Journal of the Australian Ceramic Society最新文献

This study involves preparation of self-glazed ceramic tiles by utilizing soda-lime-silica waste glass (SLS). To investigate the effect of addition of SLS with the partial substitution of clay material, three batch compositions were prepared and subjected to seven different temperatures (1050 °C, 1075 °C, 1100 °C, 1125 °C, 1150 °C, 1175 °C, 1200 °C, 1225 °C). Linear shrinkage, glossiness, modulus of rupture, and water absorption of prepared samples showed different behavior at different temperatures. XRD, UTM, and SEM instruments were employed to characterize the developed sample as well as to determine the optimum conditions for the process. For batch 2, best results were observed with value of modulus of rupture 73.35 MPa at low sintering temperature (1100 °C). The obtained result clearly exhibited the efficacy of developed self-glazed ceramic tiles as a cost-effective product and solution to waste glass management.

This feasibility study investigates the potential use of shrimp shell waste derived from peeled fresh and dried shrimp as a source of calcium (Ca) to produce value-added products (VAP). Thermal treatment of the samples was carried out by calcination at temperatures ranging from 200 to 1000 °C, and the resulting products were characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses. The results show that the shrimp shell waste changes from black to white powder, with increasing temperature during the calcination of the carbon combustion, as proven in the thermogravimetric’s (TGA) weight loss profile. The percent calcium recovery increased from 29.51 to 71.47%, and the optimum calcination temperature was reached at 1000 °C for both dried (DSS 1000) and fresh (FSS 1000) shrimp shell wastes. Spectral analysis showed that the hydroxyapatite (HAp) using calcium oxide (CaO) from FSS 1000 sample corresponded to the characteristic peaks of hydroxyapatite (JCPDS No. 9001233), while HAp produced from Ca DSS 1000 was identified as carbonate hydroxyapatite (JCPDS No. 9003552). The properties and quality of the calcium element varied according to the process used to produce shrimp shell waste. Therefore, the study suggests that shrimp shell waste could be a valuable resource for calcium recovery while mitigating the negative impacts of waste disposal on the ecosystem.

Magnesia porous insulation materials were prepared via foam-gelcasting using industrial grade mid-range magnesia powder as the main raw materials, a copolymer of isobutylene and maleic anhydride (Isobam-104) as the dispersing and gelling agent, sodium carboxymethyl cellulose (CMC) as the foam stabilizing agent, and cetyltrimethylammonium bromide (CTAB) as the foaming agent. The effects of processing parameters such as amount of Isobam-104 (0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, and 0.3 wt%) and firing temperature (1300 ℃, 1350 ℃, and 1400 ℃) on magnesia porous insulation materials were investigated. In addition, the universal testing machine (WDW-100E) and the scanning electron microscope (SEM) were employed to characterize the firing samples. The results indicated that the compressive strength of the prepared samples increased with the increase in firing temperature, and the porosity decreased gradually. When the firing temperature was 1350 °C, the internal pores of the samples were uniformly distributed, the average pore size was in the range of 26.2 μm to 35.6 μm, and the compressive strength was in the range of 7.8 MPa to 11.5 MPa when porosity varied from 65.2% to 60.4%. The thermal conductivity of the prepared magnesia porous insulation materials was in the range of 0.481 W/(m·K) to 0.842 W/(m·K).

Sintered silicate ceramics have traditionally been difficult to measure for residual stress due to their inhomogeneous microstructure and non-conductive nature, making the state-of-the-art traditional contour method ineffective. To address this issue, a self-invented Double Three-point Bending Moment Delocalization technique was developed to “cut” the ceramics and obtain the necessary sections. By modifying the filtering algorithm for the smoothing program and establishing an automatic reliability parameter for the normalization procedure, the contour method was successfully modified, eliminating errors introduced by manual normalization and the inhomogeneous microstructure. The traditional contour method yielded a residual stress value between − 75 and 117 MPa, whereas the modified contour method resulted in a value of − 12 to 12 MPa. The modified contour method was validated by the mature Hole Drilling Strain-Gage Method, which demonstrated its success in measuring residual stress in non-conductive ceramics. This work highlights the potential of the modified contour method for measuring residual stress in non-conductive ceramics.

