High-entropy materials represent the state-of-the-art on alloy design strategy for future applications in extreme environments. Recent data indicates that high-entropy alloys (HEAs) exhibit outstanding radiation resistance face of existing diluted counterparts due to suppressed damage formation and evolution. An extension HEA concept is presented this paper towards synthesis characterization novel ceramics as emergent application environments where energetic particle irradiation a major...

Multicomponent carbide thin films of (CrNbTaTiW)C (30–40 at.% C) with different metal contents were deposited at temperatures using non-reactive DC magnetron sputtering. The lattice distortion for the was estimated to vary from about 3 5%. Most crystallized in cubic B1 structure but Ta/W-rich 600 °C exhibited a tetragonal distortion. X-ray diffraction results show that near-equimolar strong (111) texture. In contrast, shift (100) texture 450 °C. in-plane relationship determined...

The multicomponent alloy HfNbTiVZr has been described as a single-phase high-entropy (HEA) in the literature, although some authors have reported that additional phases can form during annealing. thermal stability of this therefore investigated with combination experimental annealing studies and thermodynamic calculations using CALPHAD approach. show HEA is stable above about 830 °C. At lower temperatures, most state phase mixture bcc, hcp, cubic C15 Laves phase. Annealing experiments...

This study explores carbon addition as a materials design approach for simultaneously improving the hardness, crack resistance, and corrosion resistance of high entropy thin films. CoCrFeMnNi was selected starting point, due to its concentration weak carbide formers. The suppression carbides is crucial approach, formation can decrease both ductility resistance. Films with 0, 6, 11 at.% C were deposited by magnetron co-sputtering, using graphite target sintered compound target. samples 0...

In this study, we show that the phase formation of HfNbTiVZr high-entropy thin films is strongly influenced by substrate temperature. Films deposited at room temperature exhibit an amorphous microstructure and are 6.5 GPa hard. With increasing (room to 275 °C), a transition from single-phased body-centred cubic (bcc) solid solution occurs, resulting in hardness increase 7.9 GPa. A higher deposition (450 °C) leads C14 or C15 Laves precipitates bcc matrix further enhancement mechanical...

Tailoring mechanical properties of transition metal carbides by substituting carbon with nitrogen atoms is a highly interesting approach, as thereby the bonding state changes towards more metallic like character and thus ductility can be increased. Based on ab initio calculations we could prove experimentally, that up to content about 68% non-metallic sublattice, Ta-C-N crystals prevail face centered cubic structure for sputter deposited thin films. The partly stabilized well Ta vacancies -...

<italic>Ab initio</italic>DFT simulations show significant charge transfer in multi-component alloys reducing atomic mismatch, which is confirmed by X-ray photoelectron spectroscopy.

Abstract The combination of ceramic hardness with high crack resistance is a major challenge in the design protective thin films. High entropy alloys have shown earlier studies promising mechanical properties potential use as film materials. In this study, we show that small amounts carbon magnetron-sputtered multicomponent CrNbTaTiW films can lead to significant increase hardness. were strongly dependent on metal composition and most results observed for TaW-rich They crystallised bcc...

Abstract The microstructure and distribution of the elements have been studied in thin films a near-equimolar CrNbTaTiW high entropy alloy (HEA) with 8 at.% carbon added to alloy. were deposited by magnetron sputtering at 300°C. X-ray diffraction shows that metallic film crystallizes single-phase body centered cubic (bcc) structure strong (110) texture. However, more detailed analyses transmission electron microscopy (TEM) atom probe tomography (APT) show segregation Ti grain boundaries...

(Ta,W) and (Ta,W):C films with ~5 at.% C were deposited by non-reactive magnetron sputtering. They crystallised in a bcc structure columnar microstructure. The solid solubility of alloys is very low, which suggests that the are supersaturated respect to carbon. This was confirmed diffraction atom probe tomography (APT) showing carbon as-deposited homogeneously distributed without carbide formation or segregation. Annealing at 900 °C for 2 h showed no significant column coarsening but an...

In this study, the relationship between nitrogen content and corrosion resistances of non-equimolar multicomponent AlCrNbYZrN films (N = 13–49 at.%) is probed. While there was no linear resistance, results clearly show that were instead determined by their nitrogen-induced porosities i.e. less porous sample, higher resistance. The 23, 30 37 at.% N samples denser while 13 sample 49 film had an underdense nanocrystalline columnar cross section permitting ingress electrolyte.

