Issue 6
abduljabar Saad Joma; 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.
Research Paper
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/cm
3 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.