The spinel ferrites (SFs) are renowned for their distinctive magnetic and electrical characteristics. Sol-gel route was used for the fabrication of Sr_0.6 Zn_0.4 Gd_x Fe_2-x O₄ (0.00, 0.025, 0.050, 0.075, 0.100) ferrites. The structural, magnetic, microwave, and DC (direct current) properties of prepared Nps were found using of number characterization techniques. The X-ray diffraction (XRD) pattern of Sr_0.6 Zn_0.4 Gd_x Fe_2-x O₄ SFs showed a single cubic phase. The magnetic behavior was determined by applying a field of 2 kOe. The various magnetic features, including those determined based on the M-H loop, and prepared spinel ferrites showed the soft nature of magnetic materials. When amount of gadolinium (Gd) is increased, then saturation magnetization, coercivity, remanence magnetization is decreased. The Ms values decreased from 69.36 to 32.18 emu/g, coercivity reduced from 220 to 14 emu/g, and remanence magnetization is decreased from 32 to 3 emu/g. The electrical parameters revealed that direct current resistivity and activation energy (Ea) increased (from 0.16 eV to 0.28eV) with the inclusion of the Gd. The activation energy was increased from 0.16 to 0.28 eV. The dielectric constant and loss of permittivity and permeability were determined by applying the frequency 5.5–9.5 GHz. From the above enhanced parameters, it can be concluded that fabricated SFs may be suitable for high-frequency devices.

Regarding the missing texture details in the texture extraction process of Tenglong Yuan blue and white, illumination is unequal. A meta blue and white texture extraction method based on adaptive gamma correction and K-means clustering segmentation coupling algorithm has been proposed. Combining the characteristics of Tenglong Yuan blue and white texture, using grayscale transformation to adjust the brightness of blue and white images, image contrast has been enhanced. Design Gaussian filter, weighted average multiscale Gaussian convolution, constructing 2D gamma convolutions for adaptive gamma correction, enhance the texture of Tenglong Yuan blue and white, the details in the blue and white texture of Tenglong Yuan are richer and more prominent. K-means clustering segmentation algorithm based on Lab space, implementing color segmentation of blue and white images, helps to segment the blue and white texture of Tenglong Yuan. Verification indicates that this method can effectively improve the contrast of blue and white texture; the accuracy rate of Tenglong Yuan blue and white texture segmentation reaches 95%. Effectively improving the accuracy of texture extraction for blue and white elements, the protection and inheritance of Yuan blue and white cultural relics are promoted.

Calcium titanate-hydroxyapatite composites (CT-HAp) were synthesized using a conventional sintering process. The calcium source was derived from cockle shell waste. The combustion synthesis of CT (CaTiO₃) produced fine, irregular, sub-micron size particles. The precipitation synthesis of HAp (Ca₅(PO₄)₃OH) produced rod-like nanoparticles. The obtained powders were used to fabricate CT-HAp bioceramic composites sintered at 1250 °C for 2 h. The phase formation, microstructure, and physical and mechanical properties of HAp and various CT-HAp composites were investigated. A CT-HAp composite with 8%wt of CT, having a density of 3.00 ± 0.01 g/cm³ and a grain size of 0.90 ± 0.06 μm, produced the highest values for flexural strength, Vickers hardness and fracture toughness: 56.67 ± 1.122 MPa, 6.03 ± 0.02 GPa, and 7.77 MPa.m^1/2, respectively. The chemical solubility of the CT-HAp composites was very low, showing an average weight loss of 0.24% in a simulated body fluid solution. The properties of the CT-HAp composites were controlled by CT content and porosity. In-vitro biological studies demonstrated the growth and proliferation of MC3T3-E1 osteoblast cells on all composites after three days of culture. The highest cell viability was exhibited on a CT-HAp composite with a CT content of 8%wt. The expression of alkaline phosphatase (ALP) activity on the composite surface promoted cellular osteoinduction, indicating the potential of the developed composite for bone formation and repair.

Magnetite (Fe₃O₄) particles deposited with zeolite, which was made from sodium hydroxide (NaOH), sodium aluminate (NaAlO₂) and sodium trisilicate (Na₂O₇Si₃) using the hydrothermal process, were used in the adsorption of methylene blue (MB). A continuous stirred tank reactor (CSTR) system was used for the adsorption of MB using zeolite/Fe₃O₄. This study encircled the continuous reactor with a magnet to prevent the adsorbent from flowing to the output, thus producing clean water devoid of Fe₃O₄ particles. The performance of the adsorbent was assessed based on the effects of adsorbent mass, flow rate, pH and concentration. The adsorbent was able to remove approximately 90% of the 20 mg L⁻¹ methylene blue from a 500 mL solution in 2 h, with a maximum adsorption capacity of 30.8528 mg g⁻¹. This adsorption process also exhibited high removal efficiency even after 5 regeneration cycles and 55 h of operation, confirming the successful production of zeolite/Fe₃O₄ as an effective MB adsorbent.