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    Investigation of deformation mechanism in polypropylene/glass fiber composite

    , Article Journal of Applied Polymer Science ; Volume 87, Issue 13 , 2003 , Pages 2171-2176 ; 00218995 (ISSN) Zebarjad, S. M ; Bagheri, R ; Seyed Reihani, S. M ; Forunchi, M ; Sharif University of Technology
    2003
    Abstract
    A great amount of work has been done over the past few years to understand the structure-properties relationship in polypropylene/glass fiber composites. This is because of the very fast-growing rate of polypropylene applications in the automotive and other industries. This work focused on the role of glass fibers and fiber-matrix adhesion on deformation mechanism. Composites with different fiber content, with and without adhesion promoter, were fabricated. Tensile tests and microscopy techniques were conducted. Based on the results, a physical model has been proposed that illustrates the initiation and growth of the damage under static loading condition. According to this work, the... 

    Novel experimental methods for the determination of the boundaries between conventional, severe and over shot peening processes

    , Article Surfaces and Interfaces ; Volume 13 , 2018 , Pages 233-254 ; 24680230 (ISSN) Maleki, E ; Unal, O ; Amanov, A ; Sharif University of Technology
    Elsevier B. V  2018
    Abstract
    Shot peening process is one of the severe plastic deformation methods which is well-recognized for the surface layer integrity of the components. This process, according to its energy level, can be categorized into three different cases of conventional, severe, and over shot peening. The aforementioned types of shot peening have positive and/or negative effects on their related performing conditions. In this study, the boundaries between these processes were determined for the first time by presenting novel approaches. The foundations of the presented approaches are microstructural investigations. The microstructures were characterized using optical microscopy, scanning electron microscopy,... 

    Effect of copper content on tensile mechanical properties of ternary NiTiCu alloy nanowire: molecular dynamics simulation

    , Article Materials Today: Proceedings ; Volume 5, Issue 1 , 2018 , Pages 1552-1555 ; 22147853 (ISSN) Fazeli, S ; Vahedpour, M ; Sadrnezhaad, K ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Molecular dynamics (MD) simulation was used to study of mechanical properties of NiTiCu with different content of copper. It was shown that the percent composition of copper are significantly affects the stress-strain curves curve. The results showed that as the Cu content increased, the Yield Strength and Young's modulus decreased. © 2017 Elsevier Ltd  

    Manufacturing, mechanical properties and microstructural characteristics of ceramic preforms

    , Article Proceedings of the 8th Conference and Exhibition of the European Ceramic Society, Istanbul, 29 June 2003 through 3 July 2003 ; Volume 264-268, Issue II , 2004 , Pages 941-944 ; 10139826 (ISSN) Amini, S ; Javadpour, S ; Jamshidi, M. S ; Amini, S ; European Ceramic Society; Turkish Ceramic Society ; Sharif University of Technology
    Trans Tech Publications Ltd  2004
    Abstract
    The production of porous (SAFFIL) preforms and SAFFIL/SiCP hybrid preforms will be discussed. SAFFIL fibers and SiCP are dispersed into an aqueous medium that consists of colloidal silica binder, distilled water, dispersants and deflocculants using agitation, spontaneous sedimentation, followed by drying and final strengthening. The effect of different process parameters such as various deflocculants and surfactants on the mechanical properties, mixing time and volumetric change of these preforms will also be investigated  

    Effects of lubrication procedure on the consolidation, sintering and microstructural features of powder compacts

    , Article Materials and Design ; Volume 24, Issue 8 , 2003 , Pages 585-594 ; 02641275 (ISSN) Simchi, A ; Sharif University of Technology
    Elsevier Ltd  2003
    Abstract
    The role of lubrication procedure on the consolidation behavior of metallic powders and subsequent microstructural development during sintering was investigated. Iron powder and iron-0.8 w/o graphite powder mixture were used as model materials. The effects of die wall lubrication procedure were compared to the traditional admixed powder lubrication method. The influences of manufacturing parameters such as the compacting pressure in the range of 150-800 MPa and the sintering temperature from 400 to 1300 °C were studied. It was found that the lubrication procedure has a great influence on the consolidation and microstructural features of the materials investigated. Admixed lubricant aids the... 

