A numerical model for investigating the effect of material and process parameters on the running of flash sintering

Flash sintering of ceramic powders is a complex process that involves electric, thermal and mechanical phenomena. Modelling should help to better understand and control it, with a view to producing safe and homogeneous parts. A finite element model that couples all relevant phenomena, including the densification and shrinkage of the sintering material, has been worked out for this purpose. This model is used here to investigate the flash sintering of disk-shaped parts. Particular attention is paid to the appearance and growth of heterogeneities within the part, known as hot spots, which are highly dependent on material and process parameters. Leads are provided for limiting the development of such heterogeneities.