Ti Si Research Articles

Structural and photoelectrochemical properties of fibrous silica-titania (FST) photocatalyst for water splitting

Photoelectrochemical (PEC) water splitting is an ecologically friendly technique that uses effective photoanodes to generate hydrogen (H2). The microemulsion approach was used to develop a distinctive form displaying fibrous silica-titania (FST) photoanode. We examined the photocatalytic attributes of FST, hematite (Fe2O3), and zinc oxide (ZnO). XRD, N2 adsorption-desorption, FESEM, TEM, FTIR, XPS, UV–vis/DRS, and EIS were used to investigate the FST, Fe2O3, and ZnO. By using these techniques, a bicontinuous concentric lamellar arrangement with an ample surface area has been developed within FST. Characterization results demonstrate that FST has superior catalytic activity when compared to Fe2O3 and ZnO. The FST photoanode has an improved photocurrent density of 11.75 mA/cm2 and a 14.1% Solar-to-hydrogen (STH %) efficacy, which is greater than ZnO and Fe2O3, which performed at 4.7 mA/cm2 and 2.8 mA/cm2 with 5.6% and 3.36% STH efficiency, respectively. Moreover, we also compared the Solar-to-hydrogen (STH %) effectiveness of FST with different of TiO2 photoanodes. We absorbed that the band gap is decreased when Ti is added to the silica matrix, which facilitates the formation of Si–Ti bonds. FST displays a remarkable closeness of its conduction band (CB) to the hydrogen reduction potential in comparison to ZnO and Fe2O3, allowing for quick electron transfer and rapid production of H2. The geometry of FST design provides a novel way for producing robust and exceptionally productive photoanodes for PEC water splitting.

Microstructure and Mechanical Properties of Diamond–Ceramic Composites Fabricated via Reactive Spark Plasma Sintering

In order to prepare diamond composites with excellent mechanical properties under non-extreme conditions, in this study, a diamond–ceramic composite was successfully prepared via reactive spark plasma sintering using a diamond–Ti–Si powder mixture as the raw material. The microstructures and mechanical properties of the diamond–ceramic composite sintered at different temperatures were studied. When the sintering temperature was 1500 °C, the diamond–ceramic composite exhibited a volume density of 3.65 g/cm3, whereas the bending strength and fracture toughness were high at 366 MPa and 6.17 MPa·m1/2, respectively. In addition, variable-temperature sintering activated the chemical reaction at a higher temperature, whereas lowering the temperature prevented excessive graphitisation, which is conducive to optimising the microstructure and mechanical properties of the composite.

Microstructural and mechanical properties of TiN/CrN and TiSiN/CrN multilayer coatings deposited in an industrial-scale HiPIMS system: Effect of the Si incorporation

Surface engineering through the deposition of advanced coatings, particularly multilayer coatings has gained significant interest for enhancing the performance of coated parts. The incorporation of Si into TiN coatings has shown promise for improving hardness, oxidation resistance, and thermal stability, while high-power impulse magnetron sputtering (HiPIMS) has emerged as a technique to deposit coatings with exceptional properties. However, TiN/CrN and TiSiN/CrN coatings deposited by HiPIMS remain relatively unexplored. In this study, different TiN/CrN and TiSiN/CrN multilayer coatings with different bilayer periods from 5 to 85 nm were deposited using an industrial-scale HiPIMS reactor, and their microstructure and mechanical properties were investigated using advanced characterization techniques. Results revealed successful deposition of smooth and compact coatings with controlled bilayer periods. X-ray diffraction analysis showed separate crystalline phases for coatings with high bilayer periods, while those with smaller bilayer periods exhibited peak-overlapping and superlattice overtones, especially for the TiN/CrN coatings. Epitaxial grain growth was confirmed by high-resolution transmission electron microscopy (HRTEM). HRTEM and electron energy-loss spectroscopy measurements confirmed Si incorporation into the TiN crystal lattice of TiSiN/CrN coatings reducing the crystallinity, especially for coatings with smaller bilayer periods. Nanoindentation tests revealed that coatings with a bilayer period of 15–20 nm displayed the highest hardness values regardless of the composition. The mechanical properties of the TiSiN/CrN coatings showed no improvement over those of the TiN/CrN coatings, attributed to the Si induced amorphization of the Ti(Si)N phase and the absence of SiNx phase segregation within the TiN nanocrystals in these coatings. These findings provide valuable insights into the microstructure and mechanical properties of TiN/CrN and TiSiN/CrN multilayer coatings deposited by HiPIMS in an industrial scale reactor, paving the way for their application in various industrial sectors.

