@article{ author = {K.GhadarghadrJahromi, and ,A.Zarei-Hanzaki, and O.Golmahalleh,}, title = {ULTRA FINE FERRITE FORMATION IN Si-Mn TRIP STEELS}, abstract ={Abstract: In the present investigation, the effects of thermomechanical processing parameters and the steel chemical composition on the ultra fine ferrite formation characteristics were studied. This was programmed relying on the capabilities of strain induced transformation (SIT) phenomenon and applying to different grades of Si-Mn TRIP (Transformation Induced Plasticity) steels. Accordingly, wedge shaped specimens were rolled at two different temperatures, above and below the austenite-to-ferrite transformation temperature (Ar3). An ultra fine ferrite grain size, in the scale of some hundred nanometers, was obtained by rolling the specimens with lower Si content at a temperature below the related Ar3 temperature. The amount of reduction, which was resulted in the latter microstructure, was realized to be about 55%.}, Keywords = {UFF, SIT, TRIP, Wedge Test, Ferrite, Bainite, Single Pass Rolling.}, volume = {5}, Number = {1}, pages = {1-7}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-124-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {H.Fattahi, and M.H.Shariat,}, title = {INVESTIGATION ON THE EFFECTS OF MAGNETIC FIELD ON BROMIDE-INDUCED PITTING OF COMMERCIALLY PURE TITANIUM}, abstract ={Abstract: In chloride salt solutions, titanium alloys exhibit reasonably high pitting potentials as high as +10 V (vs. Ag/AgCl) at room temperatures. On the other hand, anodic pitting potentials are significantly lower in bromide solutions. In this study, pitting corrosion of commercially pure titanium in aqueous NaBr solution of 0.1 M concentration at room temperature was studied and the effect of an external magnetic field oriented both parallel and perpendicular to electrode surface was investigated. Cyclic potentiodynamic and potentiostatic polarization tests were carried out. Anodic breakdown potential of +1.45 V (vs. Ag/AgCl) obtained in the absence of magnetic field, decreasing to +1.11 V in the presence of a 0.05 T parallel magnetic field. The perpendicular magnetic field actually did not affect the breakdown potential. Applying of an external magnetic field, independent of its orientation, shifted the repassivation potential approximately 150 mV in the positive direction. SEM microscopy observations of sample surfaces indicated that applying of magnetic field results in some variations in the pit shapes and their sizes.}, Keywords = {Titanium, Bromide, Pitting, Magnetic Field, Polarization.}, volume = {5}, Number = {1}, pages = {8-14}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-125-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.Rezvani, and B.EftekhariYekta, and V.K.Marghussian,}, title = {MECHANICAL AND CHEMICAL PROPERTIES OF SiO2-Al2O3-CaO-MgO (R2O) GLASS CERAMICS IN THE PRESENCE OF VARIOUS NUCLEATING AGENTS}, abstract ={Abstract: The application of inexpensive materials such as copper, zinc, lead, iron and steel slag in manufacturing of glass and glass-ceramic products in construction industry, lining materials as anti-corrosion and anti-abrasion coatings in metals and etc, has led to considerable progress in glass technology in recent years. The composition of slag glass-ceramics is mainly located in the SiO2-Al2O3-CaO-MgO system, in which one of the most important problems is the lack of bulk crystallization. To resolve the above-mentioned problem, the crystallization behavior of various compositions containing different nucleating agents Cr2O3 , Fe2O3 and TiO2 in the single, double and triple forms were studied by differential thermal analysis (DTA).The precipitated crystalline phases was determined by the X-ray diffractometry and the micro-structural analysis was studies using the SEM micrographs. The three point bending strength, micro-hardness and the chemical resistance of the best composition were determined. According to the results, the resulted glassceramic had a better specification than the stoneware floor tiles and the porcelain one, which are considered as the two important competitors for it.}, Keywords = {Glass, Glass Ceramic, Slag Glass Ceramic, Inexpensive Materials.}, volume = {5}, Number = {1}, pages = {15-21}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-126-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {A.Ataie1,, and S.Heshmati-Manesh1,, and S.Sheibani1,, and G.R.Khayati,Y.Firozbakht,}, title = {SOLID STATE REDUCTION OF CHROMITE IN HIGH CARBON FERROCHROMIUM-CHROMITE COMPOSITE PELLETS}, abstract ={Abstract: In this paper solid state reduction of high carbon ferrochromium-chromite composite pellets in the temperature range of 900-1350°C was investigated. A two stage reduction mechanism is proposed. The first stage is likely to be controlled by the chemical reaction with activation energy of 127.2kJ/mol. In the second stage, solid state diffusion of carbon through the reaction product layer is suggested to be rate controlling. The activation energy of this stage was calculated to be 93.1kJ/mol. The reduction process was found to be favored by high temperatures as well as high vacuum. The results also show that pre-milling of initial mixture has a negative effect on the reduction degree.