Ti Si Alloys Research Articles

Developing a New Beta‐Type of Ti–Si/Sn Alloys for Targeted Orthopedic Therapeutics: Assessments of Biological Characteristics

Titanium (Ti) alloys are widely used in tissue engineering, but their applications are limited by low strength, bactericidal properties, and metal ion release. Beta Ti alloys are promising materials for load‐bearing orthopedic implants due to their excellent corrosion resistance and high biocompatibility. Herein, developed new beta‐Ti alloys including Ti–Nb–Zr–Sn (Ti–Sn) and Ti–Nb–Zr–Ta–Si (Ti–Si) to improve structural and biochemical features of the existing Ti alloys as orthopedic implants. The new Ti–Sn and Ti–Si alloys were fabricated using mechanical ball milling and spark plasma sintering techniques respectively and compared with commercially pure Ti alloys on hydrophilicity, surface characteristics and cytotoxicity, proliferative and osteogenic differentiation effects as well as biocompatibility in human bone osteosarcoma cell line (MG63). The new beta Ti alloys showed no significant differences in proliferation and cytotoxicity on the MG63 cells. Both Ti–Sn and Ti–Si alloys, compared to the commercial pure Ti, improved the biological profile and upregulated the expressions of runt‐related transcription factor 2, osterix, and collagen mRNA levels in the MG63 cells. The Ti–Si alloy showed greater cell proliferation and osteoblastic protein expression and a better biological profile compared to the Ti and Ti–Sn alloys. The novel beta Ti alloys exhibited promising potentials in orthopedic applications.

Tribological properties of alloyed TiSi-stainless steel carbide coatings deposited by reactive cathodic arc method

Alloyed TiSi-stainless steel carbide coatings were deposited by cathodic arc method on Si (100) and C45 steel substrates, from TiSi alloy and stainless-steel cathodes in C2H2 atmosphere. Different compositions were obtained by modifying the C2H2 mass flow rate and the arc current at the stainless-steel cathode. The coatings were investigated for elemental and phase composition, chemical bonding state, crystalline structure, morphology, hardness, adhesion strength, friction and wear performance. The coatings were found to possess a composite structure consisting of crystalline metallic carbide and amorphous free carbon. For carbon content higher than 43 at. %, the coatings exhibited a poor crystallinity and a random texture. All deposited coatings showed compact cross-sectional morphologies. It has been shown that the friction and wear performance of the carbide coatings were strongly dependent on the carbon content, such as the overstoichiometric carbide coatings presented superior tribological characteristics compared to the understoichiometric coatings. Depending on the carbon content, different wear mechanisms were identified: adhesive and oxidative wear for the coatings with understoichiometric carbide coatings, while for the overstoichiometric ones the adhesive and polishing wear was evidenced. The coatings containing the highest carbon content of ~64 at. % provided the best wear resistance (wear rate of 1.1 × 10−6 mm3N−1m−1) and the lowest friction coefficient (0.15).

An approach for simultaneous treatments of diamond wire saw silicon kerf and Ti-bearing blast furnace slag

Both diamond wire saw silicon kerf (DWSSK) and Ti-bearing blast furnace slag (TBBFS) are largely accumulated industrial wastes and important resources of Si and Ti. Currently, both are treated using independent approaches. In this study, a novel approach is proposed to simultaneously extract Ti from TBBFS to prepare TiO2 and recycle Si from DWSSK to prepare high-purity Si. Firstly, DWSSK (86.9 % Si) was employed as a reductant to extract Ti from TBBFS to prepare bulk Si-Ti alloys, and the largest extraction rate was 99.4 %. Secondly, Si and Ti in the bulk Si-Ti alloy were separated using a HF-containing acid solution. Ti in the Si-Ti alloy dissolved into the HF-containing acid solution, and high-purity Si was obtained after acid leaching. The purity of Si in DWSSK increased from 86.9% to 99.94%. Thereafter, a NaOH solution was used to precipitate Ti(OH)4 from the HF-containing acid solution, and TiO2 was prepared by roasting Ti(OH)4. Notably, the new approach had the advantage of concurrently eliminating impurities while recycling DWSSK. Finally, NaOH and HF solutions were used to prepare high-purity NaF (>98 %) to treat the waste solutions. The results of this study provides a new and sustainable technology for clean utilization of DWWSK and TBBFS.

