Ti Components Research Articles

Physico-thermal and geochemical behavior and alteration of the Au indicator gangue hydrothermal quartz at the Kubi Gold ore deposits

Altered and gangue quartz in hydrothermal veins from the Kubi Gold deposit in Dunkwa on Offin in the central region of Ghana are investigated for possible Au-associated indicator minerals and to provide the understanding and increase the knowledge of the mineral hosting and alteration processes in quartz. X-ray diffraction, air annealing furnace, differential scanning calorimetry, energy dispersive X-ray spectroscopy, and transmission electron microscopy have been applied on different quartz types outcropping from surface and bedrocks at the Kubi Gold Mining to reveal the material properties at different temperatures. From the diffraction results of the fresh and annealed quartz samples, we find that the samples contain indicator and the impurity minerals iron disulfide, biotite, titanium oxide, and magnetite. These minerals, under oxidation process between 574 and 1400 °C temperatures experienced hematite alterations and a transformation from α-quartz to β-quartz and further to cristobalite as observed from the calorimetry scans for hydrothermally exposed materials. The energy dispersive spectroscopy revealed elemental components of Fe, S, Mg, K, Al, Ti, Na, Si, O, and Ca contained in the samples, and these are attributed to the impurity phase minerals observed in the diffraction. The findings also suggest that during the hydrothermal flow regime, impurity minerals and metals can be trapped by voids and faults. Under favorable temperature conditions, the trapped minerals can be altered to change color at different depositional stages by oxidation and reduction processes leading to hematite alteration which is a useful indicator minerals in mineral exploration.

Critical condition for initiation of dynamic recrystallisation in electron beam powder bed fused Ti-6Al-4 V Alloy

Despite the unique capabilities of Additive Manufacturing (AM) processes for producing Ti components with complex geometries, the desired properties are only achievable if a holistic scheme is devised, considering the synergistic role of post-processing steps. This work aimed to enhance the applicability of metal AM products by improving the process chain in the manufacturing industry. For this purpose, the current work demonstrates a comprehensive investigation into the hot deformation of Ti-6Al-4 V (Ti64) pre-forms produced via the Electron Beam Powder Bed Fusion (EB-PBF) process focusing on the determination of critical conditions for initiating Dynamic Recrystallization (DRX) in these components. Following a sequential evaluation procedure, hot deformation experiments were carried out at temperatures ranging from 1000 to 1200 °C and strain rates of 0.001–1 s−1 to determine the critical stress and strain required for initiating DRX in Ti64 pre-forms and compare them to their wrought counterparts. In addition, a specific Finite Element Model (FEM) was coupled with DRX kinetics equations to predict the volume percentage of DRX grains during the hot deformation of the pre-forms. The analysis of flow stress curves showed a significant peak stress at low strains, which is then followed by a period of flow softening and eventually transitions into a nearly steady-state flow at higher strains. In addition, compared to their wrought counterparts, the EB-PBF samples exhibited a significantly superior flow softening behavior, as evidenced by a more significant volume fraction of DRX and faster recrystallisation rates. It was also revealed that the normalised strain for DRX initiation in the EB-PBF Ti64 and wrought one was 0.55 and 0.67, respectively. FEM results closely matched the experimental finding, confirming its reliability in providing valuable insights into microstructural evolution and offering a time-efficient alternative for process design and property optimisation, lowering dependence on trial-and-error approaches. Through a combination of experiments, numerical analysis, and finite element simulations, this study sheds light on the macroscopic deformation and microstructural transformations occurring during hot working processes.

Synergistic Leaching of Titanium, Aluminum, and Magnesium Components during Dilute Acid Pressure Treatment of High-Titanium Blast Furnace Slag.

This study focuses on an improved leaching process through the combination of pressurized conditions and direct filtration of acid leaching slurry, which is conductive to improving the filterability of acid leaching systems and the extraction rates of Ti, Al, and Mg components. The effects of sulfuric acid concentration, reaction temperature, particle size of materials, acid-slag ratio, and reaction time on the leaching efficiency were systematically investigated. The results showed that pressurization significantly enhances the filtration efficiency of the reaction slurry. Under the same filtration time, the filtration efficiency increased from 46% under ordinary pressure to 78% under pressurized conditions. Moreover, under the optimal reaction conditions, the extraction rates of Ti, Al, and Mg components were more than 88.21%, 97.8%, and 96.31%, respectively. Additionally, XRD and FTIR showed that titanium oxide sulfate hydrate crystals were produced in the acid-leached residues when the reaction temperature exceeded 190 °C, thereby reducing the extraction rate of Ti component. And the XRD pattern shows that when the reaction temperature is maintained at 190 °C and the reaction time is extended to 150 min, titanium oxide sulfate hydrate crystals will be formed to reduce the extraction rate of the Ti component. In summary, this study not only provides important theoretical support for the resource utilization of high-titanium blast furnace slag but also offers a feasible solution for efficient extraction and convenient filtration, thus holding significant academic and practical implications.