}, Keywords = {Reaction Kinetics, Solid State Reduction, Ferrochromium, Activation Energy.}, volume = {5}, Number = {1}, pages = {22-28}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-127-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.Kazemipour, and S.Sharafi,}, title = {THE EFFECT OF HEAT TREATMENT ON ABRASIVE WEAR RESISTANCE OF Fe-34Cr-4.5C%WT HARDFACING ALLOY}, abstract ={Abstract: Hardfacing is one of the most useful and economical ways to increase the service life of components subjected to abrasive wear. Iron based hardfacing alloys have long been considered as candidate coatings for wear-resistant applications in industry. In the present work two layer of Fe-34Cr-4.5C%wt hardfacing alloy was deposited on ASTM A36 carbon steel plates by SMAW method. The microstructure consists of large primary and eutectic M7C3 carbides, metastable austenite and small amount of secondary carbides. The microstructure was analyzed by optical and scanning electron microscopes. In the same condition of size, shape, distribution and volume fraction of carbides the as-welded matrix changed to martensite, tempered martensite and ferrite by heat treatment processes. The wear resistance was measured by pin-on-disk method under loads of 5, 10 and 20N and for sliding distance of 1500m. The results showed that the as-welded sample with austenitic matrix has the most and the ferritic matrix specimen has the least wear resistance. The predominate mechanisms for mass losses were determined to be micro-cutting, microploughing.}, Keywords = {Weld Deposited Coatings, Fe-Cr-C Hardfacing Alloys, Heat Treatment, Abrasive Wear}, volume = {5}, Number = {1}, pages = {29-36}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-128-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {C.Dehghanian, and Y.MirabolfathiNejad,}, title = {INVESTIGATION ON THE MIXTURE OF CALCIUM AND AMMONIUM NITRATES AS STEEL CORROSION INHIBITOR IN SIMULATED CONCRETE PORE SOLUTION}, abstract ={Abstract: Despite having a number of advantages, reinforced concrete can suffer rebar corrosion in high–chloride media, resulting in failure of reinforced concrete structures. In this research the corrosion inhibition capability of the mixture of calcium and ammonium nitrate of steel rebar corrosion was investigated in the simulated concrete pore solution. Cyclic polarization and Electrochemical Impedance Spectroscopy (EIS) techniques were applied on steel concrete pore solution containing 2 weight percent sodium chloride (NaCl). Results show that such mixtures had higher inhibition efficiency than calcium nitrate alone. The optimum concentration of the inhibitor mixture was determined to be 45 mgr/lit.}, Keywords = {Corrosion Inhibitor, Concrete, Calcium Nitrate, Ammonium Nitrate, Cyclic}, volume = {5}, Number = {1}, pages = {37-42}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-129-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {K.GhanbariAhari,}, title = {INVESTIGATION ON SLAG-REFRACTORY INTERACTION IN LADLE USING COMPUTATIONAL TECHNIQUES}, abstract ={Abstract: Thermodynamic computational packages MTDATA and FactSage have been used to carry out calculations on the variation with temperature of the phases precipitated on cooling in both oxidising and reducing conditions of a typical ladle slag composition, in the temperature range 1700 - 900°C. The current coverage of the databases associated with the computational packages is discussed in relation to their application to slag - refractory interaction and the validity of the results is compared with some relevant experimental data and phase equilibrium studies}, Keywords = {Thermodynamic, Prediction, Refractory Corrosion, Slag-Refractory.}, volume = {5}, Number = {1}, pages = {43-52}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-130-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {N.Hatami,, and R.Babaei, and P.Davami,}, title = {MODELING SURFACE TENSION AND WALL ADHESION IN MOLD FILLING PROCESS}, abstract ={Abstract: In this study an algorithm for mold-filling simulation with consideration of surface tension has been developed based on a SOLA VOF scheme. As the governing equations, the Navier-Stokes equations for incompressible and laminar flows were used. We proposed a way of considering surface tension in mold-filling simulation. The proposed scheme for surface tension was based on the continuum surface force (CSF) model we could confirm the remarkable effectiveness of the surface tension by experiment which concluded in very positive outcome.}, Keywords = {Simulation, Surface Tension, SOLA-VOF.