فهرست مطالب

Iranian Journal of Materials Forming - Volume:8 Issue: 3, Summer 2021

Iranian Journal of Materials Forming
Volume:8 Issue: 3, Summer 2021

  • تاریخ انتشار: 1400/05/17
  • تعداد عناوین: 7
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  • Ramin Ebrahimi * Pages 2-3

    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. This journal has been a quarterly issue, and from 2021 onwards, it will at least publish 24 articles a year with the aim of having a quantitative criterion for entering Scopus. 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. Recently, some world-renowned scientists have also been joined the editorial board, making it stronger than before. In addition, the wide range of the selected referees in this issue is a sign of its scientific quality.

    Keywords: materials, deformation, Mechanical Behavior
  • Zahra Mirzaie, GholamReza Ebrahimi *, Hamidreza Ezatpour, Saeed Ali Akbari Sani Pages 4-17

    In this work, hot deformation behavior and microstructural evolution for a novel Ni-base superalloy, AD730, were analyzed using a hyperbolic sine constitutive equation. The hot compression tests were carried out at a wide range of temperatures (950ºC-1200ºC) and strain rates (0.001-1 s-1). The modeling was done at the overall deformation conditions, and then the obtained important constitutive parameters, i.e., n and Q, were calculated to be 5.44 and 820.26 kJ/mol, respectively. Microstructural evolution showed two distinct domains at higher temperatures (1100ºC, 1150ºC, and 1200ºC) and lower ones (950ºC, 1000ºC, and 1050ºC) accomplished by dynamic recrystallization (DRX) and non-DRX behavior due to absence and presence of γ/ particles, respectively. Furthermore, the constitutive equations were analyzed based on both separated temperature domains. The obtained parameters from this approach demonstrated better results as compared with the literature, i.e., the parameters of n and Q were calculated to be 8.60 and 1160.45 kJ/mol at the lower domain, in contrast with 3.69 and 468.32 kJ/mol which were at higher ones. Additionally, the stress prediction data based on correlation coefficient factor (R2) presented the best reliable prospective at two separated domains as 0.994, as compared with overall conditions prediction with 0.963. It was found that hot working of AD730 alloy as well as flow stress can be essentially affected by the γ/-phase. Therefore, the hot deformation behavior of AD730, as a γ/-containing superalloy, should be performed at identified domains considering the solution temperature of γ/-phase.

    Keywords: AD730, Hot deformation, DRX, Hyperbolic sine modeling, γ, phase
  • MohammadReza Rezaei, MohammadReza Toroghinejad *, Fakhreddin Ashrafizadeh, Hamed Asgari, Jerzy Szpunar Pages 18-25

    A commercial Al-Mg-Si alloy (AA 6061) was deformed by using the accumulative roll bonding (ARB) process for up to five cycles at ambient temperature. The evolution of texture in this process was studied by the X-ray diffraction (XRD) method. Experimental results indicate that the combination of the shear texture composed of Rotated cube {001} component and the rolling textures that included Copper {112} and Dillamore {4, 4, 11}<11, 11, 8> components developed after the first cycle. During the first cycle, the shear texture was developed as a result of shear deformation induced by high level of friction between the rolls and the sheet. By increasing the number of cycles, the shear texture strength diminished and changed to the rolling texture. After the fifth cycle, a remarkable increase in the rolling texture intensity was observed due to homogenous deformation induced by the presence of fine non-shearable particles. Additionally, the presence of magnesium in solid solution influenced the texture evolution during ARB.

