Effective Atomic Diffusion Coefficient Dependence on Applied Pressure During Spark Plasma Sintering

Abstract It has been hypothesized that the superimposition of an applied pressure enhances mass transfer during pressure-assisted sintering; however, a pressure-related coefficient DT, representing the contribution of a diffusion flux has never been established heretofore. Here, we aim to establish a theoretical framework to determine the DT by combining the Frenkel and E-S models with an Arrhenius equation. To accomplish this goal, via gas atomization and 30 h ball-milling of elemental powders, Ti40.6Zr9.4Cu37.5Ni9.4Sn3.1 metallic glass powders were both used to validate the framework during spark plasma sintering (SPS). The quantitative results reveal that the densification rate increases as the pressure increases due to the enhanced diffusion flux DT.