Flash sintering is a very promising method with a great potential for the ultra-rapid production of objects with firing processes of mere seconds. However, the transition from few millimeters samples to larger scales is a key issue. In this study, we explore the spark plasma sintering approach allowing a stable hybrid heating in flash condition and producing near net shape sintered specimens. Two electric current configurations are employed for diameters of 15 and 30 mm to determine the effect of scale change and of electric current concentration. These experiments coupled with a Multiphysics simulation indicate that stable flash conditions can be reached for 30 mm specimens. However, even if the electrical current concentration is very effective at small sizes, it generates peripheral hot spots for large specimen dimensions. The blackening effect on zirconia flash specimens acts then as an indicator of the specimen thermal history.

快速烧结是一种非常有前途的方法，具有在仅几秒钟的烧成过程中超快速生产物体的巨大潜力。然而，从几毫米样品到更大尺度的过渡是一个关键问题。在这项研究中，我们探索了放电等离子体烧结方法，该方法允许在闪光条件下进行稳定的混合加热并生产近净形状的烧结试样。对于 15 和 30 毫米的直径，采用两种电流配置来确定尺度变化和电流集中的影响。这些实验与多物理场模拟相结合，表明 30 毫米样品可以达到稳定的闪光条件。然而，即使电流集中在小尺寸时非常有效，它也会在大尺寸样品上产生周边热点。