فصلنامه سرامیک ایران
سال هجدهم شماره 1 (پیاپی 69، بهار 1401)

The use of waste materials and industrial wastes in order to protect the environment and also to reduce costs has been considered. In this study, first, the use of slag, a waste of the steel industry, on the properties of the wall tile body was investigated. For this purpose, different percentages of slag were added to the tile body and physical properties such as density, percentage of shrinkage after sintering, open porosity, bending strength and microstructure were investigated. According to the results, the use of slag leads to the formation of anorthite and wollastonite phases in the tile body. The results showed that slag up to 30 wt% leads to increased density, reduced shrinkage and improved bending strength of tiles. The bending strength of the tile body increased from 23.6 MPa to 33.8 MPa for a body containing 30 wt% slag. The strength improvement can be attributed to the lower porosity, the formation of needle-shaped anorthite and wollastonite phases by using slag. Then, the effect of alumina nanoparticles in the amounts of 1, 2 and 3 wt% on the properties of the tile body containing 30 wt% slag was investigated. The addition of nano-alumina particles increased the bending strength of the tile body and the bending strength for the body containing 3 wt% reached 39.5 MPa. The increase in strength can be related to the higher percentage of anorthite phase in the presence of nano-alumina.

In Iranian architecture, colors were a powerful tool in design that, by using them correctly in decorations, added to the identity and impact of that space. One of the techniques of architects in decorating the space has been the use of complementary colors to create a proper harmony in the viewer's eyes. In this experimental-analytical study, CIE Lab analysis was used to quantitatively measure the complementary colors of azure and yellow historical glazes, And was tried to study the cause of different spectra of these two colors of mosaic and dual tile glazes by Edx analysis. also, petrography and Xrd analysis should be done on the tile biscuits. The results of the analysis showed that azure glazes are alkaline and cobalt is a color producer in all spectrums and lead has an effect on its intensity. Iron is present as one of the yellow color agents in all samples of yellow glazes Elements such as titanium, cadmium, tin, nickel, vanadium and lead antimony have been the cause of yellow color in various samples. And this has caused the different color tonality. Petrographic and Xrd results of tile biscuits indicate oxidation baking environment and baking temperature less than 800 degrees.

Fingerprint identification or dactyloscopy is a method for human identification. The impressions left by a human finger on surfaces are not visible to naked eyes (latent fingerprint); therefore, they require revelation to become visible and identified. Within the last century, several fingerprint revelation techniques such as optical, physical, and chemical were studied. These traditional methods have some shortcomings including hurting and destroying finger prints, long time of the revelation process and toxicity. Therefore, utilizing fluorescent quantum dot nanoparticles is under study due to their unique optical and chemical properties in fingerprint identification. In this article, the synthesis of cadmium telluride quantum dots is discussed, as they have a wide absorption spectrum, proper optical stability, greater radiation intensity, as well as high quantum efficiency, and their radiation is adjustable by composition and the size of the particles. The aim is to identify the effect of latent fingerprint on a variety of porous surfaces such as fabrics and papers or non-porous surfaces such as ceramics, glass and metals, with rapid detection with high contrast, sensitivity and selectivity and low toxicity. The synthesis method consists of using aqueous solution with Cadmium chloride and Tellurium dioxide with an alkaline pH solution. Studying photoluminescence in 540 nanometer wavelength, showed that the maximum radiation intensity is about 751, for 15 min. synthesis time. To modify and decrease toxicity a biocompatible coating (TEOS) was applied using the Stober method. Essentially, a silica layer reduced the photoluminescence by about 25%.

Spin-coating of Chalcogenide glasses is a cost-effective and flexible method to produce thin films applicable in photonics. In this paper Er was doped into Ga1As39S60 glass by melt quenching technique and solutions for spin coating were prepared from glass powders dissolved in Propylamine and Ethylendiamine. Substrates used were microscopic slides (refractive index of about 1.51). Applied layers were dried in 60 ℃  vacume for 60 min and then heat treated at 150 ℃  for 60 min in Nitrogen Atmosphere. Influence of solvent type on optical parameters of films and the amount of residual solvent was studied by examining UV visible infrared spectroscopy. According to AFM images, surface roughness of layers was about 3.3-3.5 nm. Although films demonstrated PL emission at 1.55 µm, emission intensity was higher at the films deposited from PA solvent. EDS mapping images showed no clusters of Er within the glass matrix.

One of the widely used cements for filling teeth and bones can be calcium zirconium aluminate cement Ca7ZrAl6O18, which of course can also be used as a refractory. The behavior and properties of this cement are more similar to tricalcium aluminate C3A cement. In this study, C7A3Z cement was synthesized by using commercial calcium carbonate, alumina and zirconia powders and after grinding for 4-6 hours and sintering at different temperatures of 1200-1400C for three hours. X-ray diffraction showed that C12A7, C3A, C7A3Z, CaZrO3, CaO phases exist at temperatures below 1400C, and at 1400C, almost cement only has calcium zirconium aluminate phase. The setting time of this cement was less than 5 minutes, which can be adjusted to longer times by adding citric acid. The hydrated phases of this cement included different phases of C3AH6, Al(OH)3, and similar phases, which obtained more information about their behavior using simultaneous thermal analysis (STA). The microstructure of the hydrated samples also led to the formation and growth of hydrated phases. The 3 and 7 days compressive strength of the samples was 48 and 40MPa, respectively.

MAX phases are an attractive class of layered solids that have recently attracted a great deal of attention due to their unusual and unique composition. The ternary compound Ti3SiC2 is an example of a material that combines the properties of ceramics and metals. As a ceramic, they are high stiff. Some of them are resistant to oxidation, creep, fatigue, corrosion. They are extremely refractory and have a high melting temperature. Also, their strength remains stable with temperature. When considered as a metal, this compound is a conductor of electricity and thermal and is not prone to thermal shock, has easy machining with a variety of modern tools, is relatively soft and also has high chemical resistance. Combining SiC with Ti3SiC2 for fabrication the composite is an effective way to improve the high temperature properties, because SiC as a reinforcing phase has good oxidation resistance, high hardness, abrasion resistance, and in addition, it is compatible with Ti3SiC2 at high temperatures. Fully-dense Ti3SiC2 –SiC composites were in-situ synthesized and sintered through a reactive hot-pressing process using TiC and Si powders with different molar ratios of 3TiC:3Si, 3TiC:2Si (stoichiometric composition), and 3TiC:1.5Si. Phase characterization of the hot-pressed specimens was performed by X-ray diffraction (XRD) analysis, and the microstructures were studied by scanning electron microscope (SEM). The mechanical properties of the hot-pressed composites were investigated in terms of Vickers hardness, fracture toughness, and flexural strength. It was found that the in-situ synthesized SiC particles, with platelet morphology, have been distributed in the in-situ formed Ti3SiC2 matrix. The highest Vickers hardness belonged to the 3TiC:1.5Si sample with a value of 14.2 GPa, related to the presence of SiC and residual TiC phase in the microstructure. The flexural strength enhanced with increasing the molar value of Si, due to the presence of the free Si phase in the sample and the further formation of the SiC phase. The 3TiC:3Si sample achieved the highest fracture toughness of 10.1 MPa.m1/2 and the highest flexural strength of 576 MPa.