• Particle and aerosol research
• /
• v.11 no.1
• /
• pp.9-19
• /
• 2015

This study investigated the effects of ball mill operation condition on the morphology of raw powders in the dry-type milling process using three types of ball mills traditional ball mill, stirred ball mill and planetary ball mill. Furthermore, since spherical powders offer the best combination of high hardness and high density, the optimum milling condition to produce sphere-shaped powders was studied. The applied rotation speed ranged from 200rpm (low rotation speed) to 700rpm (high rotation speed). The used ball size ranged from 1mm to 5mm. The metal powder morphology was studied using SEM, XRD and PSA. The aimed spherical powders could be obtained under the optimum experimental conditions: traditional ball mill(200rpm, 1mm ball), planetary ball mill (500rpm, 1mm ball) and also planetary ball mill (700rpm, 1 and 3 mm ball). The results show to the development of new material using spherical type copper powder/CNT composites for air-craft and automotive applications.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2009.11a
• /
• pp.27.2-27.2
• /
• 2009

Grinding characteristics for aluminium and carbon nanotubes (CNTs) powder during traditional and planetary ball milling investigated from the viewpoint of particle behaviour with the aimat developing CNT-dispersed samples ground based on powder metallurgy routes.In this work, a comparison between the pure aluminium and CNT input aluminium grinding was carried out to determine grinding time effect on size reduction.We observed that the use of the curly small-diameter multi-walled carbon nanotubes (MWCNTs) attributed to the beneficial role of the MWCNTs as grinding aids. It is suggested that careful choices of the sizes of CNTs and Al powders would allow fine-grinding of composite particles with uniformly distributed CNT reinforcements thereby ensuring improved properties of the final composites produced by low-temperature compacting.

• Journal of Powder Materials
• /
• v.22 no.3
• /
• pp.208-215
• /
• 2015

Fe-TiC composite powders were fabricated by planetary ball mill processing. Two kinds of powder mixtures were prepared from the starting materials of (a) (Fe, TiC) powders and (b) (Fe, $TiH_2$, Carbon) powders, respectively. Milling speed (300, 500 and 700 rpm) and time (1, 2, and 3 h) were varied. For (Fe, $TiH_2$, Carbon) powders, an in situ reaction synthesis of TiC after the planetary ball mill processing was added to obtain a homogeneous distribution of ultrafine TiC particulates in Fe matrix. Powder characteristics such as particle size, size distribution, shape, and mixing homogeneity were investigated.

• Korean Journal of Materials Research
• /
• v.25 no.6
• /
• pp.305-316
• /
• 2015

The study of grinding behavior characteristics on the metal powders has recently gained scientific interest due to their useful applications to enhance advanced nano materials and components. This could significantly improve the property of new mechatronics integrated materials and components. So, a new evaluation method for standardizing grinding equipment and a comparative study for the grinding experiment during the grinding process with various grinding mills were investigated. The series of grinding experiments were carried out by a traditional ball mill, stirred ball mill, and planetary ball mill with various experimental conditions. The relationship between the standardization of equipment and experimental results showed very significant conclusions. Furthermore, the comparative study on the grinding experiment, which investigated changes in particle size, particle morphology, and crystal structure of materials with changes in experimental conditions for grinding equipment, found that the value of particle size distribution is related to the various experimental conditions as a revolution speed of grinding mill and media size.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.8
• /
• pp.681-687
• /
• 2003

The syntheses of LaNiO$_3$Perovskite crystalline phase from mixtures of La$_2$O$_3$and NiO via it mechanochemical(used planetary mill) and a wet ball mill process were investigated. A single and stable LaNiO$_3$perovskite crystalline phase was successfully prepared by using a heat free mechanochemical process which produced a fine amorphous powder, while that phase was not formed in a wet ball mill process which needed heat treatment ranging from 500 to 150$0^{\circ}C$ and produced a coarse powder. It was shown that the LaNiO$_3$ceramics made of the mechanochemically synthesized powder possesed a good metallic characteristic.