Hot corrosion behavior of Mo–Si–Ti alloys

AbstractThe hot corrosion behavior of two ternary Mo–Si–Ti alloys (eutectic Mo–20.0Si–52.8Ti (at.%) and eutectoid Mo–21.0Si–34.0Ti (at.%)) was investigated at C and C for up to 100 h. Both Mo‐based alloys evidenced a hot corrosion attack, resulting in a uniform attack of the substrate surface. The higher Ti content of the eutectic alloy significantly reduced the formation of solid and volatile Mo oxides compared with the eutectoid alloy. After 24 h at C, the corrosion products formed on the eutectic alloy were only one‐tenth the thickness of the layers formed on the eutectoid alloy. The corrosion products were examined with optical and electron microscopy. Semiquantitative electron probe micro analysis and X‐ray diffraction measurements were used to identify the formed phases. The underlying corrosion mechanisms comprising not only hot corrosion‐induced fluxing but also oxidation‐induced pesting are discussed in detail.

Thermodynamic modelling on the reaction between steel and slag

An integrated thermodynamic model was developed to determine the equilibrium between the slag and the steel at high temperatures, employing the Unified Interaction Parameter Formalism (UIPF) and the Associate Model (AM) for a twelve-element molten steel system (Fe–Al–C–Ca–Cr–Mg–Mn–N–O–S–Si–Ti). A model for slag activity was based on the Ion and Molecular Coexistence Theory (IMCT) and applied to a refining slag system (CaO–MgO–FeO–MnO–CaF2–SiO2–Al2O3–Fe2O3). Comparative analyses were conducted using FactSage software and experimental data, validating the accuracy of the established model. The impact of slag modifiers, specifically aluminum granules, on slag oxidability, and the role of CaO/Al2O3 ratio in slag desulfurization were investigated. The effect of slag modifier on the oxidability and the influence of CaO/Al2O3 on the desulfurization of the slag were determined using the current model. Aluminum in the slag modifier reacted with MnO and FeO in the slag, thereby reducing the oxidability of the slag. With a 30 wt% slag modifier, the MnO content in the slag (initially 15 wt%) stabilized and showed minimal change, dropping below 1 wt%. An increase in CaO content above 80 wt% in the slag led to a reduction of equilibrium sulfur in the steel to below 10 ppm. Little amount of calcium transferred from the slag into the steel with the increase in CaO content, but the [Ca] content remained below 0.5 ppm even though the content of CaO in the slag was greater than 80 wt%. The developed model offered a versatile tool for designing slag compositions tailored to various purposes.

A modified vacuum induction melting technique with argon backfilling to produce pristine Ni–Ti–Si ternary shape memory alloys

A modified vacuum induction melting technique with argon backfilling to produce pristine Ni–Ti–Si ternary shape memory alloys

Formation of near core-shell-like structure and dual-phase nanoprecipitation behavior in Nb–Si–Ti based alloys

Dual-phase metal materials can usually take into account the advantages of both phases, but the heterogeneity of dual-phase properties will cause flow instability. Therefore, it is difficult to further improve the microstructure and properties of Nb–Si–Ti based alloys containing ductile Nbss and hard silicides through hot working. Here, we propose a method for interface modification by precipitating an intermediate phase and forming a core-shell-like structure with silicides. A novel near core-shell structure (β-Nb5Si3/Nb4FeSi) is obtained in Nb–Si–Ti based alloy by deep cryogenic quenching and annealing. The precipitation of Nb4FeSi is closely related to stacking faults, where high-density stacking faults can develop into the nanotwins during annealing at 1200 °C. In addition, two types of nanoprecipitation behaviors are observed in the Nbss and β-Nb5Si3. The nanoscale plate-like δ-Nb11Si4 is precipitated along the [100]Nbss and [010]Nbss in the Nbss matrix, while the precipitation of granular Nb4FeSi from β-Nb5Si3 satisfies (1‾10)β//(01‾0)Nb4FeSi. In addition to the twinning induced plasticity of Nb4FeSi (shell), a phase transformation from β-Nb5Si3 to α-Nb5Si3 and Nbss that occurs within the core-shell structure is beneficial for the hot forming of the alloy.