    Investigation of Mechanical Milling Effects on Al-Cu and Al-CuO Powder Mixture Morphological and Structural Characteristic and Mechanical Properties Changes Resultant from Age Hardening

    , M.Sc. Thesis Sharif University of Technology Haghighatzadeh, Mehdi (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    In the present work, nanocrystalline Al-4wt%Cu alloy reinforced with nanometric Al2O3 particles was synthesized by in-situ reactive milling of Al and CuO powder mixture and hot extrusion. The effect of nanometric Al2O3 particles on the aging behavior and mechanical properties of this alloy was investigated. During mechanical milling, copper oxide were reduced and dissolved in the aluminum lattice. consequently, Al(Cu) solid solution matrix was produced. Also, nanometric Al2O3 particles were also distributed in the matrix uniformly. The powder blend was then pressed in an Al can at 100 MPa pressure and subsequently extruded at 450 0C at the extrusion ratio of 16:1. The density of the... 

    Effects of post-annealing on the microstructure and mechanical properties of friction stir processed Al–Mg–TiO2 nanocomposites [electronic resource]

    , Article Journal of Materials & Design ; November 2014, Volume 63, Pages 30–41 Khodabakhshi, F ; Simchi, A. (Abdolreza) ; Kokabi, A. H ; Gerlich, A. P ; Nosko, M ; Sharif University of Technology
    Abstract
    Aluminum matrix nanocomposites were fabricated via friction stir processing of an Al–Mg alloy with pre-inserted TiO2 nanoparticles at different volume fractions of 3%, 5% and 6%. The nanocomposites were annealed at 300–500 °C for 1–5 h in air to study the effect of annealing on the microstructural changes and mechanical properties. Microstructural studies by scanning and transmission electron microscopy showed that new phases were formed during friction stir processing due to chemical reactions at the interface of TiO2 with the aluminum matrix alloy. Reactive annealing completed the solid-state reactions, which led to a significant improvement in the ductility of the nanocomposites (more... 

    Fabrication, characterization and mechanical properties of hybrid composites of copper using the nanoparticulates of SiC and carbon nanotubes [electronic resource]

    , Article Journal of Materials Science and Engineering: A ; 10 June 2013, Volume 572, P.83–90 Akbarpour, M. R ; Salahi, E ; Alikhani Hesari, F ; Simchi, A. (Abdolreza) ; Kim, H. S ; Sharif University of Technology
    Abstract
    Copper based hybrid composites containing nano-sized silicon carbide and carbon nanotubes reinforcements with minimal porosity were fabricated via mechanical milling followed by hot pressing technique. Microstructures of the powders and consolidated materials were studied using scanning electron microscope, X-ray diffraction, Raman spectroscopy, and scanning transmission electron microscope. Microstructural characterization of the materials revealed that the addition of nanosized silicon carbide reinforcement lowered the grain growth rate and enhanced the homogenization during mechanical milling. Microhardness measurements and compression test showed considerable improvements in mechanical... 

    Effect of particle size on the in vitro bioactivity, hydrophilicity and mechanical properties of bioactive glass-reinforced polycaprolactone composites [electronic resource]

    , Article Journal of Materials Science and Engineering: C ; 10 October 2011, Volume 31, Issue 7, Pages 1526–1533 Tamjid, E ; Bagheri, R ; Vossoughi, M ; Simchi, A. (Abdolreza) ; Sharif University of Technology
    Abstract
    Polycaprolactone (PCL) composite films containing 5 wt.% bioactive glass (BG) particles of different sizes (6 μm, 250 nm, < 100 nm) were prepared by solvent casting methods. The ultra-fine BG particles were prepared by high-energy mechanical milling of commercial 45S5 Bioglass® particles. The characteristics of bioactive glass particles were studied by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and X-ray diffraction (XRD) methods. In vitro bioactivity of the PCL/BG composite films was evaluated through immersion in the simulated body fluid (SBF). The films were analyzed by FE-SEM, energy dispersive... 

    A comprehensive investigation into the effect of water to cement ratio and powder content on mechanical properties of self-compacting concrete

    , Article Construction and Building Materials ; Vol. 57 , April , 2014 , pp. 69-80 ; ISSN: 09500618 Nikbin, I. M ; Beygi, M. H. A ; Kazemi, M. T ; Vaseghi Amiri, J ; Rabbanifar, S ; Rahmani, E ; Rahimi, S ; Sharif University of Technology
    Abstract
    Self compacting concrete (SCC), as an innovative construction material in concrete industry, offers a safer and more productive construction process due to favorable rheological performance which is caused by SCC's different mixture composition. This difference may have remarkable influence on the mechanical behavior of SCC as compared to normal vibrated concrete (NVC) in hardened state. Therefore, it is vital to know whether the use of all assumptions and relations that have been formulated for NVC in current design codes are also valid for SCC. Furthermore, this study presents an extensive evaluation and comparison between mechanical properties of SCC using current international codes and... 

