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Effect of SiC particles on the laser sintering of Al-7Si-0.3Mg alloy
, Article Scripta Materialia ; Volume 59, Issue 2 , 2008 , Pages 199-202 ; 13596462 (ISSN) ; Godlinski, D ; Sharif University of Technology
2008
Abstract
The direct laser sintering of Al-7Si-0.3Mg/SiC composites was studied. It is shown that the densification rate obeys first-order kinetics. The rate constant is found to increase at low SiC fractions but abruptly decreases at >∼5 vol.%. In the presence of ceramic particles, the melt track becomes more stable and a more continuous sintered surface is obtained. Meanwhile, significant reaction occurs between the aluminum melt and the reinforcement particles, leading to formation of Al4SiC4 and silicon particles. The solidification microstructure is also altered. © 2008 Acta Materialia Inc
Discovery of novel quaternary bulk metallic glasses using a developed correlation-based neural network approach
, Article Computational Materials Science ; Volume 186 , 2021 ; 09270256 (ISSN) ; Gholamipour, R ; Samavatian, V ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The immense space of composition-processing parameters leads to numerous trial-and-error experimental works for engineering of novel bulk metallic glasses (BMGs). To tackle this challenging problem, it is required to consider specific guidelines which are able to restrict the productive alloying compositions. In this work, a correlation-based neural network (CBNN) approach was developed, based on a dataset of 7950 alloying compositions, to design potential new MGs through prediction of casting ability, reduced glass transition (Trg) and critical thickness (Dmax). This approach involves individual and mutual characteristics of contributory factors to improve the prediction accuracy. To...
An Investigation into the Microstructure and Mechanical Properties of Biodegradable Magnesium Alloys Composite-carbon Nanotube Produced by the Mechanical Alloying and Powders Pressing Processes
, M.Sc. Thesis Sharif University of Technology ; Karimi Taheri, Ali (Supervisor)
Abstract
Properties of biomaterials, especially in application as planting, can be controlled and optimized by alloying and hardening sedimentation. In recent years, the study on the simultaneous improvement of mechanical properties, toughness and corrosion behavior of magnesium composite by carbon nanotubes (CNTs) is very limited. In this study, the behavior of mechanical properties and corrosion of magnesium alloy composites with different percentages of CNTs have been investigated. The production of magnesium alloy composite by powder metallurgy and aging process have been used as effective methods for improving mechanical properties and increasing the corrosion resistance of magnesium alloys. For...
Formability of tri-layered IF240/AZ31/IF240 composite with strong bonding: experimental and finite element modeling
, Article Journal of Materials Engineering and Performance ; Volume 30, Issue 11 , 2021 , Pages 8402-8411 ; 10599495 (ISSN) ; Akbarzadeh, A ; Hadiyan, B ; Hashemi, R ; Sharif University of Technology
Springer
2021
Abstract
In this work, the formability of a hybrid material of Interstitial-Free 240 (IF240) steel and AZ31 magnesium alloy as IF240/AZ31/IF240 tri-layered sheets was investigated. For this purpose, the bonding feasibility of the high-formability IF240 steel and low-formability AZ31 sheets was first assessed. Then, the hot formability behavior of the manufactured laminated composite was evaluated. The rolling of the preheated samples established the layer bonding. The bonding strength was determined using the shear punch test. The texture and its effects on the forming behavior were studied using the x-ray Goniometry method. Nakazima dome tests were employed at ambient and elevated temperatures to...
Formability of Tri-layered IF240/AZ31/IF240 composite with strong bonding: Experimental and finite element modeling
, Article Journal of Materials Engineering and Performance ; Volume 30, Issue 11 , 2021 , Pages 8402-8411 ; 10599495 (ISSN) ; Akbarzadeh, A ; Hadiyan, B ; Hashemi, R ; Sharif University of Technology
Springer
2021
Abstract
In this work, the formability of a hybrid material of Interstitial-Free 240 (IF240) steel and AZ31 magnesium alloy as IF240/AZ31/IF240 tri-layered sheets was investigated. For this purpose, the bonding feasibility of the high-formability IF240 steel and low-formability AZ31 sheets was first assessed. Then, the hot formability behavior of the manufactured laminated composite was evaluated. The rolling of the preheated samples established the layer bonding. The bonding strength was determined using the shear punch test. The texture and its effects on the forming behavior were studied using the x-ray Goniometry method. Nakazima dome tests were employed at ambient and elevated temperatures to...
