Zirconia Fibers Research Articles

Finite element analysis of the effect of framework materials at the bone–implant interface in the all-on-four implant system

The "All-on-four" concept for treatment of edentulous arches incorporates four implants that are placed in between mental foramina in the mandible. The prosthetic framework is an important parameter in stress/strain concentration at the implants, prosthesis, and the underlying bone. Materials such as titanium, zirconia, and carbon fibers have been used for fabrication of framework in the past. The aim of this study was to analyze the effect of framework materials in the "All-on-four" implant system. Finite element three-dimensional (3D) model of edentulous mandible was simulated using a computerized tomographic scan data of an edentulous patient. Threaded implants were replicated along with the abutments using 3D modeling software and the framework was designed and simulated using material properties of titanium, zirconia, and polyetheretherketone (PEEK). Axial and nonaxial load of 200 N was applied at the abutment region of right distal implants. The computer-generated numerical values were tabulated and analysed by ANSYS software. Principal strain, von Mises stress and micromotion were assessed in the peri-implant bone region to evaluate its stress condition. Zirconia framework showed the least stress/strain values at axial and oblique loading. Maximum strain values were seen at the PEEK framework material. Zirconia framework in all models showed the least micromotion/displacement. The stress distribution pattern at implant-bone interface was influenced by the framework material used. The framework material, loading site, and direction of forces influenced the stresses and displacement at the bone-implant interface.

Multifunctional Ceramic Composite System for Simultaneous Thermal Protection and Electromagnetic Interference Shielding for Carbon Fiber-Reinforced Polymer Composites.

Achieving a high electrical conductivity while maintaining a good thermal insulation is often contradictory in the material design for the goal of simultaneous thermal protection and electromagnetic interference shielding. The reason is that materials with a high electrical conductivity often pertain a high thermal conductivity. To address this challenge, this study reports a multifunctional ceramic composite system for carbon fiber-reinforced polymer composites. The fabricated multifunctional ceramic composite system has a multilayer structure. The polymer-derived SiCN ceramic reinforced with yttria-stabilized zirconia fibers serves as the thermal protection and impedance-matching layer, while the yttria-stabilized zirconia fiber-reinforced SiCN ceramic with carbon nanotubes provides the electromagnetic interference shielding. The thermal conductance of the multilayered ceramic composite is about 22.5% lower compared to that of the carbon fiber-reinforced polymer composites. The thermal insulation test during the steady-state condition shows that the hybrid composite can be used up to 300 °C while keeping the temperature reaching the surface of carbon fiber-reinforced polymer composites at around 167.8 °C. The flame test was used to characterize the thermal protection capability under transient conditions. The hybrid composite showed temperature differences of 72.9 and 280.7 °C during the low- and high-temperature settings, respectively. The average total shielding efficiency per thickness of the fabricated four-layered ceramic composite system was 21.45 dB/mm, which showed a high reflection-dominant electromagnetic interference shielding. The average total shielding efficiency per thickness of the eight-layered composite system was 16.57 dB/mm, revealing a high absorption-dominant electromagnetic interference shielding. Typical carbon fiber-reinforced polymer composites reveal a reflection-dominant electromagnetic interference shielding. The electrons can freely move in the percolated carbon nanotubes within the inner layers of the composite material, which provide the improved electromagnetic interference shielding ability. The movement of electrons was impeded by the top and bottom layers whose thermal conduction relies on the lattice vibrations, resulting in a satisfactory thermal insulation of the composite materials and impedance matching with the free space. Results of this study showed that materials with a good thermal insulation and electromagnetic interference shielding can be obtained simultaneously by confining the electron movement inside the materials and refraining their movement at the skin surface.

Zirconia Fiber Containing TRIP‐Matrix Composites Prepared via Paper‐Manufacturing Technology

Herein, the continuous further development of metal matrix composites prepared by the paper‐manufacturing technology is in focus. The composites are based on metastable austenitic stainless steel with the addition of magnesia partially stabilized zirconia particles or yttria‐stabilized zirconia fibers. The sintering conditions are profoundly investigated, to study and subsequently inhibit the formation of carbides, which deteriorates the mechanical performance of the paper‐derived materials in the past. The cellulose pulp fiber content as well as the filler particle content is adjusted with the aim to improve the mechanical performance of the paper‐derived materials during tensile load testing. In addition, the cellulose pulp fibers are partially replaced by yttria‐stabilized zirconia fibers. The improved composites that contain 3 and 6 vol% of yttria‐stabilized zirconia fibers exhibit the ultimate tensile strengths of 264 and 322 MPa. The tensile strain of the improved TRIP‐matrix composites as well as of the reference material is significantly increased (up to 10%) as compared with our previous study, where all materials show brittle fracture behavior. This can certainly be attributed to the improvements in the sintering process and the corresponding prevention of carbide formation during heat treatment upon cooling.