Superior corrosion-resistant Zr-Ti-Ag thin film metallic glasses as potential biomaterials

Low-cost and non-cytotoxic ternary Zr-Ti-Ag thin film metallic glasses (TFMGs) were synthesized by DC magnetron sputtering. Results revealed that Ag addition enhanced the crystallization resistance and thermal stability of TFMGs. An appropriate Ag addition favored the mechanical property and corrosion resistance of TFMGs, while the excessive Ag addition had the opposite effect. Moreover, Ag did not directly form the passive film but altered the passive film stability and anti-corrosion capacity of TFMGs by inducing the disordered atomic arrangement, forming a dense microstructure, and tuning the corrosion-resistant Zr and Ti components. With low Young’s modulus of 116.2 GPa and passive current density of 0.45 × 10−7 A/cm2, the TFMG with an Ag target sputtering power of 11 W exhibited superior corrosion resistance, suggesting its application potential as biomaterials.

ZnO/TiO2 hetero-structured nanosheets for effectively detecting formaldehyde at room temperature

In this study, ZnO/TiO2 nanosheets were synthesized using a hydrothermal method followed by annealing. The resulting hierarchical ZnO–TiO2 heterostructures exhibited improved gas-sensing performance compared with pure ZnO. We demonstrated that tuning the ratio of Zn to Ti components in the heterostructure allowed us to adjust the sensor stability, with the best- performing sample having a Zn:Ti ratio of 2:1. A notable reduction was observed in both the sensor response and recovery times, down to 22 and 17 s, respectively, by utilizing nanosheet- structured ZnO/TiO2 heterojunctions. To gain insight into the interaction between the sensing materials and formaldehyde (HCHO) molecules, we performed first-principles calculations to examine the density of states, charge transfer, and energy of adsorption. Our approach to constructing heterogeneous structures contributes to overcoming the low desorption efficiency and slow response-recovery time of pure ZnO for gas-sensing applications.

Unimodular proca theory: breaking the U(1) gauge symmetry of unimodular gravity via a mass term

We study the Hamiltonian structure of unimodular-like theories, where the cosmological constant (or other supposed constants of nature) are demoted from fixed parameters to classical constants of motion. No new local degrees of freedom are present as a result of a U(1) gauge invariance of the theory. Hamiltonian analysis of the action reveals that the only possible gauge fixing that can be enforced is setting the spatial components of the four-volume time vector Ti≈0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal{T}^{i}\\approx 0$$\\end{document}. As a consequence of this, the gauge-fixed unimodular path integral is equivalent to the minisuperspace unimodular path integral. However, should we break the U(1) gauge invariance, two things happen: a massless propagating degree of freedom appears, and the (gauge-invariant) zero-mode receives modified dynamics. The implications are investigated, with the phenomenology depending crucially on the target “constant”.

Multiple factors of regulation for transient negative capacitance in PbZr(1−x)Ti(x)O3 ferroelectric thin films

The negative capacitance (NC) of ferroelectric (FE) materials can effectively break the ‘Boltzmann tyranny’ and drive the continuation scaling of Moore’s law. In this work, to find a novel way for amplifying the transient NC, a series network of external resistors and PbZr(1−x)Ti(x)O3 (PZT) FE capacitors was constructed. Uniform modeling and simulation were performed using Kirchhoff’s current law, electrostatics equations, and Landau–Khalatnikov equations. The derived results revealed that the mismatch of switching rate between free charge and polarization during FE domain switching is responsible for the transient NC generation. Some interesting results were obtained for the regulation of the transient NC by various factors such as the strain between the FE film and substrate, the viscosity coefficient, the ratio of Ti components, the external resistance magnitude, and the operating temperature. This work provides considerable insight into the control of FE transient NC, and offers guidance for obtaining larger and longer transient NC in the widely used PZT thin films.