An Investigation on Production a Biomedical Mg Alloy-carbon Nanotube Composite Using Mechanical Alloying, Sintering & Hot Equal Channel Angular Pressing Process
, M.Sc. Thesis Sharif University of Technology ; Karimi Taheri, Ali (Supervisor)
Abstract
Nowadays, the research of biodegradable alloys with high corrosion and strength properties, along with a modulus of elasticity close to that of bone tissue, especially the magnesium alloys, which has a good biocompatibility and can be used as a biomedical material, has been considered by the medical industry. On the other hand, carbon nanotubes have been used as an reinforcing phase in composites due to their high mechanical properties. The aim of this project is to produce a biocompatible composite with magnesium alloy and carbon nanotube by powder metallurgy. In order to achieve this, first the raw powder of the alloying elements in the matrix without reinforcement and then with weight...
Facile synthesis of monodisperse thermally immiscible Ag-Ni alloy nanoparticles at room temperature
, Article Bulletin of Materials Science ; Vol. 37, issue. 6 , 2014 , pp. 1447-1452 ; Sadrnezhaad, S. K ; Sharif University of Technology
Abstract
Ag and Ni are immiscible, mainly due to their large lattice mismatch. This paper reports on their nanoscale formation of solid solution at room temperature by simple reduction reactions which lead to the amorphous Ag-Ni alloy nanoparticles (ANPs) with mono-disperse distribution. Microscopic and spectroscopic studies confirmed dependence of the alloy composition on size of nanoparticles. In the presence of different ligands such as sodium citrate, polyvinyl alcohol and potassium carbonate a mixture of silver oxide and Ag-Ni ANPs was achieved. Stoichiometry of the Ag-Ni ANPs was also found to be strongly dependent on ligands of the reduction reaction and further study shows without any ligand...
Use of response surface methodology for evaluation of effective parameters in codeposition of Cu-Sn alloys using non-cyanide electroplating solution
, Article Transactions of the Institute of Metal Finishing ; Volume 90, Issue 1 , January , 2012 , Pages 38-43 ; 00202967 (ISSN) ; Ghorbani, M ; Sharif University of Technology
2012
Abstract
A pyrophosphate based solution, as an acidic electrolyte, was developed for bronze electroplating. By using a statistical experimental design, response surface method, the effects of five factors [copper concentration (Cu), tin concentration (Sn), pyrophosphate concentration (P), current density j and pH] on the composition of the electroplated alloy as well as the process efficiency were evaluated. Statistical analysis indicated that all the parameters were significant and a second order polynomial model was successfully fitted to the data for both the alloy composition and the process efficiency. Based on the results obtained, a solution of Cu(II)8.04 g L -1, Sn(II)=26.36 g L -1, P=113.22...
Effect of anode compositions on the current efficiency of zinc electrowinning
, Article Proceedings - European Metallurgical Conference, EMC 2011 ; Volume 2 , 2011 , Pages 387-396 ; 9783940276377 (ISBN) ; Rashchi, F ; Vahidi, E ; Emami, M ; Khoshnevisan, A ; Sharif University of Technology
Abstract
The main goals in zinc electrowinning process are decreasing of power consumption and increasing of current efficiency. The purpose of this research was to investigate effect of different alloy compositions used in production of lead-based anodes on the zinc electrowinning process. The anode compositions prepared and examined in this study were binary alloys Pb - (0.5 and 2 %) Ag and quaternary alloys Pb - 0.5 % Ag - 1 % Ca - 2 % Sn, Pb - 0.5 % Ag - 1 % Ca - 1 % Sn - 1 % Sb and Pb - 0.5 % Ag - 1 % Ca - 1 % Sn - 1 % Bi. The electrowinning experiments were conducted using a laboratory-scale apparatus, at a plating time of 4 hours, a current density of 500 to 1000 A/m2, industrial zinc sulfate...
Characterization of nanostructured biodegradable Zn-Mn alloy synthesized by mechanical alloying
, Article Journal of Alloys and Compounds ; Volume 735 , 2018 , Pages 1319-1327 ; 09258388 (ISSN) ; Khaleghpanah, S ; Sheibani, S ; Khakbiz, M ; Zakeri, A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this study, nanostructured biodegradable pure Zn, Zn-4 wt. % Mn and Zn-24 wt % Mn alloys were produced by 20 h mechanical alloying and consequent cold pressing and sintering. Structural evolutions were investigated using the X-ray diffraction technique. Also, the microstructure was characterized by scanning electron microscopy. The effects of alloy composition on density, mechanical properties, corrosion behavior in Hank's solution, cell viability and cell attachment were investigated. Crystallite size of the synthesized alloys after 20 h of milling reached to less than 40 nm and remained less than 80 nm after consolidation and sintering for 1 h. Alloys contain MnZn13 as second phase...
Multiphysics modeling of an MSMA-based clamped-clamped inertial energy harvester
, Article Smart Materials and Structures ; Volume 28, Issue 3 , 2019 ; 09641726 (ISSN) ; Zakerzadeh, M. R ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
In this paper, an alternative way of harvesting energy from ambient vibration is investigated through proposing a novel inertial energy harvester using magnetic shape memory alloys (MSMAs). To this end, a clamped-clamped beam is coupled with MSMA units which are attached to its roots. A shock load is applied to a proof mass in the middle of the beam. The beam vibration causes longitudinal strain in the MSMAs and as a result the magnetic flux alters in the coils wounding around the MSMA units and produce an AC voltage. To have a reversible strain in MSMAs, a bias magnetic field is applied in transverse direction of the MSMA units. The large scale vibration of Euler-Bernoulli beam is modeled...
Electrodeposited Ni-Co alloy-particle composite coatings: A comprehensive review
, Article Surface and Coatings Technology ; Volume 382 , 2020 ; Tanhaei, M ; Ahmadipour, M. F ; Ghaffari Adli, R ; Mahdavi, S ; Walsh, F. C ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Electrodeposited composite and nanocomposite layers have attracted considerable attention as engineering coatings, due to their favourable tribological properties and corrosion resistance. Ni[sbnd]Co alloy matrix composite coatings are particularly significant due to their extensive and developing industrial applications. Ceramic nanoparticles are commonly incorporated into the Ni[sbnd]Co alloy matrix to further improve their properties, opening new windows for industrial applications. This review aims to comprehensively assess the influence of operating parameters (including the type of current control, plating bath conditions, particle loading and size) on the deposit properties....
Synthesis of a nanostructured MgH2-Ti alloy composite for hydrogen storage via combined vacuum arc remelting and mechanical alloying
, Article Materials Letters ; Volume 65, Issue 7 , 2011 , Pages 1120-1122 ; 0167577X (ISSN) ; Kaflou, A ; Simchi, A ; Sharif University of Technology
Abstract
To improve the hydrogen kinetics of magnesium hydride, TiCr 1.2Fe0.6 alloy was prepared by vacuum arc remelting (VAR) and the alloy was co-milled with MgH2 to process nanostructured MgH2-5 at.% TiCr1.2Fe0.6 powder. The hydrogen desorption properties of the composite powder were studied and compared with pure magnesium hydride. X-ray diffraction (XRD) analysis showed that the composite powder prepared by VAR/mechanical alloying (MA) procedure consisted of β-MgH2, γ-MgH2, bcc Ti-Cr-Fe alloy, and small amount of MgO. The average size of particles and their grain structure after 4 h MA were determined by a laser particle size analyzer and XRD method and found to be 194 nm and 11 nm,...
Study of shape memory effect in NiMnGa Magnetic Shape Memory Alloy single crystals by incremental modeling
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010 ; Volume 1 , 2010 , Pages 441-446 ; 9780791849156 (ISBN) ; Naghdabadi, R ; Sohrabpour, S ; Sharif University of Technology
Abstract
Magnetic Shape Memory Alloys (MSMAs) are a category of active materials which can be excited by magnetic field. These alloys have been used in sensor and actuator applications recently. MSMAs possess special properties such as large magnetic field-induced strains (up to %10) and high actuation frequency (about 1kHz), while ordinary shape memory alloys can't act in frequencies above 5Hz due to the time involved with heat transformation. In this paper, MSMAs are modeled by an incremental modeling approach which utilizes different secant moduli for different parts of stress-strain curve. Furthermore, stress-strain curve of MSMAs is approximated using an analytical expression. The incremental...
Highly sensitive nonenzymetic glucose sensing platform based on MOF-derived NiCo LDH nanosheets/graphene nanoribbons composite
, Article Journal of Electroanalytical Chemistry ; Volume 808 , 2018 , Pages 114-123 ; 15726657 (ISSN) ; Shahrokhian, S ; Iraji Zad, A ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Herein, a novel sensing platform based on NiCo layered double hydroxide (LDH) nanosheets/graphene nanoribbons (GNRs) modified glassy carbon electrode is presented for sensitive non-enzymetic determination of glucose. In the first step, nanoflower-like NiCo LDH nanosheets were grown on the surface of ZIF-67 dodecahedron nanocrystals which used as sacrificial template and were further characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and FTIR. In the next step, in order to fabricate a mechanically stable modified electrode, the as-prepared nanosheets were mixed with...