2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
- 121 -
Abstract:
This paper intends to produce fine aluminum
powder from metallic aluminum by using hybrid
atomization technique. The hybrid atomization system has
three main parts: melting unit, hybrid atomization and
powder collector. The characteristic of aluminum metal is
analyzed by X-ray Diffraction (XRD) and wet analysis
method. Processing experiments were carried out at gas
pressure (0.5, 0.6, 0.7 MPa). The resultant aluminum
powder with a mean particle size of under 75 microns was
obtained. The size of aluminum particles were calculated
by using Scherrer’s equation. Aluminum powder consisted
of crystalline structure of particle size of 71-86 nm yielded
at 710
º
C.
Keywords:
Melting Unit/ Hybrid Atomization/
Aluminum powder/ Scanning Electron Microscope
1. INTRODUCTION
Aluminum is found in many rock minerals, usually
combined with silicon and oxygen in compounds called
alumino-silicates. Under certain types of tropical soil
weathering these alumino-silicate compounds are
separated into layers of hydrated iron oxide, hydrated
alumina and silica. When such deposits are rich in
alumina, they comprise the mineral bauxite.
Aluminum is a lightweight, durable metal. It is silvery
in appearance when freshly cut, is a good conductor of
heat and electricity and is easily shaped by moulding and
extruding. Aluminum has main advantages when
compared with other metals.
Firstly, it has a low density, about one third that of iron
and copper. Secondly, although it reacts rapidly with the
oxygen in air, it forms a thin tough and impervious oxide
layer which resists further oxidation. [1].Many uses have
been purposed for various application of the aluminium,
such as aerospace, architectural construction and marine
industries, as well as many domestic uses.
Aluminum materials can be produced by a variety of
manufacturing routes. The main production routes, i.e.
those for which materials are commercially available are:
atomization, melting spinning and subsequently
pulverisation of ribbons into flakes, and mechanically
alloying [2]. Atomization process is one of the popular
process for making powder metal. Gases and water is the
liquid most widely used [3]. The main advantage of gas
atomization is due to totally inert processing conditions
and the spherical the product homogeneity, the absence of
contamination shape of the product powder.
In some conventional atomization method such as
centrifugal atomization and confined gas atomization, a
liquid film was found to form before the final break up [4].
Furthermore, because the liquid film scatters in the form
of droplet, void-free powders with preferable properties,
such as fluidity and arrangement, can be obtained.
However, with the centrifugal atomization, if the melt not
poured onto the centre of the rotating disk, the high-speed
disk would become unbalanced, making it difficult to form
a stable liquid film, and then the preparation of powders
will become impossible.
A new powder- making technique, hybrid atomization
was invented and developed recently to produce very fine
spherical powders economically. This technology
combines low-pressure gas atomization with centrifugal
atomization effectively. Its basic idea is to provide a thin
but stable liquid film on rotating disk before centrifugal
break up by a low-pressure inert gas atomization [5].
As an advantage of this method, the powder with low
content oxygen can be easily produced because the
powder is produced in an inert gas atmosphere [6]. By this
method, is easy to control the powder particle size, particle
size distribution, powder shape and other characteristics
by detail investigation of the relation between the metal
physical properties and the rotational speed of the rotary
disk [7].
Powder characterisation is a rather complex procedure
since not only the properties of individual particles (size,
shape, etc) must be determined, but also the characteristics
of the powder mass (particle size distribution, apparent
density, etc.) and of the porosity in the powder mass
(average pore size, pore volume, etc.). The suitable metals
that can be melted and it used commercially for powder
production are iron, copper, alloys steels, brass, bronze,
low melting point metals such as tin, lead, zinc and
aluminum [8].
In this paper, the primary aim of this paper was to apply
for the production of solid rocket propellant. To fulfil this
aim the following objectives is carried out; to examine the
characteristics of raw aluminum sample, to fabricate the
hybrid atomization structure and to explore aluminum
powder by using hybrid atomization technique.
PRODUCTION OF FINE ALUMINUM
POWDER FROM METALLIC ALUMINUM
Hnin Yu Khaing
1
*, Tint Tint Kywe
2
1, 2
Mandalay Technological University, Chemical Engineering, Myanmar
*email:
