Mo 나노분말의 소결거동 및 기계적 특성

Abstract

The sintering behavior and mechanical property of Mo nanopowder was investigated as a function of various sintering condition. Mo oxide nanopowders were milled using a high energy ball-milling process. After the ball milling for 20h, the crystalline size of MoO3 was about 20 nm. The MoO3 nanopowders were reduced at the temperature of 800oC without holding time in H2 atmosphere. The sinterability of Mo nanopowder and commercial Mo powder was investigated by dilatometric analysis. Mo nanopowder and commercial Mo powder were sintered at 1200oC for 1 h and 1500oC for 3 h, respectively. In both specimens the measured relative density was about 95%. But the measured hardness values were 2.34 GPa for nanopowder and 1.87 GPa for commercial powder. Probably due to finer grain size of the sintered body prepared from Mo nanopowder than that prepared using commercial Mo powder. The mean grain sizes were measured to be about 1.4 mm and 6.2 mm, respectively.