}, volume = {5}, Number = {2}, pages = {1-7}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-131-en.html}, eprint = {http://ijmse.iust.ac.ir/article-1-131-en.pdf}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {A.R.Kamali, and S.M.M.Hadavi, and H.Razavizadeh, and J.Fahim,}, title = {TITANIUM ALUMINIDES SYNTHESIS BY ALUMINO-CALCIOTHERMIC REDUCTION OF TiO2}, abstract ={Abstract: Production of titanium aluminides in TiO2-Al-Ca system has been investigated. For this purpose, different compositions of raw materials were studied in a special reaction vessel. In a special case, the non-completed reaction of TiO2 with Al and Ca resulted in the production of granulates of titanium aluminides especially Ti3Al and other Ti – Al phases as the metallic product and Ca12Al14O33 as the non-metallic product. Remelting of metallic granulates led to production of TiAl ingot.}, Keywords = {Titanium Aluminide, Titanium Dioxide, Alumino-Calciothermic.}, volume = {5}, Number = {2}, pages = {8-14}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-132-en.html}, eprint = {http://ijmse.iust.ac.ir/article-1-132-en.pdf}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.KhosraviSaghezchi, and H.Sarpoolaky, and F.Heshmatpour,}, title = {THE INFLUENCE OF pH AND UV VISIBLE ABSORBTION ON HYDROLYSIS STAGE AND GEL BEHAVIOR OF GLASSES SYNTHESIZED BY SOL-GEL}, abstract ={Abstract: Lead-containing glass borosilicate was synthesized by Sol-gel technique using metalalkoxids such as tetraethyleorthosilicate (TEOS), Al-sec-butoxide and trimethyl borate. The sol containing TEOS converts to gel during drop wise addition of Al-alkoxide while inorganic lead salt was added in the last stage of gelation to prepare the alcogels. The specimens were dried at room temperature to set then heated at 600°C quickly to avoid crystallization preparing a glass containing 63 wt% lead oxide. The influence of pH on absorption behavior of the sols studied by UV visible technique so the characteristic of the gel, alcogel and xerogel were studied in the different acidic concentrations. The UV spectrums show that the higher the acidity of the hydrolysis stages, the higher the absorbance. The results showed the sample with 63 wt% lead was found fully amorphous. Microstructure and phase analysis of the glass powders were investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM) equipped with EDS analysis.}, Keywords = {Sol Gel, Lead Glass, Uv-Vis.}, volume = {5}, Number = {2}, pages = {15-21}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-133-en.html}, eprint = {http://ijmse.iust.ac.ir/article-1-133-en.pdf}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {A.Hassani, and R.Ravaee,}, title = {CHARACTERIZATION OF TRANSVERSE CRACK AND CRACK GROWTH IN A RAILWAY RAIL}, abstract ={Abstract: To ensure the rail transportations safety, evaluation of fatigue behavior of the rail steel is necessary. High cycle fatigue behaviour of a rail steel was the subject of investigation in this research using fracture mechanics. Finite element method (FEM) was used for analyzing the distribution of the stresses on the rail, exerted by the external load. FEM analysis showed that the maximum longitudinal stresses occurred on the railhead. To find out about the relation of crack growth with its critical size, and to estimate its lifetime, the behaviour of transverse cracks to rail direction was studied using damage tolerance concept. It revealed that transverse crack growth initially occurred slowly, but it accelerated once the crack size became larger. Residual service life was calculated for defective segments of the rails. In addition, allowable crack size for different non-destructive testing intervals was determined the allowable crack size decreased as the NDT intervals increased.}, Keywords = {Rail, Critical Crack Size, Fracture Toughness, Fatigue Crack Growth, Finite Element}, volume = {5}, Number = {2}, pages = {22-31}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-134-en.html}, eprint = {http://ijmse.iust.ac.ir/article-1-134-en.pdf}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {A.Allahverdi, and E.NajafiKani, and S.Esmaeilpoor,}, title = {EFFECTS OF SILICA MODULUS AND ALKALI CONCENTRATION ON ACTIVATION OF BLAST-FURNACE SLAG}, abstract ={Abstract: The use of alkali-activated cementitious materials especially over the past decades has significantly been increased. The goal of this research is to investigate the effects of silica modulus and alkali concentration on alkali-activation of blast-furnace slag. In this research, the most important physical characteristics of cementitious systems, i.e. the 28-day compressive strength and final setting time, were studied by changing influencing parameters such as silica modulus, i.e. SiO2/Na2O, (0.44, 0.52, 0.60, and 0.68) and Na2O concentration (4, 6, 8 and 10% by weight of dry binder) at a constant water-to-dry binder ratio of 0.25. Final setting time of the studied systems varies in the range between 55-386 minutes. The obtained results show that systems cured at an atmosphere of more than 95% relative humidity at room temperature exhibit relatively high 28-day compressive strengths up to 107 MPa.