scholarly journals Reaction sintering of polycrystalline cubic boron nitride at high pressure and temperature.

1989 ◽  
Vol 36 (6) ◽  
pp. 752-755 ◽  
Author(s):  
Hitoshi Sumiya ◽  
Kazuo Tsuji ◽  
Shuji Yazu
Keyword(s):  
High Pressure ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Reaction Sintering ◽  
High Pressure And Temperature ◽  
Polycrystalline Cubic Boron Nitride

scholarly journals Production of alumo-matrix composite material modified by nanostructured cubic boron nitride

2018 ◽  
Vol 63 (3) ◽  
pp. 271-279
Author(s):  
P. A. Vityaz ◽  
V. T. Senyut ◽  
M. L. Kheifetz ◽  
A. G. Kolmakov
Keyword(s):  
High Pressure ◽  
Aluminum Alloy ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Aluminum Matrix ◽  
Treatment Temperature ◽  
Chemical Affinity ◽  
High Temperature Annealing ◽  
High Pressure And Temperature ◽  
Primary Particles

The structure and microhardness of an aluminum alloy with additives of nanostructured cubic boron nitride (cBN) after treatment under high pressure and temperature are investigated. А nanostructured powder of cBN with primary particles within 50–200 nm is used as a filler. A preliminary chemical-thermal modifying of the nanostructured cBN, which consists in its high-temperature annealing in the temperature range of 750–950 °C in a medium of aluminum-contai ning compounds, is carried out to increase the chemical affinity of the nanostructured cBN to the aluminum matrix. It is shown that the modifying of nanostructured cBN with aluminum increases the strength of the additives retention in the aluminum matrix. At the same time the increase in the concentration of BN additives from 1.5 to 5 wt.% as well as the increase in the treatment temperature at a fixed pressure promotes the increase in the microhardness of the material by a factor of 1.5 to 2 as compared with the base aluminum alloy without the addition of a modifier. An increase in the cBN concentration to 5 % by weight results in an increase in the fraction of smaller particle conglomerates (1–5 μm) in the material and in a decrease in the size of large inclusions to 10–20 μm. In this case, the distribution of BN particles in the aluminum matrix is more uniform in comparison with a material with a cBN content of 1.5 wt.%. In the material with the growth of temperature up to 1000 °С, cBN in aggregates is recrystallized with the formation of single-crystal (polycrystalline) particles with the size of 1–10 μm  with faceting specific for cBN micron particles.

Physico-mechanical properties of cBN composites produced by a high-pressure reaction sintering of cubic boron nitride and aluminum owders

2010 ◽  
Vol 32 (1) ◽  
pp. 1-13 ◽  
Author(s):  
M. P. Bezhenar ◽  
S. M. Konoval ◽  
S. A. Bozhko ◽  
M. G. Loshak ◽  
L. I. Aleksandrova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Reaction Sintering ◽  
High Pressure Reaction

X-ray observation of the formation of diamond and cubic boron nitride at high pressure and temperature

Physica B+C ◽  
1986 ◽  
Vol 139-140 ◽  
pp. 668-670 ◽  
Author(s):  
S. Yamaoka ◽  
O. Shimomura ◽  
M. Akaishi ◽  
H. Kanda ◽  
T. Nagashima ◽  
...  
Keyword(s):  
High Pressure ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
High Pressure And Temperature ◽  
X Ray

High Pressure and High Temperature Sintered PcBN Using Al, B4C and C as Sintering Additive

2016 ◽  
Vol 697 ◽  
pp. 521-525 ◽  
Author(s):  
Yao Ma ◽  
Jian Li ◽  
Hai Long Wang ◽  
Rui Zhang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
High Strength ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polycrystalline Cubic Boron Nitride ◽  
Starting Mixture ◽  
Sintering Additive

Polycrystalline cubic boron nitride (PcBN) composites were sintered by high pressure and high temperature sintering (HPHT) at 1450 °C for 3 min under a pressure of 5.0 GPa. Aluminium,boron carbide and carbon in the starting mixture reacts with cubic boron nitride (cBN) to form Al3BC3 and AlN bonding among cBN grains during sintering. X-ray diffraction (XRD) and Scanning electron microscope (SEM) were used to analyze phases and micro-structure of the sintered samples. The dense structure of super hard cBN grains bonded together with Al3BC3 and AlN offers superior hardness and high strength. The Vickers hardness of PcBN composites was 45±5 GPa, and the strength of PcBN composites was 345±15 MPa.

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