Potential Profiles through the PEM Water Electrolyzer Anode Compartment and Cost-Effective Cell Components

Potential profiles through the PEM water electrolyzer anode compartment have suggested the replacement of Pt-coated Ti components by more cost-effective materials like carbon and stainless steel [1]. Latest modelling results show that the decoupled potential of the current collector components depends on the presence of additional platinum coatings (Figure 1). These additional coatings are commonly applied at every component interface in the anode compartment to lower the contact resistance and, in turn, the electricity consumption of the electrolyzer. However, due to ionic decoupling in ultrapure feedwater the Pt-coatings can be replaced, e.g., by carbon coatings [1]. Therefore, the properties of vacuum-spray coated Ti macroporous layers (MPLs) on 316L stainless steel as demonstrated by DLR in Stuttgart [2] are well suited to protect the stainless-steel component at a distance of only tens of microns from the anode catalyst layer (ACL) especially in the absence of additional Pt coatings (Figure 1 right). Thus, a new path towards cost effective porous transport layers becomes available. Figure 1. Left. Open circuit potentials measured ex-situ (O2 saturated H2SO4 pH 4) and in situ (anode pole plate in a PEM water electrolyzer single cell). Right. Modelling of potential profiles through sprayed MPLs [2] in the absence (brown) and presence (grey) of additional Pt coatings in the anode compartment.

Controlled electrochemical hydridation of Ti surfaces – optimisation and electrochemical properties

Ti is used as a construction material in many applications including electrodes in various electrochemical technologies due to its high corrosion stability provided by the stable oxide layer on the surface. However, this oxide layer is also the reason for its resistivity causing high interfacial resistance between components and energy losses. This problem can be solved by various surface modifications such as acid etching or coating with a layer of precious metals. In this study, we present a novel method for controlled hydridation of Ti materials based on a combination of acid etching and cathodic hydridation aimed primarily for surface modification of Ti components for proton exchange membrane water electrolyser. Cathodic polarisation represents the means to increase the amount of Ti hydride and to tune its properties to obtain a Ti surface with low interfacial resistance and preserved corrosion stability. The study investigated the effects of concentration, temperature, time, and current density on cathodic polarization in H2SO4 electrolytes. The resulting samples were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, Kelvin probe and temperature-programmed desorption. This allowed finding interesting correlations between the surface composition of the Ti samples and their electrochemical properties.

Additive Manufacturing of Titanium Alloys: Processability, Properties, and Applications

The restricted number of materials available for additive manufacturing (AM) technologies is a determining impediment to AM growing into sectors and providing supply chain relief. AM, in particular, is regarded as a trustworthy manufacturing technology to replace the traditional ones for Ti alloy components. Furthermore, the AM processability of Ti alloys and their features, such as microstructure, texture, and mechanical properties, is strongly dependent on the chemical composition of the processed alloy. It is essential to consider the ultimate applications as well. β Ti alloys are gaining popularity in the biomedical industry, while α + β Ti alloys are increasingly utilized for producing components in the automotive and aerospace sectors. Consequently, the topic has garnered considerable interest, and the current text reviews the advances during the last 10 years in this area to facilitate the pathway from the demanded Ti alloy to the best‐fit AM procedure. While systematically reviewing the works published in the literature, the current text attempts to establish a link between the production method, feedstock type, chemical composition, and the ultimate application. This review also features practical applications of Ti components produced by metal AM methods and offers prospective possibilities and industrial applications.

Effect of graphene on the tribological behavior of Ti6Al6V2Sn/Gn composite produced via microwave sintering

Titanium alloys are widely used in various industrial applications due to their excellent properties. Due to its excellent heat conductivity and stability, graphene (Gn) can help Ti components last longer and experience less wear. In the current study, Ti6Al6V2Sn (Ti662) with various wt.% Gn was produced. The composite samples were subjected to metallurgical characterization to analyze the influence of Gn addition in the microstructure and phases formed. The properties such as microhardness and wear resistance were analyzed for all the samples. Variations in the load, sliding velocity, and distance were made during the wear test, and the effects of these factors on the wear rate and morphology of the worn surface were examined. Mechanical property analysis revealed that Ti662 + 0.5Gn exhibited the highest microhardness of 514.32HV, which was 1.45 times that of the matrix material. The sample with 0.5Gn exhibited increased wear resistance, the order of wear resistance observed was Ti662 + 0.5Gn > Ti662 + 0.75Gn > Ti662+1Gn > Ti662 + 0.25Gn > Ti662. The wear rate was reduced by 44.15 % at 40 N, 42.07 % and 52.02 % at 1.5 m/s and 2000 m for Ti662 + 0.5Gn composite. Worn surface morphology revealed that at elevated loads, abrasive and delamination wear was observed while at elevated velocity and distance, the formation of mechanically mixed layer (MML) was observed.