}, Keywords = {Alkali-activation, Blast-furnace Slag, Setting Time, Compressive Strength.}, volume = {5}, Number = {2}, pages = {32-35}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-135-en.html}, eprint = {http://ijmse.iust.ac.ir/article-1-135-en.pdf}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {A.Moosavi, and A.Aghaei,}, title = {EVALUATION OF SOLUTION COMBUSTION METHOD IN THE SYNTHESIS OF Fe-ZrSiO4 BASED CORAL PIGMENT}, abstract ={Abstract: Auto-ignited gel combustion process has been used for producing a red hematite-zircon based pigment. The combustible mixtures contained the metal nitrates and citric acid as oxidizers and fuel, respectively. Sodium silicate (water glass) was used as silica source for producing zircon phase. X-Ray Diffractometery, Electron Microscopy and Simultaneous Thermal Analysis were used for characterization of reactions happened in the resulted dried gel during its heat-treatment. L* a* b* color parameters were measured by the CIE (Commission International de I'Eclairage) colorimetric method. This research has showed that solution combustion was unable to produce coral pigment as the end product of combustion without the need for any further heat treatment process.}, Keywords = {Coral Pigment, Solution Combustion, Zircon, Mineralizer, Sodium Silicate.}, volume = {5}, Number = {2}, pages = {36-40}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-136-en.html}, eprint = {http://ijmse.iust.ac.ir/article-1-136-en.pdf}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {WilliamL.Headrick,, and AlirezaRezaie, and WilliamG.Fahrenholtz,}, title = {REFRACTORIES FOR BLACK LIQUOR GASIFICATION}, abstract ={gasification (BBLG). One particularly harsh application is linings for gasifiers used in the treatment of black liquor (BL). Black liquor is a water solution of the non-cellulose portion of the wood (mainly lignin) and the spent pulping chemicals (Na2CO3, K2CO3, and Na2S). Development of new refractory materials for the black liquor gasification (BLG) application is a critical issue for implementation of this technology. FactSage® thermodynamic software was used to analyze the phases present in BL smelt and to predict the interaction of BL smelt with different refractory compounds. The modeling included prediction of the phases formed under the operating conditions of high temperature black liquor gasification (BLG) process. At the operating temperature of the BLG, FactSage® predicted that the water would evaporate from the BL and that the organic portion of BL would combust, leaving a black liquor smelt composed of sodium carbonate (70-75%), potassium carbonate (2-5%), and sodium sulfide (20-25%). Exposure of aluminosilicates to this smelt leads to significant corrosion due to formation of expansive phases with subsequent cracking and spalling. Oxides (ZrO2, CeO2, La2O3, Y2O3, Li2O, MgO and CaO) were determined to be resistant to black liquor smelt but non-oxides (SiC and Si3N4) would oxidize and dissolve in the smelt. The other candidates such as MgAl2O4 and BaAl2O4 were resistant to sodium carbonate but not to potassium carbonate. LiAlO2 was stable with both sodium carbonate and potassium carbonate. Candidate materials selected on the basis of the thermodynamic calculations are being tested by sessile drop test for corrosion resistance to molten black liquor smelt. Sessile drop testing has confirmed the thermodynamic predictions for Al2O3, CeO2, MgO and CaO. Sessile drop testing showed that the thermodynamic predictions were incorrect for ZrO2.}, Keywords = {Black Liquor Gasification, Aluminosilicate, Oxide and Non-oxide Refractories.}, volume = {5}, Number = {2}, pages = {41-51}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-137-en.html}, eprint = {http://ijmse.iust.ac.ir/article-1-137-en.pdf}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.Divandari,, and H.Arabi, and H.GhasemiMianaei,}, title = {THERMAL FATIGUE RESISTANCES OF 356 AND 413 CAST Al ALLOYS}, abstract ={Abstract: Thermal fatigue is a stochastic process often showing considerable scatter even in controlled environments. Due to complexity of thermal fatigue, there is no a complete analytical solution for predicting the effect of this property on the life of various components, subjected to severe thermal fluctuations. Among these components, one can mention car cylinder, cylinder head and piston which bear damages due to thermal fatigue. All these components are usually produced by casting techniques. In order to comprehend and compare the thermal fatigue resistance of cast Al alloys 356 and 413, this research was designed and performed. For this purpose, several samples in the form of disc were cast from the