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• Morphological study of refractory composite materials based on magnesia (MgO) with additions of hercinite (Fe2Al2O4)

  C. Gomez Rodriguez, B. Escobedo-Trujillo, L. Verdeja, D. Fernández-González, A. Fernández, L. García-Quiñónez, G. Rodríguez

  Materiales Compuestos (2024). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 5 - Materiales y Estructuras), 27

  
  

  Abstract

  Since the refractory materials are immersed in aggressive environments, the deterioration is evident because they are affected by slags, gases or liquids that corrode the material. Materials used in the refractory lining of the rotary furnace of cement are densified materials with high resistance, particularly magnesia bricks (MgO) with second phases to improve their characteristics. Within this investigation, formulations with refractory powders were developed, which were uniaxially pressed at 100 MPa and sintered at 1650 °C for four hours. Up to a maximum of 20 wt.% of hercynite (Fe2Al2O4,) was added as second phase to the refractory matrix of magnesia (MgO). The morphological characteristics as well as the mechanical properties of the sintered samples, in a conventional electric furnace, were studied by scanning electron microscopy (SEM) with Energy-dispersive X-ray spectroscopy (EDX). As a result, it was checked that, the temperature used in the experiments was not sufficient to obtain sintered specimens of the MgO powders (100 wt. %). The additions of Fe2Al2O4 helped to obtain morphologically densified specimens. A 10 and 20 wt. % of Fe2Al2O4 promoted the grain growth during the sintering process.

  Abstract
  Since the refractory materials are immersed in aggressive environments, the deterioration is evident because they are affected by slags, gases or liquids that corrode the [...]

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• Graphite-chromium carbide composites with application in heat dissipation

  D. Fernández-González, M. Suárez, J. Piñuela-Noval, C. Gomez Rodriguez, L. Díaz, A. Fernández

  Materiales Compuestos (Online first).

  
  

  Abstract

  Heat dissipation is an issue that is acquiring great importance to increase the efficiency in the utilization of the energy and extending the lifespan of the equipment. Traditionally, heat dissipation has been carried out using metals, but the increase in the requirements of equipment and devices, composites have gained importance. Graphite based composites have relevance in heat dissipation, particularly when the disperse material is a metal or metal carbide. The reason is the great value of thermal conductivity combined with good mechanical properties and lightness. Research has focused until nowadays on the composite graphite-MoC, although there are other composites with great potential, as that proposed in this manuscript: graphite- Cr3C2. The preparation of the composite graphite-Cr3C2 consisted in mechanical mixing of the staring powders, subsequent obtaining of the green compact of 40 mm in diameter and, finally, sintering at 2000 °C for 20 minutes under an applied pressure of 30 MPa in the Spark Plasma Sintering apparatus. The sintered material exhibited electrical and thermal conductivities in the in-plane direction of 1.08 MS/m and 215 W/m · °C, respectively, and a flexural strength of 113 MPa, which makes this material a suitable candidate for its application in heat dissipation.

  Abstract
  Heat dissipation is an issue that is acquiring great importance to increase the efficiency in the utilization of the energy and extending the lifespan of the equipment. Traditionally, [...]

  • 2
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