Structure and Magnetic Properties of Spark Plasma Sintered NdFeB

2015 ◽  
Vol 1112 ◽  
pp. 27-31
Author(s):  
Toto Sudiro ◽  
Didik Aryanto ◽  
Nenen Rusnaeni Djauhari ◽  
Citra Wara Br Sinuraya ◽  
Syahrul Humaidi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Carbon Paper ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Product ◽  
Plasma Sintering ◽  
Different Temperatures ◽  
Spark Plasma ◽  
Effects Of Temperature ◽  
Diffraction Patterns

A spark plasma sintering technique was used to consolidate NdFeB compacts at four different temperatures as 750°C, 850°C, 950°C and 1030°C. The surface of specimens was polished to remove the carbon paper on the surface of NdFeB compacts by using SiC paper for up to #1500 in grit. The polished NdFeB compacts were then magnetized by using impulse magnetizer K-series. In this study, the effects of temperature on the structure and magnetic properties of NdFeB magnet were studied. The results show that depending on the fabrication temperature, the X-ray diffraction patterns of NdFeB compacts are distinct. This suggests that the structure of NdFeB compacts is changed with increase in fabrication temperature. Meanwhile, the remanance Br and energy product BH(max) of NdFeB magnets tend to decrease as fabrication temperature increase.

Densification of Zirconia–Hydroxyapatite Ceramics Without Phase Changes

2006 ◽  
Vol 309-311 ◽  
pp. 1141-1144 ◽  
Author(s):  
Erik Adolfsson ◽  
Z. Shen
Keyword(s):  
Hot Isostatic Pressing ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
Structural Water ◽  
X Ray ◽  
Plasma Sintering ◽  
Hydroxyapatite Ceramics ◽  
Different Temperatures ◽  
Spark Plasma ◽  
Diffraction Patterns

Zirconia-hydroxyapatite (40-60 vol%) composites were sintered at different temperatures in air. The x-ray diffraction patterns of the sintered composites showed that hydroxyapatite began to decompose to tricalcium phosphate even below 950°C. The decomposition of hydroxyapatite also involved release of structural water, which was studied using thermogravimetric analysis. By reducing the loss of structural water from the hydroxyapatite, the phase stability of the hydroxyapatite could be increased. This allowed higher temperatures to be used during the densification process where dense composites without any detectable reactions where produced by hot isostatic pressing at 1200°C as well as with spark plasma sintering at 1100°C.

Effect of the Dwell Temperature on Spark Plasma Sintered CaCu3Ti4O12

2012 ◽  
Vol 727-728 ◽  
pp. 982-987
Author(s):  
E. de Carvalho ◽  
Marcelo Bertolete ◽  
Izabel Fernanda Machado ◽  
E.N.S. Muccillo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lattice Parameter ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Scanning Electron

Polycrystalline CaCu3Ti4O12 ceramics were prepared by solid state reactions by spark plasma sintering (SPS) technique. In this study, the effects of the dwell temperature on structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. Powder mixtures were calcined at 900°C for 18 h before SPS consolidation. The dwell temperatures were 850, 900, 915 and 930°C. Sintered pellets were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. X-ray diffraction patterns show evidences of a single-phase perovskite-type structure. The calculated lattice parameter is 7.40 Å. The hydrostatic density increases slightly with increasing dwell temperature. Scanning electron microscopy observations revealed a heterogeneous microstructure for all samples. The dielectric loss remains constant over a wide temperature range. The obtained permittivity is approximately 103 at 1 kHz. The increase of the dwell temperature is found to produce a brittle ceramic.

