فهرست مطالب

Journal of advanced materials and processing
Volume:10 Issue: 3, Summer 2022

  • تاریخ انتشار: 1401/12/22
  • تعداد عناوین: 6
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  • Habib Fazelinezhad, Kourosh Hormozi, Iman Emami, Saeid Jabbarzare *, Ahmad Monshi Pages 3-19
    This research aimed to evaluate the formation reaction, substructure, crystallite size, and mechanical behavior of spinel MgAl2O4, mullite, and forsterite nanocrystalline using a combination of mechano-chemical and three-step heat treatment. The main aim was achieved by decreasing the annealing temperature to the level of nanostructures and high mechanical strength by considering three-step heat treatment. We conducted the mechanism of these phases by considering low milling and declining annealing temperatures. More specifically, phase transformation was conducted with proper activation energy to form the nanocrystalline at 1050 oC. The obtained crystallite sizes for spinel MgAl2O4, mullite, and forsterite nanocrystallites were 49.5, 70.71, and 47.8 nm, respectively, and their substructure verified the formation of 50 nm nanocrystalline. It was revealed that mechanical strengths were in order of increasing 378.33, 216.33, and 179.66 MPa. Interestingly, spinel MgAl2O4 was outstanding compared to mullite and forsterite due to the strong comparison between ionic and covalent bonds and the breaking of silicate networks by alumina and magnesia in mullite and forsterite structures. Declining the annealing temperature by three-step heat treatment proved to help develop spinel, mullite, and forsterite, and enhance their mechanical strengths as potential substrates for porous materials, ceramics, and refractory industries.
    Keywords: Forsterite, Mechanical Behavior, Mullite, Spinel, Three-step heat treatment
  • Maryam Bahmanpour *, Hamid Ghayour Pages 21-26
    In the present work, for the first time, a classical-quantum model is established for comparing the magnetization of ferromagnetic/ superparamagnetic nanoparticles under AC magnetic fields (during the magnetic hyperthermia process). For this purpose, the fundamental Brillouin function was used and the physical properties of ferromagnetic and superparamagnetic nanoparticles were separated using this function. In the following, using the presented model, the magnetization of magnetic nanoparticles was compared under AC magnetic field. The results showed that in both classical and quantum states, the magnetization of ferromagnetic nanoparticles under an AC magnetic field was higher than that of superparamagnetic ones. Also, to confirm the correctness of the presented model, the output of the model was adapted to the Curie law in the classical mode and the Curie-Weiss law in the quantum mode. The correspondence between the magnetization obtained from the proposed model and the magnetization obtained from the Weiss molecular field was also confirmed.
    Keywords: magnetic hyperthermia, ferromagnetic nanoparticles, Superparamagnetic
  • Maryam Morakabati *, Peyman Ahmadian, Parnia Parvizian Pages 27-35
    This paper aims to analyze the effect of annealing temperature on the microstructural changes and the following deformation behavior of Ti-5Al-4.2V-0.8Mo-2Fe α/β titanium alloy at high temperatures. For this purpose, the hot rolled specimens were mill annealed at 700, 750, and 800 °C for 1 hour. The deformation behavior of the milled annealed alloy was assessed using the hot tensile test at the temperature of 750 °C and the strain rate of 0.005 sec-1. It was found that, by increasing the mill annealing temperature, the layered microstructure changed to the equiaxed one due to static globularization. After the tensile test, the stress-strain curves showed that by decreasing the annealing temperature from 800 to 700 °C, the peak stress decreased and the elongation increased from 362% to 474%. Moreover, the apparent feature of flow curves suggested yield point phenomena as a result of dynamic strain aging. The maximum elongation of 474% was obtained after mill annealing at 700 °C a finding which is correlated with the promoted fine globular α phase with the grain size of 4.5 µm and the 44.5% content of the β phase due to the dynamic globularization.
    Keywords: α, β titanium alloy, mill annealing, hot tensile test, dynamic globularization, dynamic strain aging
  • Hamideh Soleymani Asl, Fatemeh Kalantarzadeh, Mina Alafzadeh *, Mojdeh Azizi, Mahyar Soheily Pages 37-44
    The aging of the middle-aged portion of the population has increased the need for bone tissue scaffolds that help in healing damaged tissue. A 3D printer would be an efficient method for faster and more accurate production of bone scaffolds. This research mainly aims to investigate the pore configuration and the effect of two common ceramic particles (hydroxyapatite (HA) and bioactive glass) on bone scaffold production via fused deposition modeling (FDM). The scaffold building began by determining the optimal scaffold design with respect to percentage porosity and pore shape. The results show that a bone scaffold with square pores and a porosity of 20% is the optimal design. Then, composite filaments made of Polylactic acid (PLA) and the mentioned ceramic particles were prepared. Subsequently, the bone scaffold with a suitable porosity was built using the 3D printer. The results indicated that an appropriate and homogeneous composite with optimal design can constitute a suitable bone scaffold that can benefit from improved biodegradability, adequate mechanical strength, and increased bone regeneration  time.
    Keywords: Bone Scaffold, 3D Printer, Polylactic Acid, Composite filament, Ceramic powder
  • Mohammad Soroush Merkani, Ghader Faraji * Pages 45-58
    Thermo-mechanical finite element simulation was used to study Copper wire drawing with PCD die. Effect of drawing angle and coefficient of friction on the distribution of stress and strain on the surface of die and cross-section of wire studied, respectively. Elasto-viscoplastic and elastic models were used to simulate copper and PCD behavior in the axisymmetric model. Regardless of the amount of the drawing angle and coefficient of friction, die entrance and exit exhibit the highest stress on the surface of the die. Maximum amounts of temperature were observed on the surface of the wire exiting the deformation zone. According to the profile of pressure and temperature, the die nib bears the highest amount of pressure and temperature on the die and is susceptible to wear. Analyzing the strain on the wire and stress on the surface of the die showed that at high drawing angles, the distribution of strain on the wire becomes uneven, also stress on the die nib will increase. In contrast, at low drawing angles, the temperature and drawing force rise because of the increase in friction effect. Choosing the drawing angle based on the optimization of the drawing force keeps all mentioned parameters in an acceptable range.
    Keywords: Wire Drawing, drawing angle, coefficient of friction, thermo-mechanical modeling, FEM
  • Zahra Asghary, Masumeh Seifollahi *, Maryam Morakabati, Seyed Mahdi Abbasi Pages 59-71