• Korean Journal of Materials Research
• /
• v.28 no.10
• /
• pp.539-543
• /
• 2018

We report the structural, morphological and magnetic properties of the $Ni_{70}Mn_{30}$ alloy prepared by Planetary Ball Mill method. Keeping the milling time constant for 30 h, the effect of different ball milling speeds on the synthesis and magnetic properties of the samples was thoroughly investigated. A remarkable variation in the morphology and average particle size was observed with the increase in milling speed. For the samples ball milled at 200 and 300 rpm, the average particle size and hence magnetization were decreased due to the increased lattice strain, distortion and surface effects which became prominent due to the increase in the thickness of the outer magnetically dead layer. For the samples ball milled at 400, 500 and 600 rpm however, the average particle size and hence magnetization were increased. This increased magnetization was attributed to the reduced surface area to volume ratio that ultimately led to the enhanced ferromagnetic interactions. The maximum saturation magnetization (75 emu/g at 1 T applied field) observed for the sample ball milled at 600 rpm and the low value of coercivity makes this material useful as soft magnetic material.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.15 no.3
• /
• pp.238-243
• /
• 2002

The dielectric properties and synthesis of $LaAIO_3$ ceramics from mixtures of $La_2O_3$ and $AI(OH)_3$ via ground(planetary ball mill) and unground(wet ball mill) were investigated. The single phase $LaAIO_3$ of ground powder was formed at $1000^{\circ}C$, while that of unground powder was formed at $1300^{\circ}C$. Density and grains of ground sample showed 98% of theory density and a uniform size of 0.75\mu\textrm{m}$, respectively, However those of unground sample showed 93% and non-uniform sizes of 4-5 $\mu\textrm{m}$. Dielectric constant and temperature coefficient of capacitance ($\tau$c) of both ground and unground samples were 21~22 and +70~74 ppm$/^{\circ}C$, respectively. Dielectric loss of ground sample(0.0004) was 10 times as low as that of unground sample(0.003) due to a uniform and small gram size.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.22 no.4
• /
• pp.207-212
• /
• 2012

A single phase $Mg_3Sb_2$ alloy was synthesized by melting the mixture of Mg and Sb metal powders at 1173 K. The figure of merit of the $Mg_3Sb_2$ prepared by melting method increased with temperature and showed a value of $2.39{\times}10^{-2}$ at 593 K. When the $Mg_3Sb_2$ powders were milled at high speed in a planetary ball mill for 12~48 h, Zintle phase ($Mg_3Sb_2$) was maintained as a main phase, but its crystallinity became deteriorated and elemental Sb phase appeared. Sb phase free $Mg_3Sb_2$ could be obtained by the mechanical alloying of high speed ball milling for 24 h using elemental Mg and Sb powder mixtures.

• Journal of the Korean Ceramic Society
• /
• v.34 no.2
• /
• pp.195-201
• /
• 1997

The present paper describes the effect of dry mixed grinding on kaolinite-aluminum trihydroxide mixture with a planetary ball mill before sintering and its influence on mullite formation during sintering. The size reduction of the mixture is market in the early stage of grinding and the obtained fine particles agglomerate subsequently with an increase of grinding time. The crystal structure of the mixture is collapsed easily into an amorphous one by planetary ball milling, of which amount increases with an increase of grinding time. Only mullite phase except for anatase as an inherent impurity in kaolinite appeared in the sintered body of the mixtures with mixed grinding as relatively lower temperature 1523K, while corundum, cristobalite, and Al-Si spinel phases, besides mullite were formed in the sintered body of the mixture without mixed grinding. Therefore, the mixed grinding treatment is very effective to improve the homogeneous mixing and disp-ersion of the mixture of raw materials on a micro scale and to decrease the thermal decomposition tem-perature by crystal structure change of them so as to obatin direct preparation of mullite with high purity at relatively low temperature.

• Journal of Power System Engineering
• /
• v.17 no.5
• /
• pp.23-29
• /
• 2013

The activation process is the key to graphene's practical application. In this study, the effect of grinding speed in planetary ball mill on structural integrity of graphene has been studied at various grinding speed such as 100 rpm, 200 rpm, 300 rpm, 400 rpm and 500 rpm. The morphology and structure of pristine graphene and ground graphenes were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy respectively. According to these results, structural properties of graphene were improved when grinding speed was increased.