Microstructure, mechanical properties and multiphase synergistic strengthening mechanisms of a novel laser additive manufactured AlNi6TiZr alloy

In this work, selective laser melting (SLM) process is used to prepare the AlNi6TiZr alloy. By analyzing the printing quality and mechanical properties of the printed specimens with different process parameters, the SLM forming window of AlNi6TiZr is obtained. The relative density of the sample printed with 270 W-1100 mm/s (laser energy density: 82 J/mm3) reaches 99.7%, exhibiting excellent mechanical properties (yield strength (YS): 421.7 MPa; ultimate tensile strength (UTS): 480.4 MPa). After an aging treatment of 325 °C-12 h, the YS and UTS of the sample increased to 494 MPa and 550.7 MPa, respectively. Adding Ni, Ti, and Zr components promoted the generation of multi-phase precipitates in the Al alloy and improved the synergistic strengthening effect of multi-phases. The hard-shell structure (HSS) formed by the Al3Ni phase at the grain boundary significantly strengthened the grain boundary strength. The precipitated Al3(Ti, Zr) phases at the grain boundaries prevent grain growth and dislocation movement. The Al3Ni and Al3(Ti, Zr) phases have good thermal stability that can still maintain excellent enhancement effects at high temperature. AlNi6TiZr alloy has great application prospects in medium and high-temperature environments.

The effect of the concentration of plastic waste on the formation of reaction products of the Ti–PET system

The paper presents research results of the synthesis, phase composition, and structure of products obtained by highly exothermic reactions between Ti and C10H8O4 mixture components, depending on the plastic waste concentration and Ti powder dispersiveness, density of initial samples, and synthesis medium. The dependence of the phase composition and structure of the synthesis products on the concentration of the polymer (plastic) component in the initial Ti -PET (C10H8O4) system was found. When the plastic waste content is 20 wt% to 25 wt%, synthesis products contain TiC0.5O0.5–TiC0.6–0.75 particle agglomerates. Further growth in the polyethylene terephthalate content from 30 wt% to 45 wt% leads to the formation of synthesis products consisting of titanium carbide (TiC0.6–1.0). The gaseous byproduct composition of the exothermic reaction is investigated for the Ti–C10H8O4 mixture composition. It is found that the gaseous by-product mostly contains hydrogen and carbon monoxide as well as impurities of different hydrocarbons (methane, acetylene, ethane, ethene) and carbon dioxide. The maximum adiabatic temperature of the gas combustion temperature is 2080 oC, which demonstrates the possibility of using gas as a fuel for energy generation devices. Based on the data obtained, it is possible to create a basis for a new plastic waste technology to fabricate carbide-containing materials.

Development of directed energy deposition strategy for a mechanically interlocked pure Ti and Al alloy component with cross-shaped internal pure Ti lattice

Directed energy deposition (DED) using multi-metal materials typically employs a metallurgical bonding approach. The components using titanium (Ti) and aluminum (Al) alloys have attracted significant interest in aerospace and automotive industries due to their ability to decrease fuel consumption through lightweight construction. However, DED using Ti and Al alloys that are difficult to fusion-bond is plagued by the formation of brittle intermetallic compounds. In particular, the deposition of a Ti alloy layer on that of Al alloy decreases the mechanical property of the entire component. This study developed a DED strategy using wire and arc discharge for the mechanical interlocking of pure Ti ERTi-2 and Al alloy ER5356. First, the effects of heat input, fabrication paths, and arc locations on the interface and composition of the adjacent beads were clarified. A fabrication strategy was developed to achieve the desired fusion state and avoid collision between welding torch-fabricated component. A mechanical interlocked component with an internal ERTi-2 cross-shaped lattice and planar ERTi-2 surface layers was successfully fabricated. In addition, these results demonstrate that the developed fabrication strategy can be applied to the other metal combinations that are difficult to fusion-bond. Subsequently, X-ray computed tomography clarified that the internal ERTi-2 lattice was fabricated in the target geometry. Tensile tests were carried out using the mechanical interlocked components with an internal cross-shaped unit lattice. The yield and ultimate tensile strength were 45.1 ± 3.4 MPa and 55.5 ± 4.6 MPa, respectively. These values and the fracture positions were in good agreement with the predictions from the mechanical properties of the used materials and the lattice geometry. Hence, this study underscores the potential of mechanical interlocking to improve the mechanical properties of the multi-metal components that pose challenges for fusion-bonding.