Preparation of zirconia fiber based on akund template

Zirconia fiber is widely used in the field of fire resistance and heat insulation because of its excellent thermal insulation performance. In this study, the hollow plant fiber, akund, was used as template to prepare zirconia fibers with hollow structure. SEM, XRD, mercury porosimetry, and TG-DSC were used to characterize the microstructure, phase and crystal structure, pore size distribution, and formation process of the zirconia fiber. The analysis shows that the hollow structure restricted the air flow and was conducive to the improvement of thermal insulation performance. Yttria doping mae the phase of zirconia fiber stable. Lower heat treatment temperature made the grain size smaller. The concentration of impregnating solution can influence on the fiber morphology.

YSZ fiber reinforced highly porous γ-(Y0.8Ho0.2)2Si2O7 ceramic with multifunctional thermal insulation and microwave-transmitting property

We report a novel yttria-stabilized zirconia (YSZ) fiber reinforced highly porous γ-(Y0.8Ho0.2)2Si2O7 material that provides multifunctional thermal insulation and microwave-transmitting capability. Through the fiber reinforcement and solid solution strengthening modifications, the porous ceramic demonstrates extremely high porosity (93.2%), high compressive strength (1.21 MPa), low dielectric constant (1.39 to 1.37) and low loss tangent (3.0 × 10−2 to 3.5 × 10−2) from 7.2 to 19.5 GHz at 1000 °C, low thermal conductivity (0.077 to 0.206 W/(m·K) from 25 to 1200 °C) and low thermal cycling shrinkage (≤0.6% at 1550 °C for 2 h).

Zirconia/polyethylene terephthalate ceramic fiber paper separator for high-safety lithium-ion battery

The non-woven mat has a three-dimensionally distributed fiber structure, but because the randomly dispersed structure caused the pore diameter of the separator to enlarge, this may lead to a short circuit of the battery. In this work, organic polyethylene terephthalate (PET) was combined with inorganic zirconia (ZrO2) ceramic fiber using a low-cost papermaking method. The addition of PET blocked part of the macropores of the fiber separator, enabling the separator a suitable pore size. The PET connected the nodes of the zirconia fibers to provide mechanical support. At the same time, the ZrO2-PET composite separator inherited the excellent high temperature resistance of zirconia ceramic fiber and a maintained dimensional stability after heating at 300 °C for 1 h, providing a strong guarantee for the safe performance of the battery. We found that when the concentration of PET was 5%, the highest electrolyte uptake (301.83%) occurred as well as electrochemical performance. In addition, the ZrO2-PET composite separator achieved an excellent cycle performance at 60 °C compared with the polypropylene (PP) separator.

Injectable calcium phosphate containing zirconia short fiber with enhanced radiopacity

ABSTRACT In this work, novel injectable and radiopaque calcium phosphate bone cements were prepared using zirconia short fiber as a radiopacifier. The radiopacity, setting time, injectability, anti-washout ability, microstructure, mechanical property, and the in vitro cytocompatibility of the novel cements were evaluated thoroughly. The results reveal that the incorporation of zirconia fiber significantly improves the radiopacity of bone cement while it has no significant effect on the setting time, anti-washout ability, and injectability. The cements are still injectable and show good manual operability. Moreover, the flexural strength and compressive strength of the composite bone cement with 2 wt% fibers are enhanced. Additionally, MTT results reveal that the zirconia fiber doped cements exhibit no cytotoxicity toward osteoblastic MG63 cells, and MG63 cells can adhere and proliferate well on the cements. Therefore, calcium phosphate bone cement containing zirconia fibers has the potential to be used as a bone repair material for minimally invasive surgery.

Phase stability and microstructure evolution of MgO‐ZrO2 and MgO‐6YSZ ceramic fibers

AbstractIn this work, MgO‐ZrO2 and MgO‐6YSZ ceramic fibers were prepared with sol‐gel method via electrospinning. Polymorph stability and microstructure evolution of zirconia fibers were fully characterized by X‐ray diffraction, Raman spectra, X‐ray photoelectron spectroscopy, and Scanning electron microscope. The results indicated that tetragonal zirconia for MgO‐ZrO2 was obtained and cubic zirconia could be fully stabilized for MgO‐6YSZ with MgO molar fractions varying from 0.1 to 0.5 at 800°C. Monoclinic phase appeared with MgO molar fractions even up to 0.5 for MgO‐ZrO2 system and partially or fully stabilized zirconia could be achieved for MgO‐6YSZ at 1000°C and 1200°C. Grain size was gradually decreased with increasing of MgO content at 800°C both for MgO‐ZrO2 and MgO‐6YSZ ceramic fibers. The grain size of both systems increased with MgO molar fractions varying from 0.1 to 0.2 and then decreased at higher contents at 1000°C and 1200°C. A discussion on relationship among MgO state and the phase stability and grain size was presented. This work shows surface excess and solid solution of MgO predominantly controlled the phase stability and microstructure evolution of zirconia fibers.

