Segmented diamond discs are used in cutting abrasive and fragile materials, such as masonry, conc... more Segmented diamond discs are used in cutting abrasive and fragile materials, such as masonry, concrete and marble. Their constant evolution over the past 15 years has allowed increasing the effectiveness of these operations. However, despite being widely used, there is still no standard test to assess their performance in representative conditions of a normal service. In this work a complete procedure to evaluate the disc performance is presented. To that end it was necessary to develop: a Computer Numeric Control (CNC) cutting machine, a test material, the operating conditions, the stopping criterion, and the evaluation methods (wear and depth of cut). Four brands of segmented diamond discs of 115 mm of diameter, nominated A, B, C and D respectively, were tested three times. . The tests were made cutting 45 prismatic blocks of concrete, 290 x 260 x 75 mm in size. As for the wear, the discs in groups A and D showed similar performance, while group B scored last , and group C scored b...
Nowadays, the use of computer simulation on forming processes as stamping and its variants, is an... more Nowadays, the use of computer simulation on forming processes as stamping and its variants, is an habitual development activity of big industries, and also it is slowly being introduced in SME (Small and Mediumsize Enterprise). One of the main advantages of it is application lies-in the reduction of costs regarding new projects, products and processes developments. Likewise, these tools are widely used to reproduce complex physical phenomena. During the deep drawing process, the material is mechanically stressed, therefore requires knowledge of it is properties, such as ductility, mechanical strength and plasticity. Thus, characterization tests like the Erichsen test are performed to recreate a controlled deep drawing process. In this paper, using the Simufact.Forming software, a deep drawing test was simulated, for a steel sheet DC06 IF-base, of nominal thickness 0.7mm. During the simulation is taken into account the conditions of lubrication, pressure of blank holder, dimensions o...
Abrasive-cutting processes are widely used to obtain semi-finished products from metal bars, slab... more Abrasive-cutting processes are widely used to obtain semi-finished products from metal bars, slabs, or tubes. Thus, the abrasive cutting-off process is applied when requiring precision cutting and productivity at a moderate price. Cut-off tools are discs composed of small abrasive particles embedded in a bonding material, called the binder. This work aims to compare the cutting performance of discs with different composition, in dry cutting of steel bars. To do that, disc wear was measured and disc final topography was digitalized in order to determine both disc surface wear patterns and if the abrasive particles bonding into the binder matrix was affected. In addition, X-Ray inspection gave information about the abrasive grit-binder bonding. Therefore, the method here presented allows identifying discs with a superior abrasive-cutting capability, by combining profilometry and tomography to define micrometrical aspects, grit size, and binder matrix structure. Results led to the conc...
Automotive car companies are using AHSS (advanced high strength steels) over the last 20 years, t... more Automotive car companies are using AHSS (advanced high strength steels) over the last 20 years, to reduce vehicle weight and improve safety. The new steels can achieve higher strength and good fatigue resistance, but some issues related to springback and low formability are also a big concern. Thus, companies need to extend their know-how regarding material behaviour, design rules and manufacturing processes. Therefore, materials characterization laboratories are working to obtain the new formability charts of the steels. The grid laser marking of test pieces is a recent approach. However, the marking process must accomplish three main aspects: indelibility during the tensile testing procedure, precision, and of course, it must not affect the mechanical properties of studied steels. This work is focused on the laser marking of test pieces, using Ytterbium fiber laser. A dual phase steel (JFE CA 1180) is studied. Process parameter are defined. Keywords: grid marking, laser, advanced ...
