Abstract
Explosive compaction is one of the efficient compacting method in forming the hard material powders. In this study, cylindrically axi-symmetric direct explosive method has been applied to the rapidly solidified Al-Si alloy powders for forming the light weight, heat- and wear-resistant materials. The effects of the mass of explosive and the sintering on the structures and properties of compacts have been investigated by means of microscopy and mechanical tests.
When the powders were compacted at the ratio of explosive mass to powder mass (E/M ratio) lower than 12, the compacts showed low density and hardness. On the other hand, radial cracks and mach stem were formed in the compacts at the E/M ratio more than 12. To form the sound and densfied compacts, it was found that all of the powders should be compacted at the E/M ratio of 12, resulting in high density (97-98%) and high hardness (97HRB) which is higher than that of the heat-extruded materials. However, the compacts were brittle even after the sintering. This seemed to be caused by some cracks and defects introduced by machining the tensile specimen.