Allura Red dye sorption onto electrospun zirconia nanofibers

Abstract Zirconia fibers were obtained by sol-gel and electrospinning techniques, using polyvinylpyrrolidone and zirconium butoxide as precursor. The as-spun fibers obtained from the precursor solutions were continuous and a mean diameter of 300 ± 95 nm was observed in samples obtained using a high precursor molar ratio (Z1: 0.1 M). The fibers were treated at different temperatures, and characterizations by thermal analysis, FTIR, Raman Spectroscopy and XRD demonstrated that monoclinic and tetragonal phases of zirconia are present. The predominant phase is monoclinic with some crystalline peaks corresponding to tetragonal zirconia. The phase transition from tetragonal to monoclinic zirconium oxide was observed at 1000 °C. At 1200 °C, the fiber morphology was preserved, while diameter decreased to 130 ± 39 nm due to the thermal decomposition of organic matter and sintering process. The adsorption behavior of the zirconia fibers was evaluated. Maximum adsorption capacity of Allura Red dye onto zirconia fibers was 0.895 mg/g. The data fitted better to pseudo-second order and Elovich kinetic models, while equilibrium data fitted to Freundlich and Temkin isotherms. The kinetic and equilibrium isotherm studies suggest that sorption of Allura Red dye on zirconia fibers takes place by a chemisorption process on a heterogeneous surface. The results showed that zirconia fibers can be used as an alternative adsorbent material for the effective removal of Allura Red dye from water. The manufacture of zirconia fibers by the electrospinning method offers an alternative to produce ceramics that can be used as adsorbent materials.

The effect of fibre content on properties of ceramifiable composites

ABSTRACTWith the development of rocket and aerospace technology in recent decades, people have put forward higher requirements on the heat resistance and ablation performance of thermal protection materials. In this paper, zirconia fibre hybrid alumina fibre/boron phenolic (ZA/BPF) ceramifiable composites, based on ceramic fillers of MgO, Al2O3, SiC and mica-modified boron phenolic resin matrix, were prepared with different hybrid fibre contents (5, 10, 15, 20, 25, 30 wt-%) by hot compression moulding. The result shows that fibre contents have little effect on the ablation resistance of composite materials which all have a low linear ablation rate below 0. 01 mm s−1. When the fiber content is 25%, the ZA/BPF composite reaches the highest bending strength 48. 86 MPa and 15. 57 MPa before and after sintering respectively. It is showed by the SEM results that too high and too low fibre content would both lead to poor bonding between resin and fibre interfaces.

Preparation of mesoporous zirconia ceramic fibers modified by dual surfactants and their phosphate adsorption characteristics

Phosphate removal is an essential measure in controlling the eutrophication of water. In this work, the electrospinning mesoporous zirconia fibers with high surface area were prepared and used as adsorbents to remove phosphate in aqueous solutions for the first time. The electrospinning mesoporous zirconia fibers which had large surface area and uniform pore size were prepared by the use of ammonium lauryl sulfate (ALS) and triblock co-polymer Pluronic (P-123) as dual surfactants. The morphology and composite were represented by XRD, TGA/DTA, FT-IR, SEM, and TEM. The specific surface area and pore properties of fibers were investigated by nitrogen adsorption-desorption method. These mesoporous zirconia fibers performed an outstanding phosphate adsorption ability whose maximum adsorption capacity could reach 222.79 mg/g, meanwhile, a nice cycle performance was also observed as the removal rate could remain 92.5% after 5 cycles on the initial concentration of 30 mg/L. The Freundlich model and the pseudo-second-order kinetic model were both fitted with the adsorption data properly. Besides, the fibers also performed a nice ability in anti-interference against the changes of solution pH value and co-existing ions. Thus, the prepared mesoporous zirconia fibers would be a potential adsorbent of phosphate removal process under the conditions of actual wastewater treatment, with the advantages of the excellent adsorption efficiency, low in production cost, high repeatable utilization and environment friendly.

