Effect of molybdenum powder micro-morphology on properties of molybdenum sheets

Using two kinds of molybdenum (Mo) powders with different micro-morphologies as raw materials, the Mo sheets with thickness of 0.5 mm and 0.2 mm respectively were prepared at the same process of pressing, sintering and rolling. The rolling method of 0.5mm Mo sheets was unidirection rolling and that of 0.2 mm Mo sheets was cross rolling. The microstructure of Mo sintering slab was observed by optical microscope and SEM, and the mechanical properties and annealed structure of different Mo sheets were comparative analyzed. The results show that the Mo powder micro-morphology has great influence on the properties of Mo sheet. Compared with that prepared by the traditional Mo powder with inhomogeneous particles and aggregation, the Mo sintering slabs prepared by the specific Mo powder with homogeneous particles, non-aggregation and better dispersion exhibit the homogeneous grain structure and better compactness, and the Mo sheets also show the favorable mechanical properties and high-temperature performances. In addition, the cross-rolling Mo sheets exhibit the good isotropy, too. The essential reason for those is the difference of Mo powder micro-morphology. Inhomogeneous particle size and aggregation of Mo powder greatly influence the microstructure of Mo sintered compacts and mechanical properties of Mo sheets.