Loading...
Search for:
impact-strength
0.006 seconds
Impact and tensile behaviour of fractional melting processed ZA-27 alloy
, Article Materials Science and Engineering A ; Volume 333, Issue 1-2 , 2002 , Pages 115-122 ; 09215093 (ISSN) ; Razavimanesh, A ; Kolahi, A ; Mohiedin, M ; Sharif University of Technology
2002
Abstract
This paper describes the influence of a fractional melting process on the reduction of interdendritic phases, which in turn have an impact on the tensile strength of ZA-27 alloys. The procedure consists of compressing a semi-solid specimen through a porous grinding disc, resulting on coarsening of the dendritic phase, reduction of the microporosity and homogenization of the alloy. © 2002 Elsevier Science B.V. All rights reserved
An Investigation on Mechanical Behavior of Polypropylene/Polyethylene Blend - Calcium Carbonate Nano Composite
,
M.Sc. Thesis
Sharif University of Technology
;
Bagheri, Reza
(Supervisor)
Abstract
Polymer blending has an important role in preparation of materials with suitable properties without synthesizing new polymers. One of these blends is polypropylene (PP)/ polyethylene (PE). PE is added for improving the impact strength and toughness of PP. For improvementof the properties, a compatibilizer is used due to incompatibility of the PP/PE blend. Improving the impact properties is usually related to the reduction in stiffness. Considering the importance of stiffness in many industrial applications, mineral fillers are employed for increasing the stiffness. In this research, the goal has been to manufacture polypropylene-based ternary composite(Polypropylene/ Polyethylene/Nanometric...
Melt preparation and investigation of properties of toughened Polyamide 66 with SEBS-g-MA and their nanocomposites
, Article Materials and Design ; Volume 29, Issue 1 , 2008 , Pages 105-111 ; 02613069 (ISSN) ; Ahmad Ramazani, S. A ; Sharif University of Technology
Elsevier Ltd
2008
Abstract
Polyamide 66/SEBS-g-M alloys and their nanocomposites were prepared by melt compounding using a twin screw extruder. The mechanical properties, rheological behavior and morphology of these alloys and their nanocomposites were investigated. Morphological investigations with different methods show pseudo-one-phase type morphology for these prepared alloys at all percentage of rubber. Impact and tensile tests results showed that rubber toughened samples exhibit significantly more impact strength and elongation at break comparing to virgin Polyamide. Samples with 20% of rubber show impact strength about 15 times and elongation at yield several times more than those of virgin Polyamide. So, these...
Role of interfacial fracture energy and laminate architecture on impact performance of aluminum laminates
, Article Composites Part A: Applied Science and Manufacturing ; Volume 39, Issue 11 , 2008 , Pages 1685-1693 ; 1359835X (ISSN) ; Bagheri, R ; Mahmudi, R ; Sharif University of Technology
2008
Abstract
The impact behavior of aluminum/epoxy laminates was studied by changing the number of layers and the interface strength. It should be noted that although the overall thickness did not changed, the individual layers decreased in thickness when the number of layers increased. The results indicate that the impact resistance of the laminate increases with the number of layers, while the interface strength has a less pronounced influence (50%) on the impact resistance of the laminate. It is also deducted that if the ratio of layer thickness to plastic zone size is smaller than or equal to 1, the impact behavior of the laminates is sensitive to the interface strength. © 2008 Elsevier Ltd. All...
Mechanical Behavior of Recycled Polyethylene Terephthalate/Polycarbonate/Glass Fiber Composites
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza (Supervisor)
Abstract
Nowadays, with the increasing number of polyethylene terephthalate wastes, the issue of its recycling has become very important. Among the problems of polyethylene terephthalate recycling are its loss of crystallinity and mechanical properties. Recycled polyethylene terephthalate does not have the properties of new polyethylene terephthalate and using its mixture with other materials is an effective way to remove its waste from nature and return it to the production cycle. The aim of this study is to produce a mixture of recycled polyethylene terephthalate with polycarbonate and glass fibers with mechanical properties such as good impact strength, which ultimately leads to the production of...
Long-term mechanical performance of polyethylene pipe materials in presence of carbon black masterbatch with different carriers
, Article Polymer Testing ; Volume 91 , 2020 ; Pircheraghi, G ; Sarafpour, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this paper, two types of carbon black (CB) masterbatch with different carriers, i.e. HDPE and LDPE, are used to produce black compounds using three PE100 resins with various short chain branching distributions. Due to difference in short chain branch (SCB) distribution, the used polyethylene resins behave differently in microstructure development and long-term creep behavior. The microstructural analysis using different DSC techniques and rheological measurements revealed more sensitivity of the polyethylene resin with uniform comonomer distribution to the carbon black aggregates and their polymeric carriers. The Full Notched Creep Test (FNCT) was performed to determine the long-term...
