The Effect of Mechanical Milling on the Compressibility of a Pre-Alloyed Mg-Al-Zn Powder

摘要

This study examined the effect of mechanical milling on the densification behavior of AZ91 Mg alloy powder during uniaxial cold compaction in the pressure range of 100 to 600 MPa. Both AZ91 and mechanically milled AZ91 (MM AZ91) powders exhibited good compressibility and reached relative green densities of 94 % and 91 %, respectively, at a compaction pressure of 600 MPa. The morphology and size distribution of AZ91 powder were found to have a significant effect on its compressibility, leading to a high densification rate at low compaction pressures. At high compaction the densification rate of MM AZ91 powder surpassed that of AZ91 powder, demonstrating the beneficial effect of a fine grain structure on the plastic deformability of MM AZ91 powder.