Dielectric Properties of Boron Nitride-Aluminium Nitride Composites Prepared by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 796-798 ◽  
Author(s):  
Bin Chen ◽  
Wei Pan
Keyword(s):  
Dielectric Constant ◽  
Boron Nitride ◽  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Hexagonal Boron Nitride ◽  
Aluminium Nitride ◽  
Dielectric Constants ◽  
Plasma Sintering ◽  
Dielectric Constant And Loss ◽  
Spark Plasma

In this study, hexagonal Boron Nitride-Aluminium Nitride composites were prepared by spark plasma sintering at 1700°Cfor 4 min under the pressure of 25 MPa, varying the amount of BN from 0 to 30 wt.%. The dielectric constants and losses of the samples were measured from 100 Hz to 1 MHz at room temperature, and the results show that with the increment of BN content, the dielectric constants and losses of AlN-BN composites decrease. When the BN content is 20 wt.%, the dielectric constant and loss of the composites at 1 MHz are 6.18, 2.1 × 10-3 respectively.

Preparation of β SiAlON-cBN Composites by Spark Plasma Sintering

2008 ◽  
Vol 403 ◽  
pp. 241-242
Author(s):  
Mikinori Hotta ◽  
Takashi Goto
Keyword(s):  
Phase Transformation ◽  
Boron Nitride ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Hexagonal Boron Nitride ◽  
Cubic Boron Nitride ◽  
Holding Time ◽  
Theoretical Density ◽  
Plasma Sintering ◽  
Spark Plasma

SiAlON-cubic boron nitride (cBN) composite was prepared by spark plasma sintering (SPS) using -SiAlON and cBN powders as starting materials, and the effect of holding time on densification, phase transformation and hardness of the composite was investigated. The SiAlON-cBN composite containing 20 vol% cBN sintered at 1650oC for 60s was densified to >97% of theoretical density. cBN phase transformed to hexagonal boron nitride (hBN) in the SiAlON-cBN composite with increasing holding time at 1650oC. Vickers hardness of the SiAlON-20vol%cBN composite sintered at 1650oC for 60-300s was 17.7GPa, and the hardness decreased with increasing holding time.

Spark Plasma Sintering and Characterization of Mixed h-BN Powders with Different Grain Sizes

2018 ◽  
Vol 281 ◽  
pp. 414-419
Author(s):  
Feng Rui Zhai ◽  
Min Lu ◽  
Ke Shan ◽  
Zhong Zhou Yi ◽  
Zhi Peng Xie
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Boron Nitride ◽  
Spark Plasma Sintering ◽  
Hexagonal Boron Nitride ◽  
Orientation Degree ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Crystallization Degree

Mixtures of two grades of hexagonal boron nitride (h-BN) powder differing in their grain size and crystallinity were spark plasma sintering in a vacuum. The influences of the mixing ratio of h-BN powders on the densification, microstructure and mechanical properties were investigated in detail. The results show that the smaller grain size, the lower crystallization degree and the higher density and mechanical properties. While the orientation degree of flake h-BN grains can be greatly enhanced by using h-BN powder with larger particle size. As the increasing of nanometer h-BN powder adding amount, the relative density has the same “V” shape changing trends with mechanical properties. In addition, the orientation of boron nitride grains varied widely, and a nearly isotropic material was prepared from a mixture containing 90wt.% nanometer powder.

Formation of a unique glass by spark plasma sintering of a zeolite

2009 ◽  
Vol 24 (10) ◽  
pp. 3241-3245 ◽  
Author(s):  
Lianjun Wang ◽  
Wan Jiang ◽  
Lidong Chen ◽  
Zhijian Shen
Keyword(s):  
Spark Plasma Sintering ◽  
Glass Sample ◽  
Room Temperature ◽  
Vickers Microhardness ◽  
Simple Approach ◽  
Electron Microscopic ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Spark Plasma

A simple approach, order–disorder transition (ODT), has been developed to synthesize a novel glass using ZSM-5 as starting materials. In this process, the ZSM-5 powders were pressed uniaxially in a graphite die and rapidly sintered using spark plasma sintering (SPS). High-resolution transmission electron microscopic images revealed that a few crystalline zeolite fragments were still preserved locally inside the SPS consolidated sample. Vickers microhardness and fracture toughness of this as-prepared transparent glass sample at room temperature reaches 7.3 ± 0.2 GPa and 2.0 ± 0.3MPa·m1/2, respectively. It is very interesting that these novel bulk transparent glasses exhibit ultraviolet photoluminescence (PL) properties at about ∼360 nm.

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.

Spark plasma sintering of aluminium nitride transparent ceramics

2004 ◽  
Vol 20 (9) ◽  
pp. 1097-1099 ◽  
Author(s):  
Z.Y. Fu ◽  
J.F. Liu ◽  
H. Wang ◽  
D.H. He ◽  
Q.J. Zhang
Keyword(s):  
Spark Plasma Sintering ◽  
Aluminium Nitride ◽  
Transparent Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

scholarly journals Tribological Characterization of Micron-/Nano-Sized WC-9%Co Cemented Carbides Prepared by Spark Plasma Sintering at Elevated Temperatures

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 920 ◽  
Author(s):  
Saleh Wohaibi ◽  
Abdul Mohammed ◽  
Tahar Laoui ◽  
Abbas Hakeem ◽  
Akeem Adesina ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Normal Load ◽  
Cemented Carbide ◽  
Plasma Sintering ◽  
Dry Conditions ◽  
Spark Plasma ◽  
Track Area

The present study investigates the high temperature tribological performance of spark plasma sintered, nano- and micron-sized tungsten carbide (WC) bonded by 9 wt.% cobalt (Co). The composites were fabricated using a two-step procedure of mixing followed by spark plasma sintering (SPS). Ball-on-disc wear tests were conducted at a normal load of 30 N, linear speed of 0.1 m/s under dry conditions and at three different temperatures (room temperature, 300 °C and 600 °C). Field emission scanning electron microscopy (FESEM), optical profilometry and energy dispersive X-ray (EDS) spectroscopy were used to analyze the surface morphology and the wear track area. At room temperature, it was observed that the nano-sized WC composites exhibited better wear resistance than the micron-sized WC composites. The wear resistance of the nano-sized samples declined significantly relative to that of the micron-sized samples with an increase in temperature. This decline in performance was attributed to the higher surface area of nano-sized WC particles, which underwent rapid oxidation at elevated temperatures, resulting in poor wear resistance. The wear rate observed at 600 °C for the micron-sized WC composites was 75% lower than that of the nano-sized cemented carbide. Oxidative wear was observed to be the predominant wear mechanism for both cemented carbide samples at elevated temperatures.

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