Showing papers on "Titanium published in 2017"
TL;DR: A battery that reversibly intercalates magnesium monochloride cations with excellent rate and cycle performances in addition to the large capacity is shown.
Abstract: Magnesium rechargeable batteries potentially offer high-energy density, safety, and low cost due to the ability to employ divalent, dendrite-free, and earth-abundant magnesium metal anode. Despite recent progress, further development remains stagnated mainly due to the sluggish scission of magnesium-chloride bond and slow diffusion of divalent magnesium cations in cathodes. Here we report a battery chemistry that utilizes magnesium monochloride cations in expanded titanium disulfide. Combined theoretical modeling, spectroscopic analysis, and electrochemical study reveal fast diffusion kinetics of magnesium monochloride cations without scission of magnesium-chloride bond. The battery demonstrates the reversible intercalation of 1 and 1.7 magnesium monochloride cations per titanium at 25 and 60 °C, respectively, corresponding to up to 400 mAh g−1 capacity based on the mass of titanium disulfide. The large capacity accompanies with excellent rate and cycling performances even at room temperature, opening up possibilities for a variety of effective intercalation hosts for multivalent-ion batteries. Magnesium rechargeable batteries potentially offer high-energy density, safety, and low cost. Here the authors show a battery that reversibly intercalates magnesium monochloride cations with excellent rate and cycle performances in addition to the large capacity.
274 citations
TL;DR: The main reason that there is not more wide-spread use of titanium alloys is the high cost as discussed by the authors and powder metallurgy (P/M) represents one cost effective approach to fabrication of titanium components.
269 citations
TL;DR: In this paper, an anticorrosion coating for stainless steel (SS) and titanium bipolar plates was evaluated to improve the corrosion resistance and electrical conductivity in PEMFC.
196 citations
TL;DR: In this article, the application of powder mixed electrical discharge machining (PMEDM) for the machining of β-phase titanium (β-Ti) alloy has been proposed.
Abstract: The present research is the first type of study in which the application of powder mixed electrical discharge machining (PMEDM) for the machining of β-phase titanium (β-Ti) alloy has been proposed....
176 citations
TL;DR: By introducing hydride, the repertoire of heterogeneous catalysts can be expanded to include formerly unexamined compositions without resorting to precious metals, and conventional scaling rules of pure metals predict essentially no activity for Ti.
Abstract: The problem of activating N2 and its subsequent hydrogenation to form NH3 has been approached from many directions. One of these approaches involves the use of transition metal hydride complexes. Recently, transition metal hydride complexes of Ti and Ta have been shown to activate N2, but without catalytic formation of NH3. Here, we show that at elevated temperatures (400 °C, 5 MPa), solid-state hydride-containing Ti compounds (TiH2 and BaTiO2.5H0.5) form a nitride-hydride surface similar to those observed with titanium clusters, but continuously (∼7 days) form NH3 under H2/N2 flow conditions to achieve a catalytic cycle, with activity (up to 2.8 mmol·g·–1·h–1) almost comparable to conventional supported Ru catalysts such as Cs–Ru/MgO or Ru/BaTiO3 that we have tested. As with the homogeneous analogues, the initial presence of hydride within the catalyst is critical. A rare hydrogen-based Mars van Krevelen mechanism may be at play here. Conventional scaling rules of pure metals predict essentially no activ...
160 citations
TL;DR: In this paper, the corrosion behavior of CP-Ti and Ti-TiB composite produced by selective laser melting (SLM) in the artificial simulated body fluid (Hank's solution) at body temperature was investigated systematically by using electrochemical measurements (potentiodynamic polarisation curves and electrochemical impedance spectroscopy), together with some detailed structural characterisations.
150 citations
TL;DR: Application of a dual layered silver–HA nanocoating to titanium alloy implants creates a surface with antibiofilm properties without compromising the HA biocompatibility required for successful osseointegration and accelerated bone healing.
