소결 공정 개선을 통한 미세 결정립 몰리브덴 소결체 제조

Abstract

In this study, the fabrication of ultra fine grained Mo bulk was conducted. MoO(3) nanopowders were prepared by a high energy ball-milling process and then reduced at the temperature of 800 degrees C without holding time in H(2) atmosphere. The particle size of Mo nanopowder was similar to 150 nm and grain size was similar to 40 nm. The two-step process was employed for the sintering of Mo nanopowder to obtain fine grain size. The densification over 90% could be obtained by the two-step sintering with a grain size of less than 660 nm. For higher density, modified two-step sintering was designed. 95% of theoretical density with the grain size of 730 nm was obtained by the modified two-step sintering.