Low-Pressure Deuterium Storage on Palladium-Coated Titanium Nanofilms: A Versatile Model System for Tritium-Based Betavoltaic Battery Applications.

Deuterium (D2(g)) storage of Pd-coated Ti ultra-thin films at relatively low pressures is fine-tuned by systematically controlling the thicknesses of the catalytic Pd overlayer, underlying Ti ultra-thin film domain, D2(g) pressure (PD2), duration of D2(g) exposure, and the thin film temperature. Structural properties of the Ti/Pd nanofilms are investigated via XRD, XPS, AFM, SEM, and TPD to explore new structure-functionality relationships. Ti/Pd thin film systems are deuterated to obtain a D/Ti ratio of up to 1.53 forming crystallographically ordered titanium deuteride (TiDx) phases with strong Tix+-Dy- electronic interactions and high thermal stability, where >90% of the stored D resides in the Ti component, thermally desorbing at >460 °C in the form of D2(g). Electronic interaction between Pd and D is weak, yielding metallic (Pd0) states where D storage occurs mostly on the Pd film surface (i.e., without forming ordered bulk PdDx phases) leading to the thermal desorption of primarily DOH(g) and D2O(g) at <265 °C. D-storage typically increases with increasing Ti film thickness, PD2, T, and t, whereas D-storage is found to be sensitive to the thickness and the surface roughness of the catalytic Pd overlayer. Optimum Pd film thickness is determined to be 10 nm providing sufficient surface coverage for adequate wetting of the underlying Ti film while offering an appropriate number of surface defects (roughness) for D immobilization and a relatively short transport pathlength for efficient D diffusion from Pd to Ti. The currently used D-storage optimization strategy is also extended to a realistic tritium-based betavoltaic battery (BVB) device producing promising β-particle emission yields of 164 mCi/cm2, an open circuit potential (VOC) of 2.04 V, and a short circuit current (ISC) of 7.2 nA.

Development, Characterization and High-Temperature Oxidation Behaviour of Hot-Isostatic-Treated Cold-Sprayed Thick Titanium Deposits

In this work, thick deposits of pure titanium (Ti), with a thickness of around 15 mm, were additively manufactured using high-pressure cold spraying. Nitrogen was employed as the process gas. Subsequently, the deposits were subjected to hot isostatic pressing (HIP). The HIP-treated Ti deposits were analyzed for their metallurgical and mechanical characteristics with the aim of exploring the viability of using cold spraying for the additive manufacturing of Ti components. Moreover, high-temperature cyclic oxidation testing was also performed on the HIP-treated Ti deposit to understand its stability at high temperatures. SEM/EDS showed a dense structure with marginal porosity for the HIP-treated Ti deposits, without any oxide formation, which was further confirmed via XRD analysis. An average microhardness of 214 HV was measured for the HIP-treated Ti deposits, which is close to that of the commercially available bulk titanium (202 HV). The high-temperature oxidation studies revealed that the cold-sprayed HIP-treated Ti has very good oxidation resistance, which could be attributed to the formation of protective titanium dioxide in its oxide scale.

Distribution and Cocrystallization Coefficients of a Wide Range of Typomorphic Elements in Magnetite, Hematite, and Sphalerite in Hydrothermal Systems

Abstract —Distribution of a wide range of elements in the systems with magnetite, hematite and sphalerite is studied by the method of thermogradient hydrothermal synthesis combined with internal fluid sampling at 450 °C temperature and 100 MPa pressure. The distribution and cocrystallization coefficients are determined; the literature and original data on these coefficients are summarized. The possibility of obtaining the reproducible data on elements distribution in the mineral − solution system in the occurrence of many typomorphic elements is substantiated. This considerably increases the experiment efficiency. A significant advantage of using cocrystallization coefficients rather than “conventional” distribution coefficients expressed by the ratio of the element concentrations in crystal and solution (fluid) is shown. The features of behavior and occurrence of elements in hydrothermal systems are provided with physico-chemical evidence, through application of cocrystallization coefficients. The examples of the behavior of typomorphic trace elements in sphalerite are considered, which support the theoretical analysis. The major (Fe, Mn, Zn and possibly Cu) and secondary (Ti, V, Al, and Co) components of ore-forming solutions are estimated according to the compositions of magnetite and hematite from hydrothermal ore deposits of various types. The similarity in compositions of magnetite and hematite does not prove their coformation from a single fluid, quite the reverse, and this fact indicates different compositions of fluids from which the minerals were deposited.

