Encontrados 6 documentos, a visualizar página 1 de 1
Improvement of Mechanical Properties with Non-Equimolar CrNbTaVW High Entropy A...
Antão, Francisco; Martins, Ricardo; Correia, J.B.; Silva, R.C. da; Gonçalves, António Pereira; Tejado, Elena; Pastor, Jose Ygnacio; Alves, E.ABSTRACT: CrNbTaVWx with (x = 1 and 1.7) high entropy alloys have been devised for thermal barriers between the plasma-facing tungsten tiles and the copper-based heat sink in the first wall of fusion nuclear reactors. These novel materials were prepared by ball milling and consolidated by Upgrade Field Assisted Sintering Technology at 1873 K under an applied pressure of 90 MPa for 10 min. In this work, the stru...
Damage threshold of CuCrFeTiV high entropy alloys for nuclear fusion reactors
Dias, Marta; Magalhães, S.; Antão, Francisco; Silva, R.C. da; Gonçalves, António Pereira; Carvalho, Patricia Almeida; Correia, J.B.; Galatanu, AndreiABSTRACT: A CuCrFeTiV high entropy alloy was prepared and irradiated with swift heavy ions in order to check its adequacy for use as a thermal barrier in future nuclear fusion reactors. The alloy was prepared from the elemental powders by ball milling, followed by consolidation by spark plasma sintering at 1178 K and 65 MPa. The samples were then irradiated at room temperature with 300 keV Ar+ ions with fluence...
The effects of mechanical alloying on the physical and thermal properties of Cu...
Antão, Francisco; Dias, Marta; Correia, J.B.; Galatanu, Andrei; Galatanu, M.; Mardolcar, U. V.; Myakush, A.; Cruz, M. M.; Casaca, AntónioABSTRACT: The present work reports the production and key properties of the CuCrFeTiV high entropy alloy synthetized mechanical alloying and spark plasma sintering. The milled powders and the as-sintered samples were analysed through scanning electron microscopy, coupled with energy dispersive X-ray spectroscopy and particle induced X-ray emission. Magnetic properties together with electrical resistivity, therm...
Influence of the substrate on structure and magnetic properties of Co-N thin films
Silva, C.; Vovk, A.; Silva, R.C. da; Strichonavec, P.; Algarabel, P.A.; Casaca, A.; Meneghini, C.; Carlomagno, I.; Godinho, M.; Cruz, M.M.Cubic cobalt nitride films were grown onto different single crystalline substrates Al2O3 (0 0 0 1) and (1 1 View the MathML source 0), MgO (1 0 0) and (1 1 0) and TiO2 (1 0 0) and (1 1 0). The films display low atomic densities compared with the bulk material, are ferromagnetic and have metallic electrical conductivity. X-ray diffraction and X-ray absorption fine structure confirm the cubic structure of the fil...
Stability and optical activity of Er implanted MgO
Pinto, J.V.; Silva, R.C. da; Alves, E.; Soares, M.J.; Monteiro, T.; González, R.MgO single crystals were implanted with Er ions to a fluence of 5×1015 ions/cm2. The implantations were carried out at room temperature with an energy of 150 keV. Despite the large amount of damage produced during the implantation the Er ions are incorporated in optically active sites. Photoluminescence measurements at 77 K reveal the presence of the fingerprint Er3+ emission at 1.54 μm due to 4I13/2→4I15/2 tra...
Structural and optical studies of Co and Ti implanted sapphire
Alves, E.; Marques, C.; Silva, R.C. da; Monteiro, T.; Soares, J.; McHargue, C.; Ononye, L.C.; Allard, L.F.Single crystals of α-Al2O3 with different orientations were implanted with several fluences of Ti and Co ions. For low fluences both Ti and Co ions are fully incorporated in Al lattice sites and remain stable up to annealing temperatures of 1000 °C. For fluences of 5 × 1016 cm-2 the implanted region becomes completely disordered (amorphous) for samples implanted with Ti while for Co the same condition is achiev...