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Effect of Deep Cryogenic Heat Treatment on the Wear Behavior of Carburized DIN 1.7131 Grade Steel

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Acta Metallurgica Sinica(English Letters) 2015年第3期28卷 348-353页

作者： kamran amini AliReza Araghi Amin Akhbarizadeh Department of Materials Science Majlesi BranchIslamic Azad University Department of Materials Science and Engineering Shiraz BranchIslamic Azad University

The effects of the deep cryogenic heat treatment on the microstructural changes,wear resistance,and hardness of carburized DIN 1.7131 grade steel were *** show that cryogenic heat treatment reduced the retained austenite and increased the carbide *** addition,after the cryogenic heat treatment,carbide shows a more uniform distribution,as compared to the conventionally treated *** was also clarified that the hardness of the cryogenically treated samples was improved,but the relative improvement decreases with the distance as the surface *** has been shown that the wear resistance improves due to the cryogenic heat treatment,and the predominant wear mechanism is a combination of the adhesive and tribo-chemical wear.

关键词： DIN 1.7131 grade steel Carburized steel Hardness Deep cryogenic heat treatment Tribo-chemical wear

Effect of deep cryogenic treatment on the formation of nano-sized carbides and the wear behavior of D2 tool steel

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International Journal of Minerals,Metallurgy and Materials 2012年第9期19卷 795-799页

作者： kamran amini Amin Akhbarizadeh Sirus Javadpour Department of Materials Science and Engineering Majlesi Branch Islamic Azad University Isfahan 86315/111 Iran Department of Materials Science and Engineering School of Engineering Shiraz University Zand Ave. Shiraz *** Fars Iran

The effect of deep cryogenic treatment on the microstructure, hardness, and wear behavior of D2 tool steel was studied by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD）, hardness test, pin-on-disk wear test, and the reciprocating pin-on-fiat wear test. The results show that deep cryogenic treatment eliminates retained austenite, makes a better carbide distribution, and increases the carbide content. Furthermore, some new nano-sized carbides form during the deep cryogenic treatment, thereby increasing the hardness and improving the wear behavior of the samples.

关键词： cryogenic treatment tool steel nano-sized carbides wear resistance hardness austenite

Surface treatment of titanium dental implant with H2O2 solution

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International Journal of Minerals,Metallurgy and Materials 2020年第9期27卷 1281-1286页

作者： Mohammad Khodaei kamran amini Alireza Valanezhad Ikuya Watanabe Department of Materials Science and Engineering Golpayegan University of TechnologyGolpayegan ***Iran Center for Advanced Engineering Research Majlesi BranchIslamic Azad UniversityIsfahan 196151194Iran Department of Dental and Biomedical Materials Science Graduate School of Biomedical SciencesNagasaki University1-7-1 SakamotoNagasaki 852-8588Japan

The surface treatment is important for titanium and its alloys as promising candidates for dental implantation due to their bioinert *** surface samples were modified using H2O2 solution at different times up to 72 h to boost their *** to the results of the field emission scanning electron microscopy test,some nanostructures are formed on the surface of treated titanium samples and increased in size by increasing the time of treatment up to 24 *** 24 h of application,the sharpness of nanostructures decreased and the micro-cracks and discontinuity in the coating surface *** results of the X-ray diffraction study and Raman spectroscopy revealed that anatase(TiO2)was formed on the surface of treated titanium *** peak intensity of Raman spectroscopy increased with an improvement in treatment time of up to 24 h and then decreased due to the discontinuity of the *** wettability and ability to form apatite were reached at 6 h of *** is clear that the treatment time has a significant effect on the surface treatment of titanium using the H2O2 solution.

关键词： titanium implant surface treatment hydrogen peroxide anatase dental implant

Evaluation the Properties of Polycaprolactone/Fluorapatite Nano-biocomposite

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Journal of Bionic Engineering 2022年第1期19卷 179-187页

作者： Mojtaba Momeni kamran amini Ali Heidari Mohammad Khodaei Department of Mechanical Engineering Khomeinishahr BranchIslamic Azad UniversityKhomeinishahr84181-48499IsfahanIran Center for Advanced Engineering Research Majlesi BranchIslamic Azad University86316-56451IsfahanIran Materials Engineering Group Golpayegan College of EngineeringIsfahan University of Technology87717-67498GolpayeganIran