Abstract: One of the most common causes of implant failure is peri-implantitis, which is caused by bacterial biofilm formation on the surfaces of dental implants. Modification of the surface nanotopography has been suggested to affect bacterial adherence to implants. Silver nanoparticles are also known for their antibacterial properties. In this study, titanium alloy implants were surface modified following silver plating, anodisation and sintering techniques to create a combination of silver, titanium dioxide and hydroxyapatite (HA) nanocoatings. Their antibacterial performance was quantitatively assessed by measuring the growth of Streptococcus sanguinis, proportion of live/dead cells and lactate production by the microbes over 24 h. Application of a dual layered silver-HA nanocoating to the surface of implants successfully inhibited bacterial growth in the surrounding media (100% mortality), whereas the formation of bacterial biofilm on the implant surfaces was reduced by 97.5%. Uncoated controls and titanium dioxide nanocoatings showed no antibacterial effect. Both silver and HA nanocoatings were found to be very stable in biological fluids with material loss, as a result of dissolution, to be less than 0.07% for the silver nanocoatings after 24 h in a modified Krebs-Ringer bicarbonate buffer. No dissolution was detected for the HA nanocoatings. Thus, application of a dual layered silver-HA nanocoating to titanium alloy implants creates a surface with antibiofilm properties without compromising the HA biocompatibility required for successful osseointegration and accelerated bone healing.
141 citations
TL;DR: Zirconia implant surfaces showed a statistically significant reduction in human plaque biofilm formation after 72 hours of incubation in an experimental anaerobic flow chamber model compared with titanium implant surfaces.
Abstract: Background: It has been hypothesized that zirconia might have a reduced bacterial adhesion compared with titanium; however, results from experimental studies are rather controversial. The aim of the present study is to compare biofilm formation on zirconia and titanium implant surfaces using an in vitro three-species biofilm and human plaque samples.Methods: Experimental disks made of titanium (Ti) or zirconia (ZrO2) with a machined (M) or a sandblasted (SLA) and acid-etched (ZLA) surface topography were produced. An in vitro three-species biofilm or human plaque samples were applied for bacterial adhesion to each type of disk, which after 72 hours of incubation was assessed using an anaerobic flow chamber model.Results: Zirconia showed a statistically significant reduction in three-species biofilm thickness compared with titanium (ZrO2-M: 8.41 μm; ZrO2-ZLA: 17.47 μm; Ti-M: 13.12 μm; Ti-SLA: 21.97 μm); however, no differences were found regarding three-species-biofilm mass and metabolism. Human plaque ana...
133 citations
TL;DR: In this article, a detailed characterization of the microstructure and the mechanical properties of commercially pure titanium (CP Ti) processed by selective laser melting (SLM) in a regulated reactive atmosphere with a slight addition of oxygen (02-04 vol%) to enhance the mechanical property of the material.
124 citations
TL;DR: Graphene reinforced bulk titanium matrix composites (TMCs) were successfully fabricated via powder metallurgy approach as mentioned in this paper, where 0.5% graphene nanoflakes (GNFs) and Ti6Al4V mixture powders were prepared by a wet process.
122 citations
TL;DR: The crystallographic study sheds light on the possible Al intercalation sites in the titanium sulfides, while the results from galvanostatic intermittent titration indicate that the low Al3+ diffusion coefficients in the sulfide crystal structures are the primary obstacle to facile Al interCalation-extraction.
Abstract: We report the electrochemical intercalation–extraction of aluminum (Al) in the layered TiS2 and spinel-based cubic Cu0.31Ti2S4 as the potential cathode materials for rechargeable Al-ion batteries. The electrochemical characterizations demonstrate the feasibility of reversible Al intercalation in both titanium sulfides with layered TiS2 showing better properties. The crystallographic study sheds light on the possible Al intercalation sites in the titanium sulfides, while the results from galvanostatic intermittent titration indicate that the low Al3+ diffusion coefficients in the sulfide crystal structures are the primary obstacle to facile Al intercalation–extraction.
TL;DR: The alloying elements proved to modify the alloy microstructure and to enhance the mechanical properties, improving the hardness and decreasing the elastic modulus of the binary and ternary alloys, respectively.
TL;DR: The bioinspired nanostructures on black titanium impart multi-biofunctional properties toward engineering the next-generation biomaterials for orthopedic implants and supported the attachment and proliferation of human mesenchymal stem cells and augmented osteogenic lineage commitment in vitro.
Abstract: We have developed a chlorine based reactive ion etching process to yield randomly oriented anisotropic nanostructures that render the titanium metal surface `black' similar to that of black silicon. The surface appears black due to the nanostructures in contrast to the conventional shiny surface of titanium. The nanostructures were found to kill bacteria on contact by mechanically rupturing the cells as has been observed previously on wings of certain insects. The etching was optimized to yield nanostructures of approximate to 1 mu m height for maximal bactericidal efficiency without compromising cytocompatibility. Within 4 hours of contact with the black titanium surface, 95% +/- 5% of E. coli, 98% +/- 2% of P. aeruginosa, 92% +/- 5% of M. smegmatis and 22% +/- 8% of S. aureus cells that had attached were killed. The killing efficiency for the S. aureus increased to 76% +/- 4% when the cells were allowed to adhere up to 24 hours. The black titanium supported the attachment and proliferation of human mesenchymal stem cells and augmented osteogenic lineage commitment in vitro. Thus, the bioinspired nanostructures on black titanium impart multi-biofunctional properties toward engineering the next-generation biomaterials for orthopedic implants.