Sputtered zirconium based metallic glassy thin films onto electrospun PCL nanofibrous scaffolds for enriching bioactivity

Surface modification of electrospun Polycaprolactone (PCL) nanoscaffold is to enhance surface properties, particularly bioactivity. In this paper, electrospinning was employed to produce PCL nanoscaffolds and enhancing the bioactivity of the electrospun PCL scaffolds by sputtering of Zirconium based thin film metallic glasses (Zr -TFMGs). The Energy Dispersive Spectroscopy (EDS) analysis exhibited the presence of Zr, Ti and Si and surface topography by Atomic Force Microscopy (AFM) revealed the smooth surface of metallic glasses with nanofibrous structures. The sputtered samples were subjected to immersion test in Simulated Body Fluid (SBF) to analyze the apatite forming ability of Zr–Ti–Si metallic glasses. After 21days of incubation, SEM clearly showed the spherical structures of apatite formed on the surface of modified electrospun PCL. Cell viability studies using L929 fibroblast cells indicates the higher proliferation rate for the Zr based TFMG sputtered PCL scaffold specimen than the uncoated neat PCL scaffold and indicating the bioactive nature of Zr based TFMG. Contact angle of TFMG sputtered sample exhibited the hydrophobic surface which is helpful in preventing the biomedical devices from blood coagulation.

Formation Mechanism of Ti–Si Multi-Layer Coatings on the Surface of Ti–6Al–4V Alloy

Titanium alloys are widely used in aerospace applications due to their high specific strength and exceptional corrosion resistance. In this study, a silicide coating with a multi-layer structure was designed and prepared via a pack cementation process to improve the high-temperature oxidation resistance of titanium alloy. A new theory based on the Le Chatelier’s principle is proposed to explain the generation mechanism of active Si atoms. Taking the chemical potential as a bridge, a functional model of the relationship between the diffusion driving force and the change in the Gibbs free energy of reaction diffusion is established. Experimental results indicate that the depth of the silicide coating increases with the siliconization temperature (1000–1100 °C) and time (0–5 h). The multi-layer coating prepared at 1075 °C for 3 h exhibits a thick and dense structure with a thickness of 23.52 μm. This coating consists of an outer layer of TiSi2 (9.40 μm), a middle layer of TiSi (3.36 μm), and an inner layer of Ti5Si3 (10.76 μm). Under this preparation parameter, increasing the temperature or prolonging the holding time will cause the outward diffusion flux of atoms in the substrate to be much larger than the diffusion flux of silicon atoms to the substrate, thus forming pores in the coating. The calculated value of the diffusion driving force FTiSi = 2.012S is significantly smaller than that of FTiSi2 = 13.120S and FTi5Si3 = 14.552S, which perfectly reveals the relationship between the thickness of each layer in the Ti–Si multi-layer coating.

Surface modifications to reduce wear in hot extrusion of copper

During hot extrusion of copper, the material tends to stick to the extrusion die due to strong adhesive forces between hot working steel and copper at high temperatures. In this context, surface modifications like nanocomposite coatings deposited by plasma enhanced chemical vapor deposition or boriding of nickel-based alloy 718 (DIN 2.4668) create hard and wear resistant thin solid films that offer high temperature stability. Ti–Si–B–C–N nanocomposite coatings consist of nanocrystalline grains embedded in a thin amorphous matrix. Due to this particular nanostructure, hardness values of up to 39.3 GPa were reached. Boriding of alloy 718 leads to formation of phases consisting of alloying elements like nickel, iron, and chromium and the diffusing element boron. The borides form a boriding zone that offers high hardness. Extrusion of Ø122 mm × 300 mm copper billets preheated to 850 °C was carried out and adhesive wear on tool's surfaces was analyzed. The comparison between hot working steel DIN 1.2367 without surface modification and with Ti–Si–B–C–N coating or borided alloy 718 showed remarkable differences between conventional tools made of hot working steels/alloy 718 and tools with surface modification. A strong decrease particle adhesion was observed.

