no aço rápido ABNT M2, durante a usinagem por descargas elétricas.The electrical discharge machining is an exceptional procedure for machining complex shapes into electric conductor Materials, mainly for those of high hardness, difficult of machining by traditional processes. At each discharge, a crater is formed in the Material and a small crater is formed in the electrode. From every molten Material produced in each discharge, only 15%, or less is removed through the dielectric liquid. The remaining of molten Material solidifies forming a wrinkled surface. The characteristics of the obtained surface, as overlap of craters, globules of sullage, “chimneys", bubbles (formed when trapped gases are released through the Resolidified Material), are revealed through an analysis by scanning electron microscopy. The proposed study aimed to examine the effect of several dielectric fluids, on the surface topography and Material removal rate, in workpiece of high speed steel (ABNT M2), during the electrical discharge machining

  • Avaliação da geração de microtrincas do aço rápido ABNT M2 no processo EDM com adição de SiC = Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder
    Editora da Universidade Estadual de Maringá, 2008
    Co-Authors: Jean Robert Pereira Rodrigues, Claudionor Cruz, Sinésio Domingues Franco, José Roberto Pereira Rodrigues, Wellinton De Assunção
    Abstract:

    É sabido que a Usinagem por Descargas Elétricas (EDM) é um processo térmico em que pode haver temperaturas muito elevadas (superiores a 1.200°C) na região de usinagem. Consequentemente é fácil de entender o fato de as peças usinadas por EDM apresentarem camadas superficiais endurecidas, refundidas e com elevado número de microtrincas superficiais. A formação de microtrincas está associada com o desenvolvimento de altas tensões térmicas que excedem a tensão máxima de resistência do Material. Além disso, as microtrincas superficiais penetram em profundidade com extensões que dependem da energia de descarga. O trabalho proposto tem por objetivo estudar o efeito da adição de pó de SiC em vários fluidos dielétricos, sobre a geração de microtrincas superficiais, no aço rápido ABNT M2, durante a usinagem por descargas elétricas. Os resultados apresentados mostramredução da quantidade de microtrincas nas superfícies usinadas, quando se adiciona pó de SiC ao dielétrico, quando comparadas com as usinadas com EDM convencional.It is known that Electrical Discharge Machining (EDM) is a thermal process in which extremely high temperatures (in excess of 1200°C) can occur in the machining area. Consequently, it is easy tounderstand that during each electric discharge, high temperatures are generated, causing local fusion or even evaporation of the machined Material. In each discharge, a crater is formed in the Material and a small crater is formed in the electrode. Of every meltedMaterial produced in each discharge, only 15% or less is removed using dielectric fluid. The remaining melted Material solidifies, forming a wrinkled surface. The characteristics of theobtained surface – overlap of craters, globules of sullage, chimneys, bubbles (formed when the gases arrested are liberated through the Resolidified Material) – are revealed through an analysis using a scanning electron microscope. The proposed work has as its objective to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2), during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presentedsignificant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM

Rodrigues Jrp - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of surface topography in electrical discharge machining of ABNT M2 high speed steel
    Brasil, 2015
    Co-Authors: Rodrigues Jrp, Cruz C., Sd Franco
    Abstract:

    Analysis of surface topography in electrical discharge machining of ABNT M2 high speed steel. The electrical discharge machining is an exceptional procedure for machining complex shapes into electric conductor Materials, mainly for those of high hardness, difficult of machining by traditional processes. At each discharge, a crater is formed in the Material and a small crater is formed in the electrode. From every molten Material produced in each discharge, only 15%, or less is removed through the dielectric liquid. The remaining of molten Material solidifies forming a wrinkled surface. The characteristics of the obtained surface, as overlap of craters, globules of sullage, "chimneys", bubbles (formed when trapped gases are released through the Resolidified Material), are revealed through an analysis by scanning electron microscopy. The proposed study aimed to examine the effect of several dielectric fluids, on the surface topography and Material removal rate, in workpiece of high speed steel (ABNT M2), during the electrical discharge machining.331273

  • Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder
    'Universidade Estadual de Maringa', 2015
    Co-Authors: Cruz C., Rodrigues Jrp, Sd Franco, De Assuncao W
    Abstract:

    Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder. It is known that Electrical Discharge Machining (EDM) is a thermal process in which extremely high temperatures (in excess of 1200 degrees C) can occur in the machining area. Consequently, it is easy to understand that during each electric discharge, high temperatures are generated, causing local fusion or even evaporation of the machined Material. In each discharge, a crater is formed in the Material and a small crater is formed in the electrode. Of every melted Material produced in each discharge, only 15% or less is removed using dielectric fluid. The remaining melted Material solidifies, forming a wrinkled surface. The characteristics of the obtained surface - overlap of craters, globules of sullage, chimneys, bubbles (formed when the gases arrested are liberated through the Resolidified Material) - are revealed through an analysis using a scanning electron microscope. The proposed work has as its objective to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2), during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presented significant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM.30217317