TL;DR: In this paper, a high-capacity supercapacitor material based on nitrogen-doped delaminated titanium carbides (N-d-Ti3C2) synthesized through facile urea-assisted delamination of large-scale Ti3C 2 and carbonization of DELAMINED Ti3c2 (dTi3c 2 ) mixed with urea was reported.
TL;DR: A microwave-assisted method was developed to substitute the zirconium with titanium in UiO-66 within a few hours compared to several days reported previously, with the crystallinity well maintained and photocatalytic activities tremendously improved.
TL;DR: In this article, a simple solvothermal method was used to synthesize a graphene oxide grafting titanium dioxide nanoparticles (TiO 2 -GO nanocomposite), which achieved a maximum degradation efficiency of 100 and 84% on methylene blue (MB) and methyl orange (MO) under UV-light irradiation.
Abstract: Graphene oxide grafting titanium dioxide nanoparticles (TiO 2 -GO nanocomposite) was successfully synthesized by a simple solvothermal method. The synthesized TiO 2 -GO nanocomposite were systematically characterized by various physico-chemical techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The XRD results confirm the crystallinity of synthesized bare titanium dioxide nanoparticles (TiO 2 NPs), pristine graphene oxide (GO) and TiO 2 -GO nanocomposite with high pure in nature. The average size of the bare TiO 2 NPs was around 5 nm and were dispersed over the wrinkled graphene layers. Raman spectrum shows the resulting GO and TiO 2 -GO nanocomposite exhibit moderate graphitization with the intensity of D to G value was 1.1 and 1.2, respectively. The chemical state, functionality and composition (carbon, oxygen and titanium) of the resulting TiO 2 -GO nanocomposite were revealed by XPS analysis. The photocatalytic activity of synthesized TiO 2 -GO nanocomposite was investigated on the degradation of hazardous organic dyes (methylene blue (MB) and methyl orange (MO)) under UV-light irradiation and was compared with bare TiO 2 NPs and were presented based on the preferred propagation path of induced electrons that leads to generation of O 2 ─ . The resulting TiO 2 -GO nanocomposite achieve a maximum degradation efficiency of 100 and 84% on MB and MO in a neutral solution within 25 and 240 min, respectively under UV-light irradiation, the results show that the GO plays an important role in the enhancement of photocatalytic performance. The high photocatalytic efficiency due to the increased light absorption, the reduced charge recombination with the introduction of GO. Moreover, the simple and affordable solvothermal derived TiO 2 -GO nanocomposite exhibit rapid photocatalytic degradation on MB in 25 min of UV-light irradiation.
14 Mar 2017-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the influence of various dispersion methods on the evolution of multi-walled carbon nanotubes (MWCNTs) in titanium (Ti) metal matrix composites (TMCs) prepared via spark plasma sintering (SPS) have been investigated.
Abstract: The influence of various dispersion methods on the evolution of multi-walled carbon nanotubes (MWCNTs) in titanium (Ti) metal matrix composites (TMCs) prepared via spark plasma sintering (SPS) have been investigated. The synthesis procedures included sonication, high energy ball milling (HEBM), and rapid consolidation of powder mixtures at different sintering temperatures. The impact energy provided to the powder mixtures during HEBM process was optimized to disperse 0.5 wt% MWCNTs into Ti matrix in two controlled ball milling processes: with and without in-situ formation of TiC during HEBM. The interfacial reactions between MWCNTs and Ti matrix were controlled by retaining the crystallinity and sp2 carbon network of the MWCNTs even at high sintering temperature of 800 °C, which enhanced their compressive strength up to 1056 MPa with a compressive strain of 27.31%. The mechanical and tribological properties of the composites consolidated from the powder mixtures with in-situ TiC formation during HEBM and pre-sonicated MWCNTs were significantly enhanced as opposed to the composites consolidated from the powder mixtures without formation of TiC during HEBM.
TL;DR: In this paper, a Spark Plasma Sintering (SPS) was employed to fabricate monolithic titanium and in-situ formed TiB whisker (TiBw) reinforced titanium matrix composites by adding different amounts of TiB2 as boron source.