The crucial role of interaction between WOx and Ti–Si composite oxide for selective hydrogenolysis of glycerol to 1,3-propanediol

Hydrogenolysis of glycerol, a by-product in the preparation of biodiesel, to synthesize 1,3-propanediol has attracted widespread attention because of its environmental and economic benefits. How to activate the secondary hydroxyl group in glycerol to suppress the formation of 1,2-propanediol is still challenging. Pt-WOx-based catalyst has been popularly studied due to high 1,3-propanediol selectivity but its stability is unsatisfactory. Here we synthesized an oxygen vacancy-rich support (HTSO) consisting of Ti–Si composite oxide to stabilize WOx species. The glycerol conversion and 1,3-propanediol selectivity of optimized 2Pt-10WOx/HTSO-1.0 catalyst achieved 40% and 46%, respectively. Moreover, the catalytic performance remained stable over 10 reaction cycles. Based on the investigation of the structure-performance relationship of catalysts, the excellent catalytic performance was attributed to the anchoring of WOx species by oxygen vacancies, thus stabilizing the chemical valence of W. The correlation between acid sites and catalyst performance was intensively investigated. This work provides an alternative approach for preparing stable Pt-WOx-based catalysts and deepens the knowledge of the correlation between acidic sites and 1,3-propanediol selectivity.

Preparation of TiO2–SiO2–CaCO3 composite opacifier by hydrophobic agglomeration and mechanism of inhibiting glaze yellowing

This study investigates the preparation of TiO2–SiO2–CaCO3 composite opacifier (Ti–Si–Ca) and its application in sanitary ceramic glazes. This approach involved hydrophobic agglomeration through surface-induced hydrophobic modification of TiO2, SiO2 and CaCO3 particles, along with the interactions between the hydrophobic carbon chains of modifiers. The Ti–Si–Ca formed a uniform coating with well-dispersed TiO2 and SiO2 particles on the CaCO3 surface and strong bonds formed among TiO2, SiO2 and CaCO3 through interpenetration of the organic carbon chains on the surface. The Ti–Si–Ca was added to the basic glazes of sanitary ceramics at a proportion of 15.5 % and fired at 1125 °C for 4 h. The resulting white ceramic glazes had chromaticity values of L*, a*, and b* at 93.76, −0.73, and 3.89, respectively, demonstrating superior glaze opacity and whiteness compared to glazes made with a ZrSiO4 opacifier (L* 90.30, b* 4.50). Glass and titanite phase make up the majority of the Ti–Si–Ca ceramic glazing layer of, with titanite serving as the opacified phase. Elimination of organic groups in Ti–Si–Ca during glaze firing formed interfacial chemical bonds among TiO2, SiO2 and CaCO3, which facilitated the synthesis of titanite from the three components at high temperatures. The Ti–Si–Ca was a highly opaque glaze without yellowing because the organic groups of Ti–Si–Ca were removed and interfacial chemical bonds formed among the TiO2, SiO2 and CaCO3 in the low-temperature stage of glaze firing. This transformed the three phases into titanite at high temperature and eliminated free TiO2. The formation of rutile TiO2, which has a yellow hue, at high temperatures was inhibited. This study provides a novel approach for low-energy preparation of TiO2–SiO2–CaCO3 composite opacifiers and addresses the challenge of replacing ZrSiO4 with TiO2 in ceramic opacifiers.

Preparation of Si3N4–TiN–SiC composite by partial substitution of Ti–Si–Fe alloy for Si under N2 atmosphere

Preparation of Si3N4–TiN–SiC composite by partial substitution of Ti–Si–Fe alloy for Si under N2 atmosphere

The Creep‐Induced Micro‐ and Nanostructural Evolution of a Eutectic Mo–Si–Ti Alloy at 1200 °C

In the present study, the creep deformation mechanisms of a eutectic Mo–Si–Ti alloy (comprising a body‐centered solid solution and a hexagonal silicide) are verified. The microstructural changes occurring at the various microstructural length scales are correlated to the nature of the creep curve. The creep curve exhibits a transient strain‐hardening region followed by a distinct minimum and then creep rate accelerates after that. The formation of a high fraction of disperse (Ti,Mo)5Si3 precipitates in the solid solution lead to significant strengthening in the transient creep regime. By the simultaneous decrease of the initially high dislocation density in the solid solution, diffusional creep contributes to effective creep behavior. At the minimum, the load and strain are also carried by the silicide phase which undergoes plastic deformation. Continuous coarsening of precipitates and loss of precipitation strengthening in the solid solution and dynamic recovery in the silicide phase lead to creep acceleration.