Phase stability (at 1000°C) of hollow t‐ZrO2 fibers costabilized by lanthana and yttria

AbstractYttrium‐stabilized ZrO2 (YSZ) hollow fibers derived from a ceiba template present a 25%–53% reduction in thermal conductivity compared with traditional YSZ solid fibers. However, after prolonged preservation at 1000°C, tetragonal ZrO2 (t‐ZrO2) can easily transform to monoclinic ZrO2 (m‐ZrO2), which destroys the hollow structure of the YSZ fibers and results in loss of the structural advantages for heat insulation. To overcome this, in this study, biomorphic lanthana and yttrium costabilized zirconia (LaYSZ) fibers with a hollow structure are fabricated by doping appropriate amounts of lanthanum in the raw materials of YSZ fibers. X‐ray diffraction, scanning electron microscopy, and thermal conductivity measurements are utilized to confirm the phase‐stability superiority of LaYSZ fibers to that of YSZ fibers under harsh conditions. After preservation at 1000°C for 150 hours, the m‐ZrO2 content in the LaYSZ hollow fibers increases from 0 to 3.4 mol%, whereas that in the YSZ fibers increases from 0 to 10.25 mol%. Furthermore, owing to their better phase stability at 1000°C, the morphologies and heat‐insulating properties of LaYSZ fibers are more improved in several aspects compared with YSZ fibers.

Successful electrospinning fabrication of ZrO2 nanofibers: A detailed physical – chemical characterization study

Electrospinning fabrication of Zirconia nanofibers was successfully achieved, followed by different thermal treatment. A careful physical characterization study was performed based on the calcination temperature effect, which was confirmed by a wide range of analysis such as SEM, TG-DT analysis, XRD, FT-IR, DRS, VSM, and PL spectra. The morphological characterization of both polymer and ceramic nanofibers was achieved by SEM images through an image analyzing software. The average diameter of the produced nanofibers was estimated below 100 nm after rising thermal treatment temperature. The thermal behavior of the as-spun ZrO2 nanofibers was studied using thermogravimetric analyses (TGA). The whole powder pattern modeling (WPPM) approach using the PM2K package and the Rietveld refinement approach were applied on the X-ray diffraction pattern to get insight into the effect of calcination temperature on the microstructure parameters of nanostructured zirconia fibers. A comprehensive study was done on the chemical properties of the fabricated samples based on the absorption bands using FT-IR spectroscopy. Chemical study shows a good correlation between the XRD and FT-IR findings. The optical properties were investigated using diffuse reflectance spectroscopy and room-temperature photoluminescence spectra. An enhancement of PL intensity of the ZrO2 calcined at 800 °C could be due to its high crystal quality. The magnetic properties of zirconia nanofibers were investigated by a vibrating sample magnetometer (VSM). Room temperature magnetization results showed a hysteresis loop formation, indicating the ferromagnetic behavior of samples.

Preparation of silk-like zirconia and investigation of its heat-insulating properties

Many life forms possess the aesthetic and unique micromorphologies after long-term evolution and inspire researchers to fabricate different types of microstructures. In this study, silk was utilized as a template to produce silk-like zirconia fibers with excellent heat-insulating properties. We soaked silk in a solution containing Zr4+ and thereafter sintered the dried silk in air at temperatures below 1000 °C to obtain the zirconia fibers. The results showed that these zirconia fibers not only maintained the structures of silk but also exhibited hollowness, which rendered them with lower thermal conductivities and higher heat-insulating properties than conventional zirconia fibers.

Preparation and Heat Transfer Mechanism of ZrO2 Fiber Flexible Heat-Insulating Materials

The high temperature insulation material of zirconia fiber and carbon fiber (CZ) was prepared by wet molding process using chopped carbon fiber and zirconia fiber as raw materials. The thermal conductivity of the block was measured by high temperature flat plate thermal conductivity instrument. The effects of content of zirconia fiber, diameter of zirconia fiber and material density on CZ thermal conductivity were studied. The heat transfer mechanism of CZ was also studied. The results showed that the heat conductivity of CZ insulation material could be reduced with the reducing the diameter of zirconia fiber. The heat conductivity of CZ insulation material also could be reduced with increasing the content of zirconia fiber.

Research on the Thermal Insulation Performance of High Temperature Gradient Composite Insulation Material

In this study, the high temperature gradient composite insulation material (SGIM) was prepared by using zirconia fiber and carbon fiber (CZ), high temperature phase-change material (HPCM), microcellular thermal insulation material of calcium silicateas (CS/AS), insulation material of nano-silica(NP) and radiation shielding material as raw materials. The thermal insulation performance was simulated by using the finite element software. The heat insulation performance of the material was tested by oxy-acetylene ablation experiment. The thickness of the insulation material was also set to 32 mm. The temperature of hot surface was controlled at 2000°C. After 600 seconds, the material of cold temperature was 54°C. The excellent performance of SGIM insulation is demonstrated.

