Open AccessProduction of alumo-matrix composite material modified by nanostructured cubic boron nitride
Author(s) -
P.A. Vityaz,
V. T. Senyut,
M. L. Kheifetz,
А. Г. Колмаков
Publication year - 2018
Publication title -
vescì nacyânalʹnaj akadèmìì navuk belarusì. seryâ fìzìka-tèhnìčnyh navuk
Language(s) - English
Resource type - Journals
eISSN - 2524-244X
pISSN - 1561-8358
DOI - 10.29235/1561-8358-2018-63-3-271-279
Subject(s) - materials science , boron nitride , alloy , aluminium , indentation hardness , annealing (glass) , particle size , boron , composite number , nitride , composite material , metallurgy , chemical engineering , microstructure , chemistry , organic chemistry , layer (electronics) , engineering
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.