Magnetic Hardening of Mechanichally Alloyed SmFe11−xCoxTi

1999 ◽  
Vol 581 ◽  
Author(s):  
L. Bessais ◽  
C. Djega-Mariadassou
Keyword(s):  
Heat Treatment ◽  
Rietveld Method ◽  
Hexagonal Phase ◽  
X Ray Diffraction ◽  
Major Phase ◽  
X Ray ◽  
Different Temperatures ◽  
Magnetic Hardening ◽  
Property Changes ◽  
Nanocrystalline Phases

ABSTRACTMechanical alloying of ternary SmFe11−xCoxTi (x = 0, 0.5, 1, 1.5, 2) alloys was carried out under an Ar atmosphere. Milled samples were annealed for 30 min in a vacuum at different temperatures Ta from 650 °C to 1150 °C. The effects of heat treatment, on structure and magnetic property changes, have been investigated by means of x-ray diffraction using the Rietveld method, Mössbauer spectroscopy and differential sample magnetometer. Tetragonal ThMn12-type structure is observed for samples annealed at Ta > 900 °C. For 650<Ta<800 °C the TbCu7 type phase was identified as the major phase. Between these two regions a mixture of TbCu7 and ThMn12-type nanocrystalline phases is obtained with a maximum of the coercive field Hc (Hc > 5kOe). The Mössbauer spectra relative to the hexagonal phase show sextuplets broadened by the statistical occupancies of the iron sites. An enhancement of the magnetic properties results from the Co substitution.

Nanostructured YSZ Thin Film for Application as Electrolyte in an Electrode Supported SOFC

2012 ◽  
Vol 727-728 ◽  
pp. 873-878
Author(s):  
Cibele Melo Halmenschlager ◽  
Matias de Angelis Korb ◽  
Roberto Neagu ◽  
Carlos Pérez Bergmann ◽  
Célia de Fraga Malfatti
Keyword(s):  
Thin Film ◽  
Heat Treatment ◽  
Treatment Process ◽  
Precursor Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Influence ◽  
Different Temperatures ◽  
Spray Pyrolysis Process ◽  
Fast Increase

The development of solid oxide fuel cell with thin film concepts for an electrode supported design based on the yttria-stabilized zirconia has demonstrated favourable results due to its high chemistry stability in oxidization and environment reduction. The spray pyrolysis process was investigated in order to obtain dense thin films of YSZ on different substrates. The precursor solution was obtained by zirconium and yttrium salt dissolutions in a mixture of water and glycerine in several ratios to study the solvent influence. The substrate was initially heated at 600 °C and during the deposition it ranged from 260-350°C, finishing at a fast increase in temperature of 600°C. The heat treatment was carried out in four different temperatures: 700 °C, 750 °C, 800 °C, and 900 °. The precursors were characterized by thermal analysis. The microstructures of the films were studied using scanning electron microscopy and X-ray diffraction. The results obtained showed that the films obtained were crystalline before the heat treatment process and have shown ionic conductivity above 800°C.

EFFECT OF NANOCRYSTALLIZATION ANNEALING ON MAGNETIC PROPERTIES AND MAGNETOIMPEDANCE OF CO-BASE RIBBONS

2012 ◽  
Vol 05 ◽  
pp. 841-846
Author(s):  
AMIR KEYVANARA ◽  
REZA GHOLAMIPOUR ◽  
SHAMSEDIN MIRDAMADI ◽  
FARZAD SHAHRI ◽  
HOSSEIN SEPEHRI AMIN
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Nanocrystalline Phases

Melt spun ribbons of Co 64 Fe 4 Ni 2 B 19 Si 8 Cr 3 alloy have been prepared and the nanocrystallization process was carried out by the heat treatment of the as spun ribbons above the crystallization temperature. Structural studies of the samples have been performed by transmission electron microscopy and X-ray diffraction. Magnetic properties of the samples and magnetoimpedance measurements were investigated and it was revealed that magnetic properties and magnetoimpedance of the samples deteriorate by the formation of nanocrystalline phases.