(Hf,Nb,Ti,V,Zr)Nx coatings with nitrogen content between 0 and 49 at.% were deposited by sputter deposition, thoroughly characterised. Nitrogen-free found to have a bcc structure, low hardness (8 GPa), an electrical resistivity of 144 μΩcm. The nitride (43–49 N) had NaCl-type consistent multi-component solid solution phase. Photoelectron core level binding energies indicate that the electronic structure differs from binary nitrides, probably result charge transfer metal atoms. exhibited...

Tungsten (W)-based materials attract significant attention due to their superior mechanical properties. Here, we present a chemical approach based on the addition of carbon (C) for increased strength via combination three strengthening mechanisms in W thin films. W:C films with C concentrations up ~4 at.% were deposited by magnetron sputtering. All exhibit body-centred-cubic structure strong <hh0> texture and columnar growth behaviour. X-ray electron diffraction measurements suggest...

The combination of strength and toughness is a major driving force for alloy design protective coatings, nanocrystalline tungsten (W)-alloys have shown to be promising candidates combining toughness. Here we investigate the elemental distribution fracture carbon (C) alloyed W thin films prepared by non-reactive magnetron sputtering. W:C with up ~4 at.% C crystallize in body-centered-cubic structure strong 〈hh0〉texture, no additional carbide phases are observed diffraction pattern. Atom probe...

Amorphous TaNiSiC and TaNiC films (with varying Ta/Ni Si/C ratios) were deposited using combinatorial magnetron sputtering. The remained X-ray amorphous after four hour-long annealings up to 700 °C, while alloys with high Ni C contents crystallized. These differences attributed a strong driving force for separation of in TaNiC, whereas the addition Si, due its solubility other elements, reduced elemental segregation TaNiSiC. as-deposited exhibited hardnesses 9–12 GPa. Annealing led an...

Several ternary phases are known in the Mo-Fe-B system. Previous ab initio calculations have predicted that they should exhibit a tempting mix of mechanical and magnetic properties. In this study, we deposited films with Fe-content varying from 0–37 at.% using non-reactive DC (direct current) magnetron sputtering. The phase composition, microstructure, properties were investigated X-ray diffraction, scanning transmission electron microscopy, nanoindentation measurements. Films at 300 °C...

High-entropy materials represent the state-of-the-art on alloy design strategy for future applications in extreme environments. Recent data indicates that high-entropy alloys (HEAs) exhibit outstanding radiation resistance face of existing diluted counterparts due to suppressed damage formation and evolution. An extension HEA concept is presented this paper towards synthesis characterization novel ceramics as emergent application environments where energetic particle irradiation a major...

Hard X-ray photoelectron spectroscopy (HAXPES) was used to perform a non-destructive depth profile of AlCrNbYZrNx (x = 0 ∼50 at.%) thin films. The outermost native oxide the pristine films contained highest coordination oxides every metal. Substoichiometric or oxynitrides were found underneath. After exposure 1.0 M HCl, increases in most highly coordinated Cr, Nb, and Al with up 37 at.% N observed, suggesting that low subsurface had been further oxidised intermediary compounds passivation...

Abstract High-entropy ceramics have been studied as potential candidates for applications in extreme environments, such nuclear fusion reactors. Their beneficial properties and increased radiation tolerance are often attributed to their compositional complexity achieved through equimolarity. A near-equimolar (CrNbTaTiW)C carbide, obtained by magnetron sputtering, was investigated using situ TEM whilst being exposed 300-keV Xe heavy ion irradiation at 573 K. The material did not show...

Carbon has a low solid solubility in bcc tungsten at equilibrium. However, metastable supersaturated solutions can be synthesized with magnetron sputtering. Here, we present systematic study on the phase stability and mechanical properties of such W–C solutions. Θ–2θ scans show split 200/020 002 peaks for films which is explained by tetragonal distortion structure. This increases increasing C content maximized 4 at.% C, where observe an a/b axis 3.15–3.16 Å c-axis 3.21–3.22 Å. We performed...

While transition metal carbides (TMCs) exhibit favourable mechanical properties, alloying according to the valence electron concentration (VEC) has potential further enhance properties of these hard but inherently brittle materials. This study investigates influence on microstructure and (NbxMo1-x)C carbide films, including binary references ternary compositions with varying ratios (x between 0.35 0.53). Furthermore, various substrate materials is studied by comparing films deposited Al2O3,...