In this study,nano-biocomposites of polycaprolactone(PCL)as the matrix and different amounts of nanofluorapatite(nFA)(0,10,20 and 30 wt.%)as the reinforcement were prepared for possible scaffold fabrication using the fused filament fabrication(FFF)3D *** Emission Scanning Electron Microscopy(FE-SEM)and Energy Dispersive Spectroscopy(EDS)showed that nFA particles were well distributed in the PCL matrix.X-ray diffraction analysis(XRD)and Fourier Transform Infrared Spectroscopy(FTIR)depicted no chemical interaction between the elements of the *** Scanning Calorimetric(DSC)analysis was then used to assess the thermal properties of the composites,suggesting that this could be due to the amorphous phase formation of the intermolecular hydrogen bonds between PCL and nFA,resulting in the suppression of PCL *** results of mechanical characterization also showed that the addition of nFA up to 20 wt.%to the PCL increased the tensile and yield strength,as well as reducing the elongation at both yield and failure points and increasing the Young *** best mechanical properties were obtained for the PCL/20nFA *** strength and Young modulus were increased by 30%and 179%,respectively;meanwhile,elongation of PCL/20nFA was decreased by 70%,as compared to the naked *** changes could be attributed to the better distribution of the nFA filler in the PCL *** to the obtained results,PCL/20nFA could be regarded as a good composite in terms of the mechanical properties for the regeneration of the bone tissue.

关键词： Nano-biocomposite Polycaprolactone Fluorapatite Bone tissue engineering Mechanical properties

Fabrication and Characterization of Poly Lactic Acid Scaffolds by Fused Deposition Modeling for Bone Tissue Engineering

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Journal of Wuhan University of Technology(Materials Science) 2020年第1期35卷 248-251页

作者： Mohammad Khodaei kamran amini Alireza Valanezhad Department of Materials Science and Engineering Golpayegan University of TechnologyGolpayeganIran Department of Materials Engineering Tiran BranchIslamic Azad UniversityIsfahanIran Center for Advanced Engineering Research Majlesi BranchIslamic Azad UniversityIsfahanIran Department of Dental and Biomedical Materials Science Nagasaki UniversityNagasakiJapan

Three-dimensional porous poly-lactic acid(PLA) scaffold was fabricated using fused deposition modeling(FDM) method including 30%, 50% and 70% nominal porosity. Study of phases in initial polymeric material and printed scaffolds was done by X-ray diffraction(XRD), and no significant phase difference was observed due to the manufacturing process, and the poly-lactic acid retains its crystalline properties. The results of the mechanical properties evaluation by the compression test show that the mechanical properties of the scaffold have decreased significantly with increasing the porosity of scaffold. The microstructure of scaffolds were studied by scanning electron microscope(SEM), showing that the pores had a regular arrangement and their morphology changed with porosity change. The mechanical properties of the poly-lactic acid scaffolds printed using fused deposition modeling, can be adapted to the surrounding tissue, by porosity change.

关键词： 3D porous scaffold fused deposition modeling poly-lactic acid biodegradable polymer

Effect of deep cryogenic treatment on the properties of 80CrMo12 5 tool steel

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International Journal of Minerals,Metallurgy and Materials 2012年第1期19卷 30-37页

作者： kamran amini Said Nategh Ali Shafyei Ahmad Rezaeian Department of Materials Engineering Majlesi Branch Islamic Azad University Department of Materials Engineering Science and Research Branch Islamic Azad University Department of Materials Engineering Isfahan University of Technology

The effect of deep cryogenic treatment on the mechanical properties of 80CrMo 12 5 tool steel was investigated. Moreover, the effects of stabilization （holding at room temperature for some periods before deep cryogenic treatment） and tempering before deep cryogenic treatment were studied. The results show that deep cryogenic treatment can eliminate the retained austenite, making a better carbide distribu- tion and a higher carbide amount. As a result, a remarkable improvement in wear resistance of cryogenically treated specimens is observed. Moreover, the ultimate tensile strength increases, and the toughness of the sample decreases. It is also found that both stabilization and tem- pering before deep cryogenic treatment decrease the wear resistance, hardness, and carbides homogeneity compared to the deep cryogeni- cally treated samples. It is concluded that deep cryogenic treatment should be performed without any delay on samples after quenching to reach the highest wear resistance and hardness.