On the chemical and microstructural requirements for the pesting-resistance of Mo–Si–Ti alloys

In recent publications [Schliephake et al. in Intermetallics 104 (2019) 133–142 and Obert, Kauffmann & Heilmaier in Acta Materialia, 184 (2020) 132–142], an unexpected pesting-stability of fully eutectic and specific eutectic–eutectoid Mo–Si–Ti alloys was found. Several potential reasons were proposed: microstructural length scale being typically very fine due to the eutectic and eutectoid reactions, the phase distribution including the fraction of the eutectic and eutectoid regions, as well as the chemical composition of the individual phases. In the present study, we prove the Ti content to be decisive for the pesting-resistance in air at 800°C by investigating the microstructure and oxidation behaviour of Mo–Si–Ti alloys with systematically varying nominal Ti content. A critical Ti content of 43at% was identified. Due to the phase equilibrium, this corresponds to a local Ti content in Mo solid solution of 35at%. Other microstructural properties such as (i) lamellar size within eutectic and eutectoid regions and (ii) volume fraction of the eutectic and eutectoid regions were demonstrated to have an insignificant influence on the pesting-resistance of the alloys. Rather, the assessment of the oxidation behaviour of the monolithic phase MoSS, which was identified to be crucial for the oxidation behaviour of the Mo–Si–Ti alloys, confirmed an improvement in oxidation behaviour with increasing Ti content.

Evolution of intermetallic phases in an Al–Si–Ti alloy during solution treatment

Abstract A cast Al–Si–Ti alloy was solution treated at 540 °C for different periods between 0 and 72 h to understand the evolution of intermetallic phases. Only an (Al,Si)3Ti intermetallic phase with a low Si content was found in the as-cast alloy. The (Al,Si)3Ti particles were converted partly into a lamellar structure, a eutectoid phase, consisting of a Si-rich phase and an Al phase during solution treatment. The amount of the lamellar structure increased with the solution treatment time, but the composition of either constitute was kept almost unchanged regardless of the solution treatment times. The lamellar Si-rich phase is (Al,Si)2Ti (τ2) with a TiSi2 (C49-type) structure based on thermodynamic calculations and high-resolution TEM analyses. FCC Al phase is the product residing between the τ2 lamellae after the completion of transformation from (Al,Si)3Ti to τ2 phase. A near-rational orientation relationship (OR) between the Al and τ2 phases is determined as Al [110]//τ2 [100], Al ( 1 1 ¯ 1 ¯ )//τ2 [060]. The phase transformation from (Al,Si)3Ti to τ2 being a result of the diffusion of Ti and Si within the original (Al,Si)3Ti particulates as well as the Si diffusion from the Al matrix during solution treatment is proposed. The formation of the lamellar structure in the microstructure is attributed mainly to the limited diffusivity of Ti element.

Effect of interlayer design on the mechanical properties of AlTiCrN and multilayered AlTiCrN/TiSiN hard coatings

The adhesion strength and mechanical properties of hard coatings on substrates can be improved by adding an interlayer, which is also known as an adhesion, buffer, or seed layer. Cathodic-arc deposition (CAD) of hard coating often results in residual stresses, and the optimized design of the hard coating interlayer helps to reduce residual stress and improve mechanical properties, which is expected to extend the useful life of high speed precision stamping die applications. AlTiCrN transition metal nitride has been used as a protective hard coating because of its high hardness (~36 GPa) and resistance to high temperature oxidation up to 1100 °C. In this study, multicomponent hard coatings of AlTiCrN and AlTiCrN/TiSiN, which in the form of AlTiCrN/TiSiN multilayers, were deposited by cathodic-arc deposition. During the coating process, gradient TiN and CrN were deposited, respectively, as interlayers with different structures to control the residual stress and adhesion strength between the coatings and substrates. AlTiCr and TiSi alloy targets were used to deposit hard AlTiCrN/TiSiN coatings. The multicomponent AlTiCrN/Ti and AlTiCrN/Cr with Ti and Cr interlayers showed high residual stresses of −8 GPa and −8.4 GPa, respectively. The multilayered AlTiCrN/TiSiN coating with intermediate CrN and transition AlTiN/CrN multilayers under the top AlTiCrN/TiSiN multilayers possessed the lowest residual stress (−3 GPa). The residual stress changed by modifying interlayer configuration before the top AlTiCrN/TiSiN multilayers. The design of AlTiCrN/TiSiN multilayered coatings with interlayers of CrN and AlTiCrN/CrN can decrease residual stress and possessed good impact fatigue performance, which can be effective to reduce damage and cracking of hard coatings during cyclic impact loading.

