Spark Plasma Sintering of Mg-based Alloys: Microstructure, Mechanical Properties, Corrosion Behavior, and Tribological Performance

Abstract

Within the past ten years, spark plasma sintering (SPS) has become an increasingly popular process for Mg manufacturing. In the SPS process, interparticle diffusion of compressed particles is rapidly achieved due to the concept of Joule heating. Compared to traditional and additive manufacturing (AM) techniques, SPS gives unique control of the structural and microstructural features of Mg components. By doing so, their mechanical, tribological, and corrosion properties can be tailored. Although great advancements in this field have been made, these pieces of knowledge are scattered and have not been contextualized into a single work. The motivation of this work is to address this scientific gap and to provide a groundwork for understanding the basics of SPS manufacturing for Mg. To do so, the existing body of SPS Mg literature was first surveyed, with a focus on their structural formation and degradation mechanisms. It was found that successful Mg SPS fabrication highly depended on the processing temperature, particle size, and particle crystallinity. The addition of metal and ceramic composites also affected their microstructural features due to the Zener pinning effect. In degradative environments, their performance depends on their structural features and whether they have secondary phased composites. In industrial applications, SPS'd Mg was found to have great potential in biomedical, hydrogen storage, battery, automotive, and recycling sectors. The prospects to advance the field include using Mg as a doping agent for crystallite size refinement and using bulk metallic Mg-based glass powders for amorphous SPS components. Despite these findings, the interactions of multi-composites on the processing-structure-property relationships of SPS Mg is not well understood. In total, this work will provide a useful direction in the SPS field and serve as a milestone for future Mg-based SPS manufacturing.