Abstract

Mo nanopowder was synthesized by ball-milling and subsequent hydrogen-reduction of MoO_3 powder. To fabricate ultra fine grained molybdenum, two-step sintering and spark plasma sintering process were employed. The grain size of specimen by two-step sintering and spark plasma sintering was around 0.6;µm and 0.4;µm, respectively. Mechanical properties of ultra fine grained Mo with relative density of above 90% were significantly improved at room and high temperatures comparing to commercial bulk Mo of 99% relative density. This result was mainly explained by the grain size refinement due to diffusion-controlled sintering.

• Keywords: Nanostructured Mo powder;Two-step sintering;Spark plasma sintering;Ultra fine grained molybdenum;