Separation and enrichment mechanism of C54–TiSi2 from hypoeutectic Ti–65 wt.% Si alloy during directional solidification via alternating electromagnetic fields

The effects of directional solidification parameters and the coupling of directional solidification parameters and alternating electromagnetic fields on separation and enrichment of the C54–TiSi2 phase were investigated in a directionally solidified hypoeutectic Ti–65 wt.% Si alloy. The results indicated that by increasing the pull-down velocity at a given position within the ingot, the cooling rate, growth rate, and temperature gradient of ingot could be increased. At a pull-down velocity near 5 μm/s, the temperature gradient, cooling rate, and growth rate decreased with increasing the thickness of the C54–TiSi2-rich layer. Electromagnetic fields enhanced mass transfer at pull-down velocities of 5, 10, 15, and 20 μm/s, with resulting enriched layer thicknesses of 15, 10, 10, and 5 mm, respectively. By increasing the percentage of Ti in the Ti–Si alloy from 25 to 35 wt.%, the thickness of the C54–TiSi2-rich layer was increased from 2.5 to 3.3 cm. However, the maximum C54–TiSi2 content obtained experimentally in this layer decreased from 92.06 to 79.49 mass%.

Studies of the Joining-Relevant Interfacial Properties in the Si-Ti/C and Si-Ti/SiC Systems

Reactive melt infiltration of Si-based alloys into C preforms and SiC/C composites may be an affordable alternative route to fabricate highly performant lightweighting metal matrix and ceramic matrix composites (CMCs), as well as to obtain reliable and long-term stable joints. In order to optimize reactive infiltration process and to tailor the joint microstructures, the knowledge of interfacial phenomena including thermodynamics, kinetics and surface properties of involved phases (i.e., metals and ceramics) as well as wettability and reactivity occurring between dissimilar materials is of crucial importance. In the present work, the feasibility study of a novel brazing method using Si-Ti alloys as filler for SiCf/SiC is reported and supported by the analysis of microstructural evolution and interfacial phenomena observed during the joining process. Namely, the CMC joining was successfully obtained via the reactive infiltration approach. The results obtained were critically discussed and compared with the know-how coming from the previously carried out investigations on the wetting and reactivity of Si-Ti melts in contact with glassy-C and HIP-SiC substrates. In particular, the microstructural evolution of the Si-Ti/C and Si-Ti/SiC interfaces during wetting tests and at the joint of CMC parts was analyzed and related to the operating conditions.

Preparation of high-purity Ti–Si alloys by vacuum directional solidification

Abstract To prepare high-purity Ti–Si alloys, we newly used vacuum directional solidification technology to purify and separate Ti–Si alloys, which have different compositions (Ti-8.45 wt%Si, Ti-63.7 wt%Si, Ti-71.6 wt%Si, and Ti-84.1%wt%Si). The pulling-down rates in the directional solidification were to be 3 μm/s, 5 μm/s, and 7 μm/s, respectively, to investigate their effects on the purification. The results showed that vacuum directional solidification can purify Ti–Si alloys efficiently without discharging waste acid, slag and gas, and the slower pulling-down rate could result in better purification results. The impurities, Fe, Al, V, and Ni, could be removed due to their segregation behavior on the boundary of the solid and liquid phases. However, the impurities Ca and Mg could be removed using the vacuum technology because their vapor pressures were significantly higher than those of Si and Ti. TiSi2 could be precipitated and separated from the Ti-63.7 wt%Si and Ti-71.6 wt%Si alloys. The precipitated TiSi2 could be agglomerated at the bottom of the Ti–Si alloys, under the effect of gravity. The phases in the Ti–Si alloys, after vacuum directional solidification, were observed and determined using an electron probe micro-analyzer (EPMA). The results showed that the eutectic Ti-8.45 wt%Si alloy consisted of Ti5Si3 and Ti, the Ti-63.7 wt%Si and Ti-71.6 wt%Si alloys consisted of TiSi2 and eutectic Si–Ti alloy at the Si-rich side, and the Ti-84.1 wt%Si alloy consisted of Si particles and eutectic Si–Ti alloy at the Si-rich side. The study shows that vacuum directional solidification is an efficient and clean technology for the purification of Ti–Si alloys, and for the preparation of TiSi2 through the separation of Ti–Si alloys.

