TY - GEN A1 - Bouras, Dikra A1 - Fellah, Mamoun A1 - Mecif, Abla A1 - Barillé, Régis A1 - Obrosov, Aleksei A1 - Rasheed, Mohammed T1 - High photocatalytic capacity of porous ceramic-based powder doped with MgO T2 - Journal of the Korean Ceramic Society N2 - To purify water at low cost for our daily life, the effect of ceramic-based (mullite–cristobalite) and (mullite–zircon) powders doped with different amounts of magnesium oxide (MgO) (10 and 20 wt%) was studied. These compounds are made of a local raw material DD3 with addition of zirconia (ZrO2) to create an open porosity. The powders were prepared by the traditional mixing method with the help of an automated crushing. The effect of MgO doping on structural, morphological and photocatalytic properties of the material was studied by various analytical techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, infrared, and UV–visible spectrometry. The results of XRD proved that there was a deformation in the crystal structure of the two types of ceramics after addition, which resulted in a shift of the spectra to the right, while SEM proved the presence of pores with a larger size as the proportion of MgO increases. The chemical composition of the basic components of the ceramic compounds as well as the additive was confirmed with EDS and IR spectra. The final results show that ceramics with added zirconia (DD3Z) and doped with 10% of MgO have a better photocatalytic efficiency than ceramics without zirconia. This important effect could be related to the higher rate of porosity, which provides a more active surface. The 10% MgO content showed a high photoactivity of 77.33% in only 15 min. The maximum hydrolysis rate obtained with Orange II was 92.95% after a period of 45 min with DD3Z/MgO powders. Y1 - 2023 UR - https://link.springer.com/article/10.1007/s43207-022-00254-5 U6 - https://doi.org/10.1007/s43207-022-00254-5 SN - 2234-0491 IS - 60 SP - 155 EP - 168 ER - TY - GEN A1 - Fellah, Mamoun A1 - Hezil, Naouel A1 - Bouras, Dikra A1 - Obrosov, Aleksei A1 - Samad, Mohammed Abdul A1 - Montagne, Alex A1 - Abd-Elmonem, Assmaa A1 - Din, Sayed M El A1 - Weiß, Sabine T1 - Structural, mechanical and tribological performance of a nano structured biomaterial Co–Cr–Mo alloy synthesized via mechanical alloying T2 - Journal of Materials Research and Technology N2 - The influence of milling time on the tribological behavior of a Co–Cr–Mo alloy designed for biomedical applications, synthesized via mechanical alloying is investigated. Elemental Co, Cr and Mo powders are milled using different milling times (2, 6, 12 and 18 h) in a high-energy ball mill. The resulting powders were subjected to cold uniaxial and hot isostatic pressing respectively, followed by sintering to obtain cylindrical samples, which were evaluated for their structural, mechanical and the wear behavior. Results showed that the grain and crystallite sizes of the powders decreased with increasing milling time, reaching low values of <10 μm and 32 μm respectively, at higher milling times. Furthermore, the wear rates and the coefficients of friction were lower, at higher milling times due to high densities (96%), and higher elasto-plastic resistance, as presented by the H/E and H3/E2 values of 0.026 and 0.0021 GPa, respectively. Increased milling time enables the refinement of grains and reduction in porosity in the Co–Cr–Mo alloy, which in turn increases the alloy's elasto-plastic resistance and enhances its wear resistance. KW - Tribology KW - Wear resistance KW - Friction KW - Powder metallurgy KW - Co–Cr–Mo alloy Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S2238785423012796 U6 - https://doi.org/10.1016/j.jmrt.2023.06.031 SN - 2214-0697 VL - 25 SP - 2152 EP - 2165 ER - TY - GEN A1 - Fellah, Mamoun A1 - Hezil, Naouel A1 - Bouras, Dikra A1 - Montagne, Alex A1 - Obrosov, Aleksei A1 - Jamshed, Wasim A1 - Ibrahim, Rabha W. A1 - Iqbal, Amjad A1 - El Din, Sayed M. A1 - Khalifa, Hamiden Abd El-Wahed T1 - Investigating the effect of milling time on structural, mechanical and tribological properties of a nanostructured hiped alpha alumina for biomaterial applications T2 - Arabian Journal of Chemistry N2 - In this work was prepared α-Al2O3 alloys from laboratory aluminum oxide powder that was milled for different periods of time and sintered at a temperature of 1450 °C. The difference between the prepared samples was studied using several experimental measurement techniques, including X-ray diffraction, scanning electron microscopy and measurement of physical and mechanical properties. Moreover, the effect of milling time on the formation and sintering of alpha-alumina, by milling the mixture at different times using high energy crushing technique was studied. An influence of milling time on density, open spaces and microstructure of the samples was analyzed. The obtained results showed that longer milling duration led to alloys with higher hardness (H) and modulus of elasticity (E). This improvement is due to lower porosity and corresponding higher density at high temperatures. A noticeable decrease in the size of the particles with the increase of the milling time led to an increase in the lattice parameter accompanied by a decrease in defects and ionic voids. The percentage of pores reached 0.04 % within 24 h of grinding after it was approximately 0.20 %, while the density reached 96 % after the same highest grinding time. Tests showed that the value of friction coefficient decreases, while it increases with the increase in the applied pressure force and this was confirmed by SEM images of the samples. the main factor to reduce friction is the increase in grinding time, regardless of the value of the applied load. The results showed that the Al2O3 alloy applied to it with a load of 2 N and milled for 24 h had a minimum value of 1.94 µm3 wear volumes and a wear rate of 1.33 (µm3∙N−1∙µm−1). The sample milled for 24 h showed the best result, characterized by the lowest wear size, specific wear rate and the highest hardness with extraordinary density of 96 %, which is important in the field of biomaterials applications. KW - α-Al2O3 KW - Milling time KW - Nanomaterials KW - Particle size KW - Hardness KW - Biomaterials KW - Biomedical applications Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S1878535223005749 U6 - https://doi.org/10.1016/j.arabjc.2023.105112 SN - 1878-5379 VL - 16 IS - 10 ER -