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Open Access Article
1 - Effect of Reinforcer Percentage and Its Distribution on Mechanical Behavior of Alumina Reinforced Epoxy Composite
محمدحسین بینا کوروش شیروانی حمید رضا سلیمی جزیIn this paper, the shear and tensile properties of alumina reinforced epoxy composite have been studied. For this purpose, the composite samples were first produced with different weight percentages of alumina particles (10 to 50 percent). Then, the shear punching test MoreIn this paper, the shear and tensile properties of alumina reinforced epoxy composite have been studied. For this purpose, the composite samples were first produced with different weight percentages of alumina particles (10 to 50 percent). Then, the shear punching test was used for the evaluation of the shear and tensile properties of composite samples; the dispersion and distribution of alumina particles, interface of particles/ matrix, and the fracture surface of the samples were examined by the scanning electron microscope (SEM) equipped with EDS analyzer. The results of the tests showed that by the addition of alumina up to 30 percent resulted in homogenous and uniform distribution as well as more shear strength of composites. But, when the rate of the reinforcer exceeds 30 percent, the rate of the aggregation of the particles increases and consequently the composite strength is reduced. Also, a significant difference was observed between the fracture surface of pure epoxy and that of composites. Unlike pure polymers, the fracture surface of the composites reinforced with alumina (up to 30 percent) was more uneven, denoting an increase in the surface roughness due to the crack path deflection. Fracture in the reinforced composites with a percentage higher than 30 percent has again taken place due to the rate of low wetting of alumina particles with epoxy resin in particle-particle contacts. Manuscript profile -
Open Access Article
2 - Investigation of Corrosion Inhibition of Two Thiazole Derivatives for AISI Steel Alloy in HCl Solution
ایمان دانایی Alireza Hoseizadeh Mohammad Hossein MaddahyIn most industrial processes, acidic solution are commonly used for the pickling, industrial acid cleaning, acid descaling, oil well acidifying, etc. Corrosion prevention systems favor the use of corrosion inhibitors with low or zero environmental impacts. In this work, MoreIn most industrial processes, acidic solution are commonly used for the pickling, industrial acid cleaning, acid descaling, oil well acidifying, etc. Corrosion prevention systems favor the use of corrosion inhibitors with low or zero environmental impacts. In this work, the inhibition ability of 2-Mercaptobenzothiazole (MBT) and 2-amino-5-nitrothiazole (Nitramine) (two thiazole derivatives) against the corrosion of AISI steel 4130 in 1 M HCl solution were evaluated by polarization and electrochemical impedance spectroscopy (EIS). Polarization studies indicated that MBT retards both the cathodic and anodic reaction and Nitramine retards anodic reaction through chemical adsorption and blocking the active corrosion sites. EIS data was analyzed to equivalent circuit model shows that as the inhibitor concentration increased the charge transfer resistance of steel increased whilst double layer capacitance decreased. Thermodynamic parameters such as activation energy, enthalpy, entropy and free energy of adsorption were calculated and Atomic force microscopy (AFM) was used to study the steel surface with and without inhibitors. Manuscript profile -
Open Access Article
3 - The effect of temperature and concentration of sulfuric acid on the concrete crown corrosion
محمد آقابابایی بنی محمود پاکشیرIt`s impossible to overhaul the sewer collection lines, or remove sewer lines from the sewage system. As a result, the necessary studies should be performed to identify appropriate strategies to prevent blockage of the pipes. One of the common problems in the field is c MoreIt`s impossible to overhaul the sewer collection lines, or remove sewer lines from the sewage system. As a result, the necessary studies should be performed to identify appropriate strategies to prevent blockage of the pipes. One of the common problems in the field is crown corrosion due to the presence of sulfuric acid. In this study, the production of sulfuric acid in the presence of microbiological agents in pipes’ crown has been studied and the effect of environmental parameters such as temperature and acid concentration on the rate of the biological crown corrosion were investigated. For this purpose, concrete samples of the type 5 of cement used in accordance with the ASTM C150 and ASTM C595 standards, and then they were exposed to the different temperatures and concentrations of sulfuric acid. The results of the weight loss indicate that the increases in the temperatures and concentrations of acid would be led to higher corrosion rates. Finally, optical microscopic investigations and XRD analysis of the corroded sample showed that the corrosion product is ettringite. Manuscript profile -
