Structural, Compositional, and Mechanical Characterization of WxCryFe1−x−y Layers Relevant to Nuclear Fusion, Obtained with TVA Technology

Abstract

Reduced activation ferritic and martensitic steel like EUROFER (9Cr-1W) are considered as potential structural materials for the first wall of the future next-generation DEMOnstration Power Station (DEMO) fusion reactor and as a reference material for the International Thermonuclear Experimental Reactor (ITER) test blanket module. The primary motivation of this work is to study the re-deposition of the main constituent materials of EUROFER, namely tungsten (W), iron (Fe), and chromium (Cr), in a DEMO type reactor by producing and analyzing complex WxCryFe1−x−y layers. The composite layers were produced in laboratory using the thermionic vacuum arc (TVA) method, and the morphology, crystalline structure, elemental composition, and mechanical properties were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-X-ray fluorescence (micro-XRF), and glow discharge optical emission spectrometry (GDOES), as well as nanoindentation and tribology measurements. The results show that the layer morphology is textured and is highly dependent on sample positioning during the deposition process. The formation of polycrystalline WxCryFe1−x−y was observed for all samples with the exception of the sample positioned closer to Fe anode during deposition. The crystalline grain size dimension varied between 10 and 20 nm. The composition and thickness of the layers were strongly influenced by the in-situ coating position, and the elemental depth profiles show a non-uniform distribution of Fe and Cr in the layers. The highest hardness was measured for the sample positioned near the Cr anode, 6.84 GPa, and the lowest was 4.84 GPa, measured for the sample positioned near the W anode. The tribology measurements showed an abrasive sliding wear behavior for most of the samples with a reduction of the friction coefficient with the increase of the normal load.

Special Issue: Carbon–Refractory Metal Nanostructures: Synthesis, Characterization and Applications

“…Reduced activation ferritic and martensitic steels, like EUROFER (9Cr-1W), are considered as potential structural materials for the first wall of the future next-generation demonstration power station (DEMO) fusion reactor and as a reference material for the International Thermonuclear Experimental Reactor (ITER) test blanket module. The primary motivation of this work is to study the re-deposition of the main constituent materials of EUROFER, namely, tungsten (W), iron (Fe), and chromium (Cr), in a DEMO-type reactor by producing and analyzing complex W x Cr y Fe 1-x-y layers produced by the same thermionic vacuum arc technology mentioned before [ 3 ].…”

Optical and Nanomechanical Properties of C Coated BN Thin Film Deposited by Thermionic Vacuum Arc Technique

“…However stainless steel and tungsten were used as well. [28][29][30][31][32][33][34][35][36][37][38] Hexagonal boron nitride (hBN) is a wide band gap ceramic material whose structure resembles graphite. 39 Also, BN is a twodimension (2D) nano material, and their properties are subject to intensive investigation.…”