Effect of Ce addition on microstructure evolution and precipitation in Cu-Co-Si-Ti alloy during hot deformation

Abstract Hot compression behavior of the Cu–Co–Si and Cu–Co–Si–Ti alloys was studied using the Gleeble-1500 simulator at 0.001–10 s−1 strain rate and 500–900 °C deformation temperature. Ti addition increased the flow stress of the Cu–Co–Si–Ti alloy compared with the Cu–Co–Si alloy at the same deformation conditions. With the deformation temperature increased from 700 °C to 900 °C, the Cu–Co–Si alloy texture transformed from the copper texture to the R texture. Due to the addition of Ti, the copper texture and R texture were substituted by the Goss texture and the copper texture, respectively. The constitutive models of the Cu–Co–Si and Cu–Co–Si–Ti alloys hot deformation behavior were obtained. The activation energy of the Cu–Co–Si alloy was 411.648 kJ/mol, and the activation energy of the Cu–Co–Si–Ti alloy was 500.794 kJ/mol, which is 27% higher. The precipitated Co2Si phase was found in both Cu–Co–Si and Cu–Co–Si–Ti alloys deformed at 700 °C and 0.001 s−1. In addition, the CoSi and Cu4Ti phases were found in the Cu–Co–Si and Cu–Co–Si–Ti alloys, respectively. The strengthening mechanisms, including dispersion strengthening, twinning and grain refinement strengthening, control the Cu–Co–Si–Ti alloy hot deformation, and lead to increased flow stress and activation energy, and inhibit dynamic recrystallization of the Cu–Co–Si–Ti alloy.

The Effects of Fe and Si Elements on Structural, Mechanical, and Electronic Properties of an Fe–Si–Ti System by First‐Principles Calculations

Herein, first‐principles calculations with density functional theory are used to investigate the structural, mechanical, and electronic properties of Fe–Si–Ti alloys, aiming to study the effects of Si and Fe in titanium alloys. The calculated lattice parameters are in good agreement with previous data. Alloying with Si/Fe can produce more brittle/ductile materials, due to the weaker/stronger metallic bonds. Furthermore, the effect of alloying with Si and Fe on the anisotropic properties is negligible. The increasing range of Debye temperatures by alloying with Si is greater than that by alloying with Fe. The capacity of Si to enhance the interatomic bonding force is greater than that of Fe due to the stronger covalent bonds. Similarly, the charge density reflects that the capacity of Si to enhance the interatomic bonding force is better than that of Fe for titanium alloys. In addition, the metallic conductivity of these alloys is verified, with there being no gaps at the Fermi level. The localization of electrons in the SiTi alloy is observed to be relatively strong around the Fermi level. In addition, the amplitude of the top of the valence band and the bottom of the conduction band is smooth, showing great effective mass.

Effects of pulling rate on metal impurity removal during Si refining in Ti-90 wt.% Si alloy directional solidification

To analyze the effects of pulling rate on the removal of impurities from a Ti-90 wt% Si alloy during the Si refining process, five samples with different pulling rates were examined. At a low pulling rate, the contents of Fe, Al, and Ca could be reduced to 9 × 10−4 wt%, 21 × 10−4 wt%, and 10 × 10−4 wt%, representing impurity removal rates of 99.68%, 98.76%, and 95%, respectively. Under our experimental conditions, we determined that a pulling rate of 5 μm/s can reduce the time taken for directional solidification and provide excellent impurity removal efficiency. The average impurity removal rates for Fe, Al, and Ca in the silicon enrichment layer were 98.431%, 99.262%, and 85.833%, respectively. The migration and removal mechanism of Fe during the directional solidification refining process was also identified. Due to the low energy of grain boundary segregation of impurities, Fe segregate at the grain boundary of TiSi2 grains, such that Fe eventually forms FeTiSi2 with TiSi2 at the grain boundary. The analysis of our study provides theoretical and experimental support for the purification of polycrystalline silicon from Ti–Si alloys, which further broadens the application of Ti–Si alloys and lays the foundation for comprehensive utilization of high-titanium blast furnace slag.