two alloys in sand mould. The microstructures of the cast samples were studied by light microscopy in order to choose the samples with the least amounts of defects for thermal fatigue tests. The results of thermal fatigue tests showed that the nucleation of microcracks in Al-356 alloy occurred at shorter time relative to those occurred in Al- 413 alloy under the same test conditions. In addition, the density of micro-cracks in Al-356 alloy was more than that of Al-413 alloy. The results of fractography on 356 alloy indicated that the cracks were generally nucleated from inter-dendritic shrinkage porosities and occasionally from the interface of silicon particles with the matrix. The growth of these micro cracks was along the dendrite arms. Fractography of 413 alloy fracture surfaces showed that nucleation of microcracks was often associated with silicon particles.}, Keywords = {Thermal Fatigue, Inter-Dendritic Fracture, Silicon Particles, Al-Alloy, Microcracks, Al}, volume = {5}, Number = {3}, pages = {1-7}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-138-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {H.Naffakh,, and M.Shamanian, and F.Ashrafizadeh,}, title = {AN EVALUATION OF THERMAL STABILITY IN DISSIMILAR WELDS BETWEEN 310 STAINLESS STEEL AND ALLOY 657}, abstract ={Abstract: The investigation is carried out to characterize welding of AISI 310 austenitic stainless steel to Inconel 657 nickel-chromium superalloy. The welds were produced using four types of filler materials: the nickel-based corresponding to Inconel 82, Inconel A, Inconel 617 and austenitic stainless steel 310. This paper describes the effects of aging treatment on the joint. The comparative evaluation was based on microstructural features and estimation of mechanical properties. While Inconel A exhibited highest thermal stability and mechanical properties (hardness and ultimate strength), Inconel 82 weld metal also showed good thermal stability and mechanical properties. On the other hand, welds produced with Inconel 617 and 310 SS filler materials showed weak thermal stability and failed in the weld metals. It is therefore concluded that for the joint between Inconel 657 and 310 stainless steel, Inconel A and Inconel 82 filler materials offered the best compromises, respectively.}, Keywords = {AISI 310, Inconel 657, Dissimilar Welding, Aging, Thermal Stability, Mechanical}, volume = {5}, Number = {3}, pages = {8-18}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-139-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {A.Nemati, and K.Pourazarang,}, title = {EFFECTS OF LANTHANUM DOPING ON THE ELECTRICAL PROPERTIES OF SOL-GEL DERIVED AND MECHANICALLY ACTIVATED Pb1.1- X LaX (Zr0.53Ti0.47) O3, NANO POWDERS}, abstract ={Abstract: The PZT-based ceramics with a composition of Pb1.1-xLax (Zr0.53Ti0.47)O3, were prepared by conventional mixed oxide followed by mechanical alloying and sol-gel methods in which x was chosen in the range of 0.02–0.06. The samples were calcined in the range of 450 °C - 750 °C for 4h. The physical and electrical properties of the samples were determined as a function of the calcination temperature. The obtained data from two methods were compared with conventional mixed oxide method. Microstructural and compositional analyses of the samples were carried out using XRD and SEM. Dielectric properties of the samples were measured with an impedance analyzer. The ferroelectric properties of the PZT and PLZT samples were measured using the frequencies applying equipment and d33 tester. The results indicated a complete tetragonal phase prepared from both methods. It was shown that the addition of La and reduction in calcination temperature improved both the dielectric and piezoelectric properties. The dielectric constant tended to increase with doping content, giving the maximum value of about 2000 at 3 mol% La3+. In addition, the mechanical coupling factor (Qm) of the doped samples showed a significant decrease. Finally, the value of planar coupling factor (kp) reached the maximum value of 0.47 at 1 mol% La3+.}, Keywords = {PLZT, Electrical Properties, Nanopowder, Microstructure, XRD and SEM.}, volume = {5}, Number = {3}, pages = {19-24}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-140-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.Ghalambaz, and M.Shahmiri,}, title = {NEURAL NETWORK MODELING OF THE EFFECT OF COOLING SLOPE CASTING PARAMETERS ON PARTICLE SIZE OF PRIMARY SILICON CRYSTALS OF SEMISOLID CAST INGOTS OF Al-20Si (wt%)}, abstract ={Abstract: Cooling slope-casting processing is a relatively new technique to produce semisolid cast feedstock for the thixoforming process. Simple equipment, ease of operation, and low processing costs are the main advantages of this process in comparison with existing processes such as mechanical stirring, electromagnetic stirring, etc. The processing parameters of cooling slope casting are length, angle and the material of the inclined plate and their combinations, which usually affect the micro structural evolutions of the primary solid phase. In order to clarify the effect of the processing parameters on the evolution of the particle size, based on experimental investigation, Artificial Neural Network (ANN) was applied to predict the primary silicon crystals (PSCs) size of semisolid cast ingot via a cooling slope casting process of Al-20%(wt.