Fabrication of porous pure magnesium by MgH2 produced by mechanical milling and spark plasma sintering (MM-SPS) process

Pure magnesium (Mg) powders with stearic acid added as process control agent (PCA) were mechanically milled (MMed) using a vibration ball mill. The MMed powders were consolidated into bulk materials by the spark plasma sintering (SPS). Changes in hardness, thickness and solid-state reactions of the SPS materials have been examined by hardness measurements, vernier caliper and an X-ray diffraction (XRD), respectively. The Vickers hardness of the SPS material decreased with increasing sintering temperature. Minimum value of Vickers hardness was 17 HV. The thickness of the SPS material increased with increasing sintering temperature. However, little effect of sintering time on the thickness was observed. In the SPS materials, the formation of MgH2 by solid phase reaction was observed during sintering. During sintering, MgH2 was decomposed to produce hydrogen gas; and it contributed to expand the SPS materials. Porous pure magnesium could be formed using only the MM-SPS process without the addition of a foaming aid. © 2023 Japan Institute of Light Metals. All rights reserved.