Investigation of the Structural Features of Boron Nitride after Mechanical Activation in Attritor and Planetary Mill Followed by Agglomeration at High Pressure and Temperature

2016 ◽  
Keyword(s):  
High Pressure ◽  
Boron Nitride ◽  
Mechanical Activation ◽  
Structural Features ◽  
Planetary Mill ◽  
High Pressure And Temperature

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.

Formation of cubic C-BN by crystallization of nano-amorphous solid at atmosphere

1998 ◽  
Vol 13 (7) ◽  
pp. 1753-1756 ◽  
Author(s):  
Bin Yao ◽  
L. Liu ◽  
W. H. Su
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
High Pressure ◽  
Boron Nitride ◽  
Amorphous Carbon ◽  
Solid Solutions ◽  
Room Temperature ◽  
Amorphous Solid ◽  
High Energy ◽  
High Pressure And Temperature

An amorphous carbon-boron nitride (C-BN) solid was prepared by ball milling the mixture of graphite and hexagonal BN powders for a period of 120 h. After annealing the amorphous C-BN solid for 1 h at atmosphere in the temperature range from 800 to 900 K and then quenching it to room temperature, a small amount of cubic C-BN solid solutions with diamond-like structure, which belong to a high energy phase and can only be synthesized previously under high pressure and temperature (30 GPa, 2000 K), were observed in the annealed amorphous C-BN solid. The lattice constant of the cubic C-BN solid solution was 0.3587 nm, and its grain size was in the range of 10 to 50 nm.

Structural transformations of the wurtzitic boron nitride-titanium nitride composition at high pressure and temperature

2011 ◽  
Vol 33 (5) ◽  
pp. 327-332 ◽  
Author(s):  
V. M. Volkogon ◽  
G. S. Oleinik ◽  
S. K. Avramchuk ◽  
A. V. Stepanenko ◽  
A. V. Kotko ◽  
...  
Keyword(s):  
High Pressure ◽  
Boron Nitride ◽  
Titanium Nitride ◽  
Structural Transformations ◽  
High Pressure And Temperature ◽  
Wurtzitic Boron Nitride

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
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