%) Si alloy. The results demonstrated that the ANN, with 2 hidden layers and topology (4, 3), could predict the primary particle size with a high accuracy of 94%. The sensitivity analysis also revealed that material of the cooling slope had the largest effect on particle size.}, Keywords = {Cooling slope casting process, Al-20Si alloy (wt. %), Primary silicon crystals (PSCs),}, volume = {5}, Number = {3}, pages = {25-32}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-141-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.Keyanpour-Rad, and S.Keyanpour-Rad,}, title = {FORMULATION AND PREPARATION OF A NOVEL DUST FREE FAST SETTING DENTAL ALGINATE IMPRESSION MATERIAL}, abstract ={Abstract: A novel dust free alginate impression material was formulated and prepared, comprising an alginate polyvinylpyrrolidone and tetraflouroethylene resins, a mixture of liquid paraffin and dimethylpolysiloxane oil as the dust generation controlling agents and processed diatomaceous earth filler which was obtained from Iranian ore. No dusting was detected during the mixing of the powder and the conventional properties of the impression material, like working and setting times and compressive strength were in the range of the required specifications for alginate dental impressions. The compressive strength was measured to be 2.6 times of the minimum requirement for such fast setting impressions.}, Keywords = {Dental Mpression Materials, Dust Generation Controlling Materials,}, volume = {5}, Number = {3}, pages = {33-37}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-142-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.Farhani,, and M.Soltanieh, and M.R.Aboutalebi,}, title = {EFFECT OF A CHLORIDE FLUX ON THE DISSOLUTION OF Mn-Al COMPACTS IN MOLTEN ALUMINUM}, abstract ={Abstract: Dissolution and recovery of Mn-Al compacts with and without a chloride flux was studied by taking samples from the melt after addition of the compact. Events occurring after the addition of the compacts into the melt were studied using water quenched specimens after holding them for a specified time in molten state. The cross sections of these specimens were characterized by SEM as well as optical imaging. The results showed that an optimized amount of flux (10 to 15%wt. in this research) considerably decreases the time to reach more than 90% recovery in comparison with non-fluxed compacts. The flux caused the intermetallic forming reactions to be started considerably sooner in fluxed compacts in comparison with the non-fluxed compact. Consequently, the incubation time decreased from about 180 seconds for non-fluxed compacts to less than 3 seconds for compacts with 10%wt. flux.}, Keywords = {Compact, Mn-Al, Dissolution, Recovery, Flux.}, volume = {5}, Number = {3}, pages = {38-42}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-143-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {A.Poladi, and M.Zandrahimi,}, title = {PHASE TRANSFORMATION DURING WEAR OF AISI STAINLESS STEEL 316}, abstract ={Abstract: Austenitic stainless steels exhibit a low hardness and weak tribological properties. The wear behaviour of austenitic stainless steel AISI 316 was evaluated through the pin on disc tribological method. For investigating the effect of wear on the changes in microstructure and resistance to wear, optical microscopy and scanning electron microscope were used. The hardness of the worn surfaces was measured with a micro-hardness tester. Worn surfaces were analyzed through X-ray diffraction. Results showed that with increasing the sliding distance and applied load, the austenite phase partially transformed to ά martensite, and there was no trace of ε phase detected. Due to the formation of probably hard and strong martensite phase, as the sliding distance and applied load increased, the hardness and the wear resistance of the material was increased. Wear mechanism was on the base of delamination and abrasion.}, Keywords = {Wear resistance, AISI 316 austenitic stainless steel, Strain-induces martensite, XRD.