RESUMEN En la actualidad, la utilización de softwares de simulación computacional aplicados a dis... more RESUMEN En la actualidad, la utilización de softwares de simulación computacional aplicados a distintos procesos de conformado, como puede ser el estampado y sus variantes, forma parte habitual de las actividades de desarrollo de las grandes industrias, y también comienzan a introducirse lentamente dentro de las PyMEs. Una de sus principales ventajas radica en la reducción significativa de los costos de desarrollo al afrontar nuevos proyectos, tanto de nuevos productos como de procesos. Asimismo, estas herramientas son ampliamente usadas para reproducir fenómenos físicos complejos. Durante un proceso de embutido (estampado profundo de chapas), el material es fuertemente solicitado, razón por la cual se requiere de un conocimiento preciso de las propiedades del mismo, como ser la ductilidad, resistencia mecánica y plasticidad. Es por ello que, se realizan ensayos de caracterización, como puede ser el ensayo Erichsen, durante el cual se recrea de manera controlada un proceso de estira...
RESUMEN La industria del forjado como proceso de fabricación intermedio resulta de vital importan... more RESUMEN La industria del forjado como proceso de fabricación intermedio resulta de vital importancia en el desarrollo industrial de un país. En este sentido Argentina cuenta con más de 60 empresas dedicadas a la producción de piezas forjadas, principalmente de acero conformado en caliente. Sin embargo la bibliografía disponible sobre este proceso, es escasa, y la habilidad de los técnicos e ingenieros involucrados, deviene en gran parte de su experiencia profesional. Para colaborar con este sector industrial, el Grupo de Forja de INTI-Mecánica, alineado con la estrategia de desarrollo de la industria llevada adelante por el Gobierno Nacional, inició sus tareas en el año 2009. En 2012 editó su primer libro: "Práctica industrial de la forja en caliente" [1], y desde entonces, entre otras actividades, se capacita en el empleo de la herramienta de simulación de procesos de conformado Simufact.Forming [2], para dar a conocer sus capacidades de desarrollo en piezas nuevas, como ...
de V B =0,5mm con y sin lubricación. Las barras de 38mm de diámetro, fueron fijadas entre plato y... more de V B =0,5mm con y sin lubricación. Las barras de 38mm de diámetro, fueron fijadas entre plato y contrapunta, con un largo expuesto de 320mm. A partir de fijar unas condiciones de corte que garantizaron la rotura de viruta, se emplearon, una profundidad de pasada de 1,25 mm en combinación con un avance de 0,125 mm/rev, y velocidades de corte en el rango de 150 a 240 m/min. Como herramienta de corte, se usaron insertos de metal duro no recubierto, designados como CNMG 120408 de calidad ISO P40. Los resultados de los ensayos realizados, arrojaron en el torneado en seco una velocidad V 15' de 278,8m/min, es decir, un valor mayor en un 12,0% al obtenido mecanizando en húmedo. Palabras Claves: insertos, metal duro, no recubiertos, torneado, lubricación.
Through of an extensive background research on the application of numerical simulation forging pr... more Through of an extensive background research on the application of numerical simulation forging process, we have found that works is mainly aimed at: analyze and resolve defects; improve the design of the toolkit used in forming; predicting the microstructure of the material in the different phases of forging process; microforming simulation; die wear evaluation; or determining lateral forces in forging dies with close warped surfaces. On the other side, afterwards five-year relationship with the industry, we know that, with the exception of a few companies, those systems are not used in Argentine forges. Although, as Arfmann says, it is better to use them in new projects, as well the benefit of its use would be maximized by eliminating the standard uncertainty of the process of trial and error, as well as their associated costs, the using of simulation in parts already in production, can promote significant improvements. The National Institute of Industrial Technology, through the F...
Tópico: S04 -Metalurgia física, deformación plástica y propiedades mecánicas Rendimiento de inser... more Tópico: S04 -Metalurgia física, deformación plástica y propiedades mecánicas Rendimiento de insertos de metal duro no recubiertos, en operaciones de torneado. La influencia de la máquina-herramienta.
En este trabajo se pretende analizar una pieza de fundición nodular por el método de los módulos ... more En este trabajo se pretende analizar una pieza de fundición nodular por el método de los módulos geométricos y simulación computacional, con el objeto de diseñar el canal de alimentación, y verificar por simulación, el proceso de solidificación.
