Reakce v Ternárním systémuAl-B2O3-C během mechanické legování

Reactions in Ternary System Al-B2O3-C during Mechanical Alloying

abstrakt

en

Nanocomposites based on the light aluminium matrix reinforced by nanoparticles obtained by in-situ reactions may possess unique performance during mechanical loading and/or other properties. One of promising system can be formed by B4C particles in Al matrix prepared by mechano-chemical reactions in Mg – B2O3 – C ternary system. Some phenomena in terms of milling duration effect in similar systems have been followed e.g. by [1], [2]. This contribution is focused on the processes that govern reactions in Al – B2O3 – C components system during mechanical milling and final microstructures that can be obtained as a result of mechano-chemical reactions. The chemical composition of starting powder material was Al (55.54 wt.%), B2O3 (40.92 wt.%) and C (3.53 wt.%). The powder mixture was activated in high-energy planetary ball mill under Argon atmosphere. Different milling times were applied the other conditions keeping the same. The characterization of phases formed in the powder during milling was carried out by X – ray diffractometry (XRD) and scanning electron microscopy (SEM) in addition to standard characterization of the powder size and morphology. After 8 hours of milling the SEM results shown, that boron oxide has reacted with carbon to form boron carbides B4C, by reactions running similarly to that described in paper [3]. At the same time, a small amount of aluminum oxide remained in the microstructure. XRD results showed a greater amount of aluminum oxide comparing to SEM results. Although it has been used over – stoichiometric amount of aluminum certain amount of aluminum oxide in the resultant powder has been found. After 40 hrs milling the XRD diffractions detected no new phases. SEM investigations supplemented by microanalysis have shown that resulting microstructure consisted of aluminium matrix containing aluminium oxide Al2O3 and finer particles of boron carbide B4C.

Nanocomposites based on the light aluminium matrix reinforced by nanoparticles obtained by in-situ reactions may possess unique performance during mechanical loading and/or other properties. One of promising system can be formed by B4C particles in Al matrix prepared by mechano-chemical reactions in Mg – B2O3 – C ternary system. Some phenomena in terms of milling duration effect in similar systems have been followed e.g. by [1], [2]. This contribution is focused on the processes that govern reactions in Al – B2O3 – C components system during mechanical milling and final microstructures that can be obtained as a result of mechano-chemical reactions. The chemical composition of starting powder material was Al (55.54 wt.%), B2O3 (40.92 wt.%) and C (3.53 wt.%). The powder mixture was activated in high-energy planetary ball mill under Argon atmosphere. Different milling times were applied the other conditions keeping the same. The characterization of phases formed in the powder during milling was carried out by X – ray diffractometry (XRD) and scanning electron microscopy (SEM) in addition to standard characterization of the powder size and morphology. After 8 hours of milling the SEM results shown, that boron oxide has reacted with carbon to form boron carbides B4C, by reactions running similarly to that described in paper [3]. At the same time, a small amount of aluminum oxide remained in the microstructure. XRD results showed a greater amount of aluminum oxide comparing to SEM results. Although it has been used over – stoichiometric amount of aluminum certain amount of aluminum oxide in the resultant powder has been found. After 40 hrs milling the XRD diffractions detected no new phases. SEM investigations supplemented by microanalysis have shown that resulting microstructure consisted of aluminium matrix containing aluminium oxide Al2O3 and finer particles of boron carbide B4C.

Nanocomposites based on the light aluminium matrix reinforced by nanoparticles obtained by in-situ reactions may possess unique performance during mechanical loading and/or other properties. One of promising system can be formed by B4C particles in Al matrix prepared by mechano-chemical reactions in Mg – B2O3 – C ternary system. Some phenomena in terms of milling duration effect in similar systems have been followed e.g. by [1], [2]. This contribution is focused on the processes that govern reactions in Al – B2O3 – C components system during mechanical milling and final microstructures that can be obtained as a result of mechano-chemical reactions. The chemical composition of starting powder material was Al (55.54 wt.%), B2O3 (40.92 wt.%) and C (3.53 wt.%). The powder mixture was activated in high-energy planetary ball mill under Argon atmosphere. Different milling times were applied the other conditions keeping the same. The characterization of phases formed in the powder during milling was carried out by X – ray diffractometry (XRD) and scanning electron microscopy (SEM) in addition to standard characterization of the powder size and morphology. After 8 hours of milling the SEM results shown, that boron oxide has reacted with carbon to form boron carbides B4C, by reactions running similarly to that described in paper [3]. At the same time, a small amount of aluminum oxide remained in the microstructure. XRD results showed a greater amount of aluminum oxide comparing to SEM results. Although it has been used over – stoichiometric amount of aluminum certain amount of aluminum oxide in the resultant powder has been found. After 40 hrs milling the XRD diffractions detected no new phases. SEM investigations supplemented by microanalysis have shown that resulting microstructure consisted of aluminium matrix containing aluminium oxide Al2O3 and finer particles of boron carbide B4C.

mechanochemical reactions, alloying, aluminium matrix composite

20.04.2016

978-80-553-2547-7

Metallography 16

124–124

1