}, volume = {5}, Number = {3}, pages = {43-48}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-144-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.Shahmiri, and S.Murphy,}, title = {A T.E.M INVESTIGATION OF THE MECHANISM OF EARLY STAGE ORDERING IN THE INTERMETTALIC COMPOUND PT2FECU}, abstract ={Abstract: The microstructural features of the early stage of ordering of the intermetallic compound Pt2FeCu have been examined using optical and transmission electron microscopy in conjunction with X-ray diffraction technique. It was found that the compound has similar morphological alteration to that of FePt in which the ordering cannot be suppressed by rapid quenching. The early stage of ordering transformation was initiated at temperatures above the critical value of 1178 oC, by a homogeneous nucleation of the intermediate short range ordered particles and ultra rapid directional-induced heterogeneous growth (burst type). As the result of these combined mechanisms, twin –related ordered domains have been formed which in turn minimize the strains produced by ordering reaction in polycrystalline material. The individual grain was divided up by different sizes of twin-related ordered domain bonded with {101} habit planes.}, Keywords = {Intermetallic compound, Pt2FeCu, ordering transformation, ordering}, volume = {5}, Number = {4}, pages = {1-9}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-145-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.GhassemiKakroudi,}, title = {NON-DESTRUCTIVE THERMAL DAMAGE CHARACTERIZATION OF CORDIERITE-MULLITE REFRACTORIES}, abstract ={Abstract: Refractory materials containing cordierite (2MgO.2Al2O3.5SiO2) and mullite (3Al2O3.2SiO2) are used as support in furnaces, because of their low thermal expansion properties which confer them a very good ability to thermal shock resistance. Composed of two phases presenting very different CTE (1.5–3×10-6 for cordierite and 4–6×10-6 K-1 for mullite), these materials can develop damage during thermal cycling due to internal stresses. The resulting network of microcracks is well known to improved thermal shock resistance of materials, since it usually involves a significant decrease in their elastic properties. This paper is devoted to the characterisation of the damage generated by this CTE mismatch, thanks to the application of a specific ultrasonic device at high temperature.}, Keywords = {CTE mismatch, damage, Young\'s modulus, thermal shock, Cordierite mullite refractories}, volume = {5}, Number = {4}, pages = {10-15}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-146-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {S.Kianfar,, and S.H.Seyedein, and M.R.Aboutalebi,}, title = {SOLIDIFICATION MODELING AND DENDRITE STRUCTURE ANALYSIS IN A HORIZONTAL CONTINUOUSLY CAST BRASS BILLET}, abstract ={Abstract: The horizontal continuous casting process has received a significant attention for near net shape casting of non ferrous metals and alloys. Numerical Simulation has been widely used for process design and optimization of continuous casting process. In the present study, a 3-dimensional heat flow model was developed to simulate the heat transfer and solidification in a horizontal billet continuous casting system in which the air gap formation and its effect on heat extraction rate from solidifying billet was also considered. In order to test the developed model, it was run to simulate the heat transfer and solidification for an industrial billet caster. The predicted temperature distribution within the mold and billet was compared with those measured on the industrial caster in which a good agreement was obtained. Finally, parametric studies were carried out by validated model to evaluate the effects of different parameters on solidification profile and temperature distribution within the model brass billet. The microstructure of cast billet was analyzed to determine the secondary dendrite arm spacing (SDAS) under different cooling conditions. Based on measured SDAS and predicted solidification rate a correlation between SDAS and cooling rate was proposed for continuously cast brass billet.}, Keywords = {Horizontal Continuous casting, Heat Transfer, Solidification, Brass, Billet, Simulation, Microstructure,Cooling Rate, Secondary Dendrite Arm Spacing.}, volume = {5}, Number = {4}, pages = {16-24}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-147-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {H.Shahmir, and M.NiliAhmadabadi, and F.Naghdi,}, title = {TRANSFORMATION BEHAVIOR OF NiTi SHAPE MEMORY ALLOYS TREATED BY THERMOMECHANICAL PROCESSING USING DSC}, abstract ={Abstract: In the present study the effect of thermomechanical treatment (cold work and annealing) on the transformation behavior of NiTi shape memory alloys was studied. Differential scanning calorimetry was used to determine transformation temperature and its relation to precipitates and defects. Three alloys including Ti-50.3at.% Ni, Ti-50.5at.% Ni (reclamated orthodontic wires) and 50.6at.% Ni alloy were annealed at 673 K and 773 K for 30 and 60 min after 15% cold rolling. It was found that the transformation characteristics of these alloys are sensitive to annealing treatment and composition. The temperature range of transformation is broadened during cold working and after subsequent annealing, the intermediate phase was appeared. The peaks become sharper and close together on each cooling and heating cycle with increasing annealing temperature and time}, Keywords = {NiTi; Shape memory alloy; Thermomechanical treatment; Cold working; Annealing; DSC.