• 제목/요약/키워드: Milling energy

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기계적 합금화시 $Ti_3Si$$TiSi_2$ 합성에 미치는 분말 혼합도의 영향 (Effect of Degrees of Powder Mixing on the Synthesis of $Ti_3Si$ and $TiSi_2$ by Mechanical Alloying)

  • 변창섭
    • 한국분말재료학회지
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    • 제6권1호
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    • pp.103-110
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    • 1999
  • Different sizes of Si powder and milling medium materials (steel and partially stabilized zirconia (PSZ)) were used to synthesize $Ti_3Si$ and $TiSi_2$ by mechanical aollying (MA) of Ti-25.0.at.%Si and Ti-66.7at.% Si powder mixtures. the formation of each titanium silicide did not occur even after 360 min of MA of as-re-ceived Si and Ti powder mixtures due to the lack of homogeneity. $Ti_3Si$, however, was synthesized after 240 min of MA of Ti and 60 min-premilled Si powder mixture. ${\alpha}-TiSi_2$ and $TiSi_2$ were produced by jar milling of Ti and 60 min-premilled Si powder mixture for 48 hr and high -energy PSZ ball-milling in a steel vial for 360 min. The formation of each titanium silicide was characterized by a slow reaction rate as the reactants and product(s) coexisted for a certain period of time. The formation of $Ti_3Si$ and $TiSi_2$ and the reaction rates appeared to be influenced by the Si particle size, the homogeneity of the powder mixtures and the milling medium materials.

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교반볼밀을 이용한 밀링공정에서 각종실험조건에 따른 구리분말의 입자형상 변화 및 DEM 시뮬레이션에 의한 정량적 에너지 변화 (Particle Morphology Change and Quantitative Input Energy Variation during Stirred Ball Milling Process by DEM Simulation on Various Experimental Conditions)

  • 보르 암갈란;오양가;자갈사이항 바체첵;이재현;최희규
    • 한국재료학회지
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    • 제28권3호
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    • pp.148-158
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    • 2018
  • This study investigated the effect of the grinding media of a ball mill under various conditions on the raw material of copper powder during the milling process with a simulation of the discrete element method. Using the simulation of the three-dimensional motion of the grinding media in the stirred ball mill, we researched the grinding mechanism to calculate the force, kinetic energy, and medium velocity of the grinding media. The grinding behavior of the copper powder was investigated by scanning electron microscopy. We found that the particle size increased with an increasing rotation speed and milling time, and the particle morphology of the copper powder became more of a plate type. Nevertheless, the particle morphology slightly depended on the different grinding media of the ball mill. Moreover, the simulation results showed that rotation speed and ball size increased with the force and energy.

고에너지 분쇄 매체 지르코니아 Beads의 미세구조 및 기계적 특성에 따른 마모율 분석 (Analysis of Attrition Rate of Y2O3 Stabilized Zirconia Beads with Different Microstructure and Mechanical Properties)

  • 김정환;윤세중;한병동;안철우;윤운하;최종진
    • 한국재료학회지
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    • 제28권6호
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    • pp.349-354
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    • 2018
  • Particle size reduction is an important step in many technological operations. The process itself is defined as the mechanical breakdown of solids into smaller particles to increase the surface area and induce defects in solids, which are needed for subsequent operations such as chemical reactions. To fabricate nano-sized particles, several tens to hundreds of micron size ceramic beads, formed through high energy milling process, are required. To minimize the contamination effects during high-energy milling, the mechanical properties of zirconia beads are very important. Generally, the mechanical properties of $Y_2O_3$ stabilized tetragonal zirconia beads are closely related to the mechanism of phase change from tetragonal to monoclinic phase via external mechanical forces. Therefore, $Y_2O_3$ distribution in the sintered zirconia beads must also be closely related with the mechanical properties of the beads. In this work, commercially available $100{\mu}m-size$ beads are analyzed from the point of view of microstructure, composition homogeneity (especially for $Y_2O_3$), mechanical properties, and attrition rate.