On the comparison of microstructural characteristics and mechanical properties of high-vanadium austenitic manganese steels with the Hadfield steel
, Article Materials Science and Engineering A ; Volume 532 , 2012 , Pages 260-266 ; 09215093 (ISSN) ; Varahram, N ; Davami, P ; Sharif University of Technology
Abstract
In this study, high-vanadium austenitic manganese steel (HV-AMS) alloys and the standard Hadfield steel were investigated. The microstructure of these high-vanadium alloyed Hadfield steels was studied thoroughly using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) and was compared to the Hadfield steel. The hardness and unnotched Charpy impact strength of HV-AMS alloys and Hadfield steel were examined at ambient temperature in the as-cast and heat-treated conditions. A pin-on-disk wear test at linear speed of 10. m/min and a 55. N normal load was employed to evaluate the wear behavior of both steel samples. Microstructural results showed that varying...
Modification of nanostructure and improvement of mechanical properties of polypropylene/polyamide 6/layered silicate ternary nanocomposites through variation of processing route
, Article Composites Part B: Engineering ; Volume 85 , February , 2016 , Pages 207-215 ; 13598368 (ISSN) ; Bagheri, R ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
Ternary nanocomposites of polypropylene/polyamide 6/layered silicate were prepared through three different processing procedures. X-ray diffraction and transmission electron microscopy were used to study the nanostructure of the samples, and tensile and impact strength measurements were conducted to assess the mechanical properties. It was shown that processing route has a significant effect on the delamination of clay platelets. Fully exfoliated nanostructure was achieved through a certain two-step processing route. Compatibilization of the blends affected microstructure as well as nanostructure. Mechanical properties were affected by changing the processing route, to a great degree....
Interface between tire and pavement
, Article Journal of Materials in Civil Engineering ; Volume 29, Issue 9 , 2017 ; 08991561 (ISSN) ; Toufigh, V ; Sharif University of Technology
Abstract
Sliding friction between a pavement and tire is an important concern in traffic safety. The British pendulum test has been used worldwide to evaluate friction characteristics of pavement surfaces. However, because of considerable differences in apparatus, procedures, and operation, significant variability can occur for evaluations of British pendulum number (BPN). In this investigation, a direct shear test (DST) device is modified and proposed to determine the sliding friction coefficient between tire and pavement surface under dry and wet conditions. Dissipated energy values obtained from DST were compared with evaluations of BPN, and a high correlation was obtained. Tests were done using...
Effect of poly (propylene-g-maleic anhydride) on the morphological, rheological, and mechanical properties of PP/HDPE blend
, Article Journal of Thermoplastic Composite Materials ; Volume 22, Issue 5 , 2009 , Pages 519-530 ; 08927057 (ISSN) ; Abdi Valami, M ; Khak, M ; Sharif University of Technology
2009
Abstract
In this study, the morphological, rheological, and mechanical properties of PP/HDPE blend compatibilized with poly (propylene-g-maleic anhydride) were studied. Necessary blends were prepared using a counter current twin-screw extruder. The blend composition ranged from 10 to 50 wt% of dispersed phase (HDPE) and compatibilizer (MAPP) with two Concentration ranges 10, 20 wt% were used for PP/HDPE (80/20) blend with respect to the dispersed phase (HDPE). The results of morphological studies shows a droplet dispersion morphology in the composition to 50wt% HDPE content, which indicates that HDPE forms a dispersed phase and PP forms a continuous phase in these composition region. Addition of the...
Use of rubber modification technique to improve fracture-resistance of hoop wound composites
, Article Materials and Design ; Volume 30, Issue 6 , 2009 , Pages 1976-1984 ; 02641275 (ISSN) ; Khademi, V ; Bagheri, R ; Haddadpour, H ; Kouchakzadeh, M. A ; Farsadi, M ; Sharif University of Technology
2009
Abstract
Toughness improvement of an epoxy resin and respective hoop wound composite were investigated systematically using amine-terminated butadiene acrylonitrile (ATBN) liquid rubber. Rubber modification improves fracture toughness of epoxy resin with slight reduction in the glass transition temperature (Tg), flexural and compressive properties of resin. Impact resistance of composite is improved by rubber modification similar to modified resin. Interlaminar shear strength (ILSS), compressive modulus and strength, and flexural strength of composite decreased slightly with rubber modification. To interpret the data, the void content of composite samples was determined and the damaged surfaces of...
