Marinelli, GianroccoMartina, FilomenoLewtas, HeatherHancock, DavidMehraban, ShahinLavery, NicholasGanguly, SupriyoWilliams, Stewart W.2020-01-212020-01-212019-05-01Marinelli G, Martina F, Lewtas H, et al., (2019) Microstructure and thermal properties of unalloyed tungsten deposited by Wire + Arc Additive Manufacture. Journal of Nuclear Materials, Volume 522, August 2019, pp. 45-530022-3115https://doi.org/10.1016/j.jnucmat.2019.04.049https://dspace.lib.cranfield.ac.uk/handle/1826/14973Tungsten is considered as one of the most promising materials for nuclear fusion reactor chamber applications. Wire + Arc Additive Manufacture has already demonstrated the ability to deposit defect-free large-scale tungsten structures, with considerable deposition rates. In this study, the microstructure of the as-deposited and heat-treated material has been characterized; it featured mainly large elongated grains for both conditions. The heat treatment at 1273 K for 6 h had a negligible effect on microstructure and on thermal diffusivity. Furthermore, the linear coefficient of thermal expansion was in the range of 4.5 × 10−6 μm m−1 K−1 to 6.8 × 10−6 μm m−1 K−1; the density of the deposit was as high as 99.4% of the theoretical tungsten density; the thermal diffusivity and the thermal conductivity were measured and calculated, respectively, and seen to decrease considerably in the temperature range between 300 K and 1300 K, for both testing conditions. These results showed that Wire + Arc Additive Manufacture can be considered as a suitable technology for the production of tungsten components for the nuclear sector.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/WAAMTungstenMicrostructureThermal propertiesNuclear fusionThermal conductivityArticle