Open Access Article
4 - The Investigation of Sensitization Effect on the Corrosion Behavior of SAF 2205 Duplex SS at Transpassive Region
خشایار مرشدبهبهانی پوریا نجفی سیار محمود پاکشیرIn this study, intergranular corrosion (IGC) behaviour of SAF 2205 duplex stainless steels (DSS) was investigated in the "2M H2SO4 + 1M HCl" solution at 30 ◦C using potentiodynamic polarization, DLEPR, X-ray diffraction, electrochemical impedance spectroscopy (EIS) and MoreIn this study, intergranular corrosion (IGC) behaviour of SAF 2205 duplex stainless steels (DSS) was investigated in the "2M H2SO4 + 1M HCl" solution at 30 ◦C using potentiodynamic polarization, DLEPR, X-ray diffraction, electrochemical impedance spectroscopy (EIS) and cyclic polarization tests. The EIS test results of the specimens, with various degrees of sensitization for 1 h and 5 h at 725 oC, shows three different responses in the trans passive region depending on the applied DC bias. Moreover, the results indicate that the charge transfer and polarization resistance (Rct and RP) of the sensitized DSS specimens decrease as a result of increasing the sensitization time which is in accordance with the optical and SEM micrographs from the corroded samples surfaces. Manuscript profile -
Open Access Article
5 - The Synthesis Of Nanocomposites (MoSi2-20% TiC) is activated by chemical Combustion Synthesis Method (COSHS)
مهدی بدرلو سید علی طیبی فرد محمد ذاکزیAdd titanium carbide in the compound molybdenum disilicide to increased mechanical strength. in this research element of the raw materials used to form MoSi2-TiC nanocomposite. the plan in this research procedure was based on combustion synthesis, chemical activation me MoreAdd titanium carbide in the compound molybdenum disilicide to increased mechanical strength. in this research element of the raw materials used to form MoSi2-TiC nanocomposite. the plan in this research procedure was based on combustion synthesis, chemical activation mechanism (COSHS). in this study, activation of elemental powders Mo, Si, Ti and C were used in chemical oven. first, on the basis of stoichiometric silicon powder raw materials including metal powder, molybdenum, titanium and carbon powder were prepared on the basis of 20% by weight of titanium carbide. to identify chemical compounds that react with itself, provides the heat necessary to react original composition (chemical oven), of compounds that have high ΔG was used. powders and tablets are pressed by uniaxial compaction of composite samples were prepared and chemical oven. synthesizing is done in atmospheric argon controlled tubular furnace the temperature between 700 - 1100 °C. to identify phases, xrd analysis and to evaluate morphology, sem and tem images were used. results show that the best process conditions for synthesis MoSi2-TiC nanocomposite with COSHS method were: temperature 850 °C selected as optimum conditions and composition (8Al + 4Mg + 3SiO2 + 5TiO2) as suitable chemical oven. the grain size calculation by reitveld method showed the size of titanium carbide crystallite and molybdenum disilicide in optimum condition of approximately was 77 nm and above 100 nm respectively. considering the images of sem and tem proved that a nanostructure composite has been synthesized Manuscript profile -
Open Access Article
6 - Investigation the effects of SiC reinforcement incorporation on mechanical properties of friction stir welded AZ31 magnesium alloy
AMIN ABDOLLAHZADEH Ali shokouhfar حمید امیدوار محمد علی صفرخانیان محمدرضا نادریIn this study, the friction stir welding process was used for simultaneously joining of AZ31 magnesium alloy and production of Mg/Sic nanocomposite in the stir zone. All combinations of three rotational speeds i.e, 600, 800, and 1000 rpm and four traveling speeds i.e, 2 MoreIn this study, the friction stir welding process was used for simultaneously joining of AZ31 magnesium alloy and production of Mg/Sic nanocomposite in the stir zone. All combinations of three rotational speeds i.e, 600, 800, and 1000 rpm and four traveling speeds i.e, 25, 75, 125 and 175 mm/min were tested and then the mechanical properties were examined. The joint fabricated with rotational speed of 800 rpm and traveling speeds of 75 mm/min, exhibited the highest mechanical properties, So that the yield strength, tensile strength and percent elongation improved by 11%, 39% and 88%, respectively. The results show that the proper distribution of nanoparticles in the stir zone can reduce the average grain size and improve mechanical properties. The main reason for this change is related to pinning effect and increased nucleation sites associated with SiC nano-particles. Moreover, reinforcement particles resulted in breaking of primary grains in stir zone of friction stir welding. Manuscript profile -