Unveiling the Intricacies of a Ductile‐Phase Toughened Intermetallic: An In‐Depth Exploration of a Eutectic Mo–Si–Ti Alloy and its Mechanical Behavior

Herein, the development of directional solidification for a novel high‐temperature Mo–20Si–52.8Ti (at%) ternary alloy using a modified Bridgeman type apparatus is presented. The resulting alloy exhibits a microstructure consisting of a body‐centered cubic solid solution (BCCss) and a hexagonal silicide (Ti,Mo)5Si3 with approximate volume fractions of 50% for each phase. The phases exhibit a crystallographic orientation relationship with and . Different solidification velocities are imposed, which reveal an inverse relationship to the lamellar spacing according to a Jackson–Hunt type scaling. Mechanical characterization using Vickers indentation demonstrates that the BCCss accommodates plasticity through dislocation motion, while the silicide phase exhibits high hardness and brittleness, serving as a crack initiation site. Crack propagation is arrested and deflected at the interface to the BCCss. Fracture toughness measurements via indentation yield a fracture toughness of 3.7 MPa√m for the silicide, somewhat higher than previously reported values for Nb‐, Mo‐, and Cr‐based silicides at room temperature. The directionally solidified specimens show an enhanced fracture toughness attributed to a greater BCCss length scale; thus, combining the ductile and hard phases results in a ductile‐phase toughened intermetallic composite. The findings open up new possibilities for the design of advanced intermetallic composites with improved toughness performance.

Novel application of high temperature solution growth method in simultaneously preparing SiC/Ti3SiC2/TiC using photovoltaic Si waste and Ti-bearing blast furnace slag

Photovoltaic silicon wastes (PVSWs) and Ti-bearing blast furnace slag (TBBFS) are typical new energy solid waste and traditional industrial solid waste respectively. The collaborative treatment of PVSW and TBBFS can realize the utilization of Si and Ti resources, as well as safeguard the ecosystems. Herein, an effective approach was proposed to prepare SiC, Ti3SiC2, and TiC using these two wastes as raw materials based on the innovative application of High Temperature Solution Growth Method (HTSGM). A Ti–Si alloy, which is rich in TiSi2 phase (stable) with a low melting point is synthesized from TBBFS through silicothermal reduction at a low operating temperature of HTSGM. Subsequently, the directional solidification process effectively optimized the segregation and carbon solubility of Ti–Si alloy, leading to the formation of TiC, Ti3SiC2, and SiC. The effect of directional solidification rate and the electromagnetic field is analyzed on in situ carburizing behavior and segregation of Ti–Si alloy, as well as controlled precipitation interval of the three carbides. Through the microcrystalline materialization treatment strategy of the associated waste slag, the entire process is devoid of solid waste or other pollution, achieving high-value and complete utilization of the two solid wastes. This work provides an innovative process for the green, clean, efficient, and high-quality collaborative treatment of PVSW and TBBFS.

Enhancing growth speed of 3C–SiC using solution growth method by a new low temperature Mn-based cosolvent

Solution growth is a promising method for rapidly and stably preparing high-quality silicon carbide (SiC) single crystals. However, the coexistence of polycrystalline parasitism and solid inclusions during the growth of SiC in high-temperature solutions above 1800 °C still poses a serious threat to the quality of single crystals. Herein, we introduce an innovative Mn-based cosolvent for controlling the stable and fast growth of cubic-type silicon carbide (3C–SiC) single crystals at low temperatures. Firstly, our thermodynamic analysis reveals that SiC is the only stable solid compound in the low-temperature solution (1500–1600 °C) of the Si–Mn–C system, which is an important condition for the stable growth of crystals. Compared to typical solvents like Si–Cr, Si–Ti, and Si–Fe, the Si–Mn solvent exhibits the highest solubility and supersaturation for carbon. Secondly, our solubility calculations of SiC in the solvent show that the Mn-rich solvent can significantly increase the solubility of SiC. Thirdly, we successfully grew 3C–SiC single crystals from Si–Mn solution at 1500 °C without other SiC polymorphs produced. Rapid growth of SiC crystals in Mn-rich solution was achieved by modulating the content of Mn. Our work highlights the superiority of Si–Mn cosolvents in facilitating rapid growth of 3C–SiC single crystals at low temperatures. It introduces a novel approach by applying phase diagram calculation techniques to design suitable solvent systems for the solution growth of SiC single crystals.