Se presenta el caso de la extrusión inversa de un pistón de aluminio, con el objeto de reproducir... more Se presenta el caso de la extrusión inversa de un pistón de aluminio, con el objeto de reproducir el defecto existente (fisura) en una muestra real. Una vez alcanzado este objetivo, se procedió a modificar el diseño para eliminar el defecto.
Background: Fragment analysis of exon 1 of the human androgen receptor, known as HUMARA, is a pol... more Background: Fragment analysis of exon 1 of the human androgen receptor, known as HUMARA, is a polymerase chain reaction (PCR)-based method for detecting X-linked agammaglobulinemia (XLA) carriers. This method takes advantage of X-chromosome inactivation (XCI) in female cells. XLA is caused by mutations in the Bruton tyrosine kinase (BTK) gene, located in Xq22.1. In this study, XCI is nonrandom or skewed in B cells. B cells with an active X-chromosome carrying a BTK mutation do not mature. Peripheral B cells in XLA carriers inactivate the mutated X-chromosome. Methods: HUMARA was performed using DNA from purified B cells and total leukocytes. DNA was digested using methylation-sensitive HhaI. The PCR of the HUMARA polymorphic marker was performed with the HhaI digested samples. The lengths of the PCR product were determined. If a suspected carrier showed skewed XCI in B cells, the marker length that corresponded with the length determined in the index patient indicated their carrier status. Results: HUMARA was conducted on purified B cells; this allowed easier identification of the mutated or inactive allele, as the active allele was enzymatically digested. Analysis of 30 possible carriers using modified HUMARA corroborated that the carrier status in all samples that were heterozygous for the marker using XCI calculation for leukocytes showed a Gaussian distribution, while the carrier B cell DNA showed a skewed XCI. Conclusion: Carrier status was successfully determined for most of the analyzed samples. B cell enrichment resulted in precise carrier determination data, reduced the sample size, and facilitated inactive and active allele identification.
Segmented diamond discs are used in cutting abrasive and fragile materials, such as masonry, conc... more Segmented diamond discs are used in cutting abrasive and fragile materials, such as masonry, concrete and marble. Their constant evolution over the past 15 years has allowed increasing the effectiveness of these operations. However, despite being widely used, there is still no standard test to assess their performance in representative conditions of a normal service. In this work a complete procedure to evaluate the disc performance is presented. To that end it was necessary to develop: a Computer Numeric Control (CNC) cutting machine, a test material, the operating conditions, the stopping criterion, and the evaluation methods (wear and depth of cut). Four brands of segmented diamond discs of 115 mm of diameter, nominated A, B, C and D respectively, were tested three times. . The tests were made cutting 45 prismatic blocks of concrete, 290 x 260 x 75 mm in size. As for the wear, the discs in groups A and D showed similar performance, while group B scored last , and group C scored b...
Nowadays, the use of computer simulation on forming processes as stamping and its variants, is an... more Nowadays, the use of computer simulation on forming processes as stamping and its variants, is an habitual development activity of big industries, and also it is slowly being introduced in SME (Small and Mediumsize Enterprise). One of the main advantages of it is application lies-in the reduction of costs regarding new projects, products and processes developments. Likewise, these tools are widely used to reproduce complex physical phenomena. During the deep drawing process, the material is mechanically stressed, therefore requires knowledge of it is properties, such as ductility, mechanical strength and plasticity. Thus, characterization tests like the Erichsen test are performed to recreate a controlled deep drawing process. In this paper, using the Simufact.Forming software, a deep drawing test was simulated, for a steel sheet DC06 IF-base, of nominal thickness 0.7mm. During the simulation is taken into account the conditions of lubrication, pressure of blank holder, dimensions o...
