• 자원리싸이클링
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• 제9권4호
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• pp.50-55
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• 2000

알루미늄 호일 스크랩의 건식 및 습식 볼밀링에 의하여 알루미늄 플레이크 분말을 체조하는 재활용 기술에 대해 여 연구하였다. 볼밀링시 알루미늄 호일 스크랩들은 볼에 의한 미소 단조에 의하여 서로 층상으로 겹쳐지고 연산되면서 작은 호일로 쪼개진 후 플레이크 분말로 변하였다. 이러한 스크랩중에 $60\mu\textrm{m}$ 이하의 호일 스크랩은 볼밀링에 의하여 알루미늄 페이스트로 재활용이 가능하였고 초기 호일의 두께가 작을수록 쉽게 플레이크 분말화가 가능 하였다. 알루미늄 호일 스크랩의 봉밀링에 의하여 얻은 풀레이크 분말을 함유하는 알루미늄 페이스트와 가스 분사된 분말을 초기원료로 사용하여 불밀링한 플레이크 분말을 함유하는 페]이스트를 유리관위에 폐인팅한 후 외관 및 광택도를 비교한 결과, 그 특성은 유사하였다.

• 공업화학
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• 제21권3호
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• pp.311-316
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• 2010

본 연구는 높은 분산 안정성을 유지하는 antimony-doped tin oxide (ATO) 분산액을 제조하기 위하여, 습식 볼밀법으로 분쇄시간에 따른 ATO의 입자크기, 입도분포, 분산성의 변화를 고찰하였다. 또한 각각의 습식 볼밀 처리된 ATO 분산액의 pH를 변화시켜 ATO 분산액의 분산 특성을 고찰하였다. 습식 볼밀 분쇄 조건에 의하여 ATO의 입자크기 및 입도 분포 변화는 레이저회절 입도분석기와 주사전자현미경을 이용하여 평가하였고, 습식 볼밀 분쇄 시간 및 pH조건에 따른 ATO 입자의 분산성은 제타전위 측정법과 다중광산란(multiple light scattering)법을 이용하여 평가하였다. 분쇄 조건 중 60 min 동안 처리된 ATO 입자 크기는 30% 이하로 작아지고, $1{\sim}35{\mu}m$에서 $0.1{\sim}5{\mu}m$로 입도분포를 갖는 균일한 입자를 얻을 수 있었다. 그러나 분쇄조건을 60 min 이상 처리한 것은 역분쇄 및 재응집 현상의 발생으로 인하여 한계 분쇄 시간이 나타나는 것을 알 수 있었다. 이러한 결과로부터 ATO 분산액은 습식 볼밀 분쇄 시간을 증가시킬수록 입자 크기가 감소하고 표면 에너지가 증가하여 입자간의 반발력이 커지게 됨을 알 수 있었고, 또한 용액의 pH를 증가시킬수록 입자의 표면 이온화도가 커짐으로 인하여 ATO 분산액의 분산성이 향상되는 것을 알 수 있었다.

• 한국분말재료학회지
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• 제20권4호
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• pp.258-263
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• 2013

We examined various ball-milling parameters which affect the structural and morphological modification of multi-wall carbon nanotubes. In particular, the effect of milling mode and the use of different milling agents were examined. Friction milling mode induced more structural changes than impact milling mode except the use of dry ice as a milling agent. Wet milling was helpful for reducing more effectively the agglomeration of nanotubes than dry milling. The use of hard solid particles such as silica and alumina as milling agents resulted in an effective shortening of nanotubes, but often susceptible to the amorphization and the destruction of crystallinity.

• 한국자기학회지
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• 제9권4호
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• pp.217-222
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• 1999

공업적으로 세라믹공정에 많이 사용되고 있는 습식 볼밀링으로 NiCuZn ferrite 제조과정 중 혼입되는 불순물의 양을 조사 검토하였다. NiO, CuO, ZnO 및 Fe2O3의 화학조성을 변화시켜 25 vol%로 혼합하고 스테인레스 볼밀로 습식방법을 이용하여 18시간 분쇄한 후 건조시켜 $700^{\circ}C$ 3시간 하소하였다. 하소한 분말을 다시 상기와 같은 방법으로 65시간 스테인레스 볼밀로 최종 분쇄하여 저온소결용 NiCuZn ferrite(NCZF) 소재를 제조하였다. NCZF 연자성 소재를 만드는 동안 혼합 분쇄과정에서 혼입되는 불순물의 스테인레스 스틸의 양은 산화철 및 산화니켈의 함량에 많은 영향을 받았고, 하소 후의 분쇄과정에서 혼입되는 불순물의 양은 결정화된 정도에 따라 영향을 받았다. 전자기적 특성을 갖는 화학조성의 조절을 위하여, 출발원료의 함량에 따라 분쇄과정에서 혼입되는 스테인레스 스틸의 함량을 도출하는 형식을 유도하였다.

• 연구논문집
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• 통권29호
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• pp.131-139
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• 1999

The effect of ball milling conditions in the milling of aluminium foil scraps was studied. Initial foil thickness, ball size. content of oleic acid. weight ratio of mineral spirits/foil. charged amount of foil were varied in wet ball milling process. It is impossible to make flake powders by milling of foil scraps with thickness $120 \mum$. As foil thickness decreases from $60\mum$ to $6.5\mum$, Mean size of powder milled for 30 h decreases from 107 µm to 17 µm. Bigger ball is slightly beneficial for milling of foils to the flake powders due to the larger impact energy produced by them. It is impossible to mill the foil without oleic acid to fabricate the flake powder. As content of oleic acid increases from 1.5 % to 5 %, mean size of flake powder milled for 30 h is drastically decreased. For the mineral spirits content below 50 %, foil scrap was not milled because sliding motion of balls by lubricant effect between balls and wall of container. As weight ratio of mineral spirits and foil increase over 100 %, foils were milled powders with mean powder size 15 - 20 때 irrespective of mineral spirits content due to reduced lubricant effect. As charged amount of foil decreases, mean powder size decreases due to increased collision frequency between ball and foil.

