Iranian Journal of Materials Forming
Volume:9 Issue: 4, Autumn 2022

The “Iranian Journal of Materials Forming (IJMF)” is an international open access journal in the fields of materials deformation and forming processes, which was established at Shiraz University in 2014. The journal is pleased to receive papers from scientists and engineers from academic and industrial areas related to all manufacturing processes. In addition, all deformations, including the elastic and plastic behaviors of materials and deformations due to failure, are part of this journal’s field of interest. The quality and credibility of the journal have been ensured by appointing some of the most well-known professors in the world as members of its editorial board. In addition, the wide range of the selected referees in this issue is a sign of its scientific quality. It is a matter of pride that this journal has been successfully released quarterly for a second consecutive year with the fourth issue being published in 2022. Unfortunately, the rate at which we used to receive high quality articles has decreased due to a rise in the rejection rates. In order to publish on time and maintain quality, we need the cooperation of more experts in this specialized field.

Cleaning the huge oil storage tanks is very costly, hazardous, and time-consuming. However, this issue is one of the main concerns of the petroleum products storage industry that is performed in different ways. In this paper, an innovative oil storage tank cleaning procedure in which vertical cylindrical tanks are cleaned without entering any labor into the tank and damaging it is introduced. In this method, before filling the tank with petroleum products (i.e., oil), a sack of PVC fabric is located at the bottom of the tank, and as time passes, the heavier particles (sludge) settle on this sack. Finally, when the sack is filled with sludge, through a mechanism, it is, firstly, shifted towards the center of the tank and, secondly, lifted and taken out through the gate that exists on the roof of the tank. Thus, the above-mentioned approach not only reduces the cost of the cleaning operation but also accelerates the speed of the performed operation. To analyze the stress which is imposed on the sack’s fabric by the weight of the sludge, the finite element method has been applied. The highest stress undertaken by the sack was obtained as 7.630 MPa, which, according to the mechanical properties of the investigated fabric, shows an acceptable safety factor of 1.5. In addition, the strength of the tank’s walls against buckling due to the weight of the sack and sludge was investigated.

The possible ductility troughs of tough pitch copper containing various oxygen contents were identified to determine the safe and unsafe thermomechanical processing domains. Tensile and compression tests were conducted in temperature range of 300-800°C. The critical strain of single/multiple peaks dynamic recrystallization decreased by increasing oxygen content up to 220 ppm, and again increased with further increment up to 390 ppm. The non-uniform elongation region increased by increasing the temperature, and above 500°C, it was the dominant portion of the tensile curves. The long post-uniform elongation was attributed to the occurrence of dynamic recrystallization which increased the resistance of the material to localized necking. Two ductility troughs (unsafe thermomechanical processing regions) were recognized at temperatures of 400±50°C and 600±50°C. The ductility drop regions shifted to lower temperatures with an increase in the strain rate. The variation of the oxygen content, however, did not have significant effects on the position of ductility drops. The current work also explores the fracture surface characteristics of the tensile tested specimens.

In this research, the finite element analysis (FEA) of the effect of forging parameters including temperature, strain rate and cooling rate on the percentage of α and β phases in forging of the two-phase Ti-6Al-4V alloy to fabricate a hip joint implant was investigated. In order to be used in FEA, the stress-strain curves of Ti-6Al-4V at temperatures ranged between 800 to 1000°C and, strain rates of 0.01, 0.1, 1 s-1 up to a total strain of 0.45 by using hot compression test were obtained. The force-displacement curve of hot compression test of a cylindrical sample made of Ti-6Al-4V alloy from FEA and experiment in similar condition was used for verification. Results showed that all three input variables have an effect on the volume percentage of final α and β phases. By increasing the cooling rate, forging temperature and strain rate, the percentage of the final α phase decreases and the amount of the β phase increases. Additionally, in all cooling rates, the amount of the final α phase decreases from the center to the sides of samples.

For sustainable development, eco-friendly epoxies, composed of recycled rubber micro-particles and core-shell rubber (CSR) nanoparticles, were processed to improve adhesion strength of an epoxy resin to structural steel substrates. To achieve this, the influence of mixing ratio of a recycled rubber micro-particles and CSR nanoparticles on the adhesion strength and adhesion fracture mechanisms of an epoxy were investigated in the present study. Synergistic adhesion strength was obtained for a certain combination of 7.5 parts per hundred resin (phr) CSR nanoparticles and 2.5 phr recycled rubber micro-particles. The remarkable increase in adhesion strength was attributable to “branching” of the crack-tip damage zone plus crack deflection to cause an adhesive to cohesive fracture transformation.

In the present investigation, the effect of welding processes on the microstructure, crystallographic texture, mechanical properties, and anisotropy of weldment joints of a high strength low alloy steel (HSLA) was studied. The main goal of this research is to establish the relationship between microstructure, texture evolutions, and mechanical properties of the weldments. GTAW and SMAW welding processes were conducted, and macro texture of samples was investigated with the X-ray diffraction technique. Mechanical properties were evaluated by using the uniaxial tensile test in three directions of 0, 45, and 90° to the weld line and a micro hardness test. Preferred orientation in the weldment develops in different welding processes based on the initial base metal texture. The texture of the base metal consisted ofγ-fiber, α-fiber, G {110} <001>, and R-Cube {001} <110> main components that evolves during the welding processes. Weakening of the γ-fiber texture component results in a significant reduction in the mechanical properties of the weldments. Moreover, the percentage of the γ-fiber component in the GTAW sample is greater than the SMAW sample, which results in superior mechanical properties.

Graphite has recently received a lot of attention due to its numerous applications as well as its unique structure. Machining and machining conditions optimization are very important in reducing machining forces among other benefits. In this study, the effect of machining parameters such as spindle speed, cutting depth and feed rate on the machining forces was investigated and the optimization of these conditions was done to minimize the forces. This research uses the design of experiments to optimize the initial parameters to minimize machining forces. These experiments are based on the response surface method and analysis of variances used to identify the most effective factors in machining forces. The values of the primary parameters that provide the experiments design software are considered to be the spindle speed between 1000 and 3000 rpm, the feed rate between 1000 and 3000 mm/min, and the cutting depth between 3 and 9 mm. The results show that the machining forces increase by increasing the cutting depth and feed rate and decrease by increasing the spindle speed. The results obtained from the optimization also indicate that the machining forces reduced to their minimum value at the feed rate of 318.2072 mm/min, the cutting depth of 0.9546 mm and the spindle speed of 2356.7439 rpm.