    Keywords: Al (and alloys), Accumulative roll bonding, Texture, X-ray diffraction (XRD)
  • Mohammad Ardestani * Pages 26-33
    The present research was conducted to synthesize and densify Ag/8wt.% ZnO composites via co-precipitation and spark plasma sintering (SPS) methods. The initial precipitates were precipitated by adding ammonium hydrogen carbonate solution to a solution mixture of silver and zinc nitrate. The precipitates were characterized by using the particle size analyzer and X-ray diffraction techniques. The precipitates were calcined at 500°C and consolidated with SPS method for 5 and 10 min at 540°C under 35 MPa in vacuum. The results showed that rearrangement and bulk deformation had a significant effect on densification of the composite powders. The scanning electron microscopy investigations revealed that the SPSed composites had nearly dense microstructures with homogenous and fine dispersion of ZnO particles within the silver matrix. Moreover, it was confirmed that prolonging the sintering time from 5 to 10 min had no significant effect on the microstructure, relative density and hardness of the samples. Composites with relative densities above 99% and 62 HV hardness were synthesized through the applied procedure.
    Keywords: Silver matrix composites, Consolidation, Composite, Spark plasma sintering
  • Seyed Mohammad Arab *, Ahmadreza Haghighi, Mahdi Khajepour, Younes Jalalizadeh, MohammadMehdi Tavallaei Pages 34-45

    An as-cast HAYNES 25 Co-based superalloy is subjected to a process, including four stages of heat treatment, hot deformation, cold working, and aging. Mechanical properties have been improved after processing; the hardness, tensile and yield strengths are enhanced while the reduction of ductility is reasonable. The process has led to break down the segregated as-cast microstructure and has given a well distributed inter-metallic reinforced microstructure with no segregation. The grain structure also includes the approximately equiaxed grains with a large density of Σ3 twins. The results showed that as the hot deformation plays an important role in the grain refinement and microstructure homogenization, it should be considered as an important phase of the manufacturing process.

    Keywords: Co superalloy, Cold working, hardness, Microstructure, Segregation
  • Hossein Ataei, Mehrdad Shahbaz *, Hyoung Seop Kim, Nima Pardis Pages 46-52
    In this study, the effect of geometrical parameters of rectangular vortex extrusion die, including twist angle (Φ), reduction in area (RA), and twist zone length (L), on deformation inhomogeneity is investigated using the finite element analysis and response surface methodology. Analysis of variance (ANOVA) was used to determine the primary parameters and accuracy of the mathematical model obtained from response surface methodology results. The results showed that the suggested mathematical model predicts the strain inhomogeneity with high accuracy. Additionally, it revealed that the input parameters of Φ, RA, L, the interaction between Φ and RA (Φ×RA), and interaction between RA and L (RA×L) are the main significant factors affecting the inhomogeneity. Perturbation plots and 3D surface diagrams were used to check the results of ANOVA, the sign, and the magnitude of the coefficient of the suggested mathematical model.
    RA
    Keywords: severe plastic deformation, Rectangular vortex extrusion, strain inhomogeneity, Finite Element Analysis, Response surface methodology
  • Hamed Dalvand, Sajad Rasaee * Pages 53-66
    The main goal of this research is to study the hot deformation process of metal-matrix composites and investigate the possibility of using classical constitutive models to calculate the flow stress of such composites during the hot deformation process. A 5083 aluminum-based metal composite reinforced with 9 wt.% of 37 micron SiC particles, and made by stir-casting method, was used for the study. Standard and improved Johnson-Cook model, Arrhenius and Zerilli-Armstrong models in the temperature range of 673-823 K, and strain rates of 0.001-1 s-1 were extracted and their accuracy was studied. Based on the results, classical models used to predict the hot deformation behavior of metal alloys can also be used to predict the behavior of aluminum-matrix composites with reasonable accuracy depending on the type of model. The hot deformation activation energy Q for the composite based on the hyperbolic-sine law Arrhenius equation, is 265.5 kJ/mol. The strain-compensated Arrhenius model was the best model to predict the behavior of the composite with the error less than 7% and can reasonably predict the trend of changing the flow stress even at high temperatures with the correlation factor of 0.989.
    Keywords: Metal matrix composite, Hot deformation, constitutive equation, Arrhenius model, Johnson-Cook model, Zerilli-Armstrong