Structural and magnetic variations in Ba0.5Sr0.5Fe9Ce1Al2O19 hexaferrites at different sintering temperatures

2021 ◽  
Author(s):  
A.R. Makhdoom ◽  
Qasim Ali Ranjha ◽  
Ubaid-ur-Rehman Ghori ◽  
Muhammad Ahsan Raza ◽  
Binish Raza ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Recording Media ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
X Ray ◽  
Pure Phase ◽  
Different Temperatures ◽  
Diffraction Patterns ◽  
Increasing Temperature

Abstract M-type hexaferrites has attracted researchers due to their ordinary magnetic properties and utilization as media for magnetic recording and microwave devices. In this study we have synthesized Ba0.5Sr0.5Fe9Ce1Al2O19 via conventional ceramic route. The synthesized material is treated against different temperatures and investigated structurally and magnetically by using several techniques such as X-ray diffraction, Scanning electron microscopy, and VSM respectively. Morphology of samples confirms the absence of secondary phases and uniform distribution of particles. X-ray diffraction patterns confirms the formation of pure phase of Hexaferrites. Microstructural analyses show the decrease in porosity and dislocations among sintered samples. Magnetic properties for the samples show a decrease in Ms and Mr with increasing temperature from 1225 °C to 1310 °C, while coercivity shows an increase with increasing temperature and maximum coercivity is observed at 1290 °C. The trends and occurrences can be well-linked to the structural variations and sintering effects. The results suggest that material can be used in various magnetic applications such as Recording media, and memory devices.

scholarly journals Properties of TiC and TiN Reinforced Alumina–Zirconia Composites Sintered with Spark Plasma Technique

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1220 ◽  
Author(s):  
Magdalena Szutkowska ◽  
Sławomir Cygan ◽  
Marcin Podsiadło ◽  
Jolanta Laszkiewicz-Łukasik ◽  
Jolanta Cyboroń ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Plasma Sintering ◽  
Different Temperatures ◽  
Spark Plasma ◽  
New Type ◽  
Diffraction Patterns

In this paper, Al2O3–ZrO2 composites with an addition of 20 wt% TiN and 10 wt% TiC were modified. The addition of zirconia in a range from 2 to 5 wt% of the monoclinic phase and 10 wt% of Y2O3 stabilised ZrO2 affected the mechanical properties of the composites. A new type of sintering technique—the spark plasma sintering (SPS) method—within a temperature range from 1575 °C to 1675 °C, was used. Vickers hardness, apparent density, wear resistance and indentation fracture toughness KIC(HV) were evaluated at room temperature. An increase of the sintering temperature resulted in an improvement of Vickers hardness and an increase of the fracture toughness of the tested composites. The tribological properties of the samples were tested using the ball-on-disc method. The friction coefficient was in a range from 0.31 to 0.55, depending on the sintering temperature. An enhancement of the specific wear rate was dependent on the sintering temperature. The mechanical properties of the samples sintered by pressureless sintering (PS) were compared. X-ray diffraction patterns were presented in order to determine the phase composition. SEM microstructure of the tested composites sintered at different temperatures was observed.

Thermal Conductivities of β-SiAlONs by Mechanically Activated Combustion Synthesis

2008 ◽  
Vol 403 ◽  
pp. 139-140 ◽  
Author(s):  
R. Sivakumar ◽  
K. Aoyagi ◽  
T. Watanabe ◽  
T. Akiyama
Keyword(s):  
Thermal Conductivity ◽  
Combustion Synthesis ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Thermal Conductivities

–sialons (Si6-zAlzOzN8-z, z=3) synthesized by mechanically activated combustion synthesis (MA-CS) at a low N2 pressure of 1 MPa, were sintered by Spark Plasma Sintering (SPS) and thermal conductivity was measured at room temperatures. Specimens were fully densified at 1600oC for 10 mins. and showed only –sialon phases confirmed by x-ray diffraction patterns though un-reacted Si was present as impurities after MA-CS. Thermal conductivities increased with sintering temperature and had a maximum value 5.49 W m-1 K-1 for specimens sintered at 1700oC.

scholarly journals Microstructure and properties of nano-laminated Y3Si2C2 ceramics fabricated via in situ reaction by spark plasma sintering

2021 ◽  
Vol 10 (3) ◽  
pp. 578-586
Author(s):  
Lin-Kun Shi ◽  
Xiaobing Zhou ◽  
Jian-Qing Dai ◽  
Ke Chen ◽  
Zhengren Huang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Atomic Scale ◽  
Max Phase ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns

AbstractA nano-laminated Y3Si2C2 ceramic material was successfully synthesized via an in situ reaction between YH2 and SiC using spark plasma sintering technology. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping were observed at the tip of the Vickers indents. The elastic modulus and Vickers hardness of Y3Si2C2 ceramics (with 5.5 wt% Y2O3) sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W·m-1·K-1 and 6.3×105 S·m-1, respectively.