scholarly journals Influence of Different Heat Treatment Temperatures on the Microstructure, Corrosion, and Mechanical Properties Behavior of Fe-Based Amorphous/Nanocrystalline Coatings

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 858
Author(s):  
Shenglin Liu ◽  
Yongsheng Zhu ◽  
Xinyue Lai ◽  
Xueping Zheng ◽  
Runnan Jia ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Heat Treatment Temperature ◽  
Annealing Treatment ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Different Temperatures ◽  
Sprayed Coating

Fe-based amorphous/nanocrystalline coatings with smooth, compact interior structure and low porosity were fabricated via supersonic plasma spraying (SPS). The coatings showed outstanding corrosion resistance in a 3.5% NaCl solution at room temperature. In order to analyze the effect of annealing treatment on the microstructure, corrosion resistance and microhardness, the as-sprayed coating was annealed for 1 h under different temperatures such as 350, 450, 550 and 650 °C, respectively. The results showed that the number of oxides and cracks in the coatings presented an obvious increase with increasing annealing temperature, and the corrosion resistance of the coatings showed an obvious reduction. However, the microhardness of coatings showed an important increase. The microhardness of the coating could reach 1018 HV when the heat treatment temperature reached 650 °C. The X-ray diffraction (XRD) results showed that there appeared a number of crystalline phases in the coating when the heat treatment temperature was at 650 °C. The crystalline phases led to the increase of the microhardness.

Amorphous Calcium Phosphates (ACP): Formation and Stability

2005 ◽  
Vol 284-286 ◽  
pp. 7-10 ◽  
Author(s):  
Racquel Z. LeGeros ◽  
Dindo Q. Mijares ◽  
J. Park ◽  
X.-F. Chang ◽  
I. Khairoun ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Synergistic Effects ◽  
Calcium Phosphates ◽  
X Ray Diffraction ◽  
Solution Composition ◽  
X Ray ◽  
Dissolution Properties ◽  
Before And After ◽  
Different Temperatures

Our earlier studies showed that several ions inhibit the crystal growth of apatite and promote the formation of amorphous calcium phosphates (ACP). These ions include: magnesium (Mg), zinc (Zn), stannous (Sn), ferrous (Fe), carbonate (CO3), pyrophosphate (P2O7). The purpose of this study was to investigate the effect of combination of these ions (e.g., Mg & CO3, Mg & P2O7, Mg & Zn, etc) on the formation and stability of ACP. ACP compounds containing the different ions were prepared at 25 and 37oC according to the method we previously described. Chemical stability was investigated by suspending the different ACP preparations in solutions with or without inhibitory ions. Thermal stability was determined by sintering the ACP at different temperatures. Dissolution properties were determined in acidic buffer. The ACP before and after chemical or thermal treatment were analyzed using X-ray diffraction, infrared spectroscopy, and thermogravimetry. Results showed synergistic effects of inhibitory ions on the formation of ACP. ACP materials, regardless of their composition, remained amorphous even after heat treatment at 400oC. Transformation of ACP to other calcium phosphate phases depended on the pH and on the solution composition.

Hydroxyapatite Coating on Ti-6Al-4V Alloy by an Electrolytic Process and with Heat-Treatment

2009 ◽  
Vol 631-632 ◽  
pp. 407-412
Author(s):  
Cheng Li Wang ◽  
Wei Jen Shih ◽  
Szu Hao Wang ◽  
Kuo Ming Chang ◽  
Wang Long Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Scanning Electron Microscopy ◽  
Calcium Phosphate ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Major Phase ◽  
X Ray ◽  
Electrolytic Process ◽  
Scanning Electron

The effect of the heat-treatment on the calcium phosphate deposited on Ti-6Al-4V substrate by an electrolytic process has been investigated. The calcium phosphate were deposited in a 0.04M Ca(H2PO4)2･H2O (MCPM) solution on Ti-6Al-4V substrate at 60 °C, 10V and 80 Torr for 1h, and calcined at different temperature for 4h. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterized the deposited samples. The XRD pattern of as-deposited sample contain the phase of dicalcium phosphate (DCPD) and HAP. When calcined at 400 °C for 4 h, the DCPD phase is vanished and HAP becomes the major phase. The XRD pattern reveals that the intensity of HAP and Ca2P2O7 (CPP) decreases, but the β-TCP, CaO and rutile TiO2 also shows up.