Open Access Article
7 - Transient liquid phase (TLP) bonding of AISI321 stainless steel using MBF-20 commercial interlayer
محمد علی میثاقی رضا بختیاریAccording to the industry’s need to an appropriate bonding process for components made of AISI 321 austenitic stainless steel, which is used in power-plant parts such as turbines, transient liquid phase (TLP) bonding of AISI 321 steel using MBF-20 interlayer MoreAccording to the industry’s need to an appropriate bonding process for components made of AISI 321 austenitic stainless steel, which is used in power-plant parts such as turbines, transient liquid phase (TLP) bonding of AISI 321 steel using MBF-20 interlayer was studied in this research. TLP bonding was performed in a vacuum furnace at 1050, 1100, 1150 and 1200oC for 30-120 minutes. The microstructural studies were conducted on the joints using an optical microscope and an scanning electron microscope (SEM). Phase analysis of the joints was also performed a SEM/EDS and XRD system. To investigate the distribution of elements across the joints, line scan analysis was used. The shear strength test and the micro hardness measurement test were conducted on the joints, in order to study the joints’ mechanical properties. The minimum time of complete isothermal solidification at 1050, 1100 and 1150oC was obtained as 75, 45 and 30 minutes, respectively. At the incomplete isothermal solidification condition, Fe-B, Cr-B, Ni-Si and Ni-B phases were observed at the joint centerline and diffusion affected zone (DAZ). With increasing bonding temperature and time, more homogenous joint, lower hardness at the different zones of the joints and higher shear strength were obtained. But for the joints made at 1200oC, higher than the critical bonding temperature, the joint shear strength was reduced. For the joints made at 1150oC for 60 minutes and also at 1050oC for 120 minutes, the maximum shear strength was obtained as 95 and 94 percent of that of the base metal, respectively. Manuscript profile -
Open Access Article
8 - Applying Nanocomposite Ni-B-ZrO2 Coating By Electroless Method on Steel CK45 and Study its Tribological Properties
yaser zakery nia Reza Bazargan LariElectroless nickel boron coatings usually due to wear and corrosion resistance that is well regarded. Electroless nickel boron through the chemical reduction of nickel ions on the surface of the catalytic caused and controlled until the solution is in contact with the r MoreElectroless nickel boron coatings usually due to wear and corrosion resistance that is well regarded. Electroless nickel boron through the chemical reduction of nickel ions on the surface of the catalytic caused and controlled until the solution is in contact with the reaction continues. In this study, Ni-B-ZrO2 nano composite coating was made by adding 4 g⁄l of ZrO2 nano particles to nickel – boron electroless solution on samples of CK45 steel; Then the coated samples heat treated for one hour at 400℃. The morphology and chemical compound was examined using SEM equipped by EDX. Electrochemical corrosion behavior of coatings in 3.5 showed by adding ZrO2nano particles the corrosion resistant of coatings improves. Electrochemical impedance spectroscopy showed that the coating after the heat treatment hadn't a protective effect And substrate are vulnerable to corrosion. Abrasion behavior by pin on disk test was measured at ambient temperature and Vickers hardness was measured by a micro hardness testing machine devices. The results showed that adding zirconia nanoparticles to the amount of 4g⁄l increased hardness and wear resistance of the coating. Coating composite samples of nickel - boron – zirconia without heat treatment the best results for the three parameters simultaneously high hardness, abrasion resistance and excellent corrosion resistance was good. Manuscript profile -
Open Access Article
9 - Synthesis and characterization of Ag and Cu nanorods and thermal conductivity investigation of nanofluids containing synthesized nanorods
صدیقه عباسی فرید نوری وطنIn this paper, we synthesized the Ag and Cu nanorods and investigated the thermal conductivity behavior of nanofluids containing of them. The samples have been characterized by Xray diffraction (XRD) and transmission electron microscopy (TEM). XRD results revealed that MoreIn this paper, we synthesized the Ag and Cu nanorods and investigated the thermal conductivity behavior of nanofluids containing of them. The samples have been characterized by Xray diffraction (XRD) and transmission electron microscopy (TEM). XRD results revealed that the crystalline structure of Ag and Cu nanorods with cubic structure were formed. TEM image showed that the synthesis of Ag and Cu leads to the rod structures. The experimental results of termal conductivity showed that by increasing the temperature in the range of from 20 to 60°C and weight fraction from 0.25 to 0 %wt, thermal conductivity of all nanofluids increased. Meanwhile, it can be observed that the minimum and maximum thermal conductivity of Ag nanofluid were 0.56 W/m.K and 2.93 W/m.K respectively, and in the Cu nanofluid were 0.33 W/m.K and 2.74 W/m.K. The results of thermal conductivity behavior of nanofluids revealed that the thermal conductivity of all nanofluids, increases with temperature and weight fraction. However the influence of temperature is more significant than that of weight fraction. Manuscript profile -