Development of WC-Fe3Al Composites by Spark Plasma Sintering Process

2016 ◽  
Vol 881 ◽  
pp. 307-312
Author(s):  
Luis Antonio C. Ybarra ◽  
Afonso Chimanski ◽  
Sergio Gama ◽  
Ricardo A.G. da Silva ◽  
Izabel Fernanda Machado ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Zinc Stearate ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Al Composite ◽  
Spark Plasma ◽  
Short Time ◽  
Vibration Mill

Tungsten carbide (WC) based composites are usually produced with cobalt, but this binder has the inconvenience of shortage, unstable price and potential carcinogenicity. The objective of this study was to develop WC composite with intermetallic Fe3Al matrix. Powders of WC, iron and aluminum, with composition WC-10 wt% Fe3Al, and 0.5 wt% zinc stearate were milled in a vibration mill for 6 h and sintered in a SPS (spark plasma sintering) furnace at 1150 °C for 8 min under pressure of 30 MPa. Measured density and microstructure analysis showed that the composite had significant densification during the (low-temperature, short time) sintering, and X-ray diffraction analysis showed the formation of intermetallic Fe3Al. Analysis by Vickers indentation resulted in hardness of 11.2 GPa and fracture toughness of 24.6 MPa.m1/2, showing the feasibility of producing dense WC-Fe3Al composite with high mechanical properties using the SPS technique.

Microstructure and Magnetic Properties of Hot-Pressed and Hot-Deformed Composite Magnets Produced by Spark Plasma Sintering Method

2011 ◽  
Vol 686 ◽  
pp. 740-744 ◽  
Author(s):  
Yi Long Ma ◽  
Deng Ming Chen ◽  
Qian Shen ◽  
Peng Jun Cao
Keyword(s):  
Magnetic Properties ◽  
Spark Plasma Sintering ◽  
Hot Pressing ◽  
Magnetic Energy ◽  
Pressing Temperature ◽  
Energy Product ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Energy Products ◽  
Fe Addition

Bulk isotropic and anisotropic Nd13.5Fe80.4Ga0.5B5.6 and Nd13.5Fe80.4Ga0.5B5.6/Fe magnets were synthesized by applying spark plasma sintering (SPS) technique. The effect of hot-pressing temperature on the magnetic properties of hot-pressed (HP) and hot-deformed (HD) magnets without additive and with 5% Fe addition was investigated. With increasing sintering temperature for HP magnets, the grain grew gradually. For HD magnets, the optimal magnetic properties could be obtained at hot-pressing temperature 680°C due to the development of desired c-axis texture and uniform microstructure, which resulted from the appropriate and uniform grain size in HP magnets. Fe addition could enhance remanence (Br) and magnetic energy products ((BH)m) of HP and HD magnets. However, the maximum magnetic energy product of HD magnets decreased when hot-pressing temperature was higher than 650°C.

Spark Plasma Sintering of Ti-4.5Al-3V-2Fe-2Mo (SP-700)

2010 ◽  
Vol 654-656 ◽  
pp. 819-822
Author(s):  
Genki Kikuchi ◽  
Hiroshi Izui ◽  
Yuya Takahashi ◽  
Shota Fujino
Keyword(s):  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Volume Fraction ◽  
Titanium Boride ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Tib2 Particles

In this study, we focused on the sintering performance of Ti-4.5Al-3V-2Mo-2Fe (SP-700) and mechanical properties of SP-700 reinforced with titanium boride (TiB/SP-700) fabricated by spark plasma sintering (SPS). TiB whiskers formed in titanium by a solid-state reaction of titanium and TiB2 particles were analyzed with scanning electron microscopy and X-ray diffraction. The TiB/SP-700 was sintered at temperatures of 1073, 1173, and 1273 K and a pressure of 70 MPa for 10, 30, and 50 min. The volume fraction of TiB ranged from 1.7 vol.% to 19.9 vol.%. Tensile tests of TiB/SP-700 were conducted at room temperature, and the effect of TiB volume fraction on the tensile properties was investigated.

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