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stainless-steel
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Laser welding of NiTi shape memory alloy: Comparison of the similar and dissimilar joints to AISI 304 stainless steel [electronic resource]
, Article Optics and Laser Technology ; Volume 54, 2013, Pages 151–158 ; Saatchi, A ; Kermanpur, A ; Sadrnezhaad, K ; Sharif Univercity of Technology
Abstract
The unique properties of NiTi alloy, such as its shape memory effect, super-elasticity and biocompatibility, make it ideal material for various applications such as aerospace, micro-electronics and medical device. In order to meet the requirement of increasing applications, great attention has been given to joining of this material to itself and to other materials during past few years. Laser welding has been known as a suitable joining technique for NiTi shape memory alloy. Hence, in this work, a comparative study on laser welding of NiTi wire to itself and to AISI 304 austenitic stainless steel wire has been made. Microstructures, mechanical properties and fracture morphologies of the...
Cosintering of powder injection molding parts made from ultrafine WC-Co and 316L stainless steel powders for fabrication of novel composite structures
, Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 41, Issue 1, January 2010, Pages 233-241 ; Petzoldt, F ; Sharif University of Technology
Abstract
Abstract Sintering response and phase formation during sintering of WC-Co/316L stainless steel composites produced by assembling of powder injection molding (PIM) parts were studied. It is shown that during cosintering a significant mismatch strain (> 4 pct) is developed in the temperature range of 1080° C to 1350° C. This mismatch strain induces biaxial stresses at the interface, leading to interface delamination. Experimental results revealed that sintering at a heating rate of 20 K/min could be used to decrease the
Application of sol-gel technique to synthesis of copper-cobalt spinel on the ferritic stainless steel used for solid oxide fuel cell interconnects
, Article Journal of Power Sources ; Vol. 266, issue , 2014 , pp. 79-87 ; ISSN: 03787753 ; Askari, M ; Ghorbanzadeh, M ; Sharif University of Technology
Abstract
The conductive CuCo2O4 spinel coating is applied on the surface of the AISI 430 ferritic stainless steel by the dip-coating sol-gel process and it is evaluated in terms of the microstructure, oxidation resistance and electrical conductivity. The results show that the CuCO2O 4 coating forms a double-layer scale consisting of a Cr, Fe-rich subscale and Cu-Co spinel top layer after 500 h in air at 800 °C. This scale is protective, acts as an effective barrier against Cr migration into the outer oxide layer and alleviates the cathode Cr-poisoning. The oxidation resistance is significantly enhanced by the protective coating with a parabolic rate constant of 5.8 × 10-13 gr2 cm-4 s -1, meanwhile...
Study on microstructure and mechanical characteristics of low-carbon steel and ferritic stainless steel joints
, Article Materials Science and Engineering A ; Vol. 608, issue , 2014 , pp. 35-45 ; ISSN: 09215093 ; Mostafaei, M. A ; Pouraliakbar, H ; Kokabi, A. H ; Sharif University of Technology
Abstract
In this work, examinations on the microstructure and mechanical properties of plain carbon steel and AISI 430 ferritic stainless steel dissimilar welds are carried out. Welding is conducted in both autogenous and using ER309L austenitic filler rod conditions through gas tungsten arc welding process. The results indicate that fully-ferritic and duplex ferritic-martensitic microstructures are formed for autogenous and filler-added welds, respectively. Carbide precipitation and formation of martensite at ferrite grain boundaries (intergranular martensite) as well as grain growth occur in the heat affected zone (HAZ) of AISI 430 steel. It is found that weld heat input can strongly affect grain...
Effects of electrophoretic deposition parameters on the photocatalytic activity of TiO2 films: Optimization by response surface methodology
, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Vol. 452, Issue. 1 , 2014 , pp. 1-8 ; ISSN: 09277757 ; Vossoughi, M ; Feilizadeh, M ; Rashtchian, D ; Moradi, S ; Alemzadeh, I ; Sharif University of Technology
Abstract
In this work, the electrophoretic deposition method was utilized to immobilize TiO2 particles on stainless steel substrates. In addition, for the first time, statistics-based experimental design using response surface methodology was employed to investigate the effect of four key coating parameters (i.e. applied voltage, calcination temperature, photocatalyst weight percentage, and deposition time) on the photocatalytic degradation. Analysis of variance revealed that the proposed model was adequate. X-ray diffraction and scanning electron microscope were used to evaluate the effects of the parameters on degradation efficiency. The optimum applied voltage, calcination temperature, catalyst...