    Effect of the bonding time on the microstructure and mechanical properties of a transient-liquid-phase bonded in718 using a Ni-Cr-B filler alloy

    , Article Materiali in Tehnologije ; Volume 47, Issue 5 , 2013 , Pages 593-599 ; 15802949 (ISSN) Pouranvari, M ; Ekrami, A ; Kokabi, A. H ; Sharif University of Technology
    2013
    Abstract
    The paper aims at addressing the effect of the bonding time on the metallurgical and mechanical properties of a transient-liquid-phase (TLP) bonded IN718 nickel-based superalloy using an Ni-15.2Cr-4B (%) amorphous filler alloy. The results showed that after a partial isothermal solidification, the residual liquid in the joint centerline transformed, during the cooling, to non-equilibrium eutectic-type microconstituents composed of Ni-rich boride, Cr-rich boride and eutectic γ-solid solution phase. The complete isothermal solidification which resulted in a formation of an intermetallic-free joint centerline occurred after a holding period 40 min at the bonding temperature of 1100 °C. An... 

    Roll bonding behaviour of Al-3003/Al-4043 and Al-3003/Zn sheets

    , Article Metals and Materials International ; Volume 17, Issue 4 , 2011 , Pages 665-670 ; 15989623 (ISSN) Movahedi, M ; Kokabi, A. H ; Madaah Hosseini, H. R ; Kiani, M ; Sharif University of Technology
    Abstract
    In the present study, the roll bonding behaviour of Al-3003/Al-4043 and Al-3003/Zn sheets were compared. The bi-layer sheets were produced by a roll bonding process at different reductions in thickness and rolling temperatures. The joint strengths of the sheets were evaluated by peel and bend testing before and after supplemental annealing treatment. The peeled surfaces were examined using a scanning electron microscope. The results indicated that the Al-3003/Al-4043 sheets were bonded with higher joint strength and lower threshold reductions in thickness with respect to the Al-3003/Zn sheets. In contrast to the Al-3003/Zn sheets, significant improvement was observed in the joint strength of... 

    The effect of aging treatment on mechanical properties ofaa6082 alloy: Modelingand experiment

    , Article Iranian Journal of Materials Science and Engineering ; Volume 7, Issue 2 , 2010 , Pages 14-21 ; 17350808 (ISSN) Anjabin, N ; Taheri, K ; Sharif University of Technology
    Abstract
    A novel constitutive equation has been proposed to predict the effect of aging treatment on mechanical properties of AA6082 aluminum alloy. Considering that aging phenomenon affects the distribution of alloying element in matrix, and the fact that different distribution of alloying elements has different impediments to dislocation movement, a material model based on microstructure, has been developed in this research. A relative volume fraction or mean radius of precipitations is introduced into the flow stress by using the appropriate relationships. The GA-based optimization technique is used to evaluate the material constants within the equations from the uni-axial tensile test data of... 

    Microstructure and mechanical properties of dual phase steels, with different martensite morphology, produced during TLP bonding of a low C-Mn steel

    , Article Metals and Materials International ; Volume 22, Issue 5 , 2016 , Pages 856-862 ; 15989623 (ISSN) Fazaeli, A ; Ekrami, A ; Kokabi, A. H ; Sharif University of Technology
    Korean Institute of Metals and Materials 
    Abstract
    In this research, production of ferrite - martensite dual phase Steels with different martensite morphology was considered during transient liquid phase bonding of a low carbon steel. The steel was bonded using an iron base interlayer with melting point of 1443 K and 40 μm thickness. Bonding process carried out at 1473 K, under pressure of 0.5 MPa, at different holding time of 10, 20, 30 and 40 minutes. Microstructural studies of joint region showed that isothermal solidification completed at the bonding time of 40 minutes. Microstructure of joints made at the bonding time of 10, 20, and 30 minutes consists of two distinct region, athermal and isothermal solidified zones. Microstructure of... 

    Effect of ECAP temperature on microstructure and mechanical properties of Al-Zn-Mg-Cu alloy

    , Article Progress in Natural Science: Materials International ; Volume 26, Issue 2 , 2016 , Pages 182-191 ; 10020071 (ISSN) Shaeri, M. H ; Shaeri, M ; Ebrahimi, M ; Salehi, M. T ; Seyyedein, S. H ; Sharif University of Technology
    Elsevier B.V  2016
    Abstract
    The effect of equal channel angular pressing (ECAP) at different temperatures (room temperature, 120, 150 and 180 °C) on microstructure and mechanical properties of Al-7075 solid solution alloy was investigated. Microstructure of the specimens was examined using orientation imaging microscopy, transmission electron microscopy as well as X-ray diffractometer, and mechanical properties were measured by Vickers microhardness and tensile tests. Microstructural investigations showed that after 3 or 4 passes of ECAP, fine grains with average grain sizes in range of 300-1000 nm could be obtained at different ECAP temperatures. Increasing ECAP temperature from 120 to 180 °C caused a decrease in... 

