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Descripción
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| Tungsten has some good high-temperature physical properties. However, is is also associated with a reduction in its mechanical properties at elevated temperatures, which is also one of the main drawbacks for tungsten being used as a plasma facing material in DEMO divertor [1]. Therefore, the main aim of this work is to improve the material properties to sustain plasma-facing conditions in divertor, especially to be able to resist high thermal loadings during operation. Among the available options, we selected the reinforcement of tungsten by incorporation of carbide nanoparticles, wherein the reinforcement should not chemically react with the matrix. In this respect, W2C nanoparticles offer an interesting option. WC nanoparticles were used as a source for the in-situ formation of W2C inclusions during the thermal treatment of powder mixtures with a field assisted sintering technique (FAST, 1900°C, 60 MPa, 5 min). In the as-sintered composites, only two phases were detected, namely cubic W and hexagonal W2C, which implies complete reaction of the selected precursor with tungsten. In addition to thorough microstructural and phase analysis, thermo-mechanical properties at room and elevated temperature, as well as high-heat-flux tests, were carried out. Results of thermo-mechanical measurements indicate that small amount (i.e. 5 wt %) of W2C reinforcements improves mechanical properties of the material, while the thermal conductivity of the composite does not drop below 100 W/m K at 1000 °C.[2] Additionally, the as-sintered samples were aged at 1250 °C and 1600 °C for 24 h. The microstructural analysis confirmed that the presence of small W2C grains enhance densification of tungsten and inhibit the tungsten grain growth at high temperatures up to at least 1250 °C. Moreover, measurements of mechanical properties confirmed the beneficial effect of W2C inclusions at tungsten grain boundaries. [1] G. Pintsuk, Reference Module in Materials Science and Materials Engineering, Comprehensive Nuclear Materials, ed. R. J. M. Konings, Elsevier: Oxford. p. 551- 581. (2012) [2] S. Novak et al., The advantageous effect of WC addition to tungsten densified by Field-Assisted-Sintering-Technology (FAST). Submitt. to J. Nucl. Mater. (2019). *Petra Jenu?: tel.: +386 1 477 3784, e-mail: petra.jenus@ijs.si (P.Jenu?) | |
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Internacional
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Si |
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Nombre congreso
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17th International Conference on Plasma-Facing Materials and Components for Fusion Applications |
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Tipo de participación
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960 |
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Lugar del congreso
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Eindhoven, Noord-Brabant, Holanda |
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Revisores
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Si |
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ISBN o ISSN
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0000-0000 |
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DOI
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Fecha inicio congreso
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21/05/2019 |
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Fecha fin congreso
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24/05/2019 |
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Desde la página
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1 |
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Hasta la página
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1 |
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Título de las actas
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Proceedings of the 17th International Conference on Plasma-Facing Materials and Components for Fusion Applications |