Development of Silicon Anode for All-Solid-State Thin-Film Secondary Battery

Thin-film batteries (TFBs) are produced by thin-film deposition technology which has special advantages that are not only intrinsically safe as their being all-solid-state but also thin, small, lightweight, and flexible [1], and also have the features such as low self-discharge and long cycle-life. As MEMS and high-density packaging technology grows, the device size becomes smaller and there is a growing demand for miniaturized devices with stand-alone power supply supported by TFBs and energy harvesting devices [2, 3]. However, Li metal that is commonly used as anode in TFBs, has low melting point as around 180 deg.C and cannot be employed for packaging process that include solder reflow, epoxy molding, and even through-silicon via (TSV). Si is promising anode material due to high specific capacity and low electrode potential, but there are the issuers such as low resistance and electrode breakage due to drastic volume change during cycles. In our previous work, TFBs with high-temperature tolerance was fabricated by all sputtering; Pt/Ti as cathode current collector, 3μm-thick-LiCoO2 with post-annealed at around 600 deg.C as cathode, 2 μm-thick-LiPON as solid electrolyte, 600 nm-thick-Si1-xTix (x=0, 0.03, and 0.12) as anode, and Ni as anode current collector [4], and finally completed by encapsulation with UV curable resin and inorganic lid. The active area of fabricated TFBs was 1.4 mm2. Ti which is inactive material against Li, was used as dopant for not only mitigating mechanical stress but also decreasing resistivity. Cycling was performed between 2.5 and 4.1 V with standard current rate condition, and cycle performance resulted well during 100 cycles. In this work, microstructure of Si-Ti alloy film was adjusted by changing sputtering condition such as process pressure and gas species. Figure 1 shows cross-sectional SEM image of each Si1-xTix films. The effect of Si1-xTix anode microstructure on electrochemical and cycle performance of full cell will be discussed.

Selective extraction of titanium from Ti-bearing slag via the enhanced depolarization effect of liquid copper cathode

Abstract Ti-bearing slag (TiO2>20 wt%) is a valuable titanium secondary resource. The extraction of titanium from the slag is difficult due to the complex composition and structure. Although molten oxide electrolysis is considered as a promising method, silicon will be preferentially electroreduced compared to titanium due to low theoretical decomposition voltage. In this work, a liquid copper cathode is used to selectively extract titanium from molten Al2O3-MgO-CaO-TiO2-SiO2 electrolyte. It is found that comparing to silicon, titanium can be preferentially reduced by one-step electron transfer due to the enhanced depolarization effect on a liquid copper cathode. So, Ti-Cu alloys are firstly obtained from molten Ti-bearing slag, and then Ti-Si alloys are co-electrodeposited in the molten oxide electrolyte with low TiO2 content. It may be ascribed to the larger binding force between titanium and copper than that between silicon and copper. It provides an effective strategy for the separation of titanium from of Ti-bearing slag.

A novel approach to prepare high-purity Si and Si/TiSi2 materials simultaneously using Ti-bearing blast furnace slag

A new approach was proposed to prepare multi-products, high-purity Si powders, bulk Si, and Si/TiSi2 materials (eutectic Si-Ti), simultaneously using inexpensive low-purity Si (99.3%) and metallurgical waste—Ti-bearing blast furnace slag. TiO2 in Ti-bearing blast furnace slag was first reduced by Si to form a Si-Ti alloy which was then separated into high-purity bulk Si (99.97%) and Si/TiSi2 materials (99.4%) using directional solidification. The bulk Si could be repeatedly recycled as a reductant, or further upgraded to prepare super-pure Si powders (99.995%) after acid leaching. The new approach shows many sustainable and economic benefits, such as no carbon gas emission, low acid consumption and Si loss, recyclable Si reductant, widely-used multi-products employing one approach, and rapid consumption of accumulated Ti-bearing blast furnace slag.

