Research on Preparation and Properties of Magnetic Abrasive by Conventional Solid-State Method

2009 ◽  
Vol 416 ◽  
pp. 553-557 ◽  
Author(s):  
Zeng Dian Zhao ◽  
Yu Hong Huang ◽  
Yu Gang Zhao ◽  
Xian Jin Yu

The silicon-coated iron powder was evenly mixed with corundum powder and high temperature binder. After tabletting and sintering, followed by crushing and screening, the magnetic abrasive with a certain size was obtained. Scanning electron microscope (SEM), Energy dispersive spectrometer (EDS) and X-ray diffraction (XRD) were respectively used to characterize the morphology, elemental composition and the crystalloid structures of magnetic abrasive. The ferromagnetic phase and abrasive phase were combined firmly. The magnetic abrasive prepared showed a good grinding ability, whose durable time was up to 24 min. Irregular particles was obtained by smashing the magnetic abrasive, mainly composed of Al2O3, Fe2O3, α-Fe, AlFeO3, (Al, Fe)7BO3(SiO4)3O3.

2019 ◽  
Vol 8 (3) ◽  
pp. 7313-7317

The solid solutions of (La0.7Ba0.3)(FexMn1-x )O3 where x = 0.1 - 0.5 ceramics were synthesized by conventional solid-state method. The structural analysis was done by X-Ray diffraction technique and the results have revealed that all the samples were crystallized into a single phase. The surface morphology was done by Scanning Electron Microscopy and the micrographs clearly indicate decreased grain size with the increasing Fe - concentration. The density of the prepared samples was done using Archimedes principle and the density values were found to be in decreasing order, which is well in agreement with the microstructure relationship. The dielectric and impedance properties have been studied at different ranges of frequency and temperature. The electrical conductivity values were found to be greater than 100 Scm-1 , which suggests it to suitable cathode material of SOFCs


2021 ◽  
Vol 1016 ◽  
pp. 379-384
Author(s):  
Eider Del Molino ◽  
Teresa Gutierrez ◽  
Mónica Serna-Ruiz ◽  
Maribel Arribas ◽  
Artem Arlazarov

The aim of this work was to study the influence of quenching and partitioning temperatures combined with various levels of Mn and Ni contents on the austenite stabilization along the quenching and partitioning (Q&P) cycle. Three steels with 2 wt.%, 4 wt.% and 6 wt.% manganese and one steel with 2 wt.% nickel content were investigated. Phase transformation temperatures and critical cooling rates were obtained experimentally using dilatometer for each alloy. Q&P cycles with different quenching and partitioning temperatures were also done in dilatometer, thus, allowing monitoring of the expansion/contraction during the whole Q&P cycle. Microstructure characterization was performed by means of a Scanning Electron Microscope and X-Ray Diffraction to measure retained austenite content. It was found that, strongly depending on the Q&P conditions, austenite stabilization or decomposition occurs during partitioning and final cooling. In case of high partitioning temperature cycles, austenite reverse transformation was observed. Certain cycles resulted in a very effective austenite stabilization and interesting microstructure.


2019 ◽  
Vol 27 (06) ◽  
pp. 1950155
Author(s):  
KWANG-HU JUNG ◽  
SEONG-JONG KIM

The corrosion characteristics of Inconel 600 were investigated at 650∘C in air and 76%[Formula: see text]%[Formula: see text]%[Formula: see text]%SO2 gas environment up to 500[Formula: see text]h. Specimens exposed to each condition were characterized by weight gain, scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction. The oxide structure consisting of the thin Cr2O3 layer and Cr2O3 nodules was observed, which increased the weight gain of specimens. In the SO2-bearing gas, it showed a bigger weight gain due to the coarsening of Cr2O3 nodules. Therefore, it was suggested that the sulfur-accelerated coarsening of Cr2O3 nodules at the high temperature.


2013 ◽  
Vol 748 ◽  
pp. 46-50 ◽  
Author(s):  
Saowanee Singsarothai ◽  
Sutham Niyomwas

Fe-W based composite have successfully been prepared using natural resource. The ferberite (Fe (Mn, Sn)WO4) tailings mixed with aluminum, carbon and boron oxide powder were used as reactants. The reactants were pressed and followed by oxy-acetylene flame ignition. The products from the self-propagating high-temperature synthesis (SHS) reaction were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) couple with dispersive X-ray (EDS).


2012 ◽  
Vol 562-564 ◽  
pp. 494-497
Author(s):  
Xiao Ming Fu

Flower-like β-Ni(OH)2 and nanoflakes have been successfully synthesized with nickel nitrate as nickel source and stronger ammonia water as precipitant via the hydrothermal method. The phase and the morphologies of the samples have been characterized and analyzed by XRD (X-ray diffraction) and SEM (Scanning electron microscope), respectively. XRD shows that the phase of the samples is β-Ni(OH)2. SEM confirms that The low reaction temperature is propitious to the synthesis of flower-like β-Ni(OH)2, and with the increase of the reaction time the nanoflakes of flower-like β-Ni(OH)2 become much thinner. However, The high temperature is in favor of the synthesis of β-Ni(OH)2 nanosflakes, and with the further increase of the reaction temperature.


