List of Articles Akbar Heidarpour

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  1 - Crystallization Kinetics Study in Al87Ni10La3 Amorphous Alloy
  Amir Rofigar Haghighi Akbar Heidarpour Mohsen Eshaghpour Soorani Mehdi Mansouri
  In this study, the crystallization behavior of melt-spun Al87Ni10La3 amorphous phase was investigated by using X-ray diffraction and non-isothermal differential thermal analysis techniques. The results demonstrated that the amorphous phase exhibited two-stage crystalliz More

  In this study, the crystallization behavior of melt-spun Al87Ni10La3 amorphous phase was investigated by using X-ray diffraction and non-isothermal differential thermal analysis techniques. The results demonstrated that the amorphous phase exhibited two-stage crystallization on heating, i.e., at first step the amorphous phase transforms into α-Al phase and at second step Al11La3 and Al3Ni intermetallic phases precipitate, simultaneously. The activation energies of the crystallizations of the amorphous phase were evaluated by the Kissinger equation using the peak temperature of the exothermic reactions. The values of two-step crystallization activation energies were approximately 173.7±6 and 278.4±5 kJ/mol, respectively. The Avrami index was calculated for the first and second step of crystallizations and obtained 0.9 and 3.8 respectively. This kinetics investigation indicated that in the first step of crystallization of Al87Ni10La3 alloy, the nucleation rate decreases with time, and the crystallization is governed by a three-dimensional diffusion-controlled growth, while the second stage was in interface control regime. Manuscript profile
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  2 - FSP pass number and cooling effects on the microstructure and properties of AZ31
  Akbar Heidarpour Saeed Ahmadifard Nadia Rohania
  In this study, the effects of passes number and cooling during friction stir processing (FSP) on the microstructure and properties of AZ31 magnesium alloy has been investigated. The process was carried out at tool rotational speed, transverse speed and tool tilt angle o More

  In this study, the effects of passes number and cooling during friction stir processing (FSP) on the microstructure and properties of AZ31 magnesium alloy has been investigated. The process was carried out at tool rotational speed, transverse speed and tool tilt angle of 1100 rpm, 52 mm/min, and 3°, respectively. Cooling was performed by water. The microstructure of FSPed samples was explored by optical microscopy, atomic force microscope (AFM), and scanning electron microscope (SEM). Microhardness and tensile tests were used to characterize the mechanical properties of the samples. In addition, wear and corrosion resistance of processed samples were evaluated. Microstructural investigations showed that the cooling process during FSP led to finer and more homogenized grains because of the suppression of grain growth and as a result, hardness and tensile strength were improved. The best properties obtained after 4 passes by an increase in hardness and tension strength equal to 57 and 21%, respectively. In addition, wear characteristics of this specimen was considerably improved and electrochemical tests showed better corrosion resistance due to the decreasing grain size. Manuscript profile
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  3 - On the fabrication and characterization of Al5083/Al2O3 surface nanocomposite via friction stir processing
  Akbar Heidarpour Saeed Ahmadifard Shahb Kazemi
  In the present study, Al5083- Al2O3 nanocomposite was successfully prepared by friction stir processing (FSP) with rotational speed of 710 rpm and travel speed of 14 mm/min. In order to improve distribution of Al2O3 particles, a net of holes were designed on the surface More

  In the present study, Al5083- Al2O3 nanocomposite was successfully prepared by friction stir processing (FSP) with rotational speed of 710 rpm and travel speed of 14 mm/min. In order to improve distribution of Al2O3 particles, a net of holes were designed on the surface of Al5083 sheet. The samples were characterized by optical and scanning electron microscopy (SEM), microhardness, tensile and wear tests. Results showed that FSP is an effective process to fabricate Al5083- Al2O3 surface nanocomposite. Microstructural observation demonstrated fine and equiaxed grains and homogenous distribution of Al2O3 nanoparticles in the stir zone (SZ). The presence of Al2O3 nanoparticles lead to a decrease in the grain size from 45 to 7 μm and an increase in microhardness from 80 to 140 Hv and tensile strength from 280 to 335 MPa. Wear test results showed improved wear resistance due to its higher hardness and the mode of wear in the all samples was abrasive. Manuscript profile
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  4 - Synthesis of (Tix,W1-x)3SiC2 MAX phase by mechanical milling
  Ali Bashirisafa Akbar Heidarpour Samad Ghasemi
  20.1001.1.2322388.2019.7.4.4.2
  This study has investigated the synthesis of (Ti1-xWx)3SiC2 MAX phase via high energy ball milling, and the effect of heat treatment and excess Si on the purity of synthesized powder were explored. In this regards, different mixtures of Ti, Si, and C were ball milled by More

  This study has investigated the synthesis of (Ti1-xWx)3SiC2 MAX phase via high energy ball milling, and the effect of heat treatment and excess Si on the purity of synthesized powder were explored. In this regards, different mixtures of Ti, Si, and C were ball milled by a planetary ball mill for various milling times up to 15h. The phase evolution of products was studied by X-ray diffraction (XRD), and the morphological changes monitored by a field emission scanning electron microscopy (FESEM) equipped with energy-dispersive spectroscopy (EDS). The results showed that after 15 hours of ball milling the reaction started, and resulted in Ti3SiC2 and TiC formation. The as-synthesized powders were then compacted and heat treated at 600, 1000, 1250 and 1400˚C. Heat treatment caused to proceed in the reaction between the intermetallic compounds in Si-Ti system and TiC, and led to increasing the purity of Ti3SiC2. In a separate run, a non-stoichiometric composition of Ti: Si:C= 3:1.2:2 was ball milled for 15 h, and heat treated at 1250˚C. The XRD results showed that the purity of the product is higher than the stoichiometric composition. The addition of W to Ti3SiC2 was also explored. In this regard, the synthesis of (Ti1-xWx)3SiC2 component (x= 0.8, 0.5) was investigated, and the results showed that some W incorporated in Ti3SiC2 structure, and the WC and TixW1-x formed during the process. Manuscript profile