关键词： tool steel cryogenic treatment stabilization wear resistance tensile strength hardness carbides

Corrosion behavior of dissimilar copper/brass joints welded by friction stir lap welding in alkaline solution

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Journal of Central South University 2019年第6期26卷 1573-1581页

作者： kamran amini Farhad GHARAVI Department of Mechanical Engineering Tiran BranchIslamic Azad UniversityIsfahanIran Center for Advanced Engineering Research Majlesi BranchIslamic Azad UniversityIsfahanIran Department of Materials Engineering Sirjan BranchIslamic Azad UniversitySirjanIran

This study was done to evaluate the nugget zone(NZ)corrosion behavior of dissimilar copper/brass joints welded by friction stir lap welding(FSLW)in a solution of 0.015 mol/L borax(pH 9.3).To this end,dissimilar copper/brass plates were welded with two dissimilar heat inputs(low and high)during the welding *** high and low heat inputs were conducted with 710 r/min,16 mm/min and 450 r/min,25 mm/min,*** open circuit potential(OCP)measurements,electrochemical impedance spectroscopy(EIS)and Tafel polarization tests,the electrochemical behavior of the specimens in borate buffer solution was *** the help of scanning electron microscope(SEM),the morphology of welded specimen surfaces was examined after immersion in the test *** to the results,the NZ grain size and resistance improvement reduced due to the nugget zone corrosion with a decreased heat *** results obtained from Tafel polarization and EIS indicated the improved corrosion behavior of the welded specimen NZ with a decrease in the heat input during the welding process unlike the copper and brass ***,an increased heat input during the welding process shows a reduction in the conditions for forming the passive films with higher protection behavior.

关键词： friction stir welding copper brass alloy corrosion behavior alkaline solution dissimilar joint

Role of interlayer composition in microstructure and mechanical properties during TLP bonding of GTD-111/IN-718 superalloys

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Transactions of Nonferrous Metals Society of China 2022年第3期32卷 908-926页

作者： Ali IZADI GHAHFEROKHI Masoud KASIRI-ASGARANI kamran amini Mahdi RAFIEI Reza EBRAHIMI-KAHRIZSANGI Advanced Materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Center for Advanced Engineering Research Majlesi BranchIslamic Azad UniversityIsfahanIran

An investigation was carried out to assess the applicability of transient liquid phase bonding of two dissimilar super-alloys with different interlayers. The effect of using three types of interlayer such as BNi-2, BNi-3, and BNi-9 on microstructure and mechanical properties was studied in the GTD-111/IN-718 system at 1100 ℃ for different bonding time. To determine the compositional changes and microstructure in the joint region, field emission scanning electron microscopy equipped with energy dispersive spectroscopy was utilized. The formation of Ni_(3)B in the athermally solidified zone(ASZ) is controlled by the B content and, accordingly, the morphology of Ni_(3)Si is governed by the Si content. The Cr content might impede the relocation of B from the interlayer into the base metal and the formation of CrB inside the ASZ is dominated by the Cr content. The high micro-hardness of the eutectic compounds is originated from the formation of boride matrixes such as Ni or Cr boride. The shear strength of the joint using BNi-9 after the completion of isothermal solidification is lower compared that that using BNi-3 and BNi-2, which could be related to the absence of Si in the filler metals constituent and the significant presence of Cr in BNi-9.

关键词： transient liquid phase bonding Ni-based superalloy isothermal solidification Ni-B compounds

A two-dimensional limit equilibrium computer code for analysis of complex toppling slope failures

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第1期13卷 114-130页

作者： Akbar Ardestani Mehdi amini kamran Esmaeili School of Mining Engineering College of EngineeringUniversity of TehranTehranIran Department of Civil and Mineral Engineering University of TorontoTorontoOntarioCanada

Evaluation of blocky or layered rock slopes against toppling failures has remained of great concern for engineers in various rock mechanics *** step-by-step analytical solutions have been developed for analyzing these types of slope ***,manual application of these analytical solutions for real case studies can be time-consuming,complicated,and in certain cases even *** study will first examine existing methods for toppling failure analyses that are reviewed,modified and generalized to consider the effects of a wide range of external and dead loads on slope ***,based on the generalized presented formulae,a Windows form computer code is programmed using Visual C#for analysis of common types of toppling *** parameters,including slope geometry,joint sets parameters,rock and soil properties,ground water level,dynamic loads,support anchor loads as well as magnitudes and forms of external forces,are first loaded into the *** input data are then saved and used to graphically draw the slope *** is followed by automatic identification of the toppling failure mode and a deterministic analysis of the slope stability against this failure *** results are presented using a graphical *** developed code allows probabilistic introduction of the input parameters via probability distribution functions(PDFs)and thus a probabilistic analysis of the toppling failure modes using Monte-Carlo simulation *** allows calculation of the probability of slope ***,several published case studies and typical examples are analyzed with the developed *** outcomes are compared with those of the main references to assess the performance and robustness of the developed computer *** comparisons demonstrate good agreement between the results.

关键词： Rock slope Toppling failures Analytical solution Windows form application Deterministic analysis Probabilistic analysis