    Investigation of adding cement kiln dust (CKD) in ordinary and lightweight concrete

    , Article Advances in Concrete Construction ; Volume 5, Issue 2 , 2017 , Pages 101-115 ; 22875301 (ISSN) Shoaei, P ; Zolfaghary, S ; Jafari, N ; Dehestani, M ; Hejazi, M ; Sharif University of Technology
    Techno Press  2017
    Abstract
    Cement kiln dust (CKD) is one of the most important waste materials in the cement industry. The large amount of this material, has encouraged researchers to propose new ways to recycle and reuse it. In this paper, effects of adding cement kiln dust to the ordinary Portland cement, on the physical and mechanical properties of ordinary and lightweight concrete were investigated. Results showed that concrete containing CKD, presents lower workability and modulus of elasticity; however, improvements in strength was observed by adding particular amounts of CKD. Eventually, it was found that adding 10% of cement weight CKD is the appropriate percentage for utilizing in manufacturing ordinary and... 

    Investigation on the effect of cold drawing process on mechanical properties and structure of seamless steel (CK60) tube

    , Article International Journal of Mechanical Engineering and Technology ; Volume 9, Issue 8 , 2018 , Pages 1300-1312 ; 09766340 (ISSN) Pourjafari Kasmaee, M ; Rouhizadeh, S ; Salehi, J ; Sharif University of Technology
    IAEME Publication  2018
    Abstract
    The cold drawing process is one of the precise metal forming techniques which have attracted attention by many researchers with respect to the given properties such as potential for improvement of mechanical properties of the material, achieving of accurate dimensional tolerances and rise of quality at final surface so that different studies are conducted on properties of various materials in the course of analysis of its effect. Using cold drawing and also exertion of special heat treatment cycle in this investigation, initially the seamless steel tube Ck60 has been produced and then effect of cold drawing has been assessed on the mechanical properties and structure of steel. The production... 

    Roles of surface coverage increase and re-peening on properties of AISI 1045 carbon steel in conventional and severe shot peening processes

    , Article Surfaces and Interfaces ; Volume 11 , 2018 , Pages 82-90 ; 24680230 (ISSN) Maleki, E ; Unal, O ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Surface coverage as one of the most effective parameters of shot peening process has substantial influence on the functionality of the peened component. The aim of this study is to investigate the effects of surface coverage increase on the properties of treated specimens experimentally before and after re-shot peening. Different shot peening treatments from conventional to severe; were performed on the AISI 1045 steel. Microstructural observations and XRD measurements were applied to characterize the circumstance of microstructure changes. In order to investigate the mechanical properties, microhardness profiles were achieved, surface roughness was evaluated and the residual stresses... 

    Effect of travel speed on quality and welding efficiency of friction stir welded AZ31B magnesium alloy

    , Article International Journal of Engineering and Technology(UAE) ; Volume 7, Issue 3 , January , 2018 , Pages 94-99 ; 2227524X (ISSN) Baghdadi, A. H ; Selamat, N. F. M ; Sajuri, Z ; Kokabi, A. H ; Sharif University of Technology
    Science Publishing Corporation Inc  2018
    Abstract
    Weight reduction is one of the most concerning issues of automotive and aircraft industries in reducing fuel consumption. Magnesium (Mg) alloys are the lightest alloys which can be used in the structure due to low density and high strength to weight ratio. Developing a reliable joining process of magnesium alloys is required due to limited ductility and low workability at room temperature. Friction stir welding (FSW) is a solid-state welding process that can be performed to produce sound joints in magnesium alloys. Researchers have performed investigations on the effect of rotation and travel speeds in FSW of AZ31B magnesium alloy. However, there is lack of study on the FSW parameters, i.e.... 

    Effects of size and shape on elastic constants of graphene sheet

    , Article Structures ; Volume 13 , February , 2018 , Pages 131-138 ; 23520124 (ISSN) Azimi Resketi, N ; Ahmadie Amiri, H ; Dehestani, M ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Nanotechnology is used in different engineering fields such as mechanical, aerospace, and civil. One of the most interesting structures which recently have come to the center of attention is the Graphene Sheet (GS). Graphene is a material with high potential of usage in civil structures like structural rehabilitation. In the present paper a finite element based structural analysis program is employed to study the mechanical properties of GS. The advantage of using this method is its simplicity and efficiency in different types of loading. The models considered here are based on a structural mechanics approach by using finite beam elements. Variations of Young's moduli of GS versus different...