XRD Analysis of Ferrite Ceramics with Different Heat Treatment

2019 ◽  
Vol 970 ◽  
pp. 314-319
Author(s):  
Anatoly P. Surzhikov ◽  
Sergei A. Ghyngazov ◽  
Vitaly A. Vlasov ◽  
Oldrich Stary ◽  
Alexey N. Sokolovskiy
Keyword(s):  
Heat Treatment ◽  
Rietveld Method ◽  
Structural Characteristics ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Qualitative And Quantitative ◽  
Diffraction Patterns

A comparative analysis of the structural characteristics of LiZnTi ferrites sintered at the temperature of 1280 and 1360 K was performed. The qualitative and quantitative X-ray diffraction (XRD) analysis of the samples, main phase structural analysis, and unit cell parameters were carried out using the non-standard method (Rietveld method). Diffraction patterns were recorded on an ARL X'TRA diffractometer in the CuKα1+α2 and CuKβ scanning modes.

Structural study of Yb1–xTbxMnO3manganites: site occupancy and coexistence of hexagonal and orthorhombic phases

2013 ◽  
Vol 46 (3) ◽  
pp. 644-648 ◽  
Author(s):  
Mónica Esperanza Bolívar Guarín ◽  
Alexandre de Melo Moreira ◽  
Nivaldo Lúcio Speziali
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Room Temperature ◽  
Unit Cell Volume ◽  
Rietveld Method ◽  
Hexagonal Phase ◽  
Site Occupancy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Compounds

Polycrystalline samples of mixed Yb1−xTbxMnO3(x= 0, 0.25, 0.50, 0.75 and 1) were prepared by a solid state reaction procedure. Detailed crystal structure studies were performed using X-ray diffraction data obtained at room temperature. The application of the Rietveld method confirmed the reported hexagonalP63cmand orthorhombicPnmaphases forx= 0 (YbMnO3) andx= 1 (TbMnO3), respectively. A single hexagonal phase was also observed forx= 0.25, while in the case ofx= 0.50 andx= 0.75 both phases coexist in the produced samples. Crystallographic parameters for the pure compounds are in agreement with those found in the literature. Changes in the lattice parameters, unit-cell volume, polyhedral distortions and tilting observed in the mixed compounds are explained as a function ofx. Sharing of Tb3+and Yb3+ions between different sites is discussed.

scholarly journals Investigation of Structural Formation of Starting Composition 2245 in the Bi-Pb-Sr-Ca-Cu-O System Superconductors

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Ashoka Nukkanahalli Venkataswamy ◽  
George Thomas Chirayil ◽  
Srinivasan Kannaiyan
Keyword(s):  
Heat Treatment ◽  
Volume Fraction ◽  
X Ray Diffraction ◽  
Structural Formation ◽  
Major Phase ◽  
X Ray ◽  
Superconducting Volume Fraction ◽  
Superconducting Compound ◽  
First Time

Structural formation of Bi1.65Pb0.35Sr2Ca4Cu5Oy (2245 phase) superconducting compound was investigated by preparing the sample in a new matrix route. The phases formed at different intervals of heat treatment are monitored by X-ray diffraction studies. Bi-2212 phase was found to be the predominant phase till 20 hours of sintering at 850°C after which Bi-2223 phase was found to be the major phase. Traces of Ca2PbO4 were also noticed along with 2212 and 2223 phases. For the first time, the highest TC onset of 127 K with maximum superconducting volume fraction was observed for the sample sintered at 850°C for 30 hours in this preparation. Further sintering is found to deteriorate the TC onset value of the sample. There was no signature of the formation of 2234 or 2245 phase in this synthesis.

scholarly journals X-ray Determination of Compressive Residual Stresses in Spring Steel Generated by High-Speed Water Quenching

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
High Speed ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
X Ray ◽  
Water Chamber ◽  
Hardened Case ◽  
Compressive Residual Stresses

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

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