2010 ◽  
Vol 135 ◽  
pp. 382-387
Author(s):  
Zeng Dian Zhao ◽  
Yu Hong Huang ◽  
Yu Gang Zhao

In this paper, ferrosilicon powder was used as the ferromagnetic phase, corundum powder as the abrasive phase, high temperature inorganic binder as the adhesive, and after the ferrosilicon powder was modified, a series of magnetic abrasive was obtained by sintering method. Scanning electron microscope (SEM) and Energy dispersive spectrometer (EDS) were respectively used to characterize the morphology and elemental composition of magnetic abrasive. and through experiments carried out on the magnetic abrasive grinding performance testing and durability analysis. The experimental results showed that the magnetic abrasive prepared had good polishing ability and longer using time, and the surface roughness of the grinding sample can reach 0.12μm and the using time is up to 25 min.


2016 ◽  
Vol 697 ◽  
pp. 526-529 ◽  
Author(s):  
Shi Xun Zhang ◽  
Jian Li ◽  
Yao Ma ◽  
Hai Long Wang ◽  
Rui Zhang

SiC-Al3BC3-cBN composites with different contents of cBN were fabricated by high pressure and high temperature sintering (HPHT) at 1450 °C for 3 min under a pressure of 5.0 GPa using SiC, Al, B4C and C as additives. The effect of SiC content on the density and mechanical properties of SiC-Al3BC3-cBN composites was investigated. X-ray diffraction (XRD) and Scanning electron microscope (SEM) were used to analyze phases and micro-structure of the sintered samples. The hardness of SiC-Al3BC3-cBN composites decreased with the increasing of SiC content, However, the fracture strength of SiC-Al3BC3-cBN composites increased with the increasing of SiC content.


2008 ◽  
Vol 368-372 ◽  
pp. 5-7
Author(s):  
J.A. Garcia ◽  
M.U. Herrera

Synthesis of Zn-doped PbTiO3 was done using solid-state method. The effects of varying amount of Zn were investigated. Stoichiometric amount of precursors were mixed and ground. The pressed mixtures were calcined at 800°C and sintered at 1,100 °C after regrinding. The samples were characterized using X-ray Diffraction (XRD), Differential Thermal Analysis (DTA), and Scanning Electron Microscopy (SEM). The XRD verifies the existence of PTO in the samples. DTA shows the thermal profile of the samples. Among the different concentrations of Zn that were added, the sample with 5% mole fraction showed the lowest melting point. For 5% mole fraction and greater, SEM images showed flattening and fusing of grains.


2015 ◽  
Vol 1107 ◽  
pp. 727-732
Author(s):  
Muhamad Izhar Sahri ◽  
Norinsan Kamil Othman ◽  
Abdul Razak Daud ◽  
Azman Jalar

The behavior of Fe-12Cr-2Mo stainless steel exposed isothermally in tube furnace at 700°C for 10 h had been studied in different environments; of mixed environment (Ar-20%O2 with coated Na2SO4-50%NaCl salts), molten salt (Na2SO4-50%NaCl) and dry oxygen (Ar-20%O2) atmospheres. The exposed samples were characterized by using optical microscopy (OM), scanning electron microscope (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD). The results indicated that, sample exposed in mixed environments undergoes highest corrosion rate compared with other samples. The main phase exists in all samples generally were iron-rich oxides which non-protective and thick. Conversely, EDX analysis on cross-sectional samples revealed the Cr-enrichment developed underneath the iron-rich oxide scales as the chromium concentration increases towards near the substrate. In presence of salt mixture, the oxide scales undergo spallation, however there is no crack observed. The catastrophic corrosion sample was occurred in combined environment due to the oxidation induced by the chloridation and sulfidation phenomena as well.


Author(s):  
Patricia Stoffyn ◽  
Dale E. Buckley

The “Titanic 91” Expedition, carried out from the Russian Academy of Science vessel “Akademik Keldysh”, recovered artifacts from the wreck of the Titanic using the manned submersible “MIR-2”. Conspicuous corrosion products are iron rusticles resembling stalactites. These rusticles can reach lengths of several tens of cm and grow from various parts of the ship (Fig. 1). The origin of the rusticles and their relation to other corrosion products was investigated using a scanning electron microscope equipped with an x-ray energy dispersive spectrometer and a separate x-ray diffraction system.Rusticles are formed of a brittle iron oxy-hydroxide shell approximately 100 to 200 μm thick, with a smooth dark red outer surface (toward seawater) and an orange rough inner surface (toward the centre of the rusticle). The core of the rusticle and the inner surface of the shell is made of a reticular framework of spherical aggregates. The small needle-like crystals forming these aggregates (Fig. 2) are goethite (α- FeO(OH)).


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