Microstructure Evolution of Multi‐Material‐Jetted Porous Architectures During Ultrafast High‐Temperature Co‐Sintering

ABSTRACT

Multi‐material additive manufacturing combined with rapid sintering offers a route to compositionally and microstructurally complex energy ceramic architectures, but the effect of ultrafast thermal profiles on layer retention, phase redistribution, and pore morphology remains insufficiently understood. Here, NiO–YSZ/NiO–GDC was used as an SOFC‐relevant system to investigate the processing–microstructure evolution of multi‐material‐jetted layered ceramic structures during ultrafast high‐temperature co‐sintering under vacuum. Structures were heated to 1300°C at 200°C–800°C/min, with dwell times of 15–60 s. SEM–EDS and XRD/Rietveld refinement were used to assess layer retention, shrinkage, pore morphology, phase redistribution, and near‐surface NiO‐to‐Ni conversion. Among the tested conditions, 400°C/min with a 60 s dwell provided the best processing conditions by better retaining the target compositional layering and avoiding the severe morphological disruption observed under the more extreme UHS conditions. The fracture surface SEM images showed layer‐dependent pore morphology. These results define a processing window for UHS co‐sintering of multi‐material‐jetted layered energy ceramic architectures and provide guidance for future SOFC‐relevant electrode development.