evolution of microstructure of magnesium materials prepared by SPS using various compacting pressures

Abstract

Compacting pressure applied during the SPS method varies in the literature. This study evaluates the influence of the applied compacting pressure on the microstructure and porosity of sintered materials. Using spark plasma sintering (SPS), cold compacted magnesium powder (green compacts) was sintered to bulk magnesium materials. The green magnesium compacts were prepared at room temperature using 100 MPa of uniaxial pressure, which was applied for 60 s. Using SPS, the green compacts sintering was carried out at 400 °C for 10 min. Various compacting pressures were applied during sintering: 20, 40, 60, 80 and 100 MPa to analyse the influence of the pressure. The resulting microstructure and porosity strongly depended on the compacting pressure applied during SPS. An increase of the compacting pressure was shown to be beneficial for material homogeneity, while this effect was pronounced up to 60 MPa, and only a slight effect on the material porosity was observed above this pressure.