Korean Journal of Materials Research (한국재료학회지)

Materials Research Society of Korea (한국재료학회)
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Densification of Mo Nanopowders by Ultra High Pressure Compaction

초고압 성형을 통한 Mo 나노 분말의 치밀화

  • Ahn, Chi Hyeong (Department of Materials Science and Engineering, Hanyang University) ;
  • Choi, Won June (Department of Materials Science and Engineering, Hanyang University) ;
  • Park, Chun Woong (Department of Materials Science and Engineering, Hanyang University) ;
  • Lee, Seung Yeong (Department of Materials Science and Engineering, Hanyang University) ;
  • Kim, Young Do (Department of Materials Science and Engineering, Hanyang University)
  • 안치형 (한양대학교 신소재공학과) ;
  • 최원준 (한양대학교 신소재공학과) ;
  • 박천웅 (한양대학교 신소재공학과) ;
  • 이승영 (한양대학교 신소재공학과) ;
  • 김영도 (한양대학교 신소재공학과)
  • Received : 2018.01.02
  • Accepted : 2018.02.12
  • Published : 2018.03.27
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Abstract

Molybdenum (Mo) is one of the representative refractory metals for its high melting point, superior thermal conductivity, low density and low thermal expansion coefficient. However, due to its high melting point, it is necessary for Mo products to be fabricated at a high sintering temperature of over $1800-2000^{\circ}C$. Because this process is expensive and inefficient, studies to improve sintering property of Mo have been researched actively. In this study, we fabricated Mo nanopowders to lower the sintering temperature of Mo and tried to consolidate the Mo nanopowders through ultra high pressure compaction. We first fabricated Mo nanopowders by a mechano-chemical process to increase the specific surface area of the Mo powders. This process includes a high-energy ball milling step and a reduction step in a hydrogen atmosphere. We compacted the Mo nanopowders with ultra high pressure by magnetic pulsed compaction (MPC) before pressureless sintering. Through this process, we were able to improve the green density of the Mo compacts by more than 20 % and fabricate a high density Mo sintered body with more than a 95 % sintered density at relatively low temperature.

Keywords

References

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