Simulación de propiedades mecánicas demulticapas de Zr/ZrN y TiN/ZrNempleando el método de elementos finitos

In this work mechanical properties of Zr/ZrN and TiN/ZrN multilayers varying the bilayerd number in 1, 2, 5 and 10, that is, multilayer periods of 2, 1, 0.4 y 0.2 μm, with thickness constant of 2 μm in a ratio 1:1 y 1:3 were studied. For the simulation the ANSYS software was employed, based on the finite elements method. Strain–stress curves, the hardness and Young’s Modulus were obtained as function of the bilayer numbers. According, the analysis carried out, the TiN/ZrN bilayers with 1:3 ratio presented the highest hardness (31±1 GPa) regarding the others and a Young’s modulus approximately of 460 GPa. Results obtained from the mechanical properties simulations of materials |based on Ti and Zr, by using methods like finite elements are promising in the new materials field, in order to predict their performance in industrial and technological applications as hard coatings grown on several tools and machine pieces and from this way reducing the production costs. Moreover, simulations presented in this work can be extended to systems composed by other materials with great utilization.PACS: 47.11.Fg, 73.21.Ac, 87.15.La, 81.40.Lm, 81.70.Bt, 81.70.PgMSC: 76M10En este trabajo se presenta el estudio de propiedades mecánicas de multicapas de Zr/ZrN y TiN/ZrN variando el número de bicapas en 1, 2, 5 y 10, es decir, períodos de 2, 1, 0,4 y 0,2 μm, con espesor constante de 2 μm en una relación de 1:1 y 1:3. Para esta simulación se empleó el software ANSYS, el cual se basa en el método de elementos finitos. Se obtuvieron curvas de Esfuerzo– Deformación, dureza y módulo de Young en función del número de bicapas. De acuerdo al análisis realizado, las bicapas de TiN/ZrN con relación 1:3 presentan mayor dureza (31±1 GPa) en relación a los demás sistemas y un módulo de Young de aproximadamente 460 GPa. Los resultados de las simulaciones de las propiedades mecánicas de materiales basados en Ti y Zr, empleando métodos como el de elementos finitos, son prometedores en el campo de los nuevos materiales para predecir su desempeño en aplicaciones tecnológicas e industriales como recubrimientos duros sobre diferentes herramientas y piezas de maquinaria y así disminuir costos de producción. Además, las simulaciones presentadas en este trabajo pueden extenderse a sistemas compuestos de otros materiales de gran utilidad.PACS: 47.11.Fg, 73.21.Ac, 87.15.La, 81.40.Lm, 81.70.Bt, 81.70.PgMSC: 76M1

Simulación de propiedades mecánicas demulticapas de Zr/ZrN y TiN/ZrNempleando el método de elementos finitos

This paper presents the study of mechanical properties of multilayers of Zr / ZrN and TiN / ZrN by varying the number of bilayers in 1, 2, 5 and 10, that is, periods of 2, 1, 0.4 and 0.2 μm, with a constant thickness of 2 μm in a ratio of 1: 1 and 1: 3. For this simulation, the ANSYS software was used, which is based on the finite element method. Effort curves were obtained - Deformation, hardness and Young's modulus depending on the number of bilayers. According to the analysis performed, the TiN / ZrN bilayers with a 1: 3 ratio have greater hardness (31 ± 1 GPa) in relation to the other systems and a Young's modulus of approximately 460 GPa. The results of the simulations of the mechanical properties of Ti and Zr-based materials, using methods such as finite elements, are promising in the field of new materials to predict their performance in technological and industrial applications such as hard coatings on different tools and pieces of machinery and thus reduce production costs. In addition, the simulations presented in this work can be extended to systems composed of other useful materials.En este trabajo se presenta el estudio de propiedades mecánicas de multicapas de Zr/ZrN y TiN/ZrN variando el número de bicapas en 1, 2, 5 y 10, es decir, períodos de 2, 1, 0,4 y 0,2 μm, con espesor constante de 2 μm en una relación de 1:1 y 1:3. Para esta simulación se empleó el software ANSYS, el cual se basa en el método de elementos finitos. Se obtuvieron curvas de Esfuerzo– Deformación, dureza y módulo de Young en función del número de bicapas. De acuerdo al análisis realizado, las bicapas de TiN/ZrN con relación 1:3 presentan mayor dureza (31±1 GPa) en relación a los demás sistemas y un módulo de Young de aproximadamente 460 GPa. Los resultados de las simulaciones de las propiedades mecánicas de materiales basados en Ti y Zr, empleando métodos como el de elementos finitos, son prometedores en el campo de los nuevos materiales para predecir su desempeño en aplicaciones tecnológicas e industriales como recubrimientos duros sobre diferentes herramientas y piezas de maquinaria y así disminuir costos de producción. Además, las simulaciones presentadas en este trabajo pueden extenderse a sistemas compuestos de otros materiales de gran utilidad

Manipulation of Agricultural Habitats to Improve Conservation Biological Control in South America

International audienceStable and diversified agroecosystems provide farmers with important ecosystem services, which are unfortunately being lost at an alarming rate under the current conventional agriculture framework. Nevertheless, this concern can be tackled by using ecological intensification as an alternative strategy to recuperate ecosystem services (e.g., biological control of pests). To this end, the manipulation of agricultural habitats to enhance natural enemy conservation has been widely explored and reported in Western Europe and North America, whereas in other parts of the world, the investigation of such topic is lagging behind (e.g., South America). In this forum, we gathered published and unpublished information on the different ecological habitat management strategies that have been implemented in South America and their effects on pest control. Additionally, we identify the various challenges and analyze the outlook for the science of conservation biological control in South America. More specifically, we reviewed how different agricultural practices and habitat manipulation in South America have influenced pest management through natural enemy conservation. The main habitat manipulations reported include plant diversification (intercropping, insectary plants, agroforestry), conservation and management of non-crop vegetation, and application of artificial foods. Overall, we noticed that there is a significant discrepancy in the amount of research on conservation biological control among South American countries, and we found that, although intercropping, polycultures, and crop rotation have been reported in agroecosystems since pre-Inca times, more systematic studies are required to evaluate the true effects of habitat management to implement conservation biological control for pest control in South America