Volume 40, Issue 6, June 2022
Abdul Jabbar S. Jomah; Akeel D. Subhi; Fadhil A. Hashim A. Hashim
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.
Israa A. Najem; Fadhil Abd Rasin; Shaker J. Edrees
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.
Shukry H. Aghdeab; Anwer Q. Abdulnabi
Electrical Discharge Machining process (EDM) is a nontraditional metal removal technique that uses thermal energy to erode the workpiece without generating any physical forces of cutting between the tool and the machining part. It is used to cutting of hard and electrical conductivity materials and product intricate shapes of products. The aim of this work is to study the effect of changing voltage values on electrode wear rate (EWR). The machining parameters includes voltage (V), peak current (Ip), pulse duration (Ton) and finally, pulse interval (Toff). The results show that the EWR was increase with rising in voltage, peak current and pulse duration values but when the pulse interval value rises, the electrode wear rate reduce. The best (EWR) value was (0.093507) mm3/min that obtained at voltage (140) V, Ip (12) A, Ton (400) µs and Toff (12) µs.
Doaa A. Yassen; Farhad M. Othman; Alaa A. Abdul Hamead
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.
Adnan I. Mohammeda; Ibrahim K. Ahmed; Munir A. Allow
The mechanical components are produced by various fabrication methods, although forged products have excellent mechanical characteristics at a minimal cost. The stress and temperature analysis process in the closed die hot forging contributed to finding failure regions in these dies through simulations in the FE program. This enables the process to be improved and reduced time and mineral losses. A simplified model was used to represent the forming process, with a temperature of (1150-950 °C) was simulated using MSC Simufact software. The forge fastener head product is formed with a horizontal mechanical press of 800 tones. In this research, the workpiece material used Ck45 alloy steel, 56NiCrMoV 7 tool material. The results illustrate the maximum equivalent stresses values, and the maximum value was 739.70 MPa / 240.64 on lower die and product at a heating temperature of 950 °C, respectively. The local plastic deformation would be expected at places where the maximum stress is generated and exceeds the yield strength of the die material.
Naeem A. Abdulhusein; Abbas F. Ibrahim; Abdullah F. Huayier
This study discussed the influence of chemical machining parameters such as (machining time, type of etchant, etching temperature, and concentration of the solution) on the surface roughness of ceramic material (silicon carbide) as a workpiece in the chemical machining (CHM) process. To achieve the best value for surface roughness. In this research, four levels of factors affecting the chemical etching process were used, the values of etching temperature (60, 80, 100, and 120) °C, the etchant concentration (50, 60, 70, and 80) %, and machining time (30, 50, 70, and 90) min, and two etchant type (HBr, HCl). Experiments proved the best value of surface roughness is obtained (2.933) µm experimentally and (2.958) µm at a predictable program when using hydrochloric acid (HCl) at a temperature (80) °C, time (50) min, and etchant concentration (50) %. The coefficient determination (R-sq) to predict the surface roughness is ((93.7).
Ameer J. Nader; Saad K. Shather
Abrasive water jet (AWJ) is one of the most advanced and valuable non-traditional machining processes because of its massive advantages of removing metal from hard and soft metals. This paper has studied the effect of jet pressure, feed rate, and standoff distance on material removal rate throughout abrasive water jet cutting of carbon steel metal workpieces. The material removal rate was assessed using a precision balance device by performing sixteen experiments to identify the ratio of weight loss to total cutting time. The Taguchi method was introduced to implement the experiments and indicate the most influential process parameters on material removal rate. The experimental results showed that feed rate and pressure jet had the most effect on material removal rate. The best material removal rate value was 3.71 g/min at jet pressure 300 MPa, feed rate 30 mm/min, and standoff distance 4mm.