A study on natural aging behavior and mechanical properties of friction stir-welded AA6061-T6 plates
, Article International Journal of Advanced Manufacturing Technology ; Vol. 71, issue. 5-8 , 2014 , pp. 933-941 ; ISSN: 02683768 ; Serajzadeh, S ; Sharif University of Technology
Abstract
Mechanical properties, microstructural events, residual stresses, and aging behavior of friction stir-welded AA6061-T6 were investigated in this work. Microstructural and mechanical characterizations of the friction stir-welded joints in as-welded and post-welded conditions were made by means of optical metallography, transmission electron microscopy, X-ray diffraction for determination of residual stresses, tensile testing, and hardness measurements. It was found that weld strength and hardness variations after welding are mainly dependent on the imposed heat input per unit length. Besides, the kinetics of natural aging in the welded samples was found to be noticeable within the first 14...
Preparation, characterization, and applications of a novel solid-phase microextraction fiber by sol-gel technology on the surface of stainless steel wire for determination of poly cyclic aromatic hydrocarbons in aquatic environmental samples
, Article Analytica Chimica Acta ; Vol. 813 , 2014 , pp. 48-55 ; ISSN: 00032670 ; Hosseininasab, V ; Bagheri, H ; Sharif University of Technology
Abstract
A novel solid-phase microextraction(SPME) fiber was prepared using sol-gel technology with ethoxylated nonylphenol as a fiber coating material. The fiber was employed to develop a headspace SPME-GC-MS method suitable for quantification of 13 polycyclic aromatic hydrocarbons (PAHs) in water samples. Surface characteristics of the fibers were inspected by energy dispersive X-ray (EDX) spectroscopy as well as by scanning electron microscopy (SEM). The SEM measurements showed the presence of highly porous nano-sized particles in the coating. Important parameters affecting the extraction efficiency such as extraction temperature and time, desorption conditions as well as ionic strength have been...
Test methodology and wear characteristics of austenitic stainless steel aisi type 316 at cryogenic environment
, Article Lecture Notes in Engineering and Computer Science ; Vol. 2 , 2-4 July , 2014 , pp. 1214-1217 ; ISSN: 20780958 ; ISBN: 9789881925350 ; Kazerani, V ; Ghorashi, M. S ; Sharif University of Technology
Abstract
Components in cryogenic milieu with relative motion, like seals and pumps cannot be lubricated by using oils or other lubricants. Therefore materials wear in cryogenic condition is a great concern. To earn valid data about the wear properties of common and super useful material in cryogenic tribosystems, reconstruction wear test apparatus at cryogenic temperature is needed. Investigations on metal-metal couple show that austenitic stainless steels have favorable and auspicious sliding properties at cryogenic temperature. This research provides the wear parameters of austenitic stainless steel AISI type 316 in cryogenic environment. For this purpose two sets of test environment are prepared,...
Synthesis and electrochemical characterization of sol-gel-derived RuO 2/carbon nanotube composites
, Article Journal of Solid State Electrochemistry ; Vol. 18, Issue 4 , April , 2014 , pp. 993-1003 ; Online ISSN: 1433-0768 ; Asnavandi, M ; Dolati, A ; Sharif University of Technology
Abstract
Ruthenium oxide was coated on multiwalled carbon nanotubes (MWCNTs) to obtain nanocomposite electrode which has a good response to the pH. To synthesize this electrode, gold and cobalt were coated on a stainless steel 304 substrates, respectively, and then, vertically aligned carbon nanotubes were grown on the prepared substrates by chemical vapor deposition. Gold reduced activity of the stainless steel, while cobalt served as a catalyst for growth of the carbon nanotube. Ruthenium oxide was then coated on MWCNTs via sol-gel method. At last, different techniques were used to characterize the properties of synthesized electrode including scanning electron microscopy (SEM), transmission...
On-line micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofibers
, Article Chromatographia ; Vol. 77, issue. 9-10 , May , 2014 , p. 723-728 ; Asgari, S ; Piri-Moghadam, H ; Sharif University of Technology
Abstract
An on-line extraction/determination set up was designed for micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofiber mats. The prepared mats were packed in a stainless steel tube which conveniently acted as a high-performance liquid chromatography injection loop. Influential parameters affecting the extraction efficiency were optimized using a distilled water sample fortified with 25 μg L-1 of clodinafop propargyl. An enrichment factor of 440 was achieved for clodinafop propargyl indicating the ability of the whole procedure. Under the optimum conditions, the linearity for the analyte was in the range of 6-700 μg L-1, while...
Designing of CK45 carbon steel and aisi 304 stainless steel dissimilar welds
, Article Materials Research ; Vol. 17, issue. 1 , Oct , 2014 , p. 106-114 ; 15161439 ; Hamedi, M ; Kokabi, A. H ; Nazari, A ; Sharif University of Technology
Abstract
Gas tungsten arc welding of CK45 and AISI304 stainless steel was performed through preparation of different types of samples using ER308L and ERNi-1 wires. Welded samples were studied by different techniques including optical metallography, scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction, hardness measurements and impact test. It was observed that in the buttered specimen, the structure of the weld metal was completely austenitic while the microstructure of unbuttered sample was duplex ferritic-austenitic. M23C6-type carbides were observed within the weld metal of both as-weld specimen types. Effects of different post-weld heat...
Double layer bioglass-silica coatings on 316L stainless steel by sol-gel method
, Article Ceramics International ; Volume 40, Issue 1, Part A , January 2014 , Pages 993–1000 ; Afshar, A ; Sharif University of Technology
Abstract
The application of bioglass coatings on metallic implants provides link between bone and materials and prevents corrosion of metallic implants in body fluid. Therefore, in this research, 45S5 bioglass-silica coatings on 316L stainless steel were prepared by the sol-gel method and were characterized by different techniques. According to X-ray diffraction (XRD) results, by sintering 45S5 bioglass at 600 C for 5 h, coatings containing both amorphous phase and Na2Ca2Si3O9 crystalline phase were obtained. Scanning electron microscopy (SEM) results showed that coatings prepared via appropriate sol aging and substrate preparations are crack-free. Potentiodynamic polarization tests in simulated body...
Diffusion brazing of cast INCONEL 718 superalloy utilising standard heat treatment cycle
, Article Materials Science and Technology (United Kingdom) ; Vol. 30, issue. 1 , January , 2014 , p. 109-115 ; Ekrami, A ; Kokabi, A. H ; Sharif University Of Technology
Abstract
The time required to ensure completion of the isothermal solidification process is the key in obtaining an intermetallic free and robust joint after diffusion brazing. In view of economic considerations, it is interesting to perform bonding process trials using standard heat treatment cycles. This paper addresses the effect of applying the standard heat treatment cycle including homogenisation, solution and double aging treatments on the microstructural and mechanical response of diffusion brazed IN718. A commercial Ni-7Cr-4·5Si- 3?2B-3Fe (wt-%) brazing alloy was used as the interlayer. Results showed that bonds made with the standard homogenisation treatment, at 1100°C, exhibited a eutectic...
Titania nanostructured coating for corrosion mitigation of stainless steel
, Article Protection of Metals and Physical Chemistry of Surfaces ; Vol. 50, issue. 3 , 2014 , p. 371-377 ; Sani, M. A. F ; Sadeghian, Z ; Ghasemi, H ; Sharif University of Technology
Abstract
Anatase nanostructured coating has been prepared on 316 L stainless steel by sol-gel dip coating. The topography of the coatings surface has been analyzed using atomic force microscopy. The anticorrosion performance of the coatings has been evaluated using polarization curves. Effects of calcination temperature, withdrawal speed and times of coating on corrosion protection have been studied. The results showed calcination temperature of 400°C and withdrawal speed of 10 cm/min are desirable conditions to achieve high corrosion protection of 316 L stainless steel in chloride containing environments. Coatings with 3 times exhibit better resistance against corrosion in 0.5 molar NaCl solutions....
Grafting the sol-gel based sorbents by diazonium salts: A novel approach toward unbreakable capillary microextraction
, Article Journal of Chromatography A ; Volume 1318 , November , 2013 , Pages 58-64 ; 00219673 (ISSN) ; Bayat, P ; Piri Moghadam, H ; Sharif University of Technology
2013
Abstract
The present work deals with a novel approach for grafting a sol-gel based sorbent, using diazonium salts for preparation of an unbreakable capillary microextraction (CME) device in on-line combination with high performance liquid chromatography (HPLC). The use of diazonium salts modifier allowed all types of metallic and non-metallic substrates to be used without any limitation. Substrates including copper, brass, stainless steel and polytetrafluoroethylene (PTFE) were chosen to be functionalized by chemical or electrochemical reduction of 4-amino phenyl acetic acid. Then, 3-(trimethoxysilyl)propylamine (3TMSPA) was selected as the precursor and the only reagent for preparation of the...
The effect of gas mixture of post-oxidation on structure and corrosion behavior of plasma nitrided AISI 316 stainless steel
, Article Applied Surface Science ; Volume 283 , 2013 , Pages 584-589 ; 01694332 (ISSN) ; Moghaddam, E. G ; Mirjani, M ; Raeissi, K ; Sharif University of Technology
2013
Abstract
In this research, microstructure and corrosion properties of plasma nitriding and post-oxidation treated AISI 316 austenitic stainless steel have been studied. The plasma nitriding treatment was carried out at 450 C for 5 h in a D.C. plasma setup with a gas mixture of 25% N2-75% H2 followed by post-oxidation in gas mixtures of O2/H2: 1/3, 1/5, 1/9 and 1/12 for 30 min. The treated samples were characterized by SEM, XRD and roughness testing. Potentiodynamic and cyclic polarization tests were also employed to evaluate the corrosion resistance of the samples. The results showed that plasma nitriding treatment decreases corrosion resistance of the steel substrate. However, post-oxidizing...
Fe doped Ni-Co spinel protective coating on ferritic stainless steel for SOFC interconnect application
, Article International Journal of Hydrogen Energy ; Volume 38, Issue 27 , 2013 , Pages 12007-12014 ; 03603199 (ISSN) ; Faghihi Sani, M. A ; Sharif University of Technology
2013
Abstract
In an attempt to reduce the oxidation and Cr evaporation rates, various protective coating layers with a nominal composition of NiCo 2-xFexO4 (x = 0, 0.5, 1) were deposited on the SUS 430 ferritic stainless steel substrate, as interconnect for solid oxide fuel cell application, by sol-gel dip coating method. Then, the coated samples were soaked at 750 C for 2.5 h in N2 and subsequently for 2.5 h in air. Phase composition and microstructure of the coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Moreover, long-term isothermal oxidation experiment and area specific resistance (ASR) measurement were also carried out on the coated samples. Results...
In vitro characterization of carbon-nanotube-reinforced hydroxyapatite composite coating on 316L stainless steel
, Article Journal of Ceramic Science and Technology ; Volume 4, Issue 3 , August , 2013 , Pages 163-168 ; 21909385 (ISSN) ; Nemati, A ; Sadeghian, Z ; Sharif University of Technology
2013
Abstract
This investigation focused on a comparison between hydroxyapatite (HA) and carbon-nanotube-reinforced hydroxyapatite composite (CNTs/HA) coatings. The HA and CNTs/HA composite (with 5wt% CNTs) coatings were prepared with the sol-gel method on 316L stainless steel. Phase evaluation by means of XRD and Raman spectroscopy was performed on the HA and CNTs/HA composite coatings. The coatings were immersed in simulated body fluid (SBF) in order to evaluate the biological properties of the coatings. During the first week of immersion, the increase in the amount of Ca2+ precipitation in the SBF when CNTs/HA was used was lower than for the HA coatings. This behavior can be related to the difference...
Effect of Sr and Ca dopants on oxidation and electrical properties of lanthanum chromite-coated AISI 430 stainless steel for solid oxide fuel cell interconnect application
, Article Ceramics International ; Volume 39, Issue 7 , September , 2013 , Pages 8123-8131 ; 02728842 (ISSN) ; Sani, M. A. F ; Dayaghi, A. M ; Sharif University of Technology
2013
Abstract
Lanthanum chromite coating occupies a noticeable position as a ceramic coating on metallic interconnects in solid oxide fuel cells because of its excellent electrical conductivity, high oxidation resistance and desirable chemical stability in both oxidizing and reducing atmospheres. In the present work, a sol-gel process based on the dip-coating technique was used to prepare dense and uniform coatings on metallic alloy for interconnect application (AISI 430 type). The effect of strontium and calcium doping into lanthanum chromite structure on electrical conductivity and oxidation behavior of the coated sample has been investigated. The oxidation behavior was evaluated by cyclic oxidation...
High-throughput micro-solid phase extraction on 96-well plate using dodecyl methacrylate-ethylen glycol dimethacrylate monolithic copolymer
, Article Analytica Chimica Acta ; Volume 792 , August , 2013 , Pages 59-65 ; 00032670 (ISSN) ; Es'haghi, A ; Es-haghi, A ; Mohammadkhani, E ; Sharif University of Technology
2013
Abstract
A novel high-throughput device based on 96-micro-solid phase extraction (96-μ-SPE) system was constructed for multiresidue determination of nine pesticides in aquatic samples. The extraction procedure was performed on a commercially available 96-well plate system. The extraction module consisted of 96 pieces of 1cm×3cm of cylindrically shaped stainless steel meshes. The prepared meshes were fixed in a home-made polytetrafluoroethylene-based constructed ninety-six holes block for possible simultaneous immersion of meshes into the center of individual wells. Dodecyl methacrylate and ethylene glycol dimethacrylate was copolymerized as a monolithic polymer and placed in the cylindrically shaped...