Fabrication of Zr-Ti-Si glassy metallic overlay on 3D printed Ti-6Al4V implant prototypes for enhanced biocompatibility

Implantable materials with enhanced corrosion resistance and bioactivity are highly desired for biomedical application. A 3D metal printed prototype surface was coated with amorphous alloy components of elements Zr, Ti and Si (Zr54Ti35 Si11) as a novel biomedical grade ternary system for the implants. A DC magnetron sputtering technique was used to sputter the films on Ti-6Al-4 V implant prototypes, exhibiting a smooth and denser coating with root means square surface roughness of 1.4 nm. Surface morphology and structural integrity of the thin film metallic glass (TFMG) was studied from electron microscopic techniques and X-ray diffraction analysis. The TFMG is thermally stable with a large supercooled liquid region (∆Tx) of 81.2 °C. Mechanical characteristics of the coatings were studied using the nanoindentation method to correlate the hardness and modulus of the implant materials. Under the simulated body fluid condition, Ti-6Al-4 V implant with 500 nm thickness coatings (Zr54Ti35Si11) exhibited the superior corrosion resistance rate 1 × 10−6 mpy with a charge transfer resistance of 34 kΩ promising for practical application. Electrochemical impedance spectra and Tafel analysis revealed that the corrosion resistance was prominent in the 500 nm thickness TFMG system than the 250 nm and uncoated bare counterparts. The in-vitro biocompatibility and cytotoxicity studies of the as-coated 3D printed implants were studied using the human osteoblast and L929 fibroblast cell lines, respectively. A hemocompatibility study on the implant materials revealed that erythrocytes remain biconcave without aggregation, platelet activation and thrombogenesis, supporting the biocompatibility of the implants. The integration of such unique properties makes these TFMG system ideal candidates for biomedical implants.

Fabrication of nanocrystalline and ultra-hard tungsten alloy by dual-particle dispersion strengthening

Alloying with heterogeneous atoms or second phase particles is an effective method for inhibiting grain growth and achieving ultrafine and nanocrystalline materials. In this work, by varying the component and content of Ti and ZrC, the synergistic effects of dual-particle reinforcement on sintering behavior and final bulk W alloys were investigated. The results revealed that adding both Ti and ZrC not only dramatically suppresses grain growth but also effectively promotes relative density. Nanocrystalline W-3Ti-1ZrC bulks were successfully fabricated with an ultra-high hardness of 1347 kgf/mm2. Further characterization showed that the alloying component and content strongly influence the milled-powder state agglomeration and morphology even in same milling condition. Additionally, the advantage of Ti and ZrC addition can be utilized simultaneously, as Ti retards grain growth and ZrC reacts with oxygen impurities to enhance grain boundary cohesion.

Influence of a Composite Polylysine-Polydopamine-Quaternary Ammonium Salt Coating on Titanium on Its Ostogenic and Antibacterial Performance.

Thin oxide layers form easily on the surfaces of titanium (Ti) components, with thicknesses of <100 nm. These layers have excellent corrosion resistance and good biocompatibility. Ti is susceptible to bacterial development on its surface when used as an implant material, which reduces the biocompatibility between the implant and the bone tissue, resulting in reduced osseointegration. In the present study, Ti specimens were surface-negatively ionized using a hot alkali activation method, after which polylysine and polydopamine layers were deposited on them using a layer-by-layer self-assembly method, then a quaternary ammonium salt (QAS) (EPTAC, DEQAS, MPA-N+) was grafted onto the surface of the coating. In all, 17 such composite coatings were prepared. Against Escherichia coli and Staphylococcus aureus, the bacteriostatic rates of the coated specimens were 97.6 ± 2.0% and 98.4 ± 1.0%, respectively. Thus, this composite coating has the potential to increase the osseointegration and antibacterial performance of implantable Ti devices.