Optimization and Application Technology of Reflective Foils Using in Zirconia Fiber Insulation Materials

Graphite paper was used as reflective foils in the zirconia fiber insulation materials system, the effects of the number, spacing and emissivity of reflective foils on the thermal insulation properties of zirconia fiber insulation materials were studied. It was found that when the number of reflective foils is 10, interlayer spacing was 1 mm, the minimum thermal conductivity of the insulation materials was obtained. Zirconia superfine powder was used to reduce the emissivity of reflective foils, the modified reflective foils was used in the zirconia fiber insulation materials system, it was found that when the emissivity of the modified reflective foils was 0.37, the minimum thermal conductivity of insulation materials was obtained.

Effect of La2O3 on Grain Refinement and Thermal Conductivity of 6 mol % Y2O3–ZrO2 Fibers

ZrO2 ceramic fibers have gained widespread study for the high temperature stability, low thermal conductivity and high mechanical properties. While for oxide fibers, grain growth is one of the limiting factors for long-term high temperature applications. In the present study, polycrystalline ZrO2–6 mol % Y2O3 ceramic fibers with the addition of ~0–5 mol % La2O3 to refine the grain size were fabricated by the dry-spinning method. The XRD and Raman spectral results showed that the pyrochlore La2Zr2O7 phase was formed as a second phase in the tetragonal zirconia fiber matrix. The formation of a second phase was an effective way to hinder grain growth for the competition phase effect and solid solution mechanism. With the addition of La2O3, the grain size decreased and concentrated in a smaller range of 50–250 nm compared with the ZrO2–6 mol % Y2O3 matrix at 1400°C. Furthermore, the thermal conductivity of the fibers decreased with the additive of La2O3 less than 3 mol %. The present system is a promising candidate for high temperature applications.

Influence of Er,Cr:YSGG Laser Irradiation on the Push-Out Bond Strength of Zirconia and Glass Fiber Posts with Radicular Dentin.

Objective This in vitro study was designed to evaluate the influence of an Er,Cr:YSGG laser on the bond strength of zirconia and glass fiber posts with root dentin. Materials and methods Ninety extracted single-rooted human teeth were randomized into 6 groups (n = 15/group) on the basis of different posts (zirconia/glass fiber) and Er,Cr:YSGG laser tips (axial and radial). Specimens were prepared for push-out testing with the help of a cutting machine; six slices (2 on each cervical, middle, and apical) of approximately 1 mm thickness were sectioned for all roots on a plane perpendicular to the long axis of the post. All specimens were placed into a universal testing machine with a defined 0.5 mm/min crosshead speed until the maximum failure load was obtained. Results The highest mean push-out bond strength of the glass fiber and zirconia groups was achieved with laser treatment. The highest push-out bond strength was achieved with the axial fiber tip (7.63 ± 1.22 MPa), and the lowest was achieved with a radial fiber tip of the glass fiber group (6.98 ± 0.96 MPa). ANOVA showed a statistically significant difference between the groups (p = 0.041). The mean push-out bond strength was found to be higher with an axial fiber tip for both cervical and apical segments in the glass fiber and zirconia groups (p < 0.05). The independent t-test resulted in the overall highest mean push-out bond strength in the apical segments (p = 0.026). Conclusion Within the limits of the present in vitro research study, an enhancement in the push-out bond strength of resin cement, mainly in the cervical region of the root canal, was achieved after irradiation with an Er,Cr:YSGG laser using an axial fiber tip.

Thermal and wear behavior of three inorganic fiber-reinforced wood-plastic composites in simulated soil aging conditions

This study investigated the effects of simulated soil aging on the thermal and wear properties of rice husk fiber/polyvinyl chloride (PVC) composites reinforced with three inorganic fibers (aluminum silicate fiber (AS); basalt fiber (BF) and zirconia fiber (ZF)). The thermal and wear behavior of the composites exhibited a downward trend during the simulated soil aging process; weak interface (pulling out of fiber) resulted in the induction of strength and anti-aging properties. However, the addition of inorganic fibers improved the anti-aging properties of the composites. When the simulated soil aging time was up to 21 d, ZF reinforced composites (ZFRC) exhibited high thermal and wear resistance properties due to superior interfacial adhesion between the fiber and PVC matrix. The average friction coefficient (μ) and specific wear rate (K) of ZFRC were reduced by 12.1% and 40.7%, respectively, compared to the unreinforced composites.