TL;DR: A visible-light-responsive metal-organic framework based on titanium hexameric cluster and high conjugation system of organic linker building block termed MOF-902 was synthesized and fully characterized as discussed by the authors.
Abstract: A visible-light-responsive metal–organic framework based on titanium hexameric cluster and high conjugation system of organic linker building block termed MOF-902 was synthesized and fully characterized. The photocatalytic properties of MOF-902 were investigated in the polymerization reaction with various monomers such as methyl methacrylate (MMA), benzyl methacrylate (BMA), and styrene (St), respectively. Gel permeation chromatography (GPC) analysis results demonstrated the high performance of MOF-902 as a catalyst, affording polymer products with high molecular weight (Mn) and low polydispersity index (PDI). The photocatalytic efficiency of MOF-902 in the polymerization transformation obviously exceeds other catalysts such as MOF-901, UiO-66, UiO-66-NH2, MIL-125(Ti), MIL-125-NH2(Ti), and commercial P25-TiO2.
TL;DR: In this article, the additive layer manufactured (ALM) titanium components were compared to a casting process and it was found that the as-deposited microstructure produced during ALM exhibits larger average grain sizes.
TL;DR: In this paper, an innovative method for surface modification of β-phase titanium alloy using hydroxyapatite mixed electric discharge machining (HAM-EDM) is presented, which enables one to deposit in-situ a biomimetic nano-porous HA-containing layer while shaping the base titanium, hence modifying the surface properties of the original substrate.
Abstract: The study presented an innovative method for surface modification of β-phase titanium alloy using hydroxyapatite mixed electric discharge machining (HAM-EDM). The process enables one to deposit in-situ a biomimetic nano-porous HA-containing layer while shaping the base titanium, hence modifying the surface properties of the original substrate. A series of the dedicated HAM-EDM on titanium alloys have been conducted. Surface integrity, topography, and elemental composition of the modified surface were investigated by FE-SEM, EDS, XRD, and indentation techniques, while in vitro cell study was performed to evaluate biocompatibility and cell attachment of the treated surface. The morphology characterization results revealed that a natural bone-like nano-porous surface topography has been imparted on the β-phae Ti implant surface using the HAM-EDM. The EDS and XRD examinations showed that the deposited layer comprised of Ti, Nb, Ta, Zr, O, Ca and P elements and formed biocompatible phases such as Ca 3 (PO 4 ) 2 , CaZrO 3 , Nb 8 P 5 , CaO, TiP, Nb 4 O 5 , and TiO 2 , TiH on the β-Ti implant surface, which improved the bioactivity of the alloy and beneficial for the promotion of osseointegration. The results revealed that a 18–20 μm thick recast layer containing biocompatible phases was generated, which has excellent metallurgical bonding with the base surface and offered mechanical interlocking to delamination. The HA deposited surface shows am improved hardness of 1275 HV which is 3-fold higher than the untreated surfaces; predominantly owing to the deposition of hard oxides on the modified surface. The HA-deposited bioceramic layer presented an excellent and higher corrosion resistance as compared to EDMed and un-treated specimens in simulated body fluid. The in-vitro bioactivity results confirmed that the nano-porous HA-containing layer exhibited the superior bioactivity and promotes adhesion, growth, proliferation, and differentiation of human osteoblastic MG-63 cells.
TL;DR: The metal injection molding (MIM) is a well-developed net or near-net shape manufacturing technique for stainless steel, copper and other metallic materials as mentioned in this paper, which has also received increasing attention over the last decade as a promising technique for the manufacture of small and intricate titanium parts for a range of applications in biomedical, aerospace, automotive and other industries.
TL;DR: In this paper, a combination of magnetron sputtering and annealing treatment was applied to a TiO 2 /CuO coating for surface modification of Ti-based implant materials, which may provide a research foundation for further development of bioactive multifunctional coatings to meet the better clinical demand.
TL;DR: In this article, a method to directly synthesize non-agglomerated TiO2 nanoparticles with different crystal phase ratios via low temperature dissolution-precipitation (LTDRP) on a porous microfiltration membrane (polyethersulfone) was presented.