Zainab I. Dhary; Alaa A. Atiyah; Saad B. H. Farid
Bioglass offers a variety of uses for tissue engineering due to its good biocompatibility and chemical composition, similar to a mineral portion of the body. The synthesis of bioglass 13-93 scaffold was achieved by salt leaching technique, and potassium chloride (KCl) was used as porogen with particle sizes of (200-250) μm. Then, sintering to 750 ◦C for around 1 hour was performed. The resultant materials were examined by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). They were immersed in a solution of simulated body fluids (SBF) for 7 and 14 days, respectively. Initially, calcium phosphate was created. After 7 and 14 days, the surface comprised of developed crystalline apatite. The bioactivity of scaffolds that were created and examined. The FTIR, SEM, and XRD experiments were done before and after immersion of the sample in SBF. The results showed that the scaffolds contained open and interconnected pores with porosities ranging between (75-78%). The maximum value of compressive strength of the prepared scaffold was about 5.6MPa. Based on the obtained results, the glass scaffolds can be considered promising for bone defects and replacement applications
Eman H. Rdewi; Ahmed M.H. Abdulkadhim Al-Ghaban; Khalid K. Abbas
In this study, zinc oxide nanoparticles (ZnO) were produced in aqueous media to photodegrade harmful carbamazepine compounds (CBZ) in aqueous solution under simulated solar-light using the sol-gel technique with zinc chloride and NaOH as precursors. X-ray diffraction (XRD), FTIR analysis, Field Emission Scanning Electron Microscopy (FE-SEM), and UV–vis diffuse reflectance spectra (UV-vis DRS) were used to analyze the ZnO NPs powder. According to the XRD results, ZnO nanoparticles showed a hexagonal symmetry shape with 13 nm particle size value. The absorption bands of ZnO nanoparticles were identified using FT-IR spectra peaking. The ZnO nanoparticles produced in this work are spherical, as seen in the SEM picture, with a band gap of about 3.6 eV. The prepared Zinc Oxide nanoheterostructured photocatalyst utilized excellent performance in reducing Carbamazepine compound with an efficiency of 90%. This study took into account pH solution, catalyst loading, kinetic studies, TOC removal, regeneration, and reusability. The synthesized ZnO successfully removed the Carbamazepine medicine at pH=4. With an R-square of 0.99855, the produced photocatalyst fits well into the pseudo second order model. The ZnO heterostructured nanophotocatalyst retained its outstanding performance after numerous cycles of usage. For these observations, the Zinc Oxide heterostructured photocatalyst for Carbamazepine reduction is a promising photocatalyst.
Farhan K. Challab; Maan A. Tawfiq; Salah K. Jawad
The present work studies three variables (cutting velocity, feed rate, and cut depth) on hard turning cutting temperature of uncoated and multilayer-coated carbide (TiN, TiN/TiCN, TiN /Al2O3/ TiCN) inserts are used in AISI 1045 alloy steel. The tool's temperature was measured simultaneously, measuring the temperature of the tool-chip interface using infrared radiation (IR) pyrometer in this investigation. This study investigated the performance of four distinct coated and uncoated PVD and CVD tools during turning operations. Four cutting speeds (56, 88, 112, 141) m/min, four feed rates (0.065, 0.08, 0.16, 0.228) mm/rev., in the experiments, a constant cutting depth of (1) mm was used. The results also show that Coarse cutting tools have a lower tool temperature than uncoated ones. In comparison to uncoated and other coated tools, the three-layer (TiN/ Al2O3/ TiCN) coating is especially effective in a range of (32% to 39%) than uncoated inserts at various cutting velocity and constant feed rates, with varying feed rates and consistent cutting velocity and lower by approximately( 34% to 40%) than uncoated inserts.
Ghofran Dhafer; Mohanad N. Al-Shroofy; Hanaa A. Al-Kaisy
316L stainless steel alloys are extensively used in orthopedic applications for the fixations and substitutions of defective bone tissues in the human body because of their excellent combination of mechanical and biological behavior. However, just like other metallic implants, they tend to release some toxic ions that may lead to serious health issues. Therefore, this study attempts to increase the alloy's resistance against corrosion while maintaining its good mechanical properties by applying a modified coating layer of PMMA-based composites titanium carbide as reinforcement material using dry electrostatic spray deposition (ESD) under constant conditions (25 kV, 15-20 cm distance, compressed air of 15 psi, and spraying angle about 45.0o for 3 0sec). The titanium carbide was added with ratios of (5, 10, 15, 20) wt. % respectively. The coatings’ surface morphology and phases were studied using Field Emission Scanning Electron Microscope, Energy-dispersive X-ray spectroscopy, and X-ray diffraction. Also, the biological behavior of the composite coated samples was studied by investigating their corrosion and wetting attributes. The results revealed that homogenous, uniform, crack-free coating layers and high surface wettability were obtained. Indicating the suability of PMMA/TiC for biomedical applications due to the alloy's improved corrosion resistance and biocompatibility.