    This study investigates the low-cycle fatigue of Nimonic105 alloy with boron and zirconium of 0.003-0.013 wt.% and 0.0-0.16 wt.%, respectively at 750 °C. The fatigue test results indicated that the alloy with boron of 0.013 wt.% had the highest fatigue life of 400 cycles, while the base alloy showed the lowest fatigue life of 21 cycles at 2% strain amplitudes. For the alloy with 0.16 wt.% Zr, and the alloy with 0.08 wt.% Zr and 0.006 wt.% B, cyclic-hardening occurred at a constant slope. Then, hardening followed a nonlinear procedure at a reducing rate. Finally, softening and fracture happened. For 0.013 wt.% Zr alloy, however, the diagram reached a stable state or slow cyclic-softening and failed after a relatively short period of cyclic - softening. The Coffin-Manson equations’ parameters verified the increased flexibility due to the addition of B. to be a factor in improving high-temperature LCF strength. The investigation of the samples’ fracture surfaces indicated that the intergranular fracture of the base alloy with the lowest fatigue life became intergranular and transgranular fracture in the alloy with 0.16 wt.% Zr content and the alloy with 0.08 wt.% Zr content and 0.006 wt.% B contents. Also, 0.013 wt.% B alloy with the highest fatigue life showed a completely transgranular fracture.

    Keywords: Nimonic 105 Super alloy, High-temperature low-cycle fatigue, Fracture surface, Boron, Zirconium