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 of βSiAlON-cBN Composite

2007 ◽  
Vol 561-565 ◽  
pp. 599-602 ◽  
Author(s):  
Mikinori Hotta ◽  
Takashi Goto
Keyword(s):  
Phase Transformation ◽  
Boron Nitride ◽  
Spark Plasma Sintering ◽  
Firing Temperature ◽  
Vickers Hardness ◽  
Cubic Boron Nitride ◽  
Theoretical Density ◽  
Maximum Value ◽  
Plasma Sintering ◽  
Spark Plasma

βSiAlON-cubic boron nitride (cBN) composites were prepared from β-SiAlON and cBN powders using spark plasma sintering (SPS) at firing temperature of 1600-1900oC under pressure of 100MPa, and densification, phase transformation and hardness of the composites were investigated. The phase transformation of cBN to hexagonal BN (hBN) was inhibited in βSiAlON-cBN composite. βSiAlON-cBN composites containing 10-30 vol% cBN fired at 1650oC were densified to 95-98% of theoretical density with no transformation of cBN to hBN. Vickers hardness of the βSiAlON-cBN composite containing 20 vol% cBN fired at 1650oC was 17.5 GPa in maximum value, and the hardness significantly decreased as cBN phase was transformed to hBN in the composites.

Influence of Technological Conditions on the Properties of PcBN Composites Fabricated by Spark Plasma Sintering

2018 ◽  
Vol 281 ◽  
pp. 420-425
Author(s):  
Yun Peng Ding ◽  
Ming Xuan Zhang ◽  
Qun Luo ◽  
Chen Jiang Dong ◽  
Jiao Jiao Yao ◽  
...  
Keyword(s):  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Cubic Boron Nitride ◽  
Holding Time ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Binder Composition ◽  
Better Than

Polycrystalline cubic boron nitride (PcBN) composites were fabricated by spark plasma sintering (SPS). The SiC, Si3N4 and Si/B were used as binder. The effects of SPS sintering process parameters, such as the sintering temperature, holding time, heating rate and binder composition, on the properties of PcBN samples were investigated. PcBN composite with a hardness of 23.12GPa was fabricated efficiently by SPS. The hardness of PcBN sample increased first and then decreased with the increase of sintering temperature. As the holding time was 20 min, the hardness of PcBN sample was the highest. The PcBN performance at the heating rate of 50 °C/min was significantly better than that of 100°C /min. When the binder component of SiC, Si3N4, and Si was 63%:27%:10%, the hardness of PcBN was the highest. With an addition of Si, the PcBN samples had higher hardness than that of B.

Preparation of SiAlON-cBN Composites Using Ni Nanoparticle Precipitated cBN Powders

2012 ◽  
Vol 508 ◽  
pp. 17-20
Author(s):  
Jian Feng Zhang ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Phase Transformation ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Holding Time ◽  
Maximum Hardness ◽  
Morphology Characteristic ◽  
Plasma Sintering ◽  
Spark Plasma

SiAlON Was Mixed with Ni Nanoparticle Precipitated cBN (SiAlON-cBN/Ni) and Sintered by Spark Plasma Sintering at 1923 K for a Holding Time (tH) of 0 to 1.8 Ks. the Effect of Ni Nanoparticle and Holding Time on the Phase Transformation of cBN to Hexagonal (hBN), Densification, Microstructure and Hardness of the SiAlON-cBN Composites Was Studied. AttH=1.8 Ks , the Relative Density of the SiAlON-20 Vol% cBN/Ni Was 99%, 7% Higher than that of SiAlON-20 Vol% cBN, Indicating that Ni Nanoparticle on cBN Promoted the Densification of SiAlON-cBN Composites. The BN Grains in SiAlON-20 Vol% cNB Showed a Round Morphology, whereas the BN Grains in SiAlON-20 Vol% cBN/Ni Composite Showed a Flake Morphology Characteristic of hBN. The Phase Transformation of cBN Was Accelerated by Ni. the Maximum Hardness of SiAlON-20 Vol% cBN/Ni Was 16.3 GPa Obtained attH= 0 Ks.

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.

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