Preparation of porous materials by Spark Plasma Sintering: Peculiarities of alloy formation during consolidation of Fe@Pt core-shell and hollow Pt(Fe) particles

In this work, the behavior of the Fe@Pt core-shell particles and hollow Pt(Fe) particles during pressureless Spark Plasma Sintering (SPS) was investigated. The Fe@Pt core-shell microparticles were synthesized by galvanic replacement reaction using reduction of H2PtCl6 aqueous solution by metallic iron. Pt(Fe) hollow particles were obtained by dissolving iron from the synthesized core-shell particles in HCl solution. Consolidation resulted in the formation of porous compacts, necking between the particles, alloying between the metals, and growth of the crystallites. The compositional design of the consolidated materials was possible through changing the order of sintering and HCl treatment stages. This work has demonstrated that acid corrosion and SPS can be used together to tailor the composition and morphology of materials derived from the core-shell particles.