• Progress in Superconductivity
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• 제10권1호
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• pp.17-22
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• 2008

We have examined the effect of ball-milling on the superconducting properties of $MgB_2$ doped with C. The ball-milling of pre-reacted $MgB_2$ powder was carried out in dry or wet state using C or diethylenetriamine ($C_{4}H_{13}N_3$) as additives. The diethylenetriamine, whose chemical formula contains no oxygen, was chosen to avoid an excess oxidation during doping. The superconducting transition temperature (Tc) of the ball-milled or doped $MgB_2$ powders was only slightly smaller than that of undoped $MgB_2$. The critical current density (Jc) of the highly ball-milled $MgB_2$ was higher than that of C-doped $MgB_2$. The addition of diethylenetriamine was detrimental to Jc, although Tc was almost unchanged.

• 한국세라믹학회지
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• 제30권8호
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• pp.623-628
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• 1993

Lead monoxide has two phases at room temperature. One is a yellow orthorhombic phase, the other is a redtetragonal phase. Sometimes two phases are hybrided. The specificity of phase transitions of lead oxide is found during the milling of the batch including lead oxide. The pure orthorhombic phase of PbO can be transformed to the tetragonal phase perfectly by wet ball milling (milling liquid is distilled water) without thermal energy. However, when ethyl alcohol, isopropyl alcohol and aceton are used as milling liquid, respectively, the hybrid form of orthorhombic andtetragonal phases is obtained by wet ball milling. From the hybrid form heat-treated at $600^{\circ}C$ for 3hrs, this work results that mechanical phase transition of orthorhombic phase make a new form as distorted type orthorhombic phase of PbO.

• Nuclear Engineering and Technology
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• 제34권1호
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• pp.60-67
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• 2002

The effects of ball-milling time(0 ~4 hrs) have been investigated on the change of powder characteristics, compaction behavior (compaction pressure range : 200 ~400MPa) and sinterability (1700'c in Ha atmosphere) of two different UO$_2$ powders (ex-ADU and ex-AUC) prepared by the wet process. It is observed that, while the ex-ADU UO$_2$ was little affected, the ex-AUC UO$_2$ was largely affected by the ball-milling treatment. This may be attributed to the characteristics of particle size formed during the preparation step, i.e.., the former has a small average size of about 1.0${\mu}{\textrm}{m}$, while the latter has a relatively large average size of about 301n. It appeared that the effective size reduction by ball-milling treatment is limited to the particle size larger than l${\mu}{\textrm}{m}$, and to the extent of maximum decrease in size of about 0.5tn. In the case of ex-AUC UO$_2$, it is observed that the particle size decreased with ball-milling time and green density and sintered density of the pellets prepared from ball-milled powder increased compared with those of pellets prepared from the as-received powder under the same conditions. This may be attributed mainly to the fine particles formed during the ball-milling treatment.

• 대한금속재료학회지
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• 제48권5호
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• pp.462-468
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• 2010

Carbon Nanotubes (CNTs) have recently emerged as a material with outstanding properties. It has shown promising potential for applications in many engineering fields as electronic devices, thermal conductors, and light-weight composites. Researchers have investigated their use as reinforcements in themetal matrix composites of CNTs. In the present work, we decorated CNTs with Ni particles by electroless plating. The CNTs were wet-ball milled for various milling times with a nickel sulfate solution. The precipitated Ni particles were observed mainly by FESEM. In this study, the dispersion of the CNTs and Ni particles was improved with the addition of the surfactant. Also, as the CNTs were shortened and widened by an increased ball milling time, the size of the precipitated Ni particles increased. It was estimated that the CNTs were deformed and caused some defects on their surface during the ball milling process. Those defects were assumed to be heterogeneous nucleation sites for the Ni particles.

• 한국응용과학기술학회지
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• 제33권4호
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• pp.734-740
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• 2016

The micron-sized indium zinc tin oxide (IZTO) particles were prepared by spray pyrolysis from aqueous precursor solution for indium, zinc, and tin and organic additives such as citric acid (CA) and ethylene glycol (EG) were added to aqueous precursor solution for indium, zinc, and tin. The obtained IZTO particles prepared by spray pyrolysis from the aqueous solution without organic additives had spherical and filled morphologies, whereas the IZTO particles obtained with organic additives had more hollow and porous morphologies. The micron-sized IZTO particles with organic additives were changed fully to nano-sized IZTO particles, whereas the micron-sized IZTO particles without organic additives were not changed fully to nano-sized IZTO particle after post-treatment at $700^{\circ}C$ for 2 hours and wet-ball milling for 24 hours. Surface resistances of micron-sized IZTO's before post-heat treatment and wet-ball milling were much higher than those of nano-sized IZTO's after post-heat treatment and wet-ball milling. From IZTO with composition of 80 wt. % $In_2O_3$, 10 wt. % ZnO, and 10 wt. % $SnO_2$ which showed a smallest surface resistance IZTO after post-heat treatment and wet-ball milling, thin films were deposited on glass substrates by pulsed DC magnetron sputtering, and the electrical and optical properties were investigated.