Abstract: Removing pollutants from water by using the photocatalyst TiO2 is a highly-promising method. A large amount of work has been done to increase the activity of TiO2, whereas the main two findings are increasing the surface area and applying mixed phase modifications (anatase, brookite, and rutile). Here, we present a method to directly synthesize non-agglomerated TiO2 nanoparticles with different crystal phase ratios via low temperature dissolution-precipitation (LTDRP) on a porous microfiltration membrane (polyethersulfone). The amount of hydrochloric acid and the temperature was varied between 0.1–1 M and 25–130 °C, respectively, while the concentration of titanium precursor (titanium(IV) isopropoxide) was kept unchanged. The TiO2 nanoparticles and the membrane were thoroughly characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), measuring the water contact angle and permeation flux, and examining the degradation of methylene blue. The mixed phase anatase/brookite with a main component being anatase exhibited the highest photocatalytic activity in removing methylene blue. Higher synthesis temperature induces enhanced crystallinity and, subsequently, the degradation rate of methylene blue was improved. Additionally, the photocatalytic activity remains high and unchanged for up to nine repeated cycles, i.e., full recovery of the photocatalytic properties is sustained.
TL;DR: In this article, the surface characteristics of oxide layers formed on commercially pure titanium samples by anodic treatment and the effect of anodic treatments on their corrosion behaviour were evaluated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves.
TL;DR: Great levels of dissolved titanium were detected in submucosal plaque around implants with peri-implantitis compared with healthy implants, indicating an association between titanium dissolution andperi-IMplantitis.
Abstract: Background: Peri-implantitis represents a disruption of the biocompatible interface between the titanium dioxide layer of the implant surface and the peri-implant tissues. Increasing preclinical data suggest that peri-implantitis microbiota not only triggers an inflammatory immune response but also causes electrochemical alterations of the titanium surfaces, i.e., corrosion, that aggravate this inflammatory response. Thus, it was hypothesized that there is an association between dissolution of titanium from dental implants, which suggests corrosion, and peri-implantitis in humans. The objective of this study is to compare levels of dissolved titanium in submucosal plaque collected from healthy implants and implants with peri-implantitis.Methods: Submucosal plaque from 20 implants with peri-implantitis and 20 healthy implants was collected with sterile curets from 30 participants. Levels of titanium were quantified using inductively coupled plasma mass spectrometry and normalized for mass of bacterial DNA ...
TL;DR: The biological experiments indicate that Zn-ZrO2/TiO2 coatings exhibit not only excellent antibacterial property against Gram-positive Staphylococcus aureus, but also favorable cytocompatibility and corrosion resistance of the coating is also appreciably improved in the simulated body fluids (SBF), which can ensure better biocompatible in body fluids.
TL;DR: In this article, the growth mechanism and properties of micro-arc oxidation (MAO) coatings on titanium (Ti) alloy were studied using different electrolytes and the adhesion and tribological properties of MAO coatings were evaluated by thermal shock tests and ball-on-disk friction tests, respectively.
Abstract: In this work, the correlations between the growth mechanism and properties of micro-arc oxidation (MAO) coatings on titanium (Ti) alloy were studied using different electrolytes. The adhesion and tribological properties of MAO coatings were evaluated by thermal shock tests and ball-on-disk friction tests, respectively. Results show that the growth mechanism as well as adhesion and tribological properties of MAO coatings are greatly influenced by electrolytes. In silicate electrolyte, the growth of MAO coatings is dominated by the deposition of silicate oxides and mostly characterized by outward growth. As a result, the coatings exhibit poor adhesion, but the presence of silicate oxides in the coatings is beneficial for improving the wear resistance. In phosphate electrolyte, the coating growth mainly results from the oxidation of the substrate and is more characterized by inward growth, resulting in high adhesion but low wear resistance. Employing the mixed silicate and phosphate electrolyte, however, is a feasible way of optimization to get relatively both high adhesion and improved wear resistance.
TL;DR: In this paper, the influence of metal composite interface (MCI) on the mechanical behaviors of Ti/CFRP/Ti laminates were experimentally investigated through indentation tests and low velocity impact tests.
TL;DR: In this article, a mesoporous nanowires (Ti(O,N)-MP-NWs) composed of iso-oriented interconnected nanocrystals with [100] preferred orientation and tunable O/N ratios are synthesized, based on an ion exchange process.
Abstract: Titanium oxynitride mesoporous nanowires (Ti(O,N)-MP-NWs) composed of iso-oriented interconnected nanocrystals with [100] preferred orientation and tunable O/N ratios are synthesized, based on an anion exchange process. By investigating the electrochemical performance, it is found to exhibit high pseudocapacitive sodium storage performance, demonstrated by kinetic analysis and experimental characterizations. Subsequently, the assembled asymmetric hybrid sodium ion capacitor (AC//Ti(O,N)) exhibits high energy and power densities. Our work proposes the high pseudocapacitance in non-aqueous sodium ion system is very promising for high-power and low-cost energy storage applications.