Open Access Article
10 - Investigation of high temperature wear properties of NiCrBSi and satellite coatings deposited on hot work tool steel DIN-1.2344
مصطفی طهری مجتبی اسماعیلیان Behrooz ShahriariIn this study, satellite 6 and NiCrBSi coatings deposited on hot work tool steel DIN-2344/1 by thermal spraying and cladding were investigated. Stellite 6 and NiCrBSi powders were deposited on the substrate by HVOF and Stellate 6 wire were cladded by GTAW. Scanning elec MoreIn this study, satellite 6 and NiCrBSi coatings deposited on hot work tool steel DIN-2344/1 by thermal spraying and cladding were investigated. Stellite 6 and NiCrBSi powders were deposited on the substrate by HVOF and Stellate 6 wire were cladded by GTAW. Scanning electron microscopy with energy dispersive spectroscopy and optical microscopy, pins on disk wear machine, macro and micro hardness meter were used to analyze the coatings. Results showed that the hardness and wear resistance of thermal spray coating were higher than cladding coating. At high temperature, the results of wear test show, that the NiCrBSi coating has the better wear resistance rather than satellite 6 coating. This behavior of NiCrBSi coating attributed to silicate and boride particles in this coating. On the other hand, the thermal spray satellite 6 coating show the very low friction coefficient due to chromium oxide formed on the surface of coatings. Manuscript profile -
Open Access Article
11 - Synthesis of Mg0.5Zn0.5Fe2O4 nanoparticles via co-precipitation method and study of its sensitivity properties
حمیدرضا ابراهیمی علی رضا امینیIn this study, synthesis and studying sensitivity of Nano sensor of zinc magnesium ferrite with common formula of Mg0.5Zn0.5Fe2O4 has been considered. Applied method for manufacturing Nano sensor is co-precipitation method that is a novel method for this combination. Na MoreIn this study, synthesis and studying sensitivity of Nano sensor of zinc magnesium ferrite with common formula of Mg0.5Zn0.5Fe2O4 has been considered. Applied method for manufacturing Nano sensor is co-precipitation method that is a novel method for this combination. Nano sensor structure was investigated using such experiments as X-ray diffraction (XRD(, transmission electron microscopy (TEM) and X-ray fluorescence (XRF). Respectively, XRD experiment confirmed the formation of ferrite phase, TEM image showed nanostructure formation of this ferrite and XRF information reconfirmed correct atomic relation of ferrite. Sensitivity of this Nano sensor was tested using a laboratory system equipped with sensor heater with the ability of temperature control on which Nano-sensor was put, a chamber for injecting various solvents and a connector electronic range that transferred Nano-sensor information to computer and it was analyzed by Lab View software. This system could control temperature and wetness and its volume was 5 litters. This Nano sensor was tested using ethanol, methanol, chloroform, acetonitrile, ammonia and acetone and sensitivity of methanol and acetonitrile was better than others. The best response temperature for this Nano sensor (between 100˚C -300˚C) was 300˚C. Manuscript profile -
Open Access Article
12 - Effect of Friction Stir Welding (FSW) on Corrosion Behavior of Pure Copper in 3.5 % wt NaCl Solution
amirhossein taheri Arash Fattah-alhosseiniIn the present study, the effect of friction stir welding (FSW) on the corrosion behavior of pure copper in 3.5 % wt NaCl solution was investigated. For this purpose, pure copper was welded using a rotation speed of 355 rpm and welding speed of 20, 28, and 40 mm/min. Th MoreIn the present study, the effect of friction stir welding (FSW) on the corrosion behavior of pure copper in 3.5 % wt NaCl solution was investigated. For this purpose, pure copper was welded using a rotation speed of 355 rpm and welding speed of 20, 28, and 40 mm/min. The microstructures of the pure copper and welded pure copper were evaluated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Also, corrosion behavior of the specimens was investigated using Tafel polarization, and electrochemical impedance spectroscopy (EIS) in 3.5 % wt NaCl solution. Results revealed that FSW decreased the grain size of pure copper and improved the corrosion resistance of the stir zone. Manuscript profile
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