}, volume = {5}, Number = {4}, pages = {25-31}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-148-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {J.Saaedi, and H.Arabi, and Sh.Mirdamadi, and Th.W.Coyle,}, title = {SIGMA PHASE FORMATION IN A HEAT TREATED NI-50CR COATING APPLIED BY HVOF PROCESS ON A STAINLESS STEEL}, abstract ={Abstract: Two different coating microstructures of Ni-50Cr alloy were obtained on a stainless steel substrate by changing combustion characteristics of a high velocity oxy-fuel (HVOF) process and the size distribution of feed powder during coating process. Use of the finer feed powder and leaner fuel in oxygen/fuel ratio (i.e. using a ratio much less than stoichiometric ratio) led to formation of an extremely dense coating with high oxide content. Heat treating of this coating at 650ºC for 4 hours caused the formation of an intermetallic sigma phase having Cr7Ni3 stoichiometry. Formation of this phase has been reported occasionally in thin films not in thermal spray coatings, as reported for the first time in this research. In addition no sigma phase was detected in the HVOF as-deposited coating with low oxide content after heat treatment of the samples. Therefore, due to the limited number of papers available in the subject of formation of phase in either Ni-Cr bulk alloys or coatings, it is considered appropriate to show up a case in this field. In this work, the formation of sigma phase in Ni-50Cr coating deposited by HVOF technique and heat treated at 650ºC was discussed and then the coating was characterized.}, Keywords = {sigma phase; HVOF; oxide phases; thermal sprayed coatings; Ni-50Cr.}, volume = {5}, Number = {4}, pages = {32-39}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-149-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {A.Nouri, and Sh.Kheirandish, and H.Saghafian,}, title = {EFFECT OF SILICON CONTENT ON THE STRAIN HARDENING OF DUAL-PHASE STEELS}, abstract ={Abstract: In the current work, the strain hardening behavior of dual-phase steels with different silicon content (0.34- 2.26 Wt. %) was examined using the modified Crussard-Jaoul analysis. It was shown that these dual-phase steels deform in two stages over a uniform strain range. Each stage exhibited a different strain hardening exponent varying with silicon content. At the first stage, work hardening exponent remind significantly constant, while during the second stage, it decreased with increasing silicon content from 0.34% to 1.51% and then increased for the higher silicon contents (1.51% to 2.26%). It was found that the strain hardening behavior of these steels was predominantly affected by the volume fraction of martensite at low silicon contet and the ferrite strengthening induced by silicon at the higher silicon content. The effect of silicon content on the volume fraction of martensite and tensile properties were also considered.}, Keywords = {Strain Hardening, Dual-Phase silicon steel, The Martensite Volume Fraction, Tensile Testing}, volume = {5}, Number = {4}, pages = {40-49}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-150-en.html}, eprint = {}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} } @article{ author = {M.Mossanef, and M.Soltanieh,}, title = {STUDY ON VANADIUM CARBIDE COATING FORMATION ON AISI L2 STEEL BY THERMO-REACTIVE DEPOSITION TECHNIQUE}, abstract ={Abstract: The possibility of vanadium carbide coating formation on AISI L2 steel was studied in molten salt bath containing 33 wt% NaCl- 67 wt% CaCl2. In this research, the effects of time, temperature and bath composition on growing layer thickness were studied. The vanadium carbide coating treatment was performed in the NaCl-CaCl2 bath at 1173, 1273 and 1373 K temperatures for 3, 6, 9 hours and in bath containing 5, 10, 15, 25 wt% ferrovanadium. The presence of VC formed on the surface of the steel substrate was confirmed by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction analysis. The layer thickness of vanadium carbide and surface hardness ranged between 4.8 to 25.7 µm and 2645 to 3600 HV, respectively. The kinetics of layer growth was analyzed by measuring the depth of vanadium carbide layer as a function of time and temperature. The mean activation energy for the process is estimated to be 133 kJ/ mol.}, Keywords = {Vanadium carbide, TRD, Layer thickness, Kinetics, AISI L2}, volume = {5}, Number = {4}, pages = {50-56}, publisher = { Iran University of Science & Technology}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijmse.iust.ac.ir/article-1-151-en.html}, eprint = {http://ijmse.iust.ac.ir/article-1-151-en.pdf}, journal = {Iranian Journal of Materials Science and Engineering}, issn = {1735-0808}, eissn = {2383-3882}, year = {2008} }