Fabrication and mechanical properties of 3-D Cf/C-SiC-TiC composites prepared by RMI

In this paper, the three-dimensional needled carbon fiber reinforced C-SiC-TiC ceramic composites (Cf/C-SiC-TiC) were successfully fabricated by chemical vapor infiltration (CVI) and Ti, Si mixed powders (Si content is the eutectic point of the Ti-Si alloy, 9.2 w.t.%) reactive melt infiltration (RMI) process. The open porosity and bulk density were about 4.71% and 2.14 g/cm3. The formation and distribution of the composites were investigated by XRD and EDS maps, and no residual Ti or Si phases were found. TiC and a layered SiC ceramics were formed in carbon fiber reinforced pyrolytic carbon (Cf/C) preforms due to the in situ reaction between pyrolytic carbon and Ti, Si powders. Their mechanical properties were improved compared with Cf/C-SiC composites. The flexural strength, flexural modulus and failure strains of the prepared composites were 218.44 ± 16.23 MPa, 68.17 ± 8.69 GPa and 2.22 ± 0.12%, respectively. In addition, the Cf/C-SiC-TiC composites showed a pseudoplastic fracture behavior because of debonding and pullout of fibers as well as propagation and deflection of cracks. Furthermore, the enhanced mechanism of the composites was proposed.

Effects of solidification parameters and magnetic field on separation of primary silicon from hypereutectic Ti–85 wt.% Si melt

In the present study, the effects of the solidification parameters and magnetic field on the enrichment of primary Si via separation of a hypereutectic Ti–85 wt.% Si alloy during directional solidification were experimentally investigated. The results indicated that increasing the pull-down rate from 5 to 15 μm/s increased the temperature gradient and growth rate at the same position of the ingot, although the Si content decreased. At a certain pull-down rate (e.g., 5 μm/s), with the increasing thickness of the Si-rich layer, the temperature gradient, growth rate, and Si content all decreased. In presence of a magnetic field, the solidification direction produced an electromagnetic force, which acted on the tip of the dendrite and changed the shape of the separation interface. Meanwhile, the electromagnetic stirring enhanced mass transfer at pull-down rates of 5, 10, and 15 μm/s, while dendritic breakdown processes maintained corresponding enrichment layer thicknesses of 45 mm, 35 mm, and 15 mm, respectively. The results could be helpful for expanding the applications of Ti–Si alloys and solving the problems presented by the solid waste of Ti-BF slag, i.e., environmental pollution and wastage of Ti resources.

Work softening behavior of Cu–Cr–Ti–Si alloy during cold deformation

Work hardening is a common method of strengthening copper-based alloys. However, softening behavior is observed in Cu–Cr–Ti–Si alloy during cold rolling processes. Cold deformation greater than 85% can induce softening behavior. We used an electron backscatter diffraction system, X-ray diffraction, and transmission electron microscopy to analyze the microstructure of alloy samples subjected to different degrees of cold deformation. A greater proportion of high-angle grain boundaries, a lower dislocation density, and certain dislocation configurations indicated that the recovery takes place during heavy cold deformation leading to softening phenomenon.

The tribological properties of Ni3Si alloys with Ti addition against different counterface materials under seawater condition

Tribological properties of Ni3Si alloys were examined in artificial seawater condition. The results indicated that the friction coefficient and wear rate increased with increase in applied load and Ti content. The friction coefficient and wear rate of the Ni–Si–Ti alloy were lower than that of Ti6Al4V alloy. It was also found that the friction coefficient was lowest when the Ni–Si–Ti alloy sliding against Al2O3 ball, but the wear rate of the alloy was lowest for the tribo-pair of Ni–Si–Ti/316 stainless steel. The wear mechanisms of Ni–Si–Ti/Si3N4 and Ni–Si–Ti/Al2O3 tribo-pairs were abrasive wear, and that of Ni–Si–Ti/316 stainless steel tribo-pair was adhesive wear.

