Search for: high-tensile-strength
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    Fabrication of porous NiTi-shape memory alloy objects by partially hydrided titanium powder for biomedical applications

    , Article Materials and Design ; Volume 30, Issue 10 , 2009 , Pages 4483-4487 ; 02641275 (ISSN) Sadrnezhaad, S. K ; Hosseini, S. A ; Sharif University of Technology
    Porous NiTi-shape memory alloy (SMA) is a promising biomaterial with desirable mechanical property and appropriate biocompatibility for human implant manufacturing. In this research, porous NiTi-SMAs have been successfully produced by using thermohydrogen process (THP). This process has capability of production of homogenous structures, appropriate pore-size distributions and short sintering times. The THP-SMA samples produced in this research have a low Young's modulus (19.8 GPa) and a high tensile strength of 255 MPa. These properties are close to those of the natural bone and can meet the mechanical property demands of the hard-tissue implants for heavy load-bearing applications. The... 

    Enhanced tensile properties and electrical conductivity of Cu-CNT nanocomposites processed via the combination of flake powder metallurgy and high pressure torsion methods

    , Article Materials Science and Engineering A ; Volume 773 , 2020 Akbarpour, M. R ; Mousa Mirabad, H ; Alipour, S ; Kim, H. S ; Sharif University of Technology
    Elsevier Ltd  2020
    Using flake powder metallurgy (FPM) technique, combined with high pressure torsion, super high strength-ductile Cu-CNT nanocomposite with high electrical conductivity is developed. The nanocomposite with 4 vol% CNT showed high tensile strength of ~474 MPa, high electrical conductivity of ~82.5% IACS as well as appreciable ductility of ~11%. According to microstructural studies, the excellent properties of the nanocomposite are attributed to the formation of trimodal grains, high density of twin and low angle grain boundaries, improvement in CNT and Cu interfacial bonding, and appropriate distribution and maintaining the microstructure of the nanotubes in the production process. The results... 

    Fiber bridging in polypropylene-reinforced high-strength concrete: An experimental and numerical survey

    , Article Structural Concrete ; 2021 ; 14644177 (ISSN) Khaloo, A ; Daneshyar, A ; Rezaei, B ; Fartash, A ; Sharif University of Technology
    John Wiley and Sons Inc  2021
    Fracture process of fiber-reinforced concrete notched beams is investigated here. Polypropylene macrosynthetic fibers are utilized for reinforcing concrete specimens, and a high-strength mix design is used to produce strong bonds between the embossed polypropylene fibers and the cementitious matrix of beams. Considering different locations for the notch, this study focuses on bridging mechanism under different conditions using both experimental and numerical approaches. First mode of fracture occurs due to opening of crack faces. This mode of failure is simulated by imposing symmetric boundary conditions on middle-notched beams. Inducing the notch with an offset from the middle, mixed-mode... 

    Analytical modeling of strength in randomly oriented PP and PPTA short fiber reinforced gypsum composites

    , Article Computational Materials Science ; Volume 50, Issue 5 , 2011 , Pages 1619-1624 ; 09270256 (ISSN) Mohandesi, J. A ; Sangghaleh, A ; Nazari, A ; Pourjavad, N ; Sharif University of Technology
    Fiber reinforced gypsum are prevalent building materials in which short fibers with high tensile strength are embedded into a gypsum matrix to produce supplemental strong and lightweight construction materials. Due to confrontation to a rising risk of death and economic disaster in earthquake-prone areas, quake-resistant materials and structures should be employed for building constructions. Gypsum based composites as a unique candidate for this purpose reduce the risks and produce much confident construction materials for residential buildings. In this work tensile strength of gypsum composites with different volume fraction of polypropylene (PP) and poly-paraphenylene terephthalamide... 

    Fabrication and characterization of low-cost, bead-free, durable and hydrophobic electrospun membrane for 3D cell culture

    , Article Biomedical Microdevices ; Volume 19, Issue 4 , 2017 ; 13872176 (ISSN) Moghadas, H ; Saidi, M. S ; Kashaninejad, N ; Kiyoumarsioskouei, A ; Trung Nguyen, N ; Sharif University of Technology
    This paper reports the fabrication of electrospun polydimethylsiloxane (PDMS) membranes/scaffolds that are suitable for three-dimensional (3D) cell culture. Through modification the ratio between PDMS and polymethylmethacrylate (PMMA) as carrier polymer, we report the possibility of increasing PDMS weight ratio of up to 6 for electrospinning. Increasing the PDMS content increases the fiber diameter, the pore size, and the hydrophobicity. To our best knowledge, this is the first report describing beads-free, durable and portable electrospun membrane with maximum content of PDMS suitable for cell culture applications. To show the proof-of-concept, we successfully cultured epithelial lung...