Engineering and Technology Journal

The welding process is one of the fabrication processes in which tubes can be performed for structural purposes and transport liquids or gases. This study is focused on the manufacturing, characterization, and evaluation of mechanical properties of welded tubes made from oxygen-free copper (C1020) sheets using friction crush welding. The welded tubes were produced using different tool rotation speeds (1500, 1600, and 1700 rpm) and feed rates (130, 140, and 150 mm/min). The flanged edge height of 2.5 mm and 0.5 mm gap between the ends of the copper sheet was used. All examinations on welded tubes were achieved using different instruments such as optical microscopy, SEM, hardness, and tensile testers. The microstructure study showed good weld quality and good material flow between the two ends of the copper sheet in the weld zone. Moreover, the weld zone was not defective. The lowest hardness was identified in the crush zone due to the coarseness of the copper grains. The highest tensile strength of 105 MPa was obtained at the tool rotation speed of 1500 rpm and 130 mm/min feed rate. The results also showed that ductile fracture is the main source of failure.

The structural characterization was discussed in the present paper of the pure MgO nanoparticles and the doped (Mg(1-x)pbxO) nanoparticles specimens, where (0 ≤ x ≤ 0.03). The modified Pechini method was used to prepare all the specimens. From (DTA), the convenient temperature of decomposition from Mg(OH)2 to MgO was above 375°C. The structure investigation (XRD) revealed that all the specimens have identical space groups and index well to cubic structures. The obtained crystallite size by Scherrer''s equation was increased with increasing the fraction of doping except for (Mg0.97Pb0.03O) due to the formation of PbO oxide. The molecular vibration by FTIR demonstrated that all the pure and doped specimens have the same framework. As the incorporation of Pb2+ ions increases, the bands get broader, and the intensities increase in the ranging 800-400 cm-1 due to vibrations of O-Mg and O-Pb bands, respectively.

Copper oxide (CuO) and zinc oxide (ZnO) are two of the most promising oxides under development right now. The sol-gel technique was used to make Nano composite particles NCPs of ZnO-CuO. The copper (II) nitrate rehydrate 0.1M and zinc nitrate hex hydrate 0.1M liquids were mixed in a 1:1 ratio, and the gel was formed at 80 °C, then dried and calcined for various times 500 °C (3, 5, and 7 hours). Particle size analyzer (PZA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and apparent density were used to characterize the CuO/MgO particles. The x-ray diffraction results showed that the phases of the composite particles were pure. FESEM scans, on the other hand, revealed nanoparticles incorporated in the ZnO-CuO matrix with particle sizes ranging from 60.76 to 145.1 nm. The density of the aforesaid samples was 0.1382, 0.1418, and 0.1469 g/cm₃ in that order, increasing as the calcined duration increased. This promotes crystal formation, and CuO/MgO has strong catalytic activity for advanced applications.

In this research, the ordinary Portland cement (OPC) was mixed with metakaolin, activator, hydrogen peroxide, and olive oil to synthesize hybrid geopolymer foam. The obtained results indicated internal heat release throughout OPC hydration in the combination. OPC was employed as a calcium source in geopolymers (Geopolymer-Portland cement (HGPF)) to explore the curing process of geopolymers at ambient temperature. The functionality of geopolymer components and (HGPF) mixture, the elemental composition, and proportion analyses have been compared. A principal aim of this research focuses on developing geopolymer foam and conducting many tests such as physical tests related to the surface area and pores size and compression of the foam to investigate the capacity of applying this foam in different applications that require good strength. Furthermore, microstructure tests using SEM and XRD techniques have been conducted to examine surface structure components. Overall, the findings presented in this research show that the materials selected to develop the geopolymer foam were compatible with each other giving high porosity with acceptable compression via optimizing the processing parameters by RSM.

Waste rubber tires are considered to have substantial environmental and economic impacts, and they are non-biodegradable.  This study aims to get rid of waste tires as much as possible and study their benefits and effects on concrete using (chips and crumbs) as an aggregate substitution to fine and coarse aggregates together in making concrete (CRC) and at different percentages of (5, 10, 15, 20, and 25) % by volume. This use can reduce the risk and effect of waste tires. The tests reported a reduction in workability, compressive, and flexural values with the increase in the substitution rate of rubber. Still, other properties such as density and thermal conductivity improved. The registered highest decrease was 2013 kg/cm³ to density and 0.56 (W/m.k) to thermal conductivity with replacement of 50% from waste rubber tiers as an aggregate. The workability registered the highest decrease of 35 mm, compressive strength was 18.5 MPa, and flexural was 3.35 MPa. However, the failure of the (CRC) samples test was not as brittle and abrupt as in the control sample (NSC) in the flexural test.

Metal corrosion is one of the most critical challenges in industrial processes. In this research, nanocomposite coating was synthesized by blending tungsten trioxide (WO₃) nanoparticles with Epoxy resin and applied on brass samples to evaluate the performance of corrosion protection under stressed environments. A dip-coating method was adopted to coat the brass sample's surface. Coated and uncoated brass samples have been subjected to corrosion tests to study the corrosion behavior when exposed to corrosive media. Obtained results indicated that the brass coated samples with mixed epoxy\tungsten trioxide (WO₃) exhibited reasonable corrosion resistance because of the ceramic protective barrier on the surface of the metal. Therefore, the proposed methodology could be considered as a promising surface coating that promotes corrosion resistance under stressed industrial conditions.

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

As the elderly population increases, the need for bone loss treatments is increasing. Vital substances used in such treatments are required to continue for a longer period and work more effectively. The particularly important biological material is poly methyl methacrylate (PMMA) bone cement, which is widely used in damaged bone replacement surgery. So, this study focused on the role of added some nanoparticles consist of zirconia (ZrO2), and magnesia (MgO) on the binary polymeric blend (Acrylic bone cement: 15% PMMA) for a bone scaffold. Where, ZrO2 and MgO nanoparticle was added with selected weight percentages (0, 0.5, 1, 1.5 and 2 wt.%), which were added to the polymer blend matrix. Some mechanical properties were studied including the tensile strength and young modulus for all the prepared samples. The chemical bonding of nanoparticles and synthetic binary polymeric blend composites was evaluated by Fourier Transform Infrared (FTIR) spectroscopy. Tensile strength and young modulus of binary polymeric blend reinforced with 1.5 wt.% ZrO2, and 1 wt.% MgO, significantly increased. The surface morphology of the fracture surface of tensile specimens was examined by Scanning electron microscope (SEM). The SEM images confirmed that the homogenous distribution of nanoparticles (ZrO2, and MgO) within the polymeric blend matrix.