Abrasive-cutting processes are widely used to obtain semi-finished products from metal bars, slab... more Abrasive-cutting processes are widely used to obtain semi-finished products from metal bars, slabs, or tubes. Thus, the abrasive cutting-off process is applied when requiring precision cutting and productivity at a moderate price. Cut-off tools are discs composed of small abrasive particles embedded in a bonding material, called the binder. This work aims to compare the cutting performance of discs with different composition, in dry cutting of steel bars. To do that, disc wear was measured and disc final topography was digitalized in order to determine both disc surface wear patterns and if the abrasive particles bonding into the binder matrix was affected. In addition, X-Ray inspection gave information about the abrasive grit-binder bonding. Therefore, the method here presented allows identifying discs with a superior abrasive-cutting capability, by combining profilometry and tomography to define micrometrical aspects, grit size, and binder matrix structure. Results led to the conc...
Automotive car companies are using AHSS (advanced high strength steels) over the last 20 years, t... more Automotive car companies are using AHSS (advanced high strength steels) over the last 20 years, to reduce vehicle weight and improve safety. The new steels can achieve higher strength and good fatigue resistance, but some issues related to springback and low formability are also a big concern. Thus, companies need to extend their know-how regarding material behaviour, design rules and manufacturing processes. Therefore, materials characterization laboratories are working to obtain the new formability charts of the steels. The grid laser marking of test pieces is a recent approach. However, the marking process must accomplish three main aspects: indelibility during the tensile testing procedure, precision, and of course, it must not affect the mechanical properties of studied steels. This work is focused on the laser marking of test pieces, using Ytterbium fiber laser. A dual phase steel (JFE CA 1180) is studied. Process parameter are defined. Keywords: grid marking, laser, advanced ...
RESUMEN En la actualidad, la utilización de softwares de simulación computacional aplicados a dis... more RESUMEN En la actualidad, la utilización de softwares de simulación computacional aplicados a distintos procesos de conformado, como puede ser el estampado y sus variantes, forma parte habitual de las actividades de desarrollo de las grandes industrias, y también comienzan a introducirse lentamente dentro de las PyMEs. Una de sus principales ventajas radica en la reducción significativa de los costos de desarrollo al afrontar nuevos proyectos, tanto de nuevos productos como de procesos. Asimismo, estas herramientas son ampliamente usadas para reproducir fenómenos físicos complejos. Durante un proceso de embutido (estampado profundo de chapas), el material es fuertemente solicitado, razón por la cual se requiere de un conocimiento preciso de las propiedades del mismo, como ser la ductilidad, resistencia mecánica y plasticidad. Es por ello que, se realizan ensayos de caracterización, como puede ser el ensayo Erichsen, durante el cual se recrea de manera controlada un proceso de estira...
RESUMEN La industria del forjado como proceso de fabricación intermedio resulta de vital importan... more RESUMEN La industria del forjado como proceso de fabricación intermedio resulta de vital importancia en el desarrollo industrial de un país. En este sentido Argentina cuenta con más de 60 empresas dedicadas a la producción de piezas forjadas, principalmente de acero conformado en caliente. Sin embargo la bibliografía disponible sobre este proceso, es escasa, y la habilidad de los técnicos e ingenieros involucrados, deviene en gran parte de su experiencia profesional. Para colaborar con este sector industrial, el Grupo de Forja de INTI-Mecánica, alineado con la estrategia de desarrollo de la industria llevada adelante por el Gobierno Nacional, inició sus tareas en el año 2009. En 2012 editó su primer libro: "Práctica industrial de la forja en caliente" [1], y desde entonces, entre otras actividades, se capacita en el empleo de la herramienta de simulación de procesos de conformado Simufact.Forming [2], para dar a conocer sus capacidades de desarrollo en piezas nuevas, como ...
