Promoting core/surface homogeneity during flash sintering of 3YSZ ceramic by current path management: experimental and modelling studies

During flash sintering (FS) of ceramics, the heat loss by surface radiation is main cause temperature gradient between core and surface, which induces inhomogeneity in microstructure. To solve this problem, judicious designing sample geometry electrodes configuration proposed. Experimental simulation results show that application dogbone shape, forked electrodes, lower cross-section aspect ratio effectively shifts current path 3YSZ samples from to near-surface during FS, compared bar-shape with a single electrode at each end. Consequently, distribution becomes more uniform throughout sample, resulting increase relative density 92.7 % 99.7 improved core/surface homogeneity These optimizations enable ceramics obtain significant flexural strength 1203 ± 17 MPa 1501 15 MPa. A multiphysics model implemented experimental results, reveals underlying mechanisms homogeneity.