Direct Synthesis of Nanotubular Si-TiO2for Lithium-Ion Batteries Anodes By Anodizing

Industry and the scientific community have been concentrating efforts on the production and development of energy storage systems ESS [1].By the energy density improvements of lithium ion battery electrodes for electronic devices (EDs) and energy vehicles (EVs), and cost of manufacturing must be taken into account, so that new developed materials can with the currently used batteries[2-4].Silicon is an important candidate as anode material for the next generation of lithium ion batteries(LIBs) because of its extremely high specific capacity (4200 mAh/g). However, Si particles degrade during the volumetric change related to lithiation/delithiation processes.Efforts have been made in the last decade in an attempt to minimize the instabilities caused by the large volumetric variation [5,6]. The most effective approaches in this regard include: (a) reduction of particle size to the nanometer size range to lower mechanical stress, (b) formation of a porous structure promoting a stable solid electrolyte interface SEI (c) dispersing Si nanoparticles in a conductive matrix to accommodate the volumetric variations and preserve the mechanical integrity of the electrode, (d) formation of amorphous SiO2 structure in small dimensions, and the(e) formation of intermetallic composite with structure layers to accommodate Si particles[7]. In the other hand, TiO2also incorporates Li(330 mAh/g)and shows a fast lithium intercalation reaction, without major volumetric effects during Li intercalation/deintercalation. In this work the aim is to produce Si nanoparticles embedded in a nanotubular TiO2 matrix, avoiding mechanical stress problems, due to volumetric changes and the formation of SEI directly between Si nanoparticles(SiNP) and the electrolyte. For this, Ti-Si alloys with 2 and 4 at.%Si were prepared by arc melting in an Ar atmosphere. A Si-Ti solid solution phase was obtained by furnace heating to 1200 ºC and rapidly cooling to a hard martensitic phase.Thin sheets of these alloys were cut and anodized in different electrolytes aiming to avoid the dissolution of the Si Particles. The structure and morphology of the Si rich TiO2 nanotubes were investigated by TEM, XPS, SEMand GID/DRX. Cell voltage transients of the anodizing of Ti2Si and Ti4Si indicate different levels of SiNP accumulation. Different electrolyte compositions, organic and inorganic, with and without fluoride were used for the growth of the porous structures. The effect of lithium addition on electrolytes is observed in favor of porous structure. SiNPs embedded in TiO2 were observed by SEM, TEM and characterized by GID/DRX.1% at. Si was measured by EDS onregular tubular TiO2 detached from Ti-2 at.%Si anodized in a fluoride based electrolyte, indicating that around 50% of the Si was not lost to the electrolyte during anodization. In the other hand, metallic Si phase was detected by grazing angle diffraction indicating that Si NP are formed. The developed process shows to be an efficient way for the direct fabrication of self-organized titania nanotubes containing silicon nanoparticles. [1]S.Goriparti, E.Miele, F. De Angelis, E. Di Fabrizio, R. P.Zaccaria, C. Capiglia, Journal of Power Sources, 257 (2014) 421-443. [2]Naoki Nitta, Feixiang Wu, Jung Tae Lee and GlebYushin. Materials Today Volume 18, Number 5 June (2015) [3] Peter G. Bruce, Bruno Scrosati, Jean-Marie TarasconAngewandteChemieAngew. Chem. Int. Ed. (2008), 47, 2930 – 2946 [4] Bruno Scrosati, Jürgen Garche, Lithium batteries: Status, prospects and future, Journal of Power Sources 195 (2010) 2419–2430 [5] Weitian Lia,1, Xianwei Guoa,1, YueLub, Lin Wanga, Ailing Fana, ManlingSuib, HaijunYua, Amorphous nanosized silicon with hierarchically porous structure for highperformance lithium ion batteries. Energy Storage Materials 7 (2017) 203–208 [6] Lucie Leveau , Barbara Laïk , Jean-Pierre Pereira-Ramos, AurelienGohier , Pierre Tran-Van ,Costel-SorinCojocaru. Silicon nano-trees as high areal capacity anodes for lithium-ion batteriesJournal of Power Sources 316 (2016) 1-7. [7] HuajunTian, FengxiaXin, Xiaoliang Wang, Wei He ,Weiqiang HanHigh capacity group-IV elements (Si, Ge, Sn) based anodes for lithium-ion batteries. Journal of Materiomics 1 (2015) 153-169 Figure 1