de V B =0,5mm con y sin lubricación. Las barras de 38mm de diámetro, fueron fijadas entre plato y... more de V B =0,5mm con y sin lubricación. Las barras de 38mm de diámetro, fueron fijadas entre plato y contrapunta, con un largo expuesto de 320mm. A partir de fijar unas condiciones de corte que garantizaron la rotura de viruta, se emplearon, una profundidad de pasada de 1,25 mm en combinación con un avance de 0,125 mm/rev, y velocidades de corte en el rango de 150 a 240 m/min. Como herramienta de corte, se usaron insertos de metal duro no recubierto, designados como CNMG 120408 de calidad ISO P40. Los resultados de los ensayos realizados, arrojaron en el torneado en seco una velocidad V 15' de 278,8m/min, es decir, un valor mayor en un 12,0% al obtenido mecanizando en húmedo. Palabras Claves: insertos, metal duro, no recubiertos, torneado, lubricación.
Through of an extensive background research on the application of numerical simulation forging pr... more Through of an extensive background research on the application of numerical simulation forging process, we have found that works is mainly aimed at: analyze and resolve defects; improve the design of the toolkit used in forming; predicting the microstructure of the material in the different phases of forging process; microforming simulation; die wear evaluation; or determining lateral forces in forging dies with close warped surfaces. On the other side, afterwards five-year relationship with the industry, we know that, with the exception of a few companies, those systems are not used in Argentine forges. Although, as Arfmann says, it is better to use them in new projects, as well the benefit of its use would be maximized by eliminating the standard uncertainty of the process of trial and error, as well as their associated costs, the using of simulation in parts already in production, can promote significant improvements. The National Institute of Industrial Technology, through the F...
Tópico: S04 -Metalurgia física, deformación plástica y propiedades mecánicas Rendimiento de inser... more Tópico: S04 -Metalurgia física, deformación plástica y propiedades mecánicas Rendimiento de insertos de metal duro no recubiertos, en operaciones de torneado. La influencia de la máquina-herramienta.
En este trabajo se pretende analizar una pieza de fundición nodular por el método de los módulos ... more En este trabajo se pretende analizar una pieza de fundición nodular por el método de los módulos geométricos y simulación computacional, con el objeto de diseñar el canal de alimentación, y verificar por simulación, el proceso de solidificación.
Se presenta el caso de la extrusión inversa de un pistón de aluminio, con el objeto de reproducir... more Se presenta el caso de la extrusión inversa de un pistón de aluminio, con el objeto de reproducir el defecto existente (fisura) en una muestra real. Una vez alcanzado este objetivo, se procedió a modificar el diseño para eliminar el defecto.
Background: Fragment analysis of exon 1 of the human androgen receptor, known as HUMARA, is a pol... more Background: Fragment analysis of exon 1 of the human androgen receptor, known as HUMARA, is a polymerase chain reaction (PCR)-based method for detecting X-linked agammaglobulinemia (XLA) carriers. This method takes advantage of X-chromosome inactivation (XCI) in female cells. XLA is caused by mutations in the Bruton tyrosine kinase (BTK) gene, located in Xq22.1. In this study, XCI is nonrandom or skewed in B cells. B cells with an active X-chromosome carrying a BTK mutation do not mature. Peripheral B cells in XLA carriers inactivate the mutated X-chromosome. Methods: HUMARA was performed using DNA from purified B cells and total leukocytes. DNA was digested using methylation-sensitive HhaI. The PCR of the HUMARA polymorphic marker was performed with the HhaI digested samples. The lengths of the PCR product were determined. If a suspected carrier showed skewed XCI in B cells, the marker length that corresponded with the length determined in the index patient indicated their carrier status. Results: HUMARA was conducted on purified B cells; this allowed easier identification of the mutated or inactive allele, as the active allele was enzymatically digested. Analysis of 30 possible carriers using modified HUMARA corroborated that the carrier status in all samples that were heterozygous for the marker using XCI calculation for leukocytes showed a Gaussian distribution, while the carrier B cell DNA showed a skewed XCI. Conclusion: Carrier status was successfully determined for most of the analyzed samples. B cell enrichment resulted in precise carrier determination data, reduced the sample size, and facilitated inactive and active allele identification.
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