Fabrication of Fine-grained Molybdenum Sintered Body via Modified Sintering Process

Abstract

In this study, the fabrication of ultra fine grained Mo bulk was conducted. MoO3 nanopowders were prepared by a high energy ball-milling process and then reduced at the temperature of 800℃ without holding time in H2 atmosphere. The particle size of Mo nanopowder was ~150 nm and grain size was ~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.