Wettability and joining of reaction-bonded silicon carbide (RBSC) by Ti–Si eutectic alloy

The high-strength joining of reaction-bonded silicon carbide (RBSC) is pivotal for its application in the semiconductor field. In this paper, the wetting and joining mechanism of Ti–Si eutectic alloy on RBSC were investigated. The contact angles observed between Ti–Si eutectic alloy and RBSC were approximately 1.9°, indicating the favorable wettability and demonstrating the feasibility of bonding RBSC joints. The temperature bending strength of the joints initially increased and then decreased as the brazing temperature increased. Moreover, the shear strength of approximately 107.38 ± 5.56 MPa was achieved at 1350 °C for 30 min. Notably, the diffusion and amalgamation of atoms, lead to the establishment of stronger bonds between adjacent particles. Thus, the Ti–Si eutectic alloy brazing filler formed a direct connection with the RBSC matrix, with Si2Ti infiltrating into the base metal on both sides. The utilization of Ti–Si eutectic alloy brazing filler in RBSC joints exhibits promising prospects.

Wide-angle ultra-wideband metamaterial absorber based on complex dielectric layer in long and very long-wave infrared

Long and very long-wave infrared are the most important bands in infrared detection technology because of their high atmospheric window radiation energy. At present, long and very long-wave infrared detectors are widely used in atmospheric monitoring, night reconnaissance, deep space exploration and other fields. In this paper, we first analyze the coupling resonance in the dual-band absorber (Ti–Si–Ti), and the absorption rates are 97.05% and 98.95% at 6.1 μm and 19.2 μm, respectively. Then, a four-layer (Ti–Si–SiO2–Ti) absorber with a complex dielectric structure is obtained by using the surface plasmon resonance and the inherent absorption of the lossy material SiO2. In addition to the traditional electromagnetic field analysis, we also used the layer absorption energy loss theory to study the inherent absorption mechanism of SiO2, and the average absorption of the absorber from 19 to 24.7 μm reached 92.87%. Finally, based on the composite dielectric layer, a thin ultra-wideband absorber with four nanorods of the same size surface structure was designed, and the average absorption was 92.03% from 13.3 to 24.6 μm. The polarization-insensitive ultra-wideband absorber proposed by us is light, simple in structure and easy to manufacture, and has potential application value in atmospheric monitoring, night reconnaissance, deep space exploration and other fields.

Structural Parameters and Behavior in Simulated Body Fluid of High Entropy Alloy Thin Films.

The structure, composition and corrosion properties of thin films synthesized using the Pulsed Laser Deposition (PLD) technique starting from a three high entropy alloy (HEA) AlCoCrFeNix produced by vacuum arc remelting (VAR) method were investigated. The depositions were performed at room temperature on Si and mirror-like polished Ti substrates either under residual vacuum (low 10-7 mbar, films denoted HEA2, HEA6, and HEA10, which were grown from targets with Ni concentration molar ratio, x, equal to 0.4, 1.2, and 2.0, respectively) or under N2 (10-4 mbar, films denoted HEN2, HEN6, and HEN10 for the same Ni concentration molar ratios). The deposited films' structures, investigated using Grazing Incidence X-ray Diffraction, showed the presence of face-centered cubic and body-centered cubic phases, while their surface morphology, investigated using scanning electron microscopy, exhibited a smooth surface with micrometer size droplets. The mass density and thickness were obtained from simulations of acquired X-ray reflectivity curves. The films' elemental composition, estimated using the energy dispersion X-ray spectroscopy, was quite close to that of the targets used. X-ray Photoelectron Spectroscopy investigation showed that films deposited under a N2 atmosphere contained several percentages of N atoms in metallic nitride compounds. The electrochemical behavior of films under simulated body fluid (SBF) conditions was investigated by Open Circuit Potential (OCP) and Electrochemical Impedance Spectroscopy measurements. The measured OCP values increased over time, implying that a passive layer was formed on the surface of the films. It was observed that all films started to passivate in SBF solution, with the HEN6 film exhibiting the highest increase. The highest repassivation potential was exhibited by the same film, implying that it had the highest stability range of all analyzed films. Impedance measurements indicated high corrosion resistance values for HEA2, HEA6, and HEN6 samples. Much lower resistances were found for HEN10 and HEN2. Overall, HEN6 films exhibited the best corrosion behavior among the investigated films. It was noticed that for 24 h of immersion in SBF solution, this film was also a physical barrier to the corrosion process, not only a chemical one.