PREPARING PARTICLE-REINFORCED AL-MMCS BY MECHANICAL ALLOYING

The properties of particle reinforced metal matrix composites (MMCs) are largely influenced by the homogeneity of the particle distribution. The possibility of the fabrication of MMC powders with a homogeneous particle distribution, a high bulk density and low gas contents by the process of mechanical alloying have been investigated. The milling atmosphere and the type of process control agent have been varied in order to optimize the gas contents and furthermore to take advantage of additional strengthening by oxide or carbide formation. Measurements of the microhardness, the bulk density, the homogeneity of the particle distribution and the gas contents have been done. The progress in reaction milling of graphite has been studied by XRD measurements.