Friction stir welding of polycarbonate lap joints: Relationship between processing parameters and mechanical properties
, Article Polymer Testing ; Volume 79 , 2019 ; 01429418 (ISSN) ; Simchi, A ; Lambiase, F ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
The relation between process parameters and properties of polycarbonate (PC) sheet after friction stir welding (FSW) was investigated. Effects of FSW tool rotation speed (ω), travelling speed (V), tilt angle (α) and plunge depth on material flow, joint tensile strength, flexural strength, impact energy and hardness were investigated. It is shown that at low and high levels of heat input sound joints cannot be attained. At low heat inputs, the local temperature is not high enough to decrease the viscosity of the polymer to fill the interface, and thus voids and large planar cracks are formed in the joint root and stir zone. At high heat inputs, expelling of materials due to high peak...
Poly(lactic acid)/coplasticized thermoplastic starch blend: Effect of plasticizer migration on rheological and mechanical properties
, Article Polymers for Advanced Technologies ; Volume 30, Issue 4 , 2019 , Pages 839-851 ; 10427147 (ISSN) ; Pircheraghi, G ; Bagheri, R ; Altstädt, V ; Sharif University of Technology
John Wiley and Sons Ltd
2019
Abstract
Polylactic acid (PLA) and thermoplastic starch (TPS) are known as bio-based and biodegradable thermoplastic polymers that can be used in different applications owing to their inherent physical and mechanical properties. In order to reduce the higher costs of PLA and tuning its physical and mechanical properties suitable for short life packaging applications, blending of PLA with the TPS, more economical biodegradable polymer, has been considered in academic and industrial researches. However, melt blending of PLA with TPS without compatibilization process caused some drawbacks such as coarsening morphology and declining mechanical properties and ductility because of thermodynamic...
Effect of polymer content and temperature on mechanical properties of lightweight polymer concrete
, Article Construction and Building Materials ; Volume 260 , 2020 ; Jafari, K ; Ozbakkaloglu, T ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
This study investigates the mechanical properties of lightweight polymer concrete (LWPC) containing four different polymer ratios (10%, 12%, 14%, and 16%) tested at three different temperatures (−15 °C, +5 °C, and +25 °C) using destructive and non-destructive tests. In addition, a series of expressions are suggested to predict the splitting-tensile, flexural and impact strength of LWPC based on the main parameters and compressive strength. The analysis of variance (ANOVA) method was also used to determine relative contributions of the experimental parameters. The results of the destructive tests show that increasing the polymer ratio caused an increase in the compressive, splitting-tensile,...
Effect of hybridization on crystallization behavior, mechanical properties, and toughening mechanisms in rubber-modified polypropylene flax fiber composites
, Article Journal of Composite Materials ; Volume 56, Issue 17 , 2022 , Pages 2677-2693 ; 00219983 (ISSN) ; Bagheri, R ; Sharif University of Technology
SAGE Publications Ltd
2022
Abstract
Nowadays, the significance of sustainability has urged composite manufacturers to replace traditional synthetic fibers with eco-friendly natural alternatives due to their environmental and economic benefits. This work aims to fabricate hybrid polypropylene (PP) composites with short flax fibers, octene-ethylene copolymer (POE) rubber particles, and maleic anhydride-grafted polypropylene (MAPP) compatibilizer. The main goal is to gain an insight into the combined effect of toughening mechanisms induced by the short fibers and rubber particles at the crack tip and wake of composites, which is a crucial step in reaching a balance between toughness and rigidity. In this regard, a novel...
The effect of bainite morphology on the mechanical properties of a high bainite dual phase (HBDP) steel
, Article Materials Science and Engineering A ; Volume 525, Issue 1-2 , 2009 , Pages 159-165 ; 09215093 (ISSN) ; Ekrami, A ; Sharif University of Technology
2009
Abstract
4340 steel bars were austenitized at 850 °C for 1 h followed by heating at 700 °C for 90 min and quenching into a salt bath at the temperature range of 300-450 °C for 1 h to obtain dual structures with 34 vol.% fraction ferrite and various bainite morphologies. SEM studies showed that by increasing the austempering temperature, bainite morphology varies from lower to upper bainite. Tensile, impact and hardness tests revealed that increasing the austempering temperature from 300 to 400 °C leads to a reduction in yield and ultimate tensile strength, hardness, uniform and total elongation and impact energy. But in dual phase steel produced by austempering at 450 °C, yield and tensile strength...