Mechanical and structural properties of bulk magnesium materials prepared via spark plasma sintering

Field-assisted sintering is a modern approach to novel magnesium materials preparation; however, it is unclear whether it is better to sinter green compact or loose powder. This work focuses on preparing bulk materials from loose and cold-compacted magnesium powder through a field-assisted sintering technique - spark plasma sintering (SPS). Green compacts were prepared under a series of compacting pressures from 100 MPa to 500 MPa. SPS was performed at 400 degrees C, 500 degrees C, and 600 degrees C applying additional pressure of 100 MPa during the sintering process. Prepared materials were analysed regarding their microstructure, hardness, and micmhardness and through the three-point bending test and fractography. The green compacts porosity decreased with increased cold-compaction pressure. The SPS positively affected porosity and mechanical properties only in loose powder and the lowest cold-compacted green compacts. Increasing cold compaction pressure of the green compacts above 200 MPa is therefore unfavourable for further SPS processing.