Flash spark plasma sintering of pure TiB2 with diless configuration" 15th International Ceramics Congress

A Spark Plasma Sintering (SPS) furnace was used to Flash-Sinter (FS) pure titanium diboride (TiB2) powder. A pre-sintering green body (Ø= 20 mm, relative density 60%) was used for the Flash-SPS using a dieless configuration with current passing entirely across the sample. The results show that the samples were densified in very short time (< 60 seconds) up to 90-95% of theoretical density. The rapid heating (?6000 °C/min ) prevented the complete evaporation of B2O3, leading to the formation of rarely seen segregation of boron at the grain boundaries. Compared to SPS or hot press, the rapid Flash-SPS processing promoted the formation boron rich grain boundaries during sintering, thus enhancing consolidation. TiB2 obtained by Flash-SPS was characterized using XRD and SEM analysis in order to quantify texturization induced by the FSPS hot forging effect. The Flash-SPS approach might be suitable to consolidate other refractory borides.