Papers by Keyword: Ceramic

Abstract: In this research, we have tried to investigate the effects of the synthesis methods on structural properties in La_0.7Ca_0.2Sr_0.1MnO₃ compound synthesized using solid-state, sol-gel, and wet-mixing methods. All samples were measured with several measurements such as X-ray diffraction (XRD), scanning electron microscope-energy dispersive X-ray (SEM-EDX), and Fourier transform infrared spectroscopy (FTIR). Our XRD analysis reveals a single phase without impurity and confirms the presence of orthorhombic structures with Pnma space group. Additionally, the average crystal size of La_0.7Ca_0.2Sr_0.1MnO₃ compound by using solid-state, sol-gel, and wet-mixing methods exhibits values of 112.51, 91.33, and 88,75 nm. For the morphological structure analysis, we have carried out SEM analysis which shows a decreasing value of grain size average of 1.70, 0.91, and 0.81 μm for solid-state, sol-gel, and wet-mixing methods samples, respectively, which have a similar trend with values of the average crystal size. The FTIR measurement confirms the presence of the internal bending mode of MnO₆ and asymmetric stretching mode of MnO₆ at a band around 518.16 - 524.24 and 548.68 - 616.57cm^-1, respectively.

Abstract: Spent Bleaching Earth (SBE) is a solid waste produced from the palm cooking oil refining industry. The commercial ceramic membranes are quite pricey, therefore SBE solid waste is possible to be an alternative for reduction of membrane material cost due to high silica content. This work demonstrates the fabrication of ceramic tubular support membrane with varied SBE addition and investigates the functionalization group of its membranes. The ceramic support membrane was prepared from regeneration SBE with varied loading composition 15 and 35 wt%. The regeneration SBE using n-Hexane as solvent. Membranes were casted into tubular configuration using centrifugal casting technique at 3000 rpm. The tubular ceramic SBE membranes were dried and followed by calcined at 900°C with heating rate 2°C/min using programable furnace for 2 h. Both of raw SBE material and membranes were analyzed using Fourier transform infrared (FTIR). The SBE material after regenerated exhibits has high Si-OH and Si-O-Si peaks over raw material. Interestingly, the fabrication ceramic support membrane with tubular configuration is successfully preparation by centrifugal casting. Ceramic SBE membrane exhibits functionalization and deconvolution the present of siloxane, Al-OH-Al, Ti-O-Ti, and Al-O bands for both of 15 and 35wt% SBE loading. It concluded this tubular ceramic support membrane from SBE has appropriated chemical functionalize properties to applicates as membrane separation.

Abstract: Piezoelectric ceramics possess very high piezoelectric coefficients but lacks the conformability for using them in flexible devices, in high-resolution sensing devices that can be integrated to human skin and other such applications. This problem can be resolved by blending them in appropriate proportion with polymers which are intrinsically light weight, stable and flexible. In this paper polymer composites xPZT– (1-x) PVDF (x= 0, 0.025, 0.05, 0.10, 0.15, 0.20 and 0.25) were prepared by solution casting method and their dielectric and its mechanical properties were studied. Given that PZT has a very high dielectric value, the composite's dielectric constant grew as the filler concentration increased which shows better dipole alignment in the composite. With an increase in filler concentration, the composite loses flexibility and tensile strength. Due to their greater Young's modulus than pure PVDF film, the films with compositions x=0.025 and x=0.05 could have better piezoelectric characteristics.

Abstract: The connection characteristics and methods of ceramic and metal were studied, and emphatically the current research status of ceramic and metal active brazing, diffusion welding, self-propagating high temperature synthesis welding, fusion welding, friction welding, ultrasonic welding, hot-press reaction sintering welding and other welding methods were introduced. The main problems and improvement methods existing in the current ceramic and metal welding are discussed, and the development trend of ceramic and metal brazing connection is prospected.

Abstract: This study focused on the production of bioactive pure cordierite ceramic and the evaluation of its bioactivity by immersing it in simulated bodily fluid (SBF) and coating it on CP-Ti utilizing the dip coating Procedure. Cordierite is created by chemical coprecipitation, which involves combining Cordierite gel with a water-based sol-gel composed of Alumina Al2O3, magnesium oxide MgO, and silicon oxide SiO2. They used a hydraulic press to form cordierite into a cylindrical shape with a pressure of 4 bar and a holding time of 30 minutes at this pressure. Firing presses reach temperatures of 1250 C^o and have a holding time of 2 hours. A Field Emission Scanning Electron Microscope (FESEM) was used to examine the microstructure, which revealed a homogenous distribution of the compounds with negligible porosities. The phase transitions that cur during the sintering Process is studied using X-ray diffraction (XRD). The structural investigation of specimens revealed the formation of the cordierite phase at 1250 C^o, as well as the development of cristobalite, spinel, protoestatite, and corundum with cordierite phase. The dip coating Procedure was utilized to cover commercial pure titanium (CP-Ti) samples with cordierite powder. CP and Tafel exploration tests show that coated CP-Ti has superior passivation than uncoated Substrate. By comparing the findings of uncoated and coated CP-Ti, this paper concludes that the cordierite system acts as a good passivation layer.

Abstract: The structure, microstructure, Fourier transformed infrared spectra, dielectric, and impact generated energy harvesting characteristics of x(Ba_0.7Ca_0.3)TiO₃–(1-x)Ba (Zr_0.2Ti_0.8)O₃; x = 0, 0.5, and 1.0 synthesized using solid-state reaction method are discussed in this work. The X-ray diffraction (XRD) process was used to examine the forming of a single-phase compound. The Rietveld refinements of XRD data were used in FullProf software to determine crystal symmetry, lattice parameters, and space groups. A scanning electron microscope was taken into use to examine the surface morphology of all of the samples. The samples' phase transition temperature was observed to lie between-10°C and 87°C, shifting toward the higher temperature side as x increased. In the case of x = 0.5, two-phase transitions were discovered at 22°C and 70°C. The value of impact generated output voltage and electrical energy increases as applied mechanical energy increases. The findings of this study point to the possibility of using 0.5(Ba_0.7Ca_0.3)TiO₃–0.5Ba (Zr_0.2Ti_0.8)O₃ ceramic for energy harvesting and sensing purposes.

Abstract: The microstructure, energy dispersive X-ray spectra, and field dependent polarization and electrostrictive strain characteristics of x(Ba_0.7Ca_0.3)TiO₃–(1-x)Ba (Zr_0.2Ti_0.8)O₃; x = 0, 0.5, and 1.0 synthesised using solid-state reaction process are discussed in this work. The X-ray diffraction process and scanning electron microscope were, respectively taken into use to examine the forming of single-phase compound and the surface morphology as well as elemental analyses of all of the samples. The grains sizes were found to lie between 3–12 μm and was largest for x = 0.5. The value of piezoelectric coefficient, converse piezoelectric effect (strain maximum to peak electric field), and electrostrictive coefficient were found to be the highest for x = 0.5 sample. Ba_0.85Ca_0.15Zr_0.10Ti_0.90O₃ was shown to be a potential lead-free electrostriction material for industrial applications, particularly in positioning actuators, based on field-dependent polarisation and strain experiments at ambient temperature.

Abstract: The Li₇La₃Ce₂O₁₂ ceramic was synthesized in this work by using a conventional solid-state reaction route and a planetary ball-mill method. At room temperature, the sample had a tetragonal structure with space group I4/mmm, according to the X-ray diffraction analysis. The pure phase of the sample was successfully synthesized using conventional solid-state reaction routes. The impedance spectroscopy was used to measure the electrical properties of the samples over a wide temperature range from 30 °C to 300 °C. At much higher temperatures, both samples showed an incomplete semicircle arc with the smallest resistance value. The samples prepared using conventional solid-state reaction routes exhibits higher conductivity as the sample has denser microstructure.

Abstract: Barium strontium titanate (BST), Ba_0.8Sr_0.2TiO₃ ceramic prepared using conventional solid-state reaction method has achieved a single phase at 1400 °C. The Ba_0.8Sr_0.2TiO₃ ceramic shows the highest dielectric constant and capacitance at 65°C about 4001 (10 Hz) and 2.92765 x10^-9 F, respectively. The conductivity of Ba_0.8Sr_0.2TiO₃ ceramic is in between the range of semi-insulator and insulator materials, and this composition also has exhibited the positive temperature coefficient resistivity (PTCR) properties jump of one order of magnitude from 2.06202 x 10⁷ Ω.cm to 3.00958 x 10^8­ Ω.cm measured at 1 kHz.

Abstract: In this work, the effect of mechanochemical synthesizing method on the properties of the Li₇La₃Ce₂O₁₂ was studied. The Li₇La₃Ce₂O₁₂ was prepared using planetary ball-mill method heated at 900 °C with intermittence grinding. The X-ray diffraction analysis shown that the sample exhibited tetragonal structure at room temperature with space group I4/mmm. An incomplete single semicircle arc was observed in the complex impedance shows that the sample was contributed by bulk effect and need a much higher frequency to measure the impedance response. The conductivity of the samples exhibits temperature dependence at lower temperature and frequency dependence at much higher temperature which associated to the ionic conductor behavior. Two